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Purpose: To understand the mutational landscape of circulating tumor DNA (ctDNA) and tumor tissue of patients with hormone receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) metastatic breast cancer (MBC) treated with abemaciclib + endocrine therapy (ET)., Methods: Blood samples for ctDNA and/or tissue samples were collected from abemaciclib-treated patients with HR+/HER2- MBC enrolled in the SCRUM-Japan MONSTAR-SCREEN project. Blood samples were collected before abemaciclib initiation (baseline) and at disease progression/abemaciclib discontinuation (post abemaciclib treatment). Clinical and genomic characteristics including neoplastic burden (measured by shedding rate and maximum variant allele frequency [VAF]) were assessed at baseline. Genomic alterations in ctDNA were compared in paired baseline and post abemaciclib treatment samples., Results: All patients (N = 97) were female (median age, 57 years [IQR, 50-67]). In baseline ctDNA (n = 77), PIK3CA (37%), TP53 (28%), ESR1 (16%), and GATA3 (11%) were the most frequently mutated genes. Baseline tissue samples (n = 79) showed similar alteration frequencies. Among patients with baseline ctDNA data, 30% had received previous ET. ESR1 alteration frequency (35% v 8%; P < .01), median shedding rate (3 v 2), and maximum somatic VAF (4 v 0.8; both P < .05) were significantly higher in ctDNA from patients with previous ET than those without previous ET. In paired ctDNA samples (n = 33), PIK3CA and ESR1 alteration frequencies were higher after abemaciclib treatment than at baseline, though not statistically significant. Among the post-treatment alterations, those newly acquired were detected most frequently in FGF3/4/19 (18%); PIK3CA , TP53 , CCND1 , and RB1 (all 15%); and ESR1 (12%)., Conclusion: We summarized the ctDNA and cancer tissue mutational landscape, including overall neoplastic burden and PIK3CA and ESR1 hotspot mutations in abemaciclib-treated patients with HR+/HER2- MBC. The data provide insights that could help optimize treatment strategies in this population.

Introduction: Neutrophil-to-lymphocyte ratio (NLR) has been recognized as a marker of systemic inflammation with a prognostic impact in patients with various cancers, including breast cancer. The aim of this study was to investigate the relationships between the preoperative NLR and breast cancer prognosis in the patients before and after menopausal age, and its relationship with other prognostic factors., Methods: A total of 1868 patients with clinical Stage I-III primary breast cancer were enrolled. The associations between clinicopathological factors and the preoperative NLR were analyzed, and relapse-free survival (RFS) and overall survival (OS) were estimated., Results: Statistical analyses stratified by the menopausal status revealed that a high NLR was significantly associated with worse RFS (P < 0.001) and OS (P = 0.001) in postmenopausal patients, but not in premenopausal patients. Although the postmenopausal patients with relapsed cancer tended to have higher NLR levels than those without relapse (P = 0.079), NLR levels of premenopausal patients with relapsed cancer were significantly lower than that of relapse-free patients (P = 0.024). In postmenopausal patients, a high NLR was only associated with worse RFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer (P < 0.001), in those managed without adjuvant chemotherapy (P = 0.003); this association was not observed in patients who received adjuvant chemotherapy., Conclusions: The preoperative NLR can be a useful prognostic marker, especially in postmenopausal breast cancer patients. The relationships between the NLR and breast cancer prognosis may be more evident when patients are assessed according to their menopausal status., (Copyright © 2023 Elsevier Inc. All rights reserved.)

This study aimed to investigate the association between daily sedentary time and the risk of breast cancer (BC) in a large Japanese population. The participants were 36,023 women aged 35-69 years from the Japan Multi-Institutional Collaborative Cohort Study. Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for BC incidence in relation to time spent sedentarily (categorical variables: <7 and ≥7 hours/day [h/d]). Additionally, the associations of BC incidence to the joint effect of sedentary time with each component of physical activity, such as leisure-time metabolic equivalents (METs), frequency of leisure-time physical activity, and daily walking time, were examined. During 315,189 person-years of follow-up, 554 incident cases of BC were identified. When compared to participants who spent <7 h/d sedentary, those who spent ≥7 h/d sedentary have a significantly higher risk of BC (HR, 1.36; 95% CI, 1.07-1.71). The corresponding HRs among participants who spent ≥7 h/d sedentary with more physical activity, such as ≥1 h/d for leisure-time METs, ≥3 days/week of leisure-time physical activity, and ≥1 h/d of daily walking were 1.58 (95% CI, 1.11-2.25), 1.77 (95% CI, 1.20-2.61), and 1.42 (95% CI, 1.10-1.83), respectively, compared with those who spent <7 h/d sedentary. This study found that spending ≥7 h/d of sedentary time is associated with the risk of BC. Neither leisure-time physical activity nor walking had a BC-preventive effect in those with ≥7 h/d of sedentary time., (© 2023 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: It is important to assess whether the early detection of breast cancer affects medical care costs. However, research remains scant on the actual medical care costs associated with breast cancer treatment in Japan. This study aimed to determine the medical care costs of breast cancer treatment based on its stage using national health insurance claims data., Methods: This was an observational study including patients with breast cancer who had undergone breast cancer treatment, as defined by the disease name and related treatment codes. Between August 2013 and June 2016, patients who underwent surgical treatment without axillary lymph node dissection and other radical treatment were classified as the curable group, while those who underwent palliative treatment were classified as the non-curable group. Patients were further stratified by subtype. The total and treatment-specific medical care costs for the five years were calculated using the national health insurance claims data of Hachioji City between August 2013 and May 2021., Results: The mean total medical care costs for the curable and non-curable groups for the 5 years were JPY 3958 thousand (standard deviation 2664) and JPY 8289 thousand (8482), respectively. The mean medical care costs for specific breast cancer treatment for the curable and non-curable groups were JPY 1142 (728) thousand and JPY 3651 thousand (5337), respectively. Further, human epidermal growth factor receptor 2 + , Hormone + patients had the highest mean cost over the 5 years., Conclusions: The results suggest that the early detection of breast cancer may reduce medical care costs at the patient level., (© 2023. The Author(s).)

