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Purpose: We previously reported that postmenopausal women with estrogen receptor-α-positive breast cancer receiving adjuvant anastrozole 1 mg/day (ANA1) with estrone (E1) ≥1.3 pg/mL and estradiol (E2) ≥0.5 pg/mL [inadequate estrogen suppression (IES)] had a threefold increased risk of a breast cancer event. The objective of this study was to determine if increasing anastrozole to 10 mg/day (ANA10) could result in adequate estrogen suppression (AES: E1 <1.3 pg/mL and/or E2 <0.5 pg/mL) among those with IES on ANA1., Patients and Methods: Postmenopausal women with estrogen receptor-α-positive breast cancer planning to receive adjuvant ANA1 were eligible. E1 and E2 were assessed pre- and post-8 to 10 weeks of ANA1. Those with IES were switched to 8- to 10-week cycles of ANA10 followed by letrozole 2.5 mg/day. E1 and E2 were assessed after each cycle. Anastrozole concentrations were measured post-ANA1 and post-ANA10. Primary analyses included patients who documented taking at least 80% of the planned treatment (adherent cohort)., Results: In total, 132 (84.6%) of 156 eligible patients were ANA1 adherent. IES occurred in 40 (30.3%) adherent patients. Twenty-five (78.1%) of 32 patients who began ANA10 were adherent, and AES was achieved in 19 (76.0%; 90% confidence interval, 58.1%-89.0%) patients. Anastrozole concentrations post-ANA1 and post-ANA10 did not differ by estrogen suppression status among adherent patients. AES was maintained/attained in 21 (91.3%) of 23 letrozole-adherent patients., Conclusions: Approximately 30% of ANA1-adherent patients had IES. Among those who switched to ANA10 and were adherent, 76% had AES. Further studies are required to validate emerging data that ANA1 results in IES for some patients and to determine the clinical benefit of switching to ANA10 or an alternative aromatase inhibitor., (©2024 The Authors; Published by the American Association for Cancer Research.)

The interest in non-surgical approaches to contraception and fertility control in female dogs has increased in recent years. In this study the effect of an aromatase inhibitor (finrozole) was evaluated in fur production animals, farmed blue fox vixens, as a model for contraception in bitches. A total of 80 vixens were divided into 4 groups, receiving orally placebo (A) or finrozole 0.5 mg/kg (B), 3.5 mg/kg (C) or 24.5 mg/kg (D) for 21 consecutive days beginning in the pre-ovulatory period of heat. Monitoring of the vixens included clinical signs of heat, measurement of vaginal electrical resistance (VER) as well as oestradiol and progesterone concentrations in plasma. The approximate relation of the start of treatment to ovulation varied from 11 days before to one day after ovulation provided that the LH peak occurred 0.5-2 days before the VER peak and ovulation was then estimated to occur 2 days after the LH peak. Seventy vixens were artificially inseminated within 8 h after a 50 Ω decline in vaginal electrical resistance was detected. Ten vixens were not inseminated. Pregnancy was confirmed by transabdominal ultrasound examination and birth of cubs was recorded. The pregnancy rates in the groups were 89.5% (A), 81.3% (B), 55.6% (C) and 52.9% (D). The average number of live born pups in the four groups was 9.4 (A), 7.0 (B), 5.8 (C), and 3.8 (D), respectively. No deleterious effects (for instance malformations) of finrozole on pups could be verified. The administration of finrozole did not have a significant effect on oestradiol parameters and VER values in vixens. Progesterone values were significantly higher in treatment groups compared with the placebo group. The results indicate that pregnancy could be avoided by finrozole provided that doses of ≥3.5 mg/kg were used and the treatment was initiated at least four days before the day of artificial insemination. This corresponds with two to six days before ovulation provided that the LH peak occurred 0.5-2 days before the VER peak and that ovulation then occurred in average 2 days after the LH peak., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Previous studies have shown that androgens, in addition to serving as precursors for ovarian estrogen synthesis, also have a fundamental role in primate ovarian follicular development by augmentation of FSH receptor expression on granulosa cells. Recent studies have shown that aromatase inhibitor, letrozole, improves ovarian response to FSH in normal and poor responder patients, possibly by increasing intraovarian androgen levels. Studies in mice also showed an effect of letrozole to increase pigment epithelium-derived factor (PEDF) and to lower vascular epithelial growth factor (VEGF), which might be expected to reduce the risk of ovarian hyperstimulation syndrome (OHSS) with stimulation. The aim of this study was to compare the VEGF and PEDF levels in the follicular fluids of normal responders treated with letrozole and gonadotropins during the ovarian stimulation with patients treated with gonadotropins only., Methods: A single center, prospective clinical trial. We collected follicular fluid from 26 patients, on a GnRH antagonist protocol, dual triggered with hCG and GnRH agonist. The patients in one group were co-treated with letrozole and gonadotropins during the ovarian stimulation and the patients in the other group were treated with gonadotropins only. VEGF, PEDF, estrogen, progesterone and testosterone levels were measured by ELISA kits., Results: The age of the patients, the total dose of gonadotropins and the number of oocytes were comparable between the two groups. In the follicular fluid, the estrogen levels (2209 nmol/l vs. 3280 nmol/l, p = 0.02) were significantly decreased, and the testosterone levels (246.5 nmol/l vs. 40.7 nmol/l, p < 0.001) were significantly increased in the letrozole group compared to the gonadotropin only group. The progesterone levels (21.4 μmol/l vs. 17.5 p = NS) were comparable between the two groups. The VEGF levels (2992 pg/ml vs. 1812 pg/ml p = 0.02) were significantly increased and the PEDF levels (9.7 ng/ml vs 17.3 ng/ml p < 0.001) were significantly decreased in the letrozole group., Conclusions: Opposite to observations in the mouse, we found that VEGF levels were increased and PEDF levels were decreased in the follicular fluid in patients treated with letrozole during the stimulation cycles. Further investigation is required to determine if patients treated with letrozole during the IVF stimulation protocol are at increased risk for developing OHSS as a result of these findings.

Numerous treatments and protocols have been used to control the reproductive cycle in cattle, with varying effectiveness and many involving the administration of steroid hormones. Steroid hormones, such as estradiol, are perceived as having a negative impact on consumer health. This internationally shared opinion has led to a ban on the use of steroid hormones in food producing animals in many countries (i.e., European Union, New Zealand, and Australia). Letrozole, a non-steroidal aromatase inhibitor, inactivates the aromatase enzyme responsible for the synthesis of estrogens by reversibly binding to the "heme" group of the P450 subunit. Letrozole is approved as an adjuvant or first-line treatment for hormone-dependent breast cancer in post-menopausal women, but has been used increasingly for ovulation induction in the treatment of infertility in women. Using the bovine model to determine the effects on ovarian function, letrozole treatment was found to extend the lifespan of the dominant follicle and thereby delay emergence of the next follicle wave and/or ovulation. Letrozole treatment also had a luteotrophic effect; that is, larger CL and/or higher circulating concentrations of progesterone were detected in letrozole-treated heifers. Results of the initial studies in cattle provided the impetus for the development of aromatase inhibitor-based synchronization and fertility treatment in cattle. Biologically active concentrations of letrozole were achieved via intravenous, intramuscular or intravaginal administration, but the intravaginal route of administration is of particular interest because it permits extended and defined treatment periods, is minimally invasive, and reduces animal handling. Recent results revealed that irrespective of the stage of the cycle, a 4-day letrozole-based protocol induced ovulation in a significantly greater proportion of animals and with significantly greater synchrony than the control treatment. Evidence and reasons for the increasing use of programmed breeding and fixed-time artificial insemination are discussed in this review as a background to current development of an innovative aromatase inhibitor-based protocol as a safe and effective method of controlling the estrous cycle and ovulation in cattle., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Rationale: Metastases of breast carcinoma to the main bronchus and choroid are rare, but have been reported in relevant literature. Late distant recurrence of breast carcinoma after more than 20 years is extremely rare. Herein, we report a 57-year-old woman with late distant recurrence and metastasis to the main bronchus and choroid almost 28 years after surgery., Patient Concerns: At the age of 29, the patient underwent chemotherapy and endocrine treatment after a right side mastectomy to remove breast carcinoma. The patient was hospitalized for a cough with blood-tinged sputum, dysphagia, and blurred vision in the left eye at the age of 57., Diagnoses: On evaluation, laboratory findings detected the elevated serum tumor markers of CA12-5, CA15-3, NSE, and Cyfra21-1. The imaging showed left lung metastase, multiple lymph node metastases, and small suspected metastases in the both sides of parietal lobes. Fundus fluorescein angiography showed choroidal occupying lesion of the left side which indicates secondary metastasis and retinal detachment. Combined with the pathological finding via fiberoptic bronchoscopic biopsy, the patient was clinically diagnosed with a late distant recurrence of breast carcinoma., Interventions: The patient received oral endocrine therapy of letrozole, but she refused chemotherapy, radiotherapy and other topical treatments., Outcomes: At the 3-month follow-up visit, the multiple lesions of the left lung and lymph nodes had partially regressed, and the lesion of right parietal lobe had disappeared. The patient's clinical symptoms, such as blood-tinged sputum and dysphagia, had significantly improved., Lessons: We have described this case and reviewed the relevant literature concerning late distant recurrence of breast carcinoma. Importantly, this case indicates that patients with HR positive breast carcinoma are more likely to develop late distant recurrence and clinicians should not ignore the follow-up examinations even more than 20 years after the surgery.

Background: Abortion, spontaneous or induced, is a common complication of pregnancy and exploration of available and safe regimens for medical abortion in developing countries seems crucial., Aims: The present study was aimed to assess the effect of letrozole in combination with misoprostol in women eligible for legal therapeutic abortion with gestational age ≤14weeks., Materials and Methods: This clinical randomized trial was conducted on 78 women who were candidate of medical abortion and eligible for legal abortion with gestational age ≤14 weeks that were randomly divided into two groups of case and controls. Case group received daily oral dose of 10mg letrozole for three days followed by vaginal misoprostol. In control group the patients received only vaginal misoprostol. The rate of complete abortion, induction-of-abortion time, and side-effects were assessed., Results: Complete abortion was observed in 30 patients (76.9%) in case group and 9 (23.1%) cases were failed. In control group there was 16 (41.03%) complete abortions and 23 (58.97%) cases were failed to abort. Patients with gestational age of between 6 and 10 weeks did not show significant difference in both groups (P=0.134). Regarding pregnancy remnants there were significant differences between two groups (P=0.034). The time form admission to discharge in case groups were significantly shorter than those in control group (P=0.001). The indication for curettage in case group was significantly less than control group (P=0.001)., Conclusion: A 3-day course of letrozole (10mg/daily) followed by misoprostol was associated with a higher complete abortion and lower curettage rates and reduction in time from admission to discharge in women with gestational age ≤14 weeks compared to misoprostol alone., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Background: In animal models of breast cancer, resistance to continuous use of letrozole can be reversed by withdrawal and reintroduction of letrozole. We therefore hypothesised that extended intermittent use of adjuvant letrozole would improve breast cancer outcome compared with continuous use of letrozole in postmenopausal women., Methods: We did the multicentre, open-label, randomised, parallel, phase 3 SOLE trial in 240 centres (academic, primary, secondary, and tertiary care centres) in 22 countries. We enrolled postmenopausal women of any age with hormone receptor-positive, lymph node-positive, and operable breast cancer for which they had undergone local treatment (surgery with or without radiotherapy) and had completed 4-6 years of adjuvant endocrine therapy. They had to be clinically free of breast cancer at enrolment and without evidence of recurrent disease at any time before randomisation. We randomly assigned women (1:1) to treatment groups of either continuous use of letrozole (2·5 mg/day orally for 5 years) or intermittent use of letrozole (2·5 mg/day orally for 9 months followed by a 3-month break in years 1-4 and then 2·5 mg/day during all 12 months of year 5). Randomisation was done by principal investigators or designee at respective centres through the internet-based system of the International Breast Cancer Study Group, was stratified by type of previous endocrine therapy (aromatase inhibitors only vs selective oestrogen receptor modulators only vs both therapies), and used permuted block sizes of four and institutional balancing. No one was masked to treatment assignment. The primary endpoint was disease-free survival, analysed by the intention-to-treat principle using a stratified log-rank test. All patients in the intention-to-treat population who initiated protocol treatment during their period of trial participation were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT00553410, and EudraCT, number 2007-001370-88; and long-term follow-up of patients is ongoing., Findings: Between Dec 5, 2007, and Oct 8, 2012, 4884 women were enrolled and randomised after exclusion of patients at a non-adherent centre, found to have inadequate documentation of informed consent, immediately withdrew consent, or randomly assigned to intervention groups in error. 4851 women comprised the intention-to-treat population that compared extended intermittent letrozole use (n=2425) with continuous letrozole use (n=2426). After a median follow-up of 60 months (IQR 53-72), disease-free survival was 85·8% (95% CI 84·2-87·2) in the intermittent letrozole group compared with 87·5% (86·0-88·8) in the continuous letrozole group (hazard ratio 1·08, 95% CI 0·93-1·26; p=0·31). Adverse events were reported as expected and were similar between the two groups. The most common grade 3-5 adverse events were hypertension (584 [24%] of 2417 in the intermittent letrozole group vs 517 [21%] of 2411 in the continuous letrozole group) and arthralgia (136 [6%] vs 151 [6%]). 54 patients (24 [1%] in the intermittent letrozole group and 30 [1%] in the continuous letrozole group) had grade 3-5 CNS cerebrovascular ischaemia, 16 (nine [<1%] vs seven [<1%]) had grade 3-5 CNS haemorrhage, and 40 (19 [1%] vs 21 [1%]) had grade 3-5 cardiac ischaemia. In total, 23 (<1%) of 4851 patients died while on trial treatment (13 [<1%] of 2417 patients in the intermittent letrozole group vs ten [<1%] of 2411 in the continuous letrozole group)., Interpretation: In postmenopausal women with hormone receptor-positive breast cancer, extended use of intermittent letrozole did not improve disease-free survival compared with continuous use of letrozole. An alternative schedule of extended adjuvant endocrine therapy with letrozole, including intermittent administration, might be feasible and the results of the SOLE trial support the safety of temporary treatment breaks in selected patients who might require them., Funding: Novartis and the International Breast Cancer Study Group., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: The optimal duration of extended endocrine therapy beyond five years after initial aromatase inhibitor-based adjuvant therapy for postmenopausal women with hormone receptor-positive breast cancer is still unknown. Therefore, we conducted a clinical trial to compare two different extended endocrine therapy durations., Methods: In the randomized phase III IDEAL trial, postmenopausal patients with hormone receptor-positive breast cancer were randomly allocated to either 2.5 or five years of letrozole after the initial five years of any endocrine therapy. The primary end point was disease free survival (DFS), and secondary end points were overall survival (OS), distant metastasis-free interval (DMFi), new primary breast cancer, and safety. Hazard ratios (HRs) were determined using Cox regression analysis. All analyses were by intention-to-treat principle., Results: A total of 1824 patients were assigned to either 2.5 years (n = 909) or five years (n = 915) of letrozole, with a median follow-up of 6.6 years. A DFS event occurred in 152 patients in the five-year group, compared with 163 patients in the 2.5-year group (HR = 0.92, 95% confidence interval [CI] = 0.74 to 1.16). OS (HR = 1.04, 95% CI = 0.78 to 1.38) and DMFi (HR = 1.06, 95% CI = 0.78 to 1.45) were not different between both groups. A reduction in occurrence of second primary breast cancer was observed with five years of treatment (HR = 0.39, 95% CI = 0.19 to 0.81). Subgroup analysis did not identify patients who benefit from five-year extended therapy., Conclusion: This study showed no superiority of five years over 2.5 years of extended adjuvant letrozole after an initial five years of adjuvant endocrine therapy., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Background: Aromatase inhibitors (AI) have been introduced to reduce estrogen exposure in women with estrogen-sensitive cancer undergoing ovarian stimulation for oocyte/embryo cryopreservation. There have been questions regarding whether the addition of AI and the presence of BRCA mutations affect cycle outcomes. We sought to determine the impact of letrozole and BRCA mutations on fertility preservation (FP) cycle outcomes of patients undergoing ovarian stimulation with an antagonist protocol., Methods: The data were generated by the secondary analysis of a prospective database of all females diagnosed with cancer who underwent embryo or oocyte cryopreservation for FP. The final analysis included 145 patients stimulated with an antagonist protocol either using letrozole combined with recombinant follicle-stimulating hormone (rFSH; LF, n = 118) or rFSH alone (FA, n = 24)., Results: The mean number of total (15.6 [7.9] vs 10.2 [7.8]; P = .004) and mature oocytes (10.4 [5.1] vs 7.8 [3.5]; P = .044) and embryos frozen (7.7 [5.3] vs 5.3 [2.7]; P = .043) were significantly higher after LF stimulation versus FA. In the LF group, women with BRCA mutations produced significantly fewer oocytes (11.0 [8.0] vs 16.4 [7.7], P = .015) and embryos (5.1 [4.4] vs 8.2 [4.7], P = .013), compared to those who were mutation negative. After adjusting for age, body mass index, baseline FSH level, and BRCA status, LF protocol still resulted in higher number of total oocytes (95% confidence interval [CI]: 1.9 to 3.6; P = .002) mature oocyte (95% CI: 0.3 to 1.4; P = .028), and embryo yield (95% CI: 0.7 to 1.4; P = .015)., Conclusion: In women with cancer undergoing FP, letrozole appears to enhance response to ovarian stimulation while the presence of BRCA mutations is associated with lower oocyte and embryo yield.

Purpose: Anastrozole (ANS) is an aromatase inhibitor that is widely used as a treatment for breast cancer in postmenopausal women. Despite the wide use of ANS, it is associated with serious side effects due to uncontrolled delivery. In addition, ANS exhibits low solubility and short plasma half-life. Nanotechnology-based drug delivery has the potential to enhance the efficacy of drugs and overcome undesirable side effects. In this study, we aimed to prepare novel ANS-loaded PLA-PEG-PLA nanoparticles (ANS-NPs) and to compare the apoptotic response of MCF-7 cell line to both ANS and ANS-loaded NPs., Method: ANS-NPs were synthesized using double emulsion method and characterized using different methods. The apoptotic response was evaluated by assessing cell viability, morphology, and studying changes in the expression of MAPK3 , MCL1 , and c-MYC apoptotic genes in MCF-7 cell lines., Results: ANS was successfully encapsulated within PLA-PEG-PLA, forming monodisperse therapeutic NPs with an encapsulation efficiency of 67%, particle size of 186±27.13, and a polydispersity index of 0.26±0.11 with a sustained release profile extended over 144 hours. In addition, results for cell viability and for gene expression represent a similar apoptotic response between the free ANS and ANS-NPs., Conclusion: The synthesized ANS-NPs showed a similar therapeutic effect as the free ANS, which provides a rationale to pursue pre-clinical evaluation of ANS-NPs on animal models., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

The aim of the present study is to investigate the pharmacokinetics of our newly developed aromatase inhibitors (cetrozole and TMD-322) in healthy subjects by a cassette microdose strategy. A cocktail of cetrozole and TMD-322 was administered intravenously or orally (1.98 μg for each drug) to six healthy volunteers in a crossover fashion. Anastrozole (1.98 μg) was also included in the oral cocktail. Total body clearance and bioavailability were 12.1 ± 7.1 mL/min/kg and 34.9 ± 32.3% for cetrozole, and 16.8 ± 3.5 mL/min/kg and 18.4 ± 12.2% for TMD-322, respectively. The area under the plasma concentration-time curves of cetrozole and TMD-322 after oral administration was markedly lower than that of anastrozole because of their high hepatic clearance. Two subjects out of six exhibited 4- and 17-fold larger exposure of cetrozole than the others following intravenous and oral administration, respectively. Such variation was not observed for TMD-322 and anastrozole. Extensive metabolism of cetrozole and TMD-322 was observed in the CYP2C19 expression system among the test CYP isoforms (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4). We report the first clinical investigation of our aromatase inhibitors by a cassette microdose strategy in healthy Japanese subjects. This strategy offers an optional approach for candidate selection as a phase zero study in drug development., (Copyright © 2017. Published by Elsevier Ltd.)

Purpose Abemaciclib, a cyclin-dependent kinase 4 and 6 inhibitor, demonstrated efficacy as monotherapy and in combination with fulvestrant in women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer previously treated with endocrine therapy. Methods MONARCH 3 is a double-blind, randomized phase III study of abemaciclib or placebo plus a nonsteroidal aromatase inhibitor in 493 postmenopausal women with HR-positive, HER2-negative advanced breast cancer who had no prior systemic therapy in the advanced setting. Patients received abemaciclib or placebo (150 mg twice daily continuous schedule) plus either 1 mg anastrozole or 2.5 mg letrozole, daily. The primary objective was investigator-assessed progression-free survival. Secondary objectives included response evaluation and safety. A planned interim analysis occurred after 189 events. Results Median progression-free survival was significantly prolonged in the abemaciclib arm (hazard ratio, 0.54; 95% CI, 0.41 to 0.72; P = .000021; median: not reached in the abemaciclib arm, 14.7 months in the placebo arm). In patients with measurable disease, the objective response rate was 59% in the abemaciclib arm and 44% in the placebo arm ( P = .004). In the abemaciclib arm, diarrhea was the most frequent adverse effect (81.3%) but was mainly grade 1 (44.6%). Comparing abemaciclib and placebo, the most frequent grade 3 or 4 adverse events were neutropenia (21.1% v 1.2%), diarrhea (9.5% v 1.2%), and leukopenia (7.6% v 0.6%). Conclusion Abemaciclib plus a nonsteroidal aromatase inhibitor was effective as initial therapy, significantly improving progression-free survival and objective response rate and demonstrating a tolerable safety profile in women with HR-positive, HER2-negative advanced breast cancer.

The optimal duration and treatment strategies involving adjuvant endocrine therapy in early breast cancer remained largely undetermined. As data emerge on the various modalities of treatment in both pre- and postmenopausal groups, debates, and discussions continue. Most studies to date focused on the 5-year duration of treatment consisting of mainly tamoxifen. The Arimidex, Tamoxifen, Alone or in Combination (ATAC) study demonstrated that anastrozole is superior to tamoxifen and has become the mainstream treatment in postmenopausal women with early breast cancer, although the duration was arbitrarily set for 5 years, analogous to tamoxifen treatment. Several clinical trials, however, have emerged to support extended endocrine therapy as it becomes clear that the recurrence risk of breast cancer does not decrease beyond the initial 5 years of treatment. The advent of molecular signatures also plays an important role in the breast cancer profiling, and where available should be incorporated in the overall decision-making. Furthermore, side effects and noncompliance pose another issue in achieving an optimal treatment benefit. The decision-making as regards to extended endocrine treatment should therefore focus not only on the cancer biology alone but also include treatment side effects, assessment of risk of recurrence and patients' preference. In this review, we present an overview of the published studies to date as well as ongoing studies on the topic to better refine the options for adjuvant hormonal therapy., (© 2017 Wiley Periodicals, Inc.)

Objectives: The aim of this study was to evaluate the efficacy and safety with gonadotropin-releasing hormone agonist (GnRHa) combined with a levonorgestrel-releasing intrauterine system or an aromatase inhibitor (letrozole) in young women with well-differentiated early endometrial carcinoma (EC) and complex atypical hyperplasia (CAH)., Methods: We performed a retrospective analysis including the clinical characteristics of 29 patients younger than 45 years with early well-differentiated endometrioid adenocarcinoma of the uterus (EC) or CAH who were treated at the Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, from January 2012 to April 2016. Eighteen patients were treated with the combination of intramuscular injections of GnRHa every 4 weeks with the levonorgestrel intrauterine hormonal system (Mirena® Bayer Health Care Pharmaceutical Inc, Wayne, NY) was inserted. Eleven patients were treated with the combination of intramuscular injections of GnRHa every 4 weeks with oral letrozole 2.5 mg daily. The patients underwent follow-up with endometrial sampling by hysteroscopy and curettage for endometrial response every 3 months., Results: After a median follow-up of 18.7 months (range, 5.6-54.9 months), 15 women (88.2%) in the EC group and 12 women (100%) in the CAH group had complete response (CR) after GnRHa combination treatment. Among the women who achieved CR, 1 woman (8.3%) with CAH and 1 woman (5.9%) with EC had recurrence after CR, and they finally underwent a hysterectomy. Time to CR was similar in the 2 groups (4.5 ± 1.9 months in the CAH group vs 5.0 ± 2.9 months in the EC group). Ten women (34.5%) had CR after the first 3 months, 8 women (27.6%) had CR after 6 months, and 9 women (31.0%) had CR after 9 months., Conclusions: Both GnRHa with the levonorgestrel-releasing intrauterine system and GnRHa with letrozole are alternative treatments for women with CAH and EC who desire fertility preservation. A larger multicenter trial of the fertility-preserving treatment is warranted.

Purpose: Aromatase inhibitors (AI), which decrease circulating estradiol concentrations in post-menopausal women, are associated with toxicities that limit adherence. Approximately one-third of patients will tolerate a different AI after not tolerating the first. We report the effect of crossover from exemestane to letrozole or vice versa on patient-reported outcomes (PROs) and whether the success of crossover is due to lack of estrogen suppression., Methods: Post-menopausal women enrolled on a prospective trial initiating AI therapy for early-stage breast cancer were randomized to exemestane or letrozole. Those that discontinued for intolerance were offered protocol-directed crossover to the other AI after a washout period. Changes in PROs, including pain [Visual Analog Scale (VAS)] and functional status [Health Assessment Questionnaire (HAQ)], were compared after 3 months on the first versus the second AI. Estradiol and drug concentrations were measured., Results: Eighty-three patients participated in the crossover protocol, of whom 91.3% reported improvement in symptoms prior to starting the second AI. Functional status worsened less after 3 months with the second AI (HAQ mean change AI #1: 0.2 [SD 0.41] vs. AI #2: -0.05 [SD 0.36]; p = 0.001); change in pain scores was similar between the first and second AI (VAS mean change AI #1: 0.8 [SD 2.7] vs. AI #2: -0.2 [SD 2.8]; p = 0.19). No statistical differences in estradiol or drug concentrations were found between those that continued or discontinued AI after crossover., Conclusions: Although all AIs act via the same mechanism, a subset of patients intolerant to one AI report improved PROs with a different one. The mechanism of this tolerance remains unknown, but does not appear to be due to non-adherence to, or insufficient estrogen suppression by, the second AI.

Rationale: Lymphangioleiomyomatosis (LAM) is a progressive cystic lung disease that predominantly affects women and can worsen with pregnancy, estrogen treatment, and the menstrual cycle, suggesting an important role for estrogen in disease pathogenesis., Objectives: To assess the efficacy and safety of the aromatase inhibitor letrozole in the treatment of LAM., Methods: Seventeen postmenopausal women with LAM were enrolled in this phase II trial and randomized to receive letrozole 2.5 mg daily (n = 9) or placebo (n = 8) for a period of 12 months. Five patients in each group were also taking sirolimus at baseline and remained on the drug throughout the treatment period. Lung function, exercise capacity, quality of life, and serum vascular endothelial growth factor D (VEGF-D) were measured at baseline and at 3-month intervals., Results: Fifteen patients completed the study. Two patients withdrew. There were no differences in adverse events in the letrozole and placebo groups. The target enrollment of 25 patients per arm was not met, so the efficacy of letrozole could not be assessed as planned. After adjusting for sirolimus use, we found that the rate of change in FEV 1 for all subjects was -3 ± 3 ml/mo (P = 0.4), and for serum VEGF-D, the rate of change was -0.024 ± 0.009 pg/ml/mo (P = 0.015), showing a steeper decline in the letrozole group (-0.029 ± 0.013; P = 0.025). All patients who were taking sirolimus had a reduction in VEGF-D levels from baseline to the last visit, compared with only half of the patients who were not taking sirolimus. In a post hoc analysis, eight matched letrozole-treated-placebo-treated pairs were constructed, six of which demonstrated better FEV 1 improvement for the letrozole-treated patients., Conclusions: Letrozole treatment appears to be safe and well tolerated in postmenopausal patients with LAM, including those taking sirolimus. Enrollment in this trial was compromised by the publication of an effective treatment (sirolimus) in the same month as the study opened, resulting in limited power to detect treatment effects. Post hoc matched pairs exploration studies provide tentative support for additional studies of letrozole in LAM. Considering the reduced rate of lung function decline in postmenopausal patients, future studies will likely require enhanced study designs, such as selective enrollment of those with prognostic biomarkers predictive of decline. Clinical trial registered with www.clinicaltrials.gov (NCT01353209).

Background and Aim: There are still open questions about ovulation induction in clomiphene citrate-(CC)-resistant infertile women. Especially little is known about efficacy and safety of letrozole (LTZ) combined with low-dose highly purified human menopausal gonadotropin (Hp-HMG) in women with polycystic ovary syndrome (PCOS)., Methods: Prospective, single-arm single-center trial in 200 infertile PCOS patients refractory for at least three CC-treatment cycles. Women with hyperandrogenism took Diane-35 for at least 3 months. All patients got LTZ on day 3 for 5 d in combination with Hp-HMG, starting with 75 IU from cycle day 7 and maintained for up to 3 d. The maximum dose was 150 IU. Primary end-points were ongoing and clinical pregnancy rate, secondary end-points mono-follicular development, ovulation rate, OHSS, multiple pregnancy and early pregnancy loss. Major safety end-point was the incidence of adverse events., Results: Within 395 cycles the ongoing pregnancy rate was 28.24%, for cycles 35.23%, for patients 68%. The rate of ovulation per cycle was 97.7%, percentage of mono-follicular development 70.9%. No severe OHSS, multiple pregnancy, local or systemic side effects were seen., Conclusions: LTZ combined with low-dose Hp-HMG is an effective and safe choice for reducing hyperstimulation and increasing pregnancy rate in CC-resistant women with PCOS.

Purpose: Letrozole showed efficacy and generally favorable toxicities, along with the convenience of oral administration in postmenopausal patients with hormone receptor (HR)-positive metastatic breast cancer (MBC). To the best of our knowledge, there have been no reports of the clinical outcomes in Korean patients, although letrozole is widely used in practice. Therefore, this studywas conducted to affirm the efficacy and toxicities of letrozole in Korean patients., Materials and Methods: This study retrospectively analyzed 84 HR-positive MBC patients who had been treated with letrozole from January 2001 to December 2012. Clinicopathological characteristics and treatment history were extracted from medicalrecords. All patients received 2.5 mg letrozole once a day until there were disease progressions or unacceptable toxicity. Progression-free survival (PFS) was the primary endpoint, and secondary endpoints were overall survival (OS), objective response rate (ORR), and toxicity., Results: The median age of the subjects was 59.3 years. Letrozole treatment resulted in a median PFS of 16.8 months (95% confidence interval [CI], 9.8 to 23.8) and a median OS of 56.4 months (95% CI, 38.1 to 74.7). The ORR was 36.9% for the 84 patients with measurable lesions. Multivariate analysis revealed symptomatic visceral disease (hazard ratio, 3.437; 95% CI, 1.576 to 7.495; p=0.002) and a disease-free interval ≤ 2 years (hazard ratio, 2.697; 95% CI, 1.262 to 5.762; p=0.010) were independently associated with shorter PFS. However, sensitivity to adjuvant hormone treatment was not related to PFS. Letrozole was generally well tolerated., Conclusion: Letrozole showed considerable efficacy and tolerability as a first-line treatment in postmenopausal patients with HR-positive MBC.

We aimed to compare the cost effectiveness of letrozole versus purified urinary follicle stimulating hormone (FSH) in treating patients with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS). This was a randomized trial conducted in Cairo University and Beni-Suef University Hospitals, Egypt. A cohort of 140 eligible women was randomized to receive either letrozole 2.5 mg twice daily for five days, or FSH using a graduated regimen starting with a dose of 75 IU. Treatment was repeated for three months if pregnancy did not occur. There were no significant differences between the two treatments in the cumulative clinical pregnancy rate (30% vs. 34%; p = 0.578), cumulative ovulation rate (47% vs. 57%; p = 0.236), miscarriage rate (9% vs. 4%, p > 0.999) or multiple pregnancy rate (0% and 8%, p = 0.491) but the FSH cycles were 4.8 times more expensive. Letrozole and FSH were both effective in treating women with CC-resistant PCOS but letrozole was more cost effective.Study registration number: NCT02304107.

The aim of this retrospective study was to determine the clinical pregnancy rate in women undergoing letrozole ovarian stimulation and artificial insemination by donor (AID). Between 2012 and 2015, 130 natural cycles, 939 letrozole cycles and 130 letrozole plus gonadotrophin cycles were conducted. Letrozole cycles were divided into three groups according to LH concentration on the day of HCG administration (LH <10 mIU/ml and follicle size ≥18 cm; LH ≤10 to <20 mIU/ml; and LH ≥20 mIU/ml). Pregnancy rates were 17.3%, 22.4% and 26.8%, respectively (P = 0.012). In women given 10 mIU/ml LH or more, logistic regression identified oestradiol (OR 1.002, 95% CI, 1.000 to 1.004, P = 0.029) and leading follicle size (OR 0.861, 95% CI, 0.772 to 0.960, P = 0.007) as significant predictive factors of pregnancy rate; the higher the oestradiol and the smaller the follicles, the better the pregnancy rate. The pregnancy rate was significantly higher in the letrozole plus gonadotrophin group than the letrozole group (P = 0.04). Better pregnancy rates can be achieved if LH surge occurs before HCG administration, especially with higher oestradiol and lower follicle size; treatment with letrozole plus gonadotrophin was significantly more effective than letrozole alone in AID., (Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

Aromatase is a critical enzyme in the irreversible conversion of androgens to oestrogens, with inhibition used clinically in hormone-dependent malignancies. We tested the hypothesis that targeted aromatase inhibition in an aggressive brain cancer called glioblastoma (GBM) may represent a new treatment strategy. In this study, aromatase inhibition was achieved using third generation inhibitor, Letrozole, encapsulated within the core of biodegradable poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs). PLGA-NPs were conjugated to human/mouse chimeric anti-GD2 antibody ch14.18/CHO, enabling specific targeting of GD2-positive GBM cells. Treatment of primary and recurrent patient-derived GBM cells with free-Letrozole (0.1 μM) led to significant decrease in cell proliferation and migration; in addition to reduced spheroid formation. Anti-GD2-ch14.18/CHO-NPs displayed specific targeting of GBM cells in colorectal-glioblastoma co-culture, with subsequent reduction in GBM cell numbers when treated with anti-GD2-ch14.18-PLGA-Let-NPs in combination with temozolomide. As miR-191 is an estrogen responsive microRNA, its expression, fluctuation and role in Letrozole treated GBM cells was evaluated, where treatment with premiR-191 was capable of rescuing the reduced proliferative phenotype induced by aromatase inhibitor. The repurposing and targeted delivery of Letrozole for the treatment of GBM, with the potential role of miR-191 identified, provides novel avenues for target assessment in this aggressive brain cancer.

Objective: To evaluate the effect of letrozole in combination with cabergoline and letrozole alone on regression of symptomatic uterine myomas in women of reproductive age., Design: Randomized controlled clinical trial., Setting: University hospital., Patients: Ninety-one women of reproductive age were enrolled in the study and 88 women were eligible. Eight participants were excluded from the study., Interventions: Eighty women of reproductive age with symptomatic myomas >4cm were evaluated in two groups. Participants in Group 1 received 2.5mg letrozole once daily and cabergoline 0.5mg/week from the first day of the menstrual cycle for 12 weeks, and participants in Group 2 received letrozole alone., Main Outcome Measures: Changes in uterine size and volume; myoma size, volume and number; and side effects of treatment., Results: Overall, 76 patients completed the study. Compared with baseline values, mean uterine volume was reduced significantly in both groups (p=0.01), and there was no significant difference between groups (p=0.99). The mean number of dominant myomas was reduced significantly in both groups (p=0.03), with no significant difference between groups (p=0.6). The mean volume of myomas was reduced significantly in both groups (p=0.01), with no significant difference between groups (p=0.45). Although a significant decrease in number and volume of myomas was documented in each group (p<0.05), the intergroup analyses did not reveal significant differences between the two groups in terms of the change in number (p=0.28) and volume (p=0.96) of myomas. Headache was significantly more common in the letrozole+cabergoline group (nine vs two cases, p=0.02), but the two groups were comparable for the remaining minor side effects., Conclusion: This study showed that 12 weeks of treatment with letrozole with and without cabergoline improved the size and volume of the uterus and myomas, led to symptom improvement, and could be used for short-term treatment prior to surgery or fertility programmes., Condensation: Condensation letrozole in combination with cabergoline in the management of uterine fibroids., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Rationale: The aromatase inhibitor anastrozole blocks the conversion of androgens to estrogen and blunts pulmonary hypertension in animals, but its efficacy in treating patients with pulmonary arterial hypertension (PAH) is unknown., Objectives: We aimed to determine the safety and efficacy of anastrozole in PAH., Methods: We performed a randomized, double-blind, placebo-controlled trial of anastrozole in patients with PAH who received background therapy at two centers., Measurements and Main Results: A total of 18 patients with PAH were randomized to anastrozole 1 mg or matching placebo in a 2:1 ratio. The two co-primary outcomes were percent change from baseline in 17β-estradiol levels (E2) and tricuspid annular plane systolic excursion (TAPSE) at 3 months. Anastrozole significantly reduced E2 levels compared with placebo (percent change: -40%; interquartile range [IQR], -61 to -26% vs. -4%; IQR, -14 to +4%; P = 0.003), but there was no difference in TAPSE. Anastrozole significantly increased the 6-minute-walk distance (median change = +26 m) compared with placebo (median change = -12 m) (median percent change: anastrozole group, 8%; IQR, 2 to 17% vs. placebo -2%; IQR, -7 to +1%; P = 0.042). Anastrozole had no effect on circulating biomarkers, functional class, or health-related quality of life. There was no difference in adverse events., Conclusions: Anastrozole significantly reduced E2 levels in patients with PAH but had no effect on TAPSE. Anastrozole was safe, well tolerated, and improved 6-minute-walk distance in this small "proof-of-principle" study. Larger and longer phase II clinical trials of anastrozole may be warranted in patients with PAH. Clinical trial registered with www.clinicaltrials.gov (NCT 1545336).

Equine pregnancy is characterized by very high circulating concentrations of estrogens. The physiological roles of estrogens during equine gestation are largely unknown, although some studies suggest a role in the regulation of uterine artery hemodynamics and a relationship between low circulating estrogen concentrations and late pregnancy loss. The objectives of this experiment were to evaluate the effects of estrogen suppression on uterine artery hemodynamics and on pregnancy outcome. Estrogen synthesis was suppressed using letrozole, a potent aromatase inhibitor. Twelve pregnant mares were randomly assigned to a control (n = 6) or treatment (n = 6; 500 mg letrozole orally every 4 days) group with treatment starting at 240 days of gestation and continuing until parturition. Weekly serum samples were analyzed to determine testosterone, dehydroepiandrosterone sulfate, estradiol, estrone sulfate, progestins, and prostaglandin F2α metabolite concentrations. Ultrasonographic examinations were performed biweekly and measurements included uterine artery hemodynamics (diameter, pulsatility, and resistance indices), fetal growth using the diameter of the fetal eye, and placental evaluation using the combined thickness of the uterus and placenta. At parturition, gestational length, foal weight, and neonatal viability were determined. Letrozole suppressed estrogen synthesis during gestation by approximately 90% compared to control values. This large reduction in circulating estrogens had no effect on uterine artery hemodynamics, normal placental development, maintenance of pregnancy, or neonatal viability. However, neonates from letrozole-treated mares had lower (P < 0.05) birth weights than controls, suggesting that estrogens may play a role in fetal growth that is not mediated through regulation of uterine blood flow.

Background: Our objective was to explore the impact of a single dose of an aromatase inhibitor (letrozole) administered at defined times of the follicular phase or immediately after ovulation on dominant follicle development, luteogenesis and new follicle wave emergence., Methods: A prospective pilot study using a randomized complete block, controlled, open label design was conducted at an academic clinical research center. Forty-five healthy, female volunteers (25.5 ± 0.9 years, BMI 25.0 ± 0.6 kg/m 2 ) who had not taken hormonal contraceptives for a minimum of 2 months were recruited. A 20 mg dose of Letrozole was administered once orally in each of 3 groups when the dominant follicle reached a diameter of 1) 12 mm, 2) 18 mm, 3) the first day following ovulation (post-ovulation), or 4) treatment was withheld (control). Serial ultrasonography and phlebotomy began on day 4 of the menstrual cycle and continued for 1.5 menstrual cycles. Participants recorded menses and daily events in a life events calendar for the duration of the study. Demographic and single point measurements were compared among groups by ANOVA. Changes in hormone concentrations over time were compared among groups by repeated measures ANOVA. Kruskal-Wallis tests were used for non-normally distributed data., Results: The dominant follicle in all treatment groups ovulated. There were no differences among experimental groups in peak follicle diameter, follicular growth rate, endometrial thickness at ovulation or inter-ovulatory interval. Plasma concentrations of estradiol dropped, while FSH and LH concentrations rose following treatment in all treatment groups. Plasma FSH and LH concentrations were higher in the 18 mm group compared to the 12 mm and post-ovulation groups (P < 0.02)., Conclusion: Administration of a single 20 mg dose of Letrozole at the times of the menstrual cycle we examined did not induce dominant follicle regression or failure of corpus luteum formation. Letrozole-induced suppression of estradiol synthesis by the dominant follicle was not detrimental to follicle growth or ovulation following follicle selection, likely due to increased circulating concentrations of FSH and LH resulting from a lack of estradiol-induced suppression of the hypothalamic-pituitary-ovarian axis., Trials Registration Number: Clinical trials registration number NCT01046578 .

Background: Aromatase inhibitors are a standard of care for hormone receptor-positive locally advanced or metastatic breast cancer. We investigated whether the selective oestrogen receptor degrader fulvestrant could improve progression-free survival compared with anastrozole in postmenopausal patients who had not received previous endocrine therapy., Methods: In this phase 3, randomised, double-blind trial, we recruited eligible patients with histologically confirmed oestrogen receptor-positive or progesterone receptor-positive, or both, locally advanced or metastatic breast cancer from 113 academic hospitals and community centres in 20 countries. Eligible patients were endocrine therapy-naive, with WHO performance status 0-2, and at least one measurable or non-measurable lesion. Patients were randomly assigned (1:1) to fulvestrant (500 mg intramuscular injection; on days 0, 14, 28, then every 28 days thereafter) or anastrozole (1 mg orally daily) using a computer-generated randomisation scheme. The primary endpoint was progression-free survival, determined by Response Evaluation Criteria in Solid Tumors version 1·1, intervention by surgery or radiotherapy because of disease deterioration, or death from any cause, assessed in the intention-to-treat population. Safety outcomes were assessed in all patients who received at least one dose of randomised treatment (including placebo). This trial is registered with ClinicalTrials.gov, number NCT01602380., Findings: Between Oct 17, 2012, and July 11, 2014, 524 patients were enrolled to this study. Of these, 462 patients were randomised (230 to receive fulvestrant and 232 to receive anastrozole). Progression-free survival was significantly longer in the fulvestrant group than in the anastrozole group (hazard ratio [HR] 0·797, 95% CI 0·637-0·999, p=0·0486). Median progression-free survival was 16·6 months (95% CI 13·83-20·99) in the fulvestrant group versus 13·8 months (11·99-16·59) in the anastrozole group. The most common adverse events were arthralgia (38 [17%] in the fulvestrant group vs 24 [10%] in the anastrozole group) and hot flushes (26 [11%] in the fulvestrant group vs 24 [10%] in the anastrozole group). 16 (7%) of 228 patients in in the fulvestrant group and 11 (5%) of 232 patients in the anastrozole group discontinued because of adverse events., Interpretation: Fulvestrant has superior efficacy and is a preferred treatment option for patients with hormone receptor-positive locally advanced or metastatic breast cancer who have not received previous endocrine therapy compared with a third-generation aromatase inhibitor, a standard of care for first-line treatment of these patients., Funding: AstraZeneca., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: McCune-Albright syndrome (MAS) is a rare disorder with a broad spectrum including precocious puberty (PP) due to recurrent estrogen-secreting ovarian cysts. This study evaluates the long-term safety and efficacy of letrozole treatment in large cohort of girls with MAS-associated PP., Design: Retrospective cohort analysis., Methods: Clinical data, including history and physical examination, bone age, and pelvic ultrasounds, were reviewed on 28 letrozole-treated girls. Adult height was reviewed for 42 historical controls. Outcomes included rate of skeletal maturation, growth velocity, predicted adult height and adult height., Results: Twenty-eight girls received letrozole treatment. Treatment duration was 4.1 ± 2.6 years (mean ± 1 s.d.) (range: 0.5-10.9) and mean follow-up was 6.0 ± 3.3 years (range: 0.5-15.0), for a total of 135.9 person-years of follow-up. Letrozole treatment was highly effective at decreasing the rate of skeletal maturation, with a decline in change in bone age over change in chronological age (ΔBA/ΔCA) from 1.7 (IQR: 2.3) to 0.5 (IQR: 0.4) (P < 0.0001), and growth velocity Z-scores, which declined from 2.2 ± 2.3 to -0.6 ± 1.6 (P = 0.0004). Predicted adult height Z-scores increased significantly from -2.9 ± 3.2 to -0.8 ± 1.5 for subjects on treatment (P = 0.004). Four subjects who completed treatment reached adult height Z-scores ranging from -1.5 to 1.7 (median: -0.6), which were increased in comparison with untreated historical controls (P = 0.02). There was no change in uterine size or ovarian volumes, and no adverse events over the treatment period., Conclusions: In this study with the longest follow-up to date, letrozole treatment resulted in sustained beneficial effects on skeletal maturation, growth velocity and predicted adult height., (© 2016 European Society of Endocrinology.)

Background: Systemic concentrations of T, estradiol (E 2 ), GH, IGF-1, and IGF binding protein-3 decline in healthy aging individuals. Conversely, T and E 2 stimulate GH and IGF-1 production in hypogonadal patients., Hypothesis: Because E 2 stimulates GH secretion, putatively via the nuclear estrogen receptor-α and E 2 and GH fall with menopause, we postulated that diminished endogenous E 2 contributes to low GH output in older women., Location: The study was conducted at the Mayo Center for Clinical and Translational Science., Study Design: This was a randomized, double-blind, controlled study in 60 healthy postmenopausal women treated with the following: 1) double placebo; 2) anastrozole, a potent inhibitor of aromatase-enzyme activity, which mediates E 2 synthesis from T; and/or 3) fulvestrant, a selective estrogen receptor-α antagonist., Methods: GH pulse generation was quantified by frequent GH sampling before and after short-term iv somatostatin infusion, thought to induce hypothalamic GHRH-mediated rebound-like GH secretion., Results: On anastrozole, E 2 fell from 3.1 ± 0.35 pg/mL to 0.36 ± 0.04 pg/mL, and estrone from 13 ± 1.4 pg/mL to 1.9 ± 0.01 pg/mL (P < .001) by mass spectrometry. Estrogen values were unchanged by fulvestrant. T concentrations did not change. One-hour peak GH rebound after somatostatin infusion declined markedly during both estrogen-deprivation schedules (P < .001). Mean (150 min) maximal GH rebound decreased comparably (P < .001). Measures of GH rebound correlated negatively with computed tomography-estimated abdominal visceral fat (all P < .05)., Conclusion: These data suggest a previously unrecognized dependence of hypothalamo-pituitary GH regulation on low levels of endogenous estrogen after menopause.

Aromatase (CYP19) is a rate-limiting enzyme that catalyzes the biosynthesis of estrogens. Imaging agents based on aromatase inhibitors (AIs) have been developed for a PET/SPECT study. A series of compounds was synthesized based on YM511, which has previously been used for breast cancer treatment. Two examples of these derivatives, 4-(((4-iodophenyl)methyl)-4H-1,2,4-triazol-4-yl-amino)-benzonitrile (5) and 4-((1H-imidazol-1-yl)(4-iodobenzyl)amino)benzonitrile (11), displayed potent binding affinities to human aromatase (IC 50 = 0.17 and 0.04 nM, respectively). Biodistribution and autoradiographic studies revealed that [ 125 I]5 and [ 125 I]11 were highly accumulated in the stomach (16.21 and 10.88% dose/g, respectively) and ovaries (8.56 and 3.32% dose/g, respectively) of female rats. Log P of [ 125 I]5 was 2.49, meaning good brain penetration. Autoradiograms of brain sections showed a high uptake in the bed nucleus of the stria terminalis and amygdala. These results suggest that [ 125 I]5 and [ 125 I]11 are potent probes for aromatase imaging in both the brain and peripheral organs.

Study Question: What are suitable doses of the aromatase inhibitor anastrozole (ATZ) and the progestin levonorgestrel (LNG), when delivered to the systemic circulation by an intravaginal ring (IVR), for further clinical development as a potential new therapy for the treatment of endometriosis?, Summary Answer: Anticipated targets for pharmacokinetics, pharmacodynamics and safety/tolerability were achieved for both drug components of the IVR at the doses investigated, supporting selection of the doses to be investigated in Phase 2 studies., What Is Known Already: Aromatase is a key enzyme in the biosynthesis of estrogens and is known to increase local levels of estradiol (E2) at extragonadal sites. Up-regulation of aromatase expression has been demonstrated in endometriotic lesions and the use of oral aromatase inhibitors has been shown to reduce endometriosis-associated pelvic pain in small-scale clinical trials., Study Design, Size, Duration: This Phase 1, randomized, multicentre, parallel-group, three-arm, open-label study assessed the pharmacokinetics, pharmacodynamics, safety and tolerability of various IVRs intended for systemic drug delivery. After screening, healthy, ovulating women aged 18-35 years were randomized to use IVRs releasing one of the three ATZ/LNG dose combinations (in vitro nominal daily drug release rates on Day 29: ATZ/LNG 500 µg/20 µg [low dose], ATZ/LNG 1000 µg/30 µg [mid dose] or ATZ/LNG 1500 µg/40 µg [high dose]) for two consecutive 28-day wearing periods without a treatment break., Participants/materials, Setting, Methods: Sixty women were included in the per protocol set. The primary variables were plasma concentrations of ATZ and LNG at the end of each treatment period and the mean size of largest follicle-like structures (FLSs) over 56 days. Serum concentrations of several hormones were also evaluated, with emphasis on E2 levels., Main Results and the Role of Chance: At the end of the first treatment period, geometric mean plasma concentrations of LNG and ATZ, respectively, were 0.228 and 12.5 µg/l for the low dose, 0.269 and 19.8 µg/l for the mid dose and 0.384 and 37.3 µg/l for the high dose; results were similar at the end of the second treatment period. Over the entire treatment period, mean FLS sizes were higher in all three treatment groups than during the pretreatment cycle; more women in the mid- and high-dose groups had FLSs of at least 30 mm (32-45%) than those in the low-dose group (14-24%). Changes in the mean size of FLSs were similar to those reported for low-dose progestin-only oral contraceptives and generally resolved during the 2-month treatment period. Serum E2 levels were decreased, but only one woman in each of the mid- and high-dose groups, and no woman in the low-dose group, had a serum E2 level below 20 pg/ml in both cycles. All ATZ and LNG combinations showed good tolerability., Limitations, Reasons for Caution: This was an exploratory study; no formal power calculation was performed., Wider Implications of the Findings: The results of this first-in-human study of the ATZ/LNG IVR facilitated the selection of ATZ and LNG doses to be investigated in the Phase 2 studies of patients with endometriosis., Study Funding/competing Interest: The study was funded by Bayer Pharma AG. T.R. is an employee of DINOX GmbH, which received funding from Bayer Pharma AG to perform this study. M.-H.S.-M., K.W., R.N., S.K., J.K., H.S. and B.R. are or have been employees of Bayer Pharma AG. H.S. is a named inventor on EP 2 552 404 B1, a patent application relating to this work., Trial Registration Number: EudraCT number: 2011-005620-18., Trial Registration Date: 16 November 2011., Date of First Patient's Enrolment: 14 March 2012., (© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Treatment with an aromatase inhibitor for 5 years as up-front monotherapy or after tamoxifen therapy is the treatment of choice for hormone-receptor-positive early breast cancer in postmenopausal women. Extending treatment with an aromatase inhibitor to 10 years may further reduce the risk of breast-cancer recurrence., Methods: We conducted a double-blind, placebo-controlled trial to assess the effect of the extended use of letrozole for an additional 5 years. Our primary end point was disease-free survival., Results: We enrolled 1918 women. After a median follow-up of 6.3 years, there were 165 events involving disease recurrence or the occurrence of contralateral breast cancer (67 with letrozole and 98 with placebo) and 200 deaths (100 in each group). The 5-year disease-free survival rate was 95% (95% confidence interval [CI], 93 to 96) with letrozole and 91% (95% CI; 89 to 93) with placebo (hazard ratio for disease recurrence or the occurrence of contralateral breast cancer, 0.66; P=0.01 by a two-sided log-rank test stratified according to nodal status, prior adjuvant chemotherapy, the interval from the last dose of aromatase-inhibitor therapy, and the duration of treatment with tamoxifen). The rate of 5-year overall survival was 93% (95% CI, 92 to 95) with letrozole and 94% (95% CI, 92 to 95) with placebo (hazard ratio, 0.97; P=0.83). The annual incidence rate of contralateral breast cancer in the letrozole group was 0.21% (95% CI, 0.10 to 0.32), and the rate in the placebo group was 0.49% (95% CI, 0.32 to 0.67) (hazard ratio, 0.42; P=0.007). Bone-related toxic effects occurred more frequently among patients receiving letrozole than among those receiving placebo, including a higher incidence of bone pain, bone fractures, and new-onset osteoporosis. No significant differences between letrozole and placebo were observed in scores on most subscales measuring quality of life., Conclusions: The extension of treatment with an adjuvant aromatase inhibitor to 10 years resulted in significantly higher rates of disease-free survival and a lower incidence of contralateral breast cancer than those with placebo, but the rate of overall survival was not higher with the aromatase inhibitor than with placebo. (Funded by the Canadian Cancer Society and others; ClinicalTrials.gov numbers, NCT00003140 and NCT00754845.).

Breast cancer (BC) is the leading cancer in women worldwide. Metastasis occurs in stage IV BC with bone and lung being common metastatic sites. Here we evaluate the effects of the aromatase inhibitor letrozole on BC micro-metastatic tumor growth in bone and lung metastasis in intact and ovariectomized (OVX) mice with murine estrogen receptor negative (ER-) BC cells inoculated in tibia. Forty-eight BALB/c mice were randomly assigned to one of four groups: OVX, OVX + Letrozole, Intact, and Intact + Letrozole, and injected with 4T1 cells intra-tibially. Letrozole was subcutaneously injected daily for 23 days at a dose of 1.75 µg/g body weight. Tumor progression was monitored by bioluminescence imaging (BLI). Following necropsy, inoculated tibiae were scanned via µCT and bone response to tumor was scored from 0 (no ectopic mineralization/osteolysis) to 5 (extensive ectopic mineralization/osteolysis). OVX mice had higher tibial pathology scores indicative of more extensive bone destruction than intact mice, irrespective of letrozole treatment. Letrozole decreased serum estradiol levels and reduced lung surface tumor numbers in intact animals. Furthermore, mice receiving letrozole had significantly fewer tumor colonies and fewer proliferative cells in the lung than OVX and intact controls based on H&E and Ki-67 staining, respectively. In conclusion, BC-inoculated OVX animals had higher tibia pathology scores than BC-inoculated intact animals and letrozole reduced BC metastases to lungs. These findings suggest that, by lowering systemic estrogen level and/or by interacting with the host organ, the aromatase inhibitor letrozole has the potential to reduce ER- BC metastasis to lung.

Background: Despite the effectiveness of adjuvant endocrine therapy in preventing breast cancer recurrence, breast cancer events continue at a high rate for at least 10 years after completion of therapy., Patients and Methods: This randomised open label phase III trial recruited postmenopausal women from 29 Australian and New Zealand sites, with hormone receptor-positive early breast cancer, who had completed ≥4 years of endocrine therapy [aromatase inhibitor (AI), tamoxifen, ovarian suppression, or sequential combination] ≥1 year prior, to oral letrozole 2.5 mg daily for 5 years, or observation. Treatment allocation was by central computerised randomisation, stratified by institution, axillary node status and prior endocrine therapy. The primary outcome was invasive breast cancer events (new invasive primary, local, regional or distant recurrence, or contralateral breast cancer), analysed by intention to treat. The secondary outcomes were disease-free survival (DFS), overall survival, and safety., Results: Between 16 May 2007 and 14 March 2012, 181 patients were randomised to letrozole and 179 to observation (median age 64.3 years). Endocrine therapy was completed at a median of 2.6 years before randomisation, and 47.5% had tumours of >2 cm and/or node positive. At 3.9 years median follow-up (interquartile range 3.1-4.8), 2 patients assigned letrozole (1.1%) and 17 patients assigned observation (9.5%) had experienced an invasive breast cancer event (difference 8.4%, 95% confidence interval 3.8% to 13.0%, log-rank test P = 0.0004). Twenty-four patients (13.4%) in the observation and 14 (7.7%) in the letrozole arm experienced a DFS event (log-rank P = 0.067). Adverse events linked to oestrogen depletion, but not serious adverse events, were more common with letrozole., Conclusion: These results should be considered exploratory, but lend weight to emerging data supporting longer duration endocrine therapy for hormone receptor-positive breast cancer, and offer insight into reintroduction of AI therapy., Clinical Trials Number: Australian New Zealand Clinical Trials Registry (www.anzctr.org.au), ACTRN12607000137493., (© The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Women with breast cancer and diabetes mellitus (DM) have poorer survival. Mechanisms include insulin dysregulation and/or DM related co-morbidities (CM). In MA.17 adjuvant letrozole (LET) after 5 years of tamoxifen (TAM) reduced the risk of recurrence and improved survival. We evaluated DM, hypertension (HTN), and coronary artery disease (CAD) as prognostic and predictive factors in MA.17., Patients and Methods: Disease free survival, distant disease free survival (DDFS) and overall survival (OS) were compared using Cox regression model adjusting for other prognostic factors: in women treated by placebo (PLAC) based on the presence or absence of baseline DM (n = 462), HTN (n = 1627), CAD (n = 604) or any one of these CM (n = 2049), and between LET and PLAC groups in each CM. Analyses based on nodal status were performed., Results: DM was neither prognostic nor predictive for women on extended LET. Women with one CM had similar outcomes on LET compared to women free of CM. For node positive women, the difference between LET and PLAC in DDFS was greater among women with one CM (hazard ratio [HR] = 0.30 [0.15-0.60], p = 0.001) compared to those without CM (HR = 0.72 [0.45-1.16], p = 0.17, p interaction = 0.04). Women on PLAC with HTN trended towards lower DDFS (HR = 1.50 [0.98-2.3], p = 0.06) and OS (HR = 1.61 [0.95-2.72], p = 0.08) than non-HTN women. HTN women had better DDFS on LET than non-HTN women. Women with one CM on PLAC had lower OS (HR = 2.10 [1.26-3.51], p = 0.004) than those free of CM., Conclusions: DM was not prognostic or predictive of outcomes. Women with CM who remain disease free after 5 years of TAM should be offered LET. HTN trended towards a negative prognosticator and outcomes among this group were improved on LET. More studies are needed to assess impact of adrenergic stimulation as a possible link to poorer breast cancer outcomes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: The NSABP B-35 trial compared 5 years of treatment with anastrozole versus tamoxifen for reducing subsequent occurrence of breast cancer in postmenopausal patients with ductal carcinoma in situ. This report assesses the effect of these drugs on quality of life and symptoms., Methods: The study was done at 333 hospitals in North America. Postmenopausal women with hormone-positive ductal carcinoma in situ treated by lumpectomy with clear resection margins and whole breast irradiation were randomly assigned to receive either tamoxifen (20 mg/day) or anastrazole (1 mg/day) for 5 years, stratified by age (<60 years vs ≥60 years). Patients and investigators were masked to treatment allocation. Patients completed questionnaires at baseline and every 6 months thereafter for 6 years. The primary outcomes were SF-12 physical and mental health component scale scores, and vasomotor symptoms (as per the BCPT symptom scale). Secondary outcomes were vaginal symptoms and sexual functioning. Exploratory outcomes were musculoskeletal pain, bladder symptoms, gynaecological symptoms, cognitive symptoms, weight problems, vitality, and depression. We did the analyses by intention to treat, including patients who completed questionnaires at baseline and at least once during follow-up. This study is registered with ClinicalTrials.gov, NCT00053898., Findings: Between Jan 6, 2003, and June 15, 2006, 3104 patients were enrolled in the study, of whom 1193 were included in the quality-of-life substudy: 601 assigned to tamoxifen and 592 assigned to anastrozole. We detected no significant difference between treatment groups for: physical health scores (mean severity score 46·72 for tamoxifen vs 45·85 for anastrozole; p=0·20), mental health scores (52·38 vs 51·48; p=0·38), energy and fatigue (58·34 vs 57·54; p=0·86), or symptoms of depression (6·19 vs 6·39; p=0·46) over 5 years. Vasomotor symptoms (1·33 vs 1·17; p=0·011), difficulty with bladder control (0·96 vs 0·80; p=0·0002), and gynaecological symptoms (0·29 vs 0·18; p<0·0001) were significantly more severe in the tamoxifen group than in the anastrozole group. Musculoskeletal pain (1·50 vs 1·72; p=0·0006) and vaginal symptoms (0·76 vs 0·86; p=0·035) were significantly worse in the anastrozole group than in the tamoxifen group. Sexual functioning did not differ significantly between the two treatments (43·65 vs 45·29; p=0·56). Younger age was significantly associated with more severe vasomotor symptoms (mean severity score 1·45 for age <60 years vs 0·65 for age ≥60 years; p=0·0006), vaginal symptoms (0·98 vs 0·65; p<0·0001), weight problems (1·32 vs 1·02; p<0·0001), and gynaecological symptoms (0·26 vs 0·22; p=0·014)., Interpretation: Given the similar efficacy of tamoxifen and anastrozole for women older than age 60 years, decisions about treatment should be informed by the risk for serious adverse health effects and the symptoms associated with each drug. For women younger than 60 years old, treatment decisions might be driven by efficacy (favouring anastrozole); however, if the side-effects of anastrozole are intolerable, then switching to tamoxifen is a good alternative., Funding: US National Cancer Institute, AstraZeneca Pharmaceuticals., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Third-generation aromatase inhibitors are more effective than tamoxifen for preventing recurrence in postmenopausal women with hormone-receptor-positive invasive breast cancer. However, it is not known whether anastrozole is more effective than tamoxifen for women with hormone-receptor-positive ductal carcinoma in situ (DCIS). Here, we compare the efficacy of anastrozole with that of tamoxifen in postmenopausal women with hormone-receptor-positive DCIS., Methods: In a double-blind, multicentre, randomised placebo-controlled trial, we recruited women who had been diagnosed with locally excised, hormone-receptor-positive DCIS. Eligible women were randomly assigned in a 1:1 ratio by central computer allocation to receive 1 mg oral anastrozole or 20 mg oral tamoxifen every day for 5 years. Randomisation was stratified by major centre or hub and was done in blocks (six, eight, or ten). All trial personnel, participants, and clinicians were masked to treatment allocation and only the trial statistician had access to treatment allocation. The primary endpoint was all recurrence, including recurrent DCIS and new contralateral tumours. All analyses were done on a modified intention-to-treat basis (in all women who were randomised and did not revoke consent for their data to be included) and proportional hazard models were used to compute hazard ratios and corresponding confidence intervals. This trial is registered at the ISRCTN registry, number ISRCTN37546358., Results: Between March 3, 2003, and Feb 8, 2012, we enrolled 2980 postmenopausal women from 236 centres in 14 countries and randomly assigned them to receive anastrozole (1449 analysed) or tamoxifen (1489 analysed). Median follow-up was 7·2 years (IQR 5·6-8·9), and 144 breast cancer recurrences were recorded. We noted no statistically significant difference in overall recurrence (67 recurrences for anastrozole vs 77 for tamoxifen; HR 0·89 [95% CI 0·64-1·23]). The non-inferiority of anastrozole was established (upper 95% CI <1·25), but its superiority to tamoxifen was not (p=0·49). A total of 69 deaths were recorded (33 for anastrozole vs 36 for tamoxifen; HR 0·93 [95% CI 0·58-1·50], p=0·78), and no specific cause was more common in one group than the other. The number of women reporting any adverse event was similar between anastrozole (1323 women, 91%) and tamoxifen (1379 women, 93%); the side-effect profiles of the two drugs differed, with more fractures, musculoskeletal events, hypercholesterolaemia, and strokes with anastrozole and more muscle spasm, gynaecological cancers and symptoms, vasomotor symptoms, and deep vein thromboses with tamoxifen., Conclusions: No clear efficacy differences were seen between the two treatments. Anastrozole offers another treatment option for postmenopausal women with hormone-receptor-positive DCIS, which may be be more appropriate for some women with contraindications for tamoxifen. Longer follow-up will be necessary to fully evaluate treatment differences., Funding: Cancer Research UK, National Health and Medical Research Council Australia, Breast Cancer Research Fund, AstraZeneca, Sanofi Aventis., (Copyright © 2016 Forbes et al. Open Access article distributed under the terms of CC BY. Published by Elsevier Ltd.. All rights reserved.)

Background: Ductal carcinoma in situ is currently managed with excision, radiotherapy, and adjuvant hormone therapy, usually tamoxifen. We postulated that an aromatase inhibitor would be safer and more effective. We therefore undertook this trial to compare anastrozole versus tamoxifen in postmenopausal women with ductal carcinoma in situ undergoing lumpectomy plus radiotherapy., Methods: The double-blind, randomised, phase 3 National Surgical Adjuvant Breast and Bowel Project (NSABP) B-35 trial was done in 333 participating NSABP centres in the USA and Canada. Postmenopausal women with hormone-positive ductal carcinoma in situ treated by lumpectomy with clear resection margins and whole-breast irradiation were enrolled and randomly assigned (1:1) to receive either oral tamoxifen 20 mg per day (with matching placebo in place of anastrozole) or oral anastrozole 1 mg per day (with matching placebo in place of tamoxifen) for 5 years. Randomisation was stratified by age (<60 vs ≥60 years) and patients and investigators were masked to treatment allocation. The primary outcome was breast cancer-free interval, defined as time from randomisation to any breast cancer event (local, regional, or distant recurrence, or contralateral breast cancer, invasive disease, or ductal carcinoma in situ), analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00053898, and is complete., Findings: Between Jan 1, 2003, and June 15, 2006, 3104 eligible patients were enrolled and randomly assigned to the two treatment groups (1552 to tamoxifen and 1552 to anastrozole). As of Feb 28, 2015, follow-up information was available for 3083 patients for overall survival and 3077 for all other disease-free endpoints, with median follow-up of 9·0 years (IQR 8·2-10·0). In total, 212 breast cancer-free interval events occurred: 122 in the tamoxifen group and 90 in the anastrozole group (HR 0·73 [95% CI 0·56-0·96], p=0·0234). A significant time-by-treatment interaction (p=0·0410) became evident later in the study. There was also a significant interaction between treatment and age group (p=0·0379), showing that anastrozole is superior only in women younger than 60 years of age. Adverse events did not differ between the groups, except for thrombosis or embolism--a known side-effect of tamoxifen-for which there were 17 grade 4 or worse events in the tamoxifen group versus four in the anastrozole group., Interpretation: Compared with tamoxifen, anastrozole treatment provided a significant improvement in breast cancer-free interval, mainly in women younger than 60 years of age. This finding means that women will benefit from having a choice of effective agents for ductal carcinoma in situ., Funding: US National Cancer Institute and AstraZeneca Pharmaceuticals LP., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Purpose: Carpal tunnel syndrome (CTS) occurs when the median nerve is compressed at the wrist in the carpal tunnel. It has been suggested that hormonal risk factors may be involved in the pathogenesis of CTS, and a higher incidence of CTS has been reported in randomized clinical trials with aromatase inhibitors (AIs) compared with tamoxifen., Patients and Methods: This was an exploratory analysis of the International Breast Cancer Intervention Study II, a double-blind randomized clinical trial in which women at increased risk of breast cancer were randomly assigned to receive anastrozole or placebo. This is the first report of risk factors for and characteristics of CTS in women taking an AI in a placebo-controlled trial., Results: Overall, 96 participants with CTS were observed: 65 (3.4%) in the anastrozole arm and 31 (1.6%) in the placebo arm (odds ratio, 2.16 [1.40 to 3.33]; P < .001). Ten participants were reported as having severe CTS, of which eight were taking anastrozole (P = .08). Eighteen women (0.9%) in the anastrozole arm and six women (0.3%) in the placebo arm reported surgical intervention, which was significantly different (odds ratio, 3.06 [1.21 to 7.72], P = .018). Six women discontinued with the allocated treatment because of the onset of CTS. Apart from treatment allocation, a high body mass index and an a prior report of musculoskeletal symptoms after trial entry were the only other risk factors for CTS identified in these postmenopausal women., Conclusions: The use of anastrozole was associated with a higher incidence of CTS but few participants required surgery. Further investigations are warranted into the risk factors and treatment of AI-induced CTS., (© 2015 by American Society of Clinical Oncology.)

Objective: To investigate the effect of co-administration of letrozole in an ovarian stimulation protocol using recombinant FSH and GnRH antagonists for ICSI in normo/high responders., Methods: Computerized data of 320 antagonist ICSI/ET cycles with or without letrozole were retrospectively analyzed. In 105 cases, letrozole (5 mg/day) was started at the second day of the cycle continued for 5 days. At the second day of letrozole, gonadotropins were added. The remaining 215 cases were stimulated with recombinant FSH only. In all cases on day 6, GnRH antagonist was started. Ovarian stimulation protocols with or without letrozole were compared for cycle outcome parameters., Results: In cycles with letrozole, significantly lower gonadotropin consumption and lower peak estradiol levels were found. In cycles with letrozole, mean number of metaphase II and fertilized oocytes retrieved were significantly higher compared to cycles without letrozole. The pregnancy and clinical pregnancy rates were similar., Conclusion: Should the number of oocytes retrieved being higher in letrozole group might indicate that letrozole might contribute to successful ovarian stimulation with a lower dosage of gonadotropins. Despite the lower peak estradiol levels, pregnancy rates being similar to other group also support the idea that letrozole can contribute to normal potential of implantation.

Objective: To present a case of twin pregnancy obtained by in vitro fertilization and embryo transfer (IVF-ET) with variable dose letrozole-FSH protocol of lower peak estradiol level, after treatment of carcinoma of the breast., Materials and Methods: A 34-year-old patient diagnosed with mucinous breast carcinoma undergoing assisted fertilization treatment after breast cancer operation and treatment including controlled ovarian stimulation (COS), oocyte retrieval, IVF, and embryo culture and transfer., Results: Four oocytes were obtained in three COS procedures in the three IVF cycle. All oocytes were fertilized. In the third cycle, two fresh embryos were transferred, and two healthy girls were born at 37 gestational weeks., Conclusion: Variable dose letrozole-FSH protocol can maintain lower peak estradiol levels and reduce estrogen exposure after breast cancer operation and chemotherapy.

Purpose: To compare overall survival (OS) for fulvestrant 500 mg versus anastrozole as first-line endocrine therapy for advanced breast cancer., Patients and Methods: The Fulvestrant First-Line Study Comparing Endocrine Treatments (FIRST) was a phase II, randomized, open-label, multicenter trial. Postmenopausal women with estrogen receptor-positive, locally advanced/metastatic breast cancer who had no previous therapy for advanced disease received either fulvestrant 500 mg (days 0, 14, 28, and every 28 days thereafter) or anastrozole 1 mg (daily). The primary end point (clinical benefit rate [72.5% and 67.0%]) and a follow-up analysis (median time to progression [23.4 months and 13.1 months]) have been reported previously for fulvestrant 500 mg and anastrozole, respectively. Subsequently, the protocol was amended to assess OS by unadjusted log-rank test after approximately 65% of patients had died. Treatment effect on OS across several subgroups was examined. Tolerability was evaluated by adverse event monitoring., Results: In total, 205 patients were randomly assigned (fulvestrant 500 mg, n = 102; anastrozole, n = 103). At data cutoff, 61.8% (fulvestrant 500 mg, n = 63) and 71.8% (anastrozole, n = 74) had died. The hazard ratio (95% CI) for OS with fulvestrant 500 mg versus anastrozole was 0.70 (0.50 to 0.98; P = .04; median OS, 54.1 months v 48.4 months). Treatment effects seemed generally consistent across the subgroups analyzed. No new safety issues were observed., Conclusion: There are several limitations of this OS analysis, including that it was not planned in the original protocol but instead was added after time-to-progression results were analyzed, and that not all patients participated in additional OS follow-up. However, the present results suggest fulvestrant 500 mg extends OS versus anastrozole. This finding now awaits prospective confirmation in the larger phase III FALCON (Fulvestrant and Anastrozole Compared in Hormonal Therapy Naïve Advanced Breast Cancer) trial (ClinicalTrials.gov identifier: NCT01602380)., (© 2015 by American Society of Clinical Oncology.)

Study Question: Are progesterone levels after letrozole-associated controlled ovarian stimulation (COS) for fertility preservation in breast cancer patients, lower than after standard in vitro fertilization (IVF) cycles?, Summary Answer: During the luteal phase of letrozole-associated COS cycles (triggered with human chorionic gonadotrophin (hCG)) progesterone levels are similarly elevated to those obtained after standard COS without letrozole., What Is Known Already: Current fertility preservation strategies for breast cancer patients include association of COS with the aromatase inhibitor letrozole to harvest several mature oocytes while maintaining low estradiol levels. Data on progesterone levels are however lacking despite growing evidence of the role of progesterone in breast tumorigenesis., Study Design, Size, Duration: This is a prospective observational study comparing estradiol and progesterone levels of 21 breast cancer patients undergoing letrozole-associated COS with 21 infertile patients undergoing standard COS for IVF and/or intra cytoplasmic sperm injection (ICSI)., Participants/materials, Setting, Methods: All patients underwent COS with a GnRH antagonist protocol. In the fertility preservation group, ovulation induction was started in the follicular or luteal phase depending on the chemotherapy schedule and in 10 cases a GnRH antagonist was administered during luteal phase to induce luteolysis. Final oocyte maturation was induced by hCG in all patients. Estradiol and progesterone levels were measured on the day of hCG, at oocyte retrieval, and on days 3 and 8 after oocyte retrieval. Hormone levels in fertility preservation patients were compared with those observed in infertility patients., Main Results and the Role of Chance: While estradiol levels were significantly lower in the fertility preservation group compared with the control group (P < 0.001), progesterone levels were similar at all times, including patients receiving a GnRH antagonist during the luteal phase., Limitations, Reasons for Caution: The studied populations (breast cancer and infertile patients) are different, which may induce selection bias. The small sample size limits the study's statistical power and the possibility to perform multivariate analysis. Recruitment of the study and control patients was completed at the same time; however, enrollment of controls started at a later time., Wider Implications of the Findings: While the use of letrozole in fertility preservation patients has a favorable effect on estrogen levels, no benefit is seen for progesterone levels which are high and comparable with progesterone levels after standard COS in IVF patients. As progesterone has been associated with tumor cell proliferation, caution is mandatory. Modified protocols including GnRH agonist triggering should be investigated., (© The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Luteinized unruptured follicle (LUF) syndrome is considered a cause of ovulation failure and a subtle cause of infertility. Preovulatory injection of human chorionic gonadotropin (HCG) prevents or treats LUF syndrome, but it has also occurred after the induction of ovulation with clomiphene/HMG and HCG. This study was designed for evaluation and comparison of LUF incidence in eligible infertile women undergoing two stimulation protocols (clomiphene + HMG and letrozole + HMG) in addition to intrauterine insemination (IUI). Some related factors were compared between LUF and non-LUF cycles as secondary outcomes., Methods: The study was designed as a prospective randomized controlled trial. Patients were randomized using a table of random numbers into two equal protocol groups. For group A, (n = 90) clomiphene citrate was administrated orally in doses of 100 mg/day, and group B (n = 90) orally received letrozole 5 mg/day from day 3 to 7 of the menstrual cycle. Then HMG 75IU/day was administered intramuscularly in both groups on day 8 of the menstrual cycle and the dose was adjusted on the basis of ovarian response. The optimum size of preovulatory follicles for the injection of HCG (10,000 IU) was considered 18-23 mm. The number and size of preovulatory follicles were assessed by vaginal ultrasound 12 h before HCG (D0). Endometrial thickness was measured as well. IUI was performed on all patients 38-40 h after HCG. The second ultrasound examination was performed to observe the evidence of oocyte releasing at the time of IUI (D1). If the follicles were unruptured, a third sonography was performed on day 7 after HCG (D7) to observe LUF syndrome., Results: There was a significant difference between clomiphene-HMG and letrozole-HMG in LUF (p = 0.021) and pregnancy (p = 0.041). The complete LUF in letrozole-HMG was lower than the alternative group and the pregnancy rate was higher. The patients in the non-LUF group had higher midluteal progesterone and a thicker endometrium compared to LUF cycles (p = 0.039) and (p < 0.001). The results of our multivariate logistic regression indicate that size 18-19.9 mm leads to the complete LUF  less than ≥22 mm [AOR: 0.25, P = 0.005], and  in size 20- 21.9 mm  as well [AOR: 0.17, P = 0.002]., Conclusion: Letrozole, with lower incidences of LUF, is more effective than clomiphene citrate for the induction of ovulation in IUI cycles. In our study, we illustrated that larger follicles of ≥22 mm diameter were associated with higher incidences of LUF. We recommend that further studies investigate and focus on the relationship between follicular size and/or full hormonal profiles and LUF.

Palbociclib is a selective inhibitor of cyclin-dependent kinases 4 and 6 that acts by reducing phosphorylation of the tumor suppressor gene retinoblastoma. When added to the aromatase inhibitor letrozole in a randomized phase II trial for first-line therapy of estrogen receptor-positive, HER2-negative metastatic breast cancer, palbociclib significantly increased progression-free survival compared with letrozole alone [palbociclib + letrozole: 20.2 months; 95% confidence interval (CI), 13.8-27.5; letrozole: 10.2 months; 95% CI, 5.7-12.6; HR, 0.49; 95% CI, 0.32-0.75; P = 0.0004]. On the basis of these results, the drug was recently granted accelerated approval by the FDA, and confirmatory studies are ongoing. Because this drug has a rational target in an oncologic pathway, concurrent biomarker development is of interest. In breast cancer, the most useful predictive biomarkers identified thus far are estrogen receptor and HER2 receptor status, although additional studies are ongoing. In this article, we review the development of palbociclib and its use in treatment of hormone receptor-positive metastatic breast cancer in the context of other FDA-approved agents in this setting., (©2015 American Association for Cancer Research.)

Purpose: We have previously reported an approach to ovarian stimulation for the purpose of fertility preservation (FP) in women with breast cancer via embryo freezing with the concurrent use of letrozole. The aim of this study was to provide the pregnancy and FP outcomes when embryos generated with the same protocol are used., Patients and Methods: In all, 131 women with stage ≤ 3 breast cancer underwent ovarian stimulation and received concurrent letrozole 5 mg per day before receiving adjuvant chemotherapy and cryopreserving embryos., Results: Thirty-three of the 131 women underwent 40 attempts to transfer embryos to their own uterus (n = 18) or via the use of a gestational carrier (n = 22) at a mean age of 41.5 ± 4.3 years with a median 5.25 years after embryo cryopreservation. The overall live birth rate per embryo transfer was similar to the US national mean among infertile women of a similar age undergoing in vitro fertilization-embryo transfer (45.0 v 38.2; P = .2). Seven (38.8%) of the 18 pregnancies were twins with no higher-order pregnancies being encountered. No fetal anomalies or malformations were reported in 25 children after a mean follow-up of 40.4 ± 26.4 months. Seventeen of the 33 women attempting pregnancy had at least one child, translating into an FP rate of 51.5% per attempting woman., Conclusion: Embryo cryopreservation after ovarian stimulation with the letrozole and follicle-stimulating hormone protocol preserves fertility in women with breast cancer and results in pregnancy rates comparable to those expected in a noncancer population undergoing in vitro fertilization., (© 2015 by American Society of Clinical Oncology.)