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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 effect of extended adjuvant aromatase inhibition in hormone receptor-positive breast cancer after sequential endocrine therapy of tamoxifen followed by an aromatase inhibitor for a 5-year treatment period still needs clarification. To address this issue, we began the DATA study to assess different durations of anastrozole therapy after tamoxifen., Methods: DATA was a prospective, randomised, open-label, multicentre, phase 3 study done in 79 hospitals in the Netherlands. We randomly assigned postmenopausal women with hormone receptor-positive early breast cancer with no signs of disease recurrence after 2-3 years of adjuvant tamoxifen to either 3 or 6 years of anastrozole treatment (1 mg orally once a day) in a 1:1 ratio. We used TENALEA (Trans European Network for Clinical Trials Services) for the randomisation procedure. Stratification factors were nodal status, hormone receptor status, HER2 status, and tamoxifen treatment duration. The primary study endpoint of this analysis was disease-free survival starting beyond 3 years after randomisation (adapted disease-free survival). Here we report the final analysis from the DATA trial, which is registered with ClinicalTrials.gov, number NCT00301457., Findings: Between June 28, 2006, and Aug 10, 2009, we screened 1912 patients of whom 955 were assigned to the 3-year group and 957 to the 6-year anastrozole treatment group. 1860 patients were eligible (931 in the 6-year group and 929 in the 3-year group) and 1660 were disease free 3 years after randomisation. The 5-year adapted disease-free survival was 83·1% (95% CI 80·0-86·3) in the 6-year group and 79·4% (76·1-82·8) in the 3-year group (hazard ratio [HR] 0·79 [95% CI 0·62-1·02]; p=0·066). Patients in the 6-year treatment group had more adverse events than those in the 3-year treatment group, including all-grade arthralgia or myalgia (478 [58%] of 827 in the 6-year treatment group vs 438 [53%] of 833 in the 3-year treatment group) and osteopenia or osteoporosis (173 [21%] vs 137 [16%])., Interpretation: We cannot recommend the use of extended adjuvant aromatase inhibition after 5 years of sequential endocrine therapy in all postmenopausal women with hormone receptor-positive breast cancer., Funding: AstraZeneca., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Enzalutamide is an oral androgen-receptor inhibitor that has been shown to improve survival in two placebo-controlled phase 3 trials, and is approved for patients with metastatic castration-resistant prostate cancer. The objective of the TERRAIN study was to compare the efficacy and safety of enzalutamide with bicalutamide in patients with metastatic castration-resistant prostate cancer., Methods: TERRAIN was a double-blind, randomised phase 2 study, that recruited asymptomatic or minimally symptomatic men with prostate cancer progression on androgen-deprivation therapy (ADT) from academic, community, and private health-care provision sites across North America and Europe. Eligible patients were randomly assigned (1:1) via an interactive voice response system to receive enzalutamide 160 mg/day or bicalutamide 50 mg/day, both taken orally, in addition to ADT, until disease progression. Patients were stratified by a permutated block method (block size of four), by whether bilateral orchiectomy or receipt of luteinising hormone-releasing hormone agonist or antagonist therapy started before or after the diagnosis of metastases, and by study site. Participants, investigators, and those assessing outcomes were masked to group assignment. The primary endpoint was progression-free survival, analysed in all randomised patients. Safety outcomes were analysed in all patients who received at least one dose of study drug. The open-label period of the trial is in progress, wherein patients still on treatment at the end of the double-blind treatment period were offered open-label enzalutamide at the discretion of the patient and study investigator. This trial is registered with ClinicalTrials.gov, number NCT01288911., Findings: Between March 22, 2011, and July 11, 2013, 375 patients were randomly assigned, 184 to enzalutamide and 191 to bicalutamide. 126 (68%) and 168 (88%) patients, respectively, discontinued their assigned treatment before study end, mainly due to progressive disease. Median follow-up time was 20·0 months (IQR 15·0-25·6) in the enzalutamide group and 16·7 months (10·2-21·9) in the bicalutamide group. Patients in the enzalutamide group had significantly improved median progression-free survival (15·7 months [95% CI 11·5-19·4]) compared with patients in the bicalutamide group (5·8 months [4·8-8·1]; hazard ratio 0·44 [95% CI 0·34-0·57]; p<0·0001). Of the most common adverse events, those occurring more frequently with enzalutamide than with bicalutamide were fatigue (51 [28%] of 183 patients in the enzalutamide group vs 38 [20%] of 189 in the bicalutamide group), back pain (35 [19%] vs 34 [18%]), and hot flush (27 [15%] vs 21 [11%]); those occurring more frequently with bicalutamide were nausea (26 [14%] vs 33 [17%]), constipation (23 [13%] vs 25 [13%]), and arthralgia (18 [10%] vs 30 [16%]). The most common grade 3 or worse adverse events in the enzalutamide or bicalutamide treatment groups, respectively, were hypertension (13 [7%] vs eight [4%]), hydronephrosis (three [2%] vs seven [4%]), back pain (five [3%] vs three [2%]), pathological fracture (five [3%] vs two [1%]), dyspnoea (four [2%] vs one [1%]), bone pain (one [1%] vs four [2%]), congestive cardiac failure (four [2%] vs two [1%]), myocardial infarction (five [3%] vs none), and anaemia (four [2%] vs none]). Serious adverse events were reported by 57 (31%) of 183 patients and 44 (23%) of 189 patients in the enzalutamide and bicalutamide groups, respectively. One of the nine deaths in the enzalutamide group was thought to be possibly related to treatment (due to systemic inflammatory response syndrome) compared with none of the three deaths in the bicalutamide group., Interpretation: The data from the TERRAIN trial support the use of enzalutamide rather than bicalutamide in patients with asymptomatic or mildly symptomatic metastatic castration-resistant prostate cancer., Funding: Astellas Pharma, Inc and Medivation, Inc., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Treatment of breast cancer with aromatase inhibitors is associated with damage to bones. NCIC CTG MA.27 was an open-label, phase 3, randomised controlled trial in which women with breast cancer were assigned to one of two adjuvant oral aromatase inhibitors-exemestane or anastrozole. We postulated that exemestane-a mildly androgenic steroid-might have a less detrimental effect on bone than non-steroidal anastrozole. In this companion study to MA.27, we compared changes in bone mineral density (BMD) in the lumbar spine and total hip between patients treated with exemestane and patients treated with anastrozole., Methods: In MA.27, postmenopausal women with early stage hormone (oestrogen) receptor-positive invasive breast cancer were randomly assigned to exemestane 25 mg versus anastrozole 1 mg, daily. MA.27B recruited two groups of women from MA.27: those with BMD T-scores of -2·0 or more (up to 2 SDs below sex-matched, young adult mean) and those with at least one T-score (hip or spine) less than -2·0. Both groups received vitamin D and calcium; those with baseline T-scores of less than -2·0 also received bisphosphonates. The primary endpoints were percent change of BMD at 2 years in lumbar spine and total hip for both groups. We analysed patients according to which aromatase inhibitor and T-score groups they were allocated to but BMD assessments ceased if patients deviated from protocol. This study is registered with ClinicalTrials.gov, NCT00354302., Findings: Between April 24, 2006, and May 30, 2008, 300 patients with baseline T-scores of -2·0 or more were accrued (147 allocated exemestane, 153 anastrozole); and 197 patients with baseline T-scores of less than -2·0 (101 exemestane, 96 anastrozole). For patients with T-scores greater than -2·0 at baseline, mean change of bone mineral density in the spine at 2 years did not differ significantly between patients taking exemestane and patients taking anastrozole (-0·92%, 95% CI -2·35 to 0·50 vs -2·39%, 95% CI -3·77 to -1·01; p=0·08). Respective mean loss in the hip was -1·93% (95% CI -2·93 to -0·93) versus -2·71% (95% CI -4·32 to -1·11; p=0·10). Likewise for those who started with T-scores of less than -2·0, mean change of spine bone mineral density at 2 years did not differ significantly between the exemestane and anastrozole treatment groups (2·11%, 95% CI -0·84 to 5·06 vs 3·72%, 95% CI 1·54 to 5·89; p=0·26), nor did hip bone mineral density (2·09%, 95% CI -1·45 to 5·63 vs 0·0%, 95% CI -3·67 to 3·66; p=0·28). Patients with baseline T-score of -2·0 or more taking exemestane had two fragility fractures and two other fractures, those taking anastrozole had three fragility fractures and five other fractures. For patients who had baseline T-scores of less than -2·0 taking exemestane, one had a fragility fracture and four had other fractures, whereas those taking anastrozole had five fragility fractures and one other fracture., Interpretation: Our results demonstrate that adjuvant treatment with aromatase inhibitors can be considered for breast cancer patients who have T-scores less than -2·0., Funding: Canadian Cancer Society Research Institute, Pfizer, Canadian Institutes of Health Research., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: The optimum endocrine treatment for postmenopausal women with advanced hormone-receptor-positive breast cancer that has progressed on non-steroidal aromatase inhibitors (NSAIs) is unclear. The aim of the SoFEA trial was to assess a maximum double endocrine targeting approach with the steroidal anti-oestrogen fulvestrant in combination with continued oestrogen deprivation., Methods: In a composite, multicentre, phase 3 randomised controlled trial done in the UK and South Korea, postmenopausal women with hormone-receptor-positive breast cancer (oestrogen receptor [ER] positive, progesterone receptor [PR] positive, or both) were eligible if they had relapsed or progressed with locally advanced or metastatic disease on an NSAI (given as adjuvant for at least 12 months or as first-line treatment for at least 6 months). Additionally, patients had to have adequate organ function and a WHO performance status of 0-2. Participants were randomly assigned (1:1:1) to receive fulvestrant (500 mg intramuscular injection on day 1, followed by 250 mg doses on days 15 and 29, and then every 28 days) plus daily oral anastrozole (1 mg); fulvestrant plus anastrozole-matched placebo; or daily oral exemestane (25 mg). Randomisation was done with computer-generated permuted blocks, and stratification was by centre and previous use of an NSAI as adjuvant treatment or for locally advanced or metastatic disease. Participants and investigators were aware of assignment to fulvestrant or exemestane, but not of assignment to anastrozole or placebo. The primary endpoint was progression-free survival (PFS). Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, numbers NCT00253422 (UK) and NCT00944918 (South Korea)., Findings: Between March 26, 2004, and Aug 6, 2010, 723 patients underwent randomisation: 243 were assigned to receive fulvestrant plus anastrozole, 231 to fulvestrant plus placebo, and 249 to exemestane. Median PFS was 4·4 months (95% CI 3·4-5·4) in patients assigned to fulvestrant plus anastrozole, 4·8 months (3·6-5·5) in those assigned to fulvestrant plus placebo, and 3·4 months (3·0-4·6) in those assigned to exemestane. No difference was recorded between the patients assigned to fulvestrant plus anastrozole and fulvestrant plus placebo (hazard ratio 1·00, 95% CI 0·83-1·21; log-rank p=0·98), or between those assigned to fulvestrant plus placebo and exemestane (0·95, 0·79-1·14; log-rank p=0·56). 87 serious adverse events were reported: 36 in patients assigned to fulvestrant plus anastrozole, 22 in those assigned to fulvestrant plus placebo, and 29 in those assigned to exemestane. Grade 3-4 adverse events were rare; the most frequent were arthralgia (three in the group assigned to fulvestrant plus anastrozole; seven in that assigned to fulvestrant plus placebo; eight in that assigned to exemestane), lethargy (three; 11; 11), and nausea or vomiting (five; two; eight)., Interpretation: After loss of response to NSAIs in postmenopausal women with hormone-receptor-positive advanced breast cancer, maximum double endocrine treatment with 250 mg fulvestrant combined with oestrogen deprivation is no better than either fulvestrant alone or exemestane., (Copyright © 2013 Johnston et al. Open Access article distributed under the terms of CC BY-NC-SA. Published by Elsevier Ltd. All rights reserved.)

Background: Aromatase inhibitors have shown increased efficacy compared with tamoxifen in postmenopausal early breast cancer. We aimed to assess the efficacy and safety of anastrozole versus tamoxifen in premenopausal women receiving goserelin for early breast cancer in the neoadjuvant setting., Methods: In this phase 3, randomised, double-blind, parallel-group, multicentre study, we enrolled premenopausal women with oestrogen receptor (ER)-positive, HER2-negative, operable breast cancer with WHO performance status of 2 or lower. Patients were randomly assigned (1:1) to receive goserelin 3·6 mg/month plus either anastrozole 1 mg per day and tamoxifen placebo or tamoxifen 20 mg per day and anastrozole placebo for 24 weeks before surgery. Patients were randomised sequentially, stratified by centre, with randomisation codes. All study personnel were masked to study treatment. The primary endpoint was best overall tumour response (complete response or partial response), assessed by callipers, during the 24-week neoadjuvant treatment period for the intention-to-treat population. The primary endpoint was analysed for non-inferiority (with non-inferiority defined as the lower limit of the 95% CI for the difference in overall response rates between groups being 10% or less); in the event of non-inferiority, we assessed the superiority of the anastrozole group versus the tamoxifen group. We included all patients who received study medication at least once in the safety analysis set. We report the primary analysis; treatment will also continue in the adjuvant setting for 5 years. This trial is registered with ClinicalTrials.gov, number NCT00605267., Findings: Between Oct 2, 2007, and May 29, 2009, 204 patients were enrolled. 197 patients were randomly assigned to anastrozole (n=98) or tamoxifen (n=99), and 185 patients completed the 24-week neoadjuvant treatment period and had breast surgery (95 in the anastrazole group, 90 in the tamoxifen group). More patients in the anastrozole group had a complete or partial response than did those in the tamoxifen group during 24 weeks of neoadjuvant treatment (anastrozole 70·4% [69 of 98 patients] vs tamoxifen 50·5% [50 of 99 patients]; estimated difference between groups 19·9%, 95% CI 6·5-33·3; p=0·004). Two patients in the anastrozole group had treatment-related grade 3 adverse events (arthralgia and syncope) and so did one patient in the tamoxifen group (depression). One serious adverse event was reported in the anastrozole group (benign neoplasm, not related to treatment), compared with none in the tamoxifen group., Interpretation: Given its favourable risk-benefit profile, the combination of anastrozole plus goserelin could represent an alternative neoadjuvant treatment option for premenopausal women with early-stage breast cancer., Funding: AstraZeneca., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Letrozole radiosensitises breast cancer cells in vitro. In clinical settings, no data exist for the combination of letrozole and radiotherapy. We assessed concurrent and sequential radiotherapy and letrozole in the adjuvant setting., Methods: This phase 2 randomised trial was undertaken in two centres in France and one in Switzerland between Jan 12, 2005, and Feb 21, 2007. 150 postmenopausal women with early-stage breast cancer were randomly assigned after conserving surgery to either concurrent radiotherapy and letrozole (n=75) or sequential radiotherapy and letrozole (n=75). Randomisation was open label with a minimisation technique, stratified by investigational centres, chemotherapy (yes vs no), radiation boost (yes vs no), and value of radiation-induced lymphocyte apoptosis (< or = 16% vs >16%). Whole breast was irradiated to a total dose of 50 Gy in 25 fractions over 5 weeks. In the case of supraclavicular and internal mammary node irradiation, the dose was 44-50 Gy. Letrozole was administered orally once daily at a dose of 2.5 mg for 5 years (beginning 3 weeks pre-radiotherapy in the concomitant group, and 3 weeks post-radiotherapy in the sequential group). The primary endpoint was the occurrence of acute (during and within 6 weeks of radiotherapy) and late (within 2 years) radiation-induced grade 2 or worse toxic effects of the skin. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00208273., Findings: All patients were analysed apart from one in the concurrent group who withdrew consent before any treatment. During radiotherapy and within the first 12 weeks after radiotherapy, 31 patients in the concurrent group and 31 in the sequential group had any grade 2 or worse skin-related toxicity. The most common skin-related adverse event was dermatitis: four patients in the concurrent group and six in the sequential group had grade 3 acute skin dermatitis during radiotherapy. At a median follow-up of 26 months (range 3-40), two patients in each group had grade 2 or worse late effects (both radiation-induced subcutaneous fibrosis)., Interpretation: Letrozole can be safely delivered shortly after surgery and concomitantly with radiotherapy. Long-term follow-up is needed to investigate cardiac side-effects and cancer-specific outcomes., Funding: Novartis Oncology France., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Background: When the mechanism of action behind treatment toxicity reflects the intended effect on the treatment target, the toxicity might be a useful marker for efficacy. During endocrine treatment of breast cancer, the occurrence of symptoms related to oestrogen depletion or oestrogen blockade might thus be a predictor of treatment effectiveness. In this retrospective analysis, the relation between the reported incidence of vasomotor or joint symptoms and breast cancer recurrence in the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial is assessed., Methods: Women with hormone-receptor-positive tumours who reported vasomotor or joint symptoms at the first follow-up visit (3 months) in the ATAC trial, (which assessed tamoxifen or anastrozole for adjuvant treatment of postmenopausal breast cancer), were compared with women without these symptoms to see if there was a relation between these symptoms and subsequent recurrence. The ATAC trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230., Findings: 1486 of 3964 (37.5%) eligible women reported newly emergent vasomotor symptoms at the 3-month follow-up visit and had lower subsequent recurrence than those who did not report these symptoms (223 during 10 752 women-years of follow-up vs 366 during 11 573 woman-years of follow-up, respectively; hazard ratio [HR] 0.84 [95% CI 0.71-1.00], p=0.04; adjusted for age, body-mass index, previous hormone-replacement therapy, nodal status, tumour size, and tumour grade). A greater decrease in breast-cancer recurrence was seen for the 1245 of 3964 (31.4%) eligible women who reported new joint symptoms at the 3-month follow-up visit compared with those not reporting these symptoms (158 during 9242 women-years of follow-up vs 366 during 11 573 women-years of follow-up; adjusted HR 0.60 [0.50-0.72], p<0.0001)., Interpretation: The appearance of new vasomotor symptoms or joint symptoms within the first 3 months of treatment is a useful biomarker, suggesting a greater response to endocrine treatment compared with women without these symptoms. Awareness of the relation between early treatment-emergent symptoms and beneficial response to therapy might be useful when reassuring patients who present with them, and might help to improve long-term treatment adherence when symptoms cannot be alleviated effectively.

Background: Mild cognitive impairments have been recorded in cross-sectional studies of women with breast cancer receiving endocrine treatment. More comprehensive studies were warranted because aromatase inhibitors are being used increasingly in both chemoprevention and adjuvant settings. We report findings from the cognitive subprotocol of the International Breast Intervention Study (IBIS II), a double-blind placebo-controlled trial of anastrozole in postmenopausal women at high risk of developing breast cancer. We aimed to study and compare the effect of anastrozole versus placebo on memory and attention in these women., Methods: Between Jan 3, 2003, and Dec 21, 2005, participants were recruited into the cognitive subprotocol from five UK centres. Cognitive assessments were done before randomisation, at 6 months, and at 24 months. 227 of 249 women approached completed a comprehensive set of standardised cognitive tasks at baseline and were randomly assigned to receive anastrozole (1 mg/day for 5 years) or placebo. Psychological morbidity, endocrine symptoms, and self-reported cognitive complaints were also measured. The main outcomes were cognitive task scores at baseline, 6 months, and 24 months. Analyses were done by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN31488319., Findings: 111 women were assigned to anastrozole and 116 women to placebo. At 6 months, ten women in each group were excluded from analysis, leaving a total of 207 of 227 (91%) women available for further assessments. At 24 months, 24 women were excluded from the anastrozole group and 32 from the placebo group, leaving 151 of 227 (67%) women. We did not note any significant differences between the groups for any of the cognitive tasks. By 6 months, 13 women in both groups reported changes to their memory and this had decreased to five women in the placebo group and three women in the anastrozole group by the 24-month assessment. Significantly more women in the anastrozole group complained of hot flushes at 24 months (23 of 76 [30%] vs 11 of 73 [15%], p=0.032, not corrected for multiple comparison), but this was the only difference in reported endocrine symptoms., Interpretation: These findings show little or no impairment of cognitive performance with the use of anastrozole compared with placebo in postmenopausal women at high risk of developing breast cancer who were able to tolerate endocrine-related side-effects. Future studies assessing cognition should be done within randomised trials with baseline assessments to ascertain the true extent of the putative effects that treatments for breast cancer might have on memory and attention., Funding: Cancer Research UK, London, UK (grant numbers C6280/A3162 and C6280/A6764).

Background: Joint symptoms (eg, arthralgia and arthritis) are a well-known side-effect of aromatase inhibitors. Low oestrogen concentrations and postmenopausal status are associated with the development of these symptoms. Chemotherapy can also induce joint symptoms, but tamoxifen seems to have little effect on their incidence. The aim of this study was to assess the relative importance of different risk factors for treatment-emergent joint symptoms in patients assigned to anastrozole or tamoxifen as adjuvant treatment for postmenopausal breast cancer., Methods: The Arimidex Tamoxifen Alone or in Combination (ATAC) trial randomly assigned 9366 postmenopausal women to anastrozole (1 mg/day), to tamoxifen (20 mg/day), or to a combination of both. Our analyses were based on data from case reports of 5433 women who were randomly assigned to anastrozole or tamoxifen, who started with their allocated treatment, and who did not have joint symptoms at entry (anastrozole group: n=2698; tamoxifen group: n=2735). The analysis was restricted to the occurrence of joint symptoms at any time during active treatment or within 14 days of its discontinuation. Joint symptoms were defined as any report of arthralgia, arthrosis, arthritis, or joint disorder on a case-report form. Joint disorders were defined as reports of cervical spondylosis, osteoarthritis, and disc herniation. The date of occurrence was recorded, along with a severity score (ie, mild, moderate, or severe). Our analyses were done by use of logistic regression. The ATAC trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230., Findings: 777 of 1914 women (40.6%) who used hormone replacement therapy (HRT) before trial entry developed joint symptoms compared with 1001 of 3519 women (28.4%) without previous HRT use (odds ratio [OR] 1.72 [95% CI 1.53-1.93]). Women with hormone-receptor-negative breast cancer developed significantly fewer joint symptoms compared with those with hormone-receptor-positive tumours (124 of 461 [26.9%] vs 1556 of 4548 [34.2%]; OR 0.71 [0.57-0.88]). Women for whom chemotherapy was part of their initial treatment developed significantly more joint symptoms than those who did not receive it (461 of 1219 women [37.8%] vs 1317 of 4214 women [31.3%]; OR 1.34 [1.17-1.53]). Obese women (body-mass index [BMI] >30 kg/m(2)) reported more joint symptoms than women with a BMI of 25-30 kg/m(2) or those with a BMI <25 kg/m(2) (504 of 1354 women [37.2%] vs 502 of 1926 women [31.3%; OR 1.01 (0.88-1.16)] vs 592 of 1908 women [31.0%; OR 1.32 (1.14-1.53)]) and women on anastrozole reported more joint symptoms compared with those on tamoxifen (949 of 2698 women [35.2%] vs 829 of 2735 women [30.3%]; OR 1.25 [1.11-1.40]). All significant risk factors from the univariate analysis were included in a multivariate analysis and remained significant with little change., Interpretation: In this trial, the major risk factors for developing joint symptoms were previous HRT, hormone-receptor positivity, previous chemotherapy, obesity, and treatment with anastrozole. Discussion of identified risk factors is appropriate when counselling women before initiation of adjuvant hormonal treatment.

Background: The Breast International Group (BIG) 1-98 trial (a randomised double-blind phase III trial) has shown that letrozole significantly improves disease-free survival (DFS) compared with tamoxifen in postmenopausal women with endocrine-responsive early breast cancer. Our aim was to establish whether the benefit of letrozole versus tamoxifen differs according to the ERBB2 status of tumours., Methods: The BIG 1-98 trial consists of four treatment groups that compare 5 years of monotherapy with letrozole or tamoxifen, and sequential administration of one drug for 2 years followed by the other drug for 3 years. Our study includes data from the 4922 patients randomly assigned to the two monotherapy treatment groups (letrozole or tamoxifen for 5 years; 51 months median follow-up [range <1 to 90 months]). A central assessment of oestrogen receptor (ER), progesterone receptor (PgR) and ERBB2 status using paraffin-embedded primary tumour material was possible for 3650 (74%) patients. ER, PgR, and ERBB2 expression were measured by immunohistochemistry (IHC) and ERBB2-positivity was confirmed by fluorescence in-situ hybridisation (FISH). Positive staining in at least 1% of cells was considered to show presence of ER or PgR expression. Tumours were deemed ERBB2-positive if amplified by FISH, or, for the few tumours with unassessable or unavailable FISH results, if they were IHC 3+. Hazard ratios (HR) estimated by Cox modelling were used to compare letrozole with tamoxifen for DFS, which was the primary endpoint, and to assess treatment-by-covariate interactions. The BIG 1-98 trial is registered on the clinical trials site of the US National Cancer Institute website http://www.clinicaltrials.gov/ct/show/NCT00004205., Findings: By central assessment 7% (257 of 3650) of tumours were classified as ERBB2-positive. In 3533 patients with tumours confirmed to express ER, DFS was poorer in patients with ERBB2-positive tumours (n=239) than in those with ERBB2-negative tumours (n=3294; HR 2.09 [95% CI 1.59-2.76]; p<0.0001). There was no statistical evidence of heterogeneity in the treatment effect according to ERBB2 status of the tumour (p=0.60 for interaction), thus, letrozole improves DFS compared with tamoxifen regardless of ERBB2 status. The observed HRs were 0.62 (95% CI 0.37-1.03) for ERBB2-positive tumours and 0.72 (0.59-0.87) for ERBB2-negative tumours., Interpretation: A benefit of letrozole over tamoxifen was noted, irrespective of ERBB2 status of the tumour, and, therefore, ERBB2 status does not seem to be a selection criterion for treatment with letrozole versus tamoxifen in postmenopausal women with endocrine-responsive early breast cancer.

Background: Little data exist on whether efficacy benefits or side-effects persist after 5 years of adjuvant treatment with an aromatase inhibitor. We aimed to study long-term outcomes in the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial that compares anastrozole with tamoxifen after a median follow-up of 100 months., Methods: We analysed postmenopausal women with localised invasive breast cancer. The primary endpoint disease-free survival (DFS), and the secondary endpoints time to recurrence (TTR), incidence of new contralateral breast cancer (CLBC), time to distant recurrence (TTDR), overall survival (OS), and death after recurrence were assessed in the total population (intention to treat; ITT: anastrozole, n=3125; tamoxifen, n=3116; total 6241) and the hormone-receptor-positive subpopulation, the clinically important subgroup for which endocrine treatment is now known to be effective (84% of ITT: anastrozole, n=2618; tamoxifen, n=2598; total 5216). After treatment completion, fractures and serious adverse events continued to be collected blindly (safety population: anastrozole, n=3092; tamoxifen, n=3094; total 6186). This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230., Findings: At a median follow-up of 100 months (range 0-126), DFS, TTR, TTDR, and CLBC were improved significantly in the ITT and hormone-receptor-positive populations. For hormone-receptor-positive patients: DFS hazard ratio (HR) 0.85 (95% CI 0.76-0.94), p=0.003; TTR HR 0.76 (0.67-0.87), p=0.0001; TTDR HR 0.84 (0.72-0.97), p=0.022; and CLBC HR 0.60 (0.42-0.85), p=0.004. Absolute differences in time to recurrence increased over time (TTR 2.8% [anastrozole 9.7%vs tamoxifen 12.5%] at 5 years and 4.8% [anastrozole 17.0%vs tamoxifen 21.8%] at 9 years) and recurrence rates remained significantly lower on anastrozole compared with tamoxifen after treatment completion (HR 0.75 [0.61-0.94], p=0.01). The fewer deaths after recurrence (anastrozole 245 vs tamoxifen 269) was not significant (HR 0.90 [0.75-1.07], p=0.2), and no effect was noted for OS (anastrozole 472 vs tamoxifen 477) HR 0.97 [0.86-1.11], p=0.7). Fracture rates were higher in patients receiving anastrozole than in those receiving tamoxifen during active treatment (number [annual rate]: 375 [2.93%] vs 234 [1.90%]; incidence rate ratio [IRR] 1.55 [1.31-1.83], p<0.0001), but were not different after treatment was completed (off treatment: 146 [1.56%] vs 143 [1.51%]; IRR 1.03 [0.81-1.31], p=0.79). We did not note any significant difference in risk of cardiovascular morbidity or mortality between anastrozole and tamoxifen treatment groups., Interpretation: These data show long-term safety findings and establish clearly the long-term efficacy of anastrozole compared with tamoxifen as initial adjuvant treatment for postmenopausal women with hormone-sensitive, early breast cancer, and provide statistically significant evidence of a larger carryover effect after 5 years of adjuvant treatment with anastrozole compared with tamoxifen.

Background: The Arimidex (anastrozole), Tamoxifen, Alone or in Combination (ATAC) trial was designed to compare the efficacy and safety of anastrozole with tamoxifen as adjuvant treatment for postmenopausal women with early-stage breast cancer. After an extended follow-up beyond the 5 years of treatment, we aimed to assess the safety, tolerability, and risk-benefit indices of these compounds., Methods: We analysed postmenopausal women (mean age 64 years [SD 9]) with localised breast cancer randomly assigned to anastrozole (n=3125) or tamoxifen (n=3116). Efficacy measures, including death and risk-benefit indices, were analysed by intention to treat. Safety analyses were based on treatment first received (n=3092 for anastrozole and n=3094 tamoxifen). We calculated a risk-benefit analysis using the two global indices for the Women's Health Initiative and for Disease-Free Survival and Serious Adverse Events. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230., Findings: At median follow-up of 68 months (range 1-93), treatment-related adverse events occurred significantly less often with anastrozole than with tamoxifen (1884 [61%] vs 2117 [68%]; p<0.0001), as did treatment-related serious adverse events (146 [5%] vs 277 [9%]; p<0.0001) and adverse events leading to withdrawal (344 [11%] vs 442 [14%]; p=0.0002). Patients given anastrozole had significantly fewer overall events for the Global Index of the Women's Health Initiative (744 [24%] vs 851 [27%]; hazard ratio 0.85 [95% CI 0.77-0.94], p=0.001) and the Global Index of Disease-Free Survival and Serious Adverse Events (1453 [46%] vs 1594 [51%]; 0.88 [0.82-0.94]; p=0.0004)., Interpretation: Anastrozole is tolerated better than tamoxifen by postmenopausal women with early-stage breast cancer, and results in fewer serious adverse events. Furthermore, it has a more favourable overall risk-benefit profile and lower recurrence rate than tamoxifen.