HER2-positive metastatic colorectal cancer occurs in 2-4% of all colorectal cancers, about 5% in RAS wild-type colorectal cancer, and only 0.2-1.4% in RAS mutant colorectal cancer. The TRIUMPH trial was conducted in Japan for patients with HER2-positive colorectal cancer, and its results led to the approval of the combination therapy of pertuzumab and trastuzumab for the treatment of HER2-positive unresectable advanced or recurrent colorectal cancer that has progressed during chemotherapy in March 2022 in Japan. In the field of colorectal cancer, the development of new HER2-targeted drugs such as antibody-drug conjugates and bispecific antibodies is ongoing, and future developments are expected to be of interest.

Utilizing real-world data (RWD) for effective clinical implementation is becoming more and more appealing as the cost of drug development rises, especially for patients with rare diseases and rare molecular subtypes for whom conducting randomized controlled trials is challenging. If a regulatory approval methodology based on RWD as an external control group can be established, drug development for rarer fractions can be accelerated by lowering costs and time, as well as reducing physical and emotional burdens on both patients and healthcare professionals. Since 2017, we have been prospectively collecting the clinical data of standard therapies in patients with rare molecular fractions under the SCRUM-Japan Registry platform, which is a qualified registry utilized as external control data for regulatory submission. Based on the results of the phase II TRIUMPH study (UMIN000027887) and the extracted data from the SCRUM-Japan Registry, the pharmaceutical company submitted an application for pertuzumab and trastuzumab in patients with HER2-positive metastatic colorectal cancer in April 2021. Pertuzumab and trastuzumab were approved as expanded indications on March 28, 2022, as 6 cases out of 14 extracted from the SCRUM-Japan Registry were classified and utilized as "evaluation material" under the review process of the Pharmaceuticals and Medical Devices Agency (PMDA). Through the TRIUMPH study and the SCRUM-Japan Registry, we have paved the way for regulatory approval of RWD in Japan. In future, we must define the steps for constructing regulatory-grade registries and the method/process for utilizing RWD by accumulating case experiences., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Gene amplification and protein overexpression of human epidermal growth factor receptor type 2 (HER2) are specific targets for HER2-targeting drugs in breast, gastric, salivary gland, and colorectal cancers. The histopathological determination of HER2 status is crucial for treatment, highlighting the importance of improving HER2 detection accuracy in clinical practice. We prepared tissue microarray (TMA) slides for use as control slides for the standardization of gastric HER2 testing. Four human gastric cancer cell lines with HER2 scores of 3+, 2+, 1+, and 0 were xenografted in NOG mice. The TMA slides were constructed using samples from three different areas in these tumors. Staining properties were determined using six clinical kits for HER2. In TMA, HER2-positive tumors with HER2 scores of 3+ and 2+ showed good staining with all diagnostic kits, and the tissue images were similar to those of clinical samples. Xenograft tumor slides could potentially be used as external controls to standardize staining conditions for a variety of kits and may improve the accuracy of HER2 detection in clinical practice., (© 2022 The Authors. Pathology International published by Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Docetaxel(DTX)is a key drug for breast cancer treatment; however, its formulation contains alcohol, which can cause several problems. We have been preparing original DTX without using its accompanying alcohol-solubilizing solution since 2013 and switched to generic DTX without alcohol in 2015. In this study, we compared adverse events between the original and generic DTX, both of which did not contain alcohol. We retrospectively investigated the occurrence of adverse events in breast cancer patients who were treated with DTX(75 mg/m2)as neoadjuvant or adjuvant chemotherapy from January 2013 to December 2017. 201 patients participated in the study(75/126 in the original/generic groups). The incidence of febrile neutropenia, hypersensitivity reactions, and skin toxicities did not differ between the groups(p=0.620, 0.066, 0.205). The severity of edema and peripheral neuropathy was significantly worse in the patients receiving the generic DTX (p<0.01, <0.01). The findings suggest a difference in the incidence of edema and peripheral neuropathy following treatment with the original and generic DTX, regardless of the inclusion of alcohol.

Women who are heterozygous for deleterious BRCA1 germline mutations harbor a high risk of hereditary breast cancer. Previous Brca1-heterozygous animal models do not recapitulate the breast cancer phenotype, and thus all currently used knockout models adopt conditional, mammary-specific homozygous Brca1 loss or addition of Trp53 deficiency. Herein, we report the creation and characterization of a novel Brca1 mutant rat model harboring the germline L63X mutation, which mimics a founder mutation in Japan, through CRISPR-Cas9-based genome editing. Homozygotes (Brca1 L63X/L63X ) were embryonic lethal, whereas heterozygotes (Brca1 L63X/+ ) showed apparently normal development. Without carcinogen exposure, heterozygotes developed mammary carcinoma at a comparable incidence rate with their wild-type (WT) littermates during their lifetime. Intraperitoneal injection of 1-methyl-1-nitrosourea (25 or 50 mg/kg) at 7 weeks of age induced mammary carcinogenesis at comparable levels among the heterozygotes and their littermates. After exposure to ionizing radiation (0.1-2 Gy) at 7 weeks of age, the heterozygotes, but not WT littermates, displayed dose-dependent mammary carcinogenesis with 0.8 Gy -1 excess in hazard ratio during their middle age; the relative susceptibility of the heterozygotes was more prominent when rats were irradiated at 3 weeks of age. The heterozygotes had tumors with a lower estrogen receptor α immunopositivity and no evidence of somatic mutations of the WT allele. The Brca1 L63X/+ rats thus offer the first single-mutation, heterozygous model of BRCA1-associated breast cancer, especially with exposure to a DNA break-inducing carcinogen. This implies that such carcinogens are causative and a key to breast cancer prevention in individuals who carry high-risk BRCA1 mutations., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Secondary lymphoid tissues, such as the spleen and lymph nodes (LNs), contribute to breast cancer development and metastasis in both anti- and pro-tumoral directions. Although secondary lymphoid tissues have been extensively studied, very little is known about the immune conversion in mesenteric LNs (mLNs) during breast cancer development. Here, we demonstrate inflammatory immune conversion of mLNs in a metastatic 4T1 breast cancer model. Splenic T cells were significantly decreased and continuously suppressed IFN-γ production during tumor development, while myeloid-derived suppressor cells (MDSCs) were dramatically enriched. However, T cell numbers in the mLN did not decrease, and the MDSCs only moderately increased. T cells in the mLN exhibited conversion from a pro-inflammatory state with high IFN-γ expression to an anti-inflammatory state with high expression of IL-4 and IL-10 in early- to late-stages of breast cancer development. Interestingly, increased migration of CD103 + CD11b + dendritic cells (DCs) into the mLN, along with increased (1→3)-β-D-glucan levels in serum, was observed even in late-stage breast cancer. This suggests that CD103 + CD11b + DCs could prime cancer-reactive T cells. Together, the data indicate that the mLN is an important lymphoid tissue contributing to breast cancer development.

Purpose: The Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer 2018 indicated that operation is the standard treatment for breast cancer in elderly patients. This study aimed to assess the safety and efficacy of surgery for elderly patients with breast cancer., Methods: Between April 2009 and November 2019, 545 patients underwent surgery in our hospital. The medical records of the elderly group(≥80 years, n=62)and the control(55-65 years, n=128)groups were compared and analyzed retrospectively., Results: The elderly group had more comorbidities(p<0.001)than those of the control group. Although no significant difference in the pathological stage was noted between the 2 groups, dermal infiltrations were more common(p=0.003)in the elderly group than those of the other, and 27% of them did not undergo any surgery to the axilla. This group experienced more post-surgery complications than those of the other; however, such complications did not extend beyond the duration of hospital stays. No difference in the recurrence rate between the groups was noted. In the elderly group, 64% died of comorbidities. The 3-year survival rate was 88.3% and 95.4% in the elderly and control groups, respectively(p=0.18)., Conclusions: Our study revealed that surgery was safe for the management of breast cancer in elderly patients. However, their prognosis was poor owing to their comorbidities. Hence, careful therapy for their comorbidity is also important.

Breast cancer is primarily classified into ductal and lobular types, as well as into noninvasive and invasive cancer. Invasive cancer involves lymphatic and hematogenous metastasis. In breast cancer patients with distant metastases, a neutrophil-derived serine protease; cathepsin G (Cat G), is highly expressed in breast cancer cells. Cat G induces cell migration and multicellular aggregation of MCF-7 human breast cancer cells; however, the mechanism is not clear. Recently, platelet-activating factor (PAF)-acetylhydrolase (PAF-AH), the enzyme responsible for PAF degradation, was reported to be overexpressed in some tumor types, including pancreatic and breast cancers. In this study, we investigated whether PAF-AH is involved in Cat G-induced aggregation and migration of MCF-7 cells. We first showed that Cat G increased PAF-AH activity and elevated PAFAH1B2 expression in MCF-7 cells. The elevated expression of PAFAH1B2 was also observed in human breast cancer tissue specimens by immunohistochemical analysis. Furthermore, knockdown of PAFAH1B2 in MCF-7 cells suppressed the cell migration and aggregation induced by low concentrations, but not high concentrations, of Cat G. Carbamoyl PAF (cPAF), a nonhydrolyzable PAF analog, completely suppressed Cat G-induced migration of MCF-7 cells. In addition, PAF receptor (PAFR) inhibition induced cell migration of MCF-7 cells even in the absence of Cat G, suggesting that Cat G suppresses the activation of PAFR through enhanced PAF degradation due to elevated expression of PAFAH1B2 and thereby induces malignant phenotypes in MCF-7 cells. Our findings may lead to a novel therapeutic modality for treating breast cancer by modulating the activity of Cat G/PAF signaling., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Trastuzumab deruxtecan (DS-8201) is an antibody-drug conjugate composed of a humanized monoclonal anti-HER2 antibody, a cleavable tetrapeptide-based linker and a potent topoisomerase I inhibitor. The drug's efficacy has been proven in HER2-positive breast and gastric cancers. The rate of HER2 positivity in biliary tract cancer (BTC) has been reported to be 5-20%, and case reports and clinical trials have suggested that HER2 inhibitors might be active in HER2-positive BTC. Here we describe the rationale and design of the phase II HERB trial that will evaluate the efficacy and safety of trastuzumab deruxtecan in patients with HER2-expressing unresectable or recurrent BTC. The primary end point will be the centrally assessed objective response rate in HER2-positive patients.

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) significantly improve progression-free survival and have become the standard therapy for estrogen receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer patients. Treatment surveillance by radiological imaging has some limitations in detection and repeated biopsy genomic profiling is not clinically feasible. Serial circulating tumor DNA (ctDNA) analysis may provide insights into treatment response. Here we performed serial ctDNA analysis (n = 178) on 33 patients. Serial ctDNA analysis identified disease progression with sensitivity of 75% and specificity of 92%. In eight of 12 patients (61%) responding to CDK4/6i who eventually developed progressive disease, serial sampling every 3 or 6 months captured the initial rise of ctDNA with an average lead time of 3 months. In three of eight patients that did not respond to CDK4/6i (progressive disease at first radiological assessment, 3 months), biweekly sequencing within the first cycle of CDK4/6i treatment (1 month) detected sustained ctDNA levels (≥0.2% variant allele frequency), with lead time of 2 months. Serial ctDNA analysis tracked RECIST response, including clinically challenging scenarios (bone metastases or small-sized target lesions), as well as detecting acquired genetic alterations linked to CDK4/6i resistance in the G 1 to S transition phase. Circulating tumor DNA analysis was more sensitive than carcinoembryonic antigen or cancer antigen 15-3 serum tumor markers at monitoring tumor response to CDK4/6i treatment. Our findings indicated the possible clinical utility of serial ctDNA analysis for earlier progressive disease detection and real-time monitoring of CDK4/6i response., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: Several studies have recently reported that the relationships between serum vitamin D and the prognosis or the pathological response to neoadjuvant chemotherapy (NAC) in breast cancer. However, there are no data regarding the clinical impacts of the vitamin D in Japanese breast cancer patients so far., Patients and Methods: In the present study, a total of 250 patients with clinical Stage I-III primary breast cancer who were treated with NAC and subsequently underwent definitive surgery were included. Serum 25-hydroxvitamin D (25(OH)D) levels were evaluated using blood samples obtained before NAC., Results: The serum 25(OH)D was positively associated with age, and the serum 25(OH)D was significantly higher in postmenopausal women than that in pre/peri-menopausal women. Serum 25(OH)D level was not associated with the achievement of pathological complete response (pCR) in this cohort. The low 25(OH)D levels were significantly associated with shorter time to distant recurrence (TTDR). According to the univariate analysis, high clinical stage before NAC (cStage III) and low serum 25(OH)D level were significantly associated with the shorter TTDR, and pCR was significantly associated with the longer TTDR. According to a multivariate analysis, low serum 25(OH)D level were independent poor prognostic factors for TTDR., Conclusions: The low 25(OH)D levels were significantly associated with poorer prognosis in Japanese women with operable breast cancer patients treated with NAC., (© 2021. The Author(s).)

The cyclin-dependent kinase (CDK) 4/6 inhibitors, palbociclib and abemaciclib, have been approved in Japan. However, the selection criteria for these drugs have not been established. Hence, we aimed to identify the risk factors for CDK4/6 inhibitor-induced intolerable adverse events requiring dose reduction or therapy cessation and to establish useful markers for choosing the appropriate CDK4/6 inhibitor, based on the incidence of the intolerable adverse events. This retrospective cohort analysis included patients with advanced breast cancer who received 125 mg/d palbociclib or 300 mg/d abemaciclib. We defined significant adverse events (SAEs) as side effects requiring dose reduction or therapy cessation. Thirty-six percent of the patients who received palbociclib (9/25) and 27.3% of those who received abemaciclib (9/33) experienced SAEs. In palbociclib and abemaciclib groups, baseline white blood cell (WBC) counts and serum albumin (ALB) levels, respectively, were significantly lower in patients who experienced SAEs than in those who did not (palbociclib: p = 0.007; abemaciclib: p = 0.004). According to the receiver operating characteristic curve analysis, the optimal cutoff values for baseline WBC count and ALB level were 5700/µL and 4.0 g/dL, respectively. Among patients with ALB levels >4.0 g/dL, the incidence of abemaciclib-induced SAEs was significantly lower than that of the palbociclib-induced SAEs (1/17 (5.9%) vs. 6/14 (42.9%), odds ratio: 11.0, 95% confidence interval: 1.07-583, p = 0.0281). Thus, a baseline WBC count ≤5700/µL and ALB level ≤4.0 g/dL may be risk factors for palbociclib and abemaciclib-induced SAEs, respectively. Also, high ALB levels can serve as a useful marker for choosing abemaciclib.

Breast cancer is a heterogeneous disease that develops through a multistep process via the accumulation of genetic/epigenetic alterations in various cancer-related genes. Current treatment options for breast cancer patients include surgery, radiotherapy, and chemotherapy including conventional cytotoxic and molecular-targeted anticancer drugs for each intrinsic subtype, such as endocrine therapy and antihuman epidermal growth factor receptor 2 (HER2) therapy. However, these therapies often fail to prevent recurrence and metastasis due to resistance. Overall, understanding the molecular mechanisms of breast carcinogenesis and progression will help to establish therapeutic modalities to improve treatment. The recent development of comprehensive omics technologies has led to the discovery of driver genes, including oncogenes and tumor-suppressor genes, contributing to the development of molecular-targeted anticancer drugs. Here, we review the development of anticancer drugs targeting cancer-specific functional therapeutic targets, namely, MELK (maternal embryonic leucine zipper kinase), TOPK (T-lymphokine-activated killer cell-originated protein kinase), and BIG3 (brefeldin A-inhibited guanine nucleotide-exchange protein 3), as identified through comprehensive breast cancer transcriptomics., (© 2021. The Author(s).)

Neoantigens are tumour-specific antigens that arise from non-synonymous mutations in tumour cells. However, their effect on immune responses in the tumour microenvironment remains unclear in breast cancer. We performed whole exome and RNA sequencing of 31 fresh breast cancer tissues and neoantigen prediction from non-synonymous single nucleotide variants (nsSNVs) among exonic mutations. Neoantigen profiles were determined by predictive HLA binding affinity (IC 50  < 500 nM) and mRNA expression with a read count of ≥ 1. We evaluated the association between neoantigen load and expression levels of immune-related genes. Moreover, using primary tumour cells established from pleural fluid of a breast cancer patient with carcinomatous pleurisy, we induced cytotoxic T lymphocytes (CTLs) by coculturing neoantigen peptide-pulsed dendritic cells (DCs) with autologous peripheral lymphocytes. The functions of CTLs were examined by cytotoxicity and IFN-γ ELISpot assays. Neoantigen load ranged from 6 to 440 (mean, 95) and was positively correlated to the total number of nsSNVs. Although no associations between neoantigen load and mRNA expression of T cell markers were observed, the coculture of neoantigen-pulsed DCs and lymphocytes successfully induced CTLs ex vivo. These results suggest that neoantigen analysis may have utility in developing strategies to elicit T cell responses.

Background: Clinical Treatment Score post-5 years (CTS5) is a promising prognostic tool to evaluate late distant recurrence (DR) risk for breast cancer after 5-year adjuvant endocrine therapy., Patients and Methods: Among 560 postmenopausal women with pathological stage I-III estrogen receptor-positive (ER+) primary breast cancer, 383 women who had received 5-year adjuvant endocrine therapy without any recurrence at 5 years after surgery were included in this study. The CTS5 was calculated for each patient using a previously published formula, and the patients were stratified by their CTS5 values into the low-, intermediate- and high-CTS5 risk groups., Results: According to the CTS5, 205 (53.5%), 106 (27.7%) and 72 (18.8%) patients were classified into the low-, intermediate-, and high-CTS5 risk groups, respectively. A higher ER expression level was significantly associated with the low CTS5. The increased administration of adjuvant chemotherapy was significantly associated with a high CTS5. The occurrence of DR was higher in the intermediate and high CTS5 groups than in the low CTS5 group. The DRFS in the low CTS5 risk group was significantly better than that in the intermediate- or high-risk groups. In the ER-high or HER2-negative (HER2-) group, the DRFS in the low-risk group was significantly better than that of the intermediate- or high-risk groups. However, in the low-ER or HER2-positive group, there was no significant difference in DRFS among the three risk groups., Conclusions: In postmenopausal women with ER+ breast cancer, low CTS5 was considered to be associated with a very low risk of late DR. Thus, extended endocrine therapy may be unnecessary for patients with low CTS5 scores. Extended endocrine therapy should be offered for patients with intermediate or high CTS5 scores, especially those with high-ER and HER2- breast cancer.

The biological influence of antidiabetic drugs on cancer cells and diabetic cancer patients has not yet been completely elucidated. We reported that a dipeptidyl peptidase (DPP)-4 inhibitor accelerates mammary cancer metastasis by inducing epithelial-mesenchymal transition (EMT) through the CXCL12/CXCR4/mTOR axis. Metformin has been shown to inhibit the mTOR signaling pathway. In this study, we investigated whether metformin mitigates breast cancer metastasis induced by a DPP-4 inhibitor via suppression of mTOR signaling. In cultured mouse mammary and human breast cancer cells, metformin suppressed DPP-4 inhibitor KR62436 (KR)-induced EMT and cell migration via suppression of the mTOR pathway associated with AMPK activation. For the in vivo study, metformin intervention was performed in an allograft 4T1 breast cancer model mouse with or without KR. We also analyzed mice transplanted with shRNA-mediated DPP-4 knockdown 4T1 cells. Treatment with metformin inhibited the lung metastasis of DPP-4-deficient 4T1 mammary tumor cells generated by either KR administration or DPP-4 knockdown. Immunostaining of primary tumors indicated that DPP-4 suppression promoted the expression of EMT-inducing transcription factor Snail through activation of the CXCR4-mediated mTOR/p70S6K pathway in an allograft breast cancer model; metformin abolished this alteration. Metformin treatment did not alter DPP-4-deficiency-induced expression of CXCL12 in either plasma or primary tumors. Our findings suggest that metformin may serve as an antimetastatic agent by mitigating the undesirable effects of DPP-4 inhibitors in patients with certain cancers. IMPLICATIONS: Metformin could combat the detrimental effects of DPP-4 inhibitor on breast cancer metastasis via mTOR suppression, suggesting the potential clinical relevance. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/1/61/F1.large.jpg., (©2020 American Association for Cancer Research.)

We present a study to evaluate the feasibility and clinical utility of amplicon-based Oncomine Pan-Cancer cell-free assay to detect circulating tumor DNA (ctDNA) in patients with early or advanced breast cancer. In this study, 109 early and metastatic breast cancer patients were recruited before the initiation of treatment. ctDNA mutation profiles were assessed through unique molecular tagging (UMT) and ultradeep next generation sequencing (NGS). For patients with mutations, DNA from corresponding white blood cells (WBC) was sequenced to exclude variants of clonal-hematopoietic (CH) origin. UMT targeted sequencing from plasma of 109 patients achieved a median total coverage of 55 498X and a median molecular coverage of 4187X. Among 53 ctDNA positive samples, 38% were mutation positive by WBC sequencing, indicating potentially false-positive results contributed by CH origin. Prevalence of CH-related mutations was associated with age (P = 7.51 × 10 -4 ). After exclusion of CH mutations, ctDNA detection rates were 37% for local or locally advanced breast cancer (stage I-III) and 81% for metastatic or recurrent breast cancer. The ctDNA detection rate correlated with disease stage (P = 2.60 × 10 -4 ), nodal spread (P = 6.49 × 10 -3 ) and the status of distant metastases (P = 5.00 × 10 -4 ). ctDNA variants were detected mostly in TP53, PIK3CA and AKT1 genes, with variants showing therapeutic relevance. This pilot study endorses the use of targeted NGS for non-invasive molecular profiling of breast cancer. Paired sequencing of plasma ctDNA and WBC should be implemented to improve accurate interpretation of liquid biopsy., (© 2020 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: The TNM system, which reflects the anatomical extent of disease, was used for stage definition. In the recently published AJCC 8th edition, the new staging system of the clinical and pathological prognostic stage, which incorporates biological factors, is introduced., Patients and Methods: A total of 2622 patients with primary breast cancer at stage I-III were included in this study. The anatomic stage (aStage) and the pathological prognostic stage (ppStage) for each case were determined according to the definition of the AJCC 8th edition, and the influence of these stages on the prognosis was compared., Results: The stage distributions of aStage and ppStage were as follows: aStage, stage IA (54.8%), IB (1.1%), IIA (26.1%), IIB (9.2%), IIIA (5.6%), IIIB (0.1%), and IIIC (3.1%); and ppStage, stage IA (66.6%), IB (13.1%), IIA (11.1%), IIB (3.2%), IIIA (3.3%), IIIB (1.4%), and IIIC (1.2%). Compared with the aStage, the ppStage stayed the same in 1710 patients (65.2%), was downstaged in 778 patients (29.7%), and was upstaged in 134 patients. The pathological tumor size (pT2) and lymph node metastasis (pN1) were associated with downstaging, and histological grade 3 was associated with upstaging. ER positivity, PgR positivity, and HER2-positivity were significantly associated with downstaging, and the TN subtype was associated with upstaging. Both the aStage and ppStage were significantly associated with the prognosis; however, the Kaplan-Meier curves for the relapse-free survival (RFS), distant recurrence-free survival (DRFS), and overall survival were better stratified by the ppStage., Conclusion: The ppStage reflects the prognosis of patients with early breast cancer more accurately than the aStage.

Background: Taxanes are the current first-line treatment for advanced cutaneous angiosarcoma (CAS) for patients who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. However, no effective second-line therapy for such patients has been established., Methods: We designed a single-arm prospective observational study of eribulin mesylate (ERB) administered at a dose of 1·4 mg m -2 on days 1 and 8 in a 21-day cycle. Patients with advanced CAS who were previously treated with a taxane and were scheduled to begin ERB treatment were enrolled. The primary endpoint was overall survival (OS) and the secondary endpoints were response rate (RR), progression-free survival (PFS) and toxicity assessment., Results: We enrolled a total of 25 patients. The median OS and PFS were 8·6 months and 3·0 months, respectively. The best overall RR was 20% (five of 25). In total, 16 grade 3/4 severe adverse events (SAEs) occurred; however, all patients recovered. Patients who achieved partial response or stable disease as best response had longer OS than those with progressive disease (median OS not reached and 3·3 months, respectively; P < 0·001). Patients who did not experience SAEs showed longer OS than those who did (median OS 18·8 months and 7·5 months, respectively; P < 0·05). Patients with distant metastasis had shorter median OS than those with locoregional disease, but without statistically significant difference., Conclusions: ERB showed a promising RR and is a potential candidate for second-line treatment for patients with CAS, after treatment with taxanes. However, owing to the occurrence of SAEs in over half of the participants, caution should be exercised regarding ERB use in elderly patients. What is already known about this topic? Taxanes are the current first-line treatment for patients with advanced cutaneous angiosarcoma (CAS) who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. No effective therapy for taxane-resistant CAS has been established thus far. Eribulin suppresses microtubule polymerization and elicits an antitumour effect similar to that of taxanes. What does this study add? In our single-arm prospective observational study to evaluate the efficacy of eribulin for treating patients with advanced CAS who previously received taxanes, the median overall survival and progression-free survival were 8·6 and 3·0 months, respectively. Response rates at weeks 7, 13 and 25 were 20%, 17% and 14%, respectively. Although 16 grade 3/4 severe adverse events occurred, all patients recovered. Eribulin showed a promising response rate and is a potential candidate for second-line treatment in CAS after taxane treatment. Linked Comment: Smrke and Benson. Br J Dermatol 2020; 183:797-798., (© 2020 British Association of Dermatologists.)

Objective: We examined the therapeutic effect of adding of pertuzumab in combination with trastuzumab as neoadjuvant chemotherapy for HER2-positive breast cancer., Participants: Overall, 27 patients with HER2-positive breast cancer who had completed neoadjuvant chemotherapy and undergone surgery between January 2014 and January 2020 were included in the study. We performed a retrospective analysis of the relationship between HER2 gene amplification and the therapeutic effect of pertuzumab in this group. For the anti-HER2 treatment, only trastuzumab was administered to all patients until December 2018, and then a combination of trastuzumab and pertuzumab was administered to 4 patients from January 2019., Results: The case distribution based on histological therapeutic effect was: 4 patients with Grade 1, 12 patients with Grade 2, and 11 patients with Grade 3. Patients with immunohistochemistry scores of 3+ and high signal ratios of HER2/ CEP17 in FISH testing tended to have better therapeutic outcomes than other patients., Discussion: Outcomes similar to those observed in this study were reported in other cases where pertuzumab was used for anti-HER2 treatment. We expected that the therapeutic effects of pertuzumab would be better in patients with high HER2 expression. However, further research is required to understand the effects of pertuzumab in patients with cT1c that were not included in the Neo Sphere trial. The therapeutic effects of adding pertuzumab to the treatment in patients with cT1c and lymph node-positive breast cancer were indicated by comparison with our cases.

Background/aim: To evaluate the improvement in the prognosis by adjuvant trastuzumab in clinical practice and the risk factors for distant recurrence, we retrospectively investigated the prognosis of HER2-positive early breast cancer in our department before and after the introduction of adjuvant trastuzumab., Patients and Methods: Cohorts A and B included 161 and 182 cases, respectively, who underwent surgery before (2000-2007) and after (2008-2015) the introduction of adjuvant trastuzumab., Results: The rates of relapse-free and distant metastasis-free survival were significantly better in cohort B than in cohort A. The risk factors of distant recurrence found in cohort A, such as the presence of lymph node metastasis, lymphatic invasion, and a low histological grade, did not increase the risk in cohort B., Conclusion: Many risk factors seemed to have been negated by adjuvant trastuzumab administration. Therefore, further escalation of adjuvant treatment should be carefully considered., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose: In this study, we aim to investigate the mutation spectrum of circulating tumor DNA among hormone receptor-positive metastatic breast cancer (HR-MBC) patients using ultradeep targeted resequencing. In addition, we also evaluate the correlation of mutations detected from this study with progression-free survival (PFS)., Materials and Methods: A total of 56 HR-MBC patients were enrolled. Cell-free DNA (cfDNA) was extracted from plasma and sequenced by using Oncomine Breast cancer cfDNA assay in this study., Result: Concentration of cfDNA is correlated with a number of metastatic organs and serum CEA levels (Spearman's rank correlation p = 0.0018, p = 0.0015 respectively). Cases with high cfDNA levels (≥ 2.6 ng/μl of plasma) showed worse progression-free survival (PFS) and overall survival compared with cases with low cfDNA levels (p = 0.043 and 0.046, respectively). Among these patients, 29 patients (51.7%) have TP53 mutations, 12 patients (30.3%) have PIK3CA mutations, and 9 patients (16.0%) have ESR1 mutations. Acquisition of ESR1 mutation increased according to the lines of hormone therapy. In addition, patients with ESR1 mutation showed shorter PFS than those without mutation (log-rank p = 0.047). In the multivariate analysis, ESR1 mutation and cfDNA concentration were significant for PFS (p = 0.027 and 0.006, respectively). In conclusion, assessment of ESR1 mutation and cfDNA concentration could be useful in predicting prognosis for HR-MBCs.

Background/aim: Metaplastic breast carcinoma (MBC) is a rare malignancy, which is often triple-negative for the hormone receptors and human epidermal growth factor receptor 2, and thus, does not benefit from targeted therapy. In this study, we examined the expression of methylation and demethylation enzymes by immunostaining MBC and the adjacent normal tissues or triple-negative ductal carcinoma (TNDC), and identified alterations that may be used as therapeutic targets., Materials and Methods: We retrospectively studied surgical specimens from 15 patients who underwent surgery for MBC at Kanagawa Cancer Center between 2005 and 2016, and similarly from 14 patients with TNDC. The frequencies of high methylation/demethylation enzyme expression were compared among them., Results: The frequencies of high enhancer of zeste homolog 2 (EZH2) and multiple myeloma SET domain (MMSET) expression were significantly higher in both MBC and TNDC than in normal tissue., Conclusion: EZH2 and MMSET may be useful therapeutic targets in MBC., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Polypeptide N‑acetylgalactosaminyltransferase 6 (GALNT6), which is involved in the initiation of O‑glycosylation, has been reported to play crucial roles in mammary carcinogenesis through binding to several substrates; however, its biological roles in mediating growth‑promoting effects remain unknown. The present study demonstrated a crucial pathophysiological role of GALNT6 through its O‑glycosylation of lectin galactoside‑binding soluble 3 binding protein (LGALS3BP), a secreted growth‑promoting glycoprotein, in breast cancer growth. The Cancer Genome Atlas data analysis revealed that high expression levels of GALNT6 were significantly associated with poor prognosis of breast cancer. GALNT6 O‑glycosylated LGALS3BP in breast cancer cells, whereas knockdown of GALNT6 by siRNA led to the inhibition of both the O‑glycosylation and secretion of LGALS3BP, resulting in the suppression of breast cancer cell growth. Notably, LGALS3BP is potentially O‑glycosylated at three sites (T556, T571 and S582) by GALNT6, thereby promoting autocrine cell growth, whereas the expression of LGALS3BP with three Ala substitutions (T556A, T571A and S582A) in cells drastically reduced GALNT6‑dependent LGALS3BP O‑glycosylation and secretion, resulting in suppression of autocrine growth‑promoting effect. The findings of the present study suggest that the GALNT6‑LGALS3BP axis is crucial for breast cancer cell proliferation and may be a therapeutic target and biomarker for mammary tumors.

In this study, we examined 239 outpatients receiving chemotherapy for breast cancer for a period of 6 months from July 2016 to December 2016. Using a questionnaire, we investigated the patients' symptom score and uneasiness. A symptom score of 2 and over was found in 24.7%(59)of the cases. Twenty-seven of the 59 cases experienced adverse effects of chemotherapy. Peripheral neuropathy was observed in 20 cases, of which only 2 cases improved after providing palliative care. Palliative care was effective against nausea, constipation, malaise, and sleeping disorders. Thirty-two cases(13.4%)had 5 or more painful feeling score. Among these, 10 cases resulted from the adverse effects of treatment, 10 cases from the aggravation of existing cancer, and 6 cases showed anxiety for the illness, family, and future. In 15 of the 32 cases, the pain score improved by providing palliative care, conversation with the nursing staff, reduction in the quantity of drug intake, etc.

Genome-wide association studies (GWAS) have successfully identified about 70 genomic loci associated with breast cancer. Owing to the complexity of linkage disequilibrium and environmental exposures in different populations, it is essential to perform regional GWAS for better risk prediction. This study aimed to investigate the genetic architecture and to assess common genetic risk model of breast cancer with 6,669 breast cancer patients and 21,930 female controls in the Japanese population. This GWAS identified 11 genomic loci that surpass genome-wide significance threshold of P < 5.0 × 10 -8 with nine previously reported loci and two novel loci that include rs9862599 on 3q13.11 (ALCAM) and rs75286142 on 21q22.12 (CLIC6-RUNX1). Validation study was carried out with 981 breast cancer cases and 1,394 controls from the Aichi Cancer Center. Pathway analyses of GWAS signals identified association of dopamine receptor medicated signaling and protein amino acid deacetylation with breast cancer. Weighted genetic risk score showed that individuals who were categorized in the highest risk group are approximately 3.7 times more likely to develop breast cancer compared to individuals in the lowest risk group. This well-powered GWAS is a representative study to identify SNPs that are associated with breast cancer in the Japanese population.

Alteration of protein O-glycosylation in various human cancers including breast cancer is well known, but molecular roles of their aberrant glycosylations on cancer have not been fully understood. We previously reported critical roles of polypeptide N-acetylgalactosaminyltransferase 6 (GALNT6 or GalNAc-T6) that was upregulated in a great majority of breast cancer tissues. Here we further report O-glycosylation of estrogen receptor alpha (ER-α) by GALNT6 and the significant role of its nuclear localization in breast cancer cells. Knockdown of GALNT6 expression in two breast cancer cell lines, T47D and MCF7, in which both ER-α and GALNT6 were highly expressed, by small interfering RNA could significantly attenuate expression of ER-α. Immunocytochemical analysis clearly demonstrated the drastic decrease of ER-α protein in the nucleus of these cancer cells. Accordingly, the downstream genes of the ER-α pathway such as MYC, CCND1, and CTSD were significantly downregulated. We confirmed GALNT6-dependent ER-α O-glycosylation and identified O-glycosylation of S573 in an F domain of ER-α by GALNT6 through LC-MS/MS analysis. We also obtained evidences showing that the glycosylation of ER-α at S573 by GALNT6 is essential for protein stability and nuclear localization of ER-α in breast cancer cells. Furthermore, we designed cell membrane-permeable peptides including the O-glycosylation site and found a significant decrease of the cell viability of breast cancer cells by treatment of these peptides in a GALNT6 expression-dependent manner. Our study suggests that targeting the GALNT6 enzymatic activity as well as the GALNT6/ER-α interaction could be a promising therapeutic approach to ER-α-positive breast cancer patients., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Cancer is a complex genetic disease that develops from the accumulation of genomic alterations in which germline variations predispose individuals to cancer and somatic alterations initiate and trigger the progression of cancer. For the past 2 decades, genomic research has advanced remarkably, evolving from single-gene to whole-genome screening by using genome-wide association study and next-generation sequencing that contributes to big genomic data. International collaborative efforts have contributed to curating these data to identify clinically significant alterations that could be used in clinical settings. Focusing on breast cancer, the present review summarizes the identification of genomic alterations with high-throughput screening as well as the use of genomic information in clinical trials that match cancer patients to therapies, which further leads to cancer precision medicine. Furthermore, cancer screening and monitoring were enhanced greatly by the use of liquid biopsies. With the growing data complexity and size, there is much anticipation in exploiting deep machine learning and artificial intelligence to curate integrative "-omics" data to refine the current medical practice to be applied in the near future., (© 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: Previous studies have suggested that the presence of visceral metastasis is a parameter useful in predicting the treatment efficacy of fulvestrant in patients with advanced breast cancer., Patients and Methods: We retrospectively examined the association between treatment efficacy and presence of visceral metastasis in 75 patients with hormone receptor-positive recurrent breast cancer who were treated with fulvestrant or no more than five lines of other endocrine monotherapy after recurrence., Results: Nineteen patients received fulvestrant, 10 of whom had visceral metastasis. The median time to progression was 4 months for the overall study population; it was significantly longer for patients with non-visceral metastasis (5.4 months; 95% confidence interval=3.7-11.2 months) than for those with visceral metastasis (3.3 months; 95% confidence interval, 0.4-5.3 months; p=0.01). No differences in time to progression were found between the groups of patients with visceral metastasis and non-visceral metastasis who underwent other endocrine therapies., Conclusion: Fulvestrant is more effective for patients with non-visceral metastasis of recurrent breast cancer with than for those with visceral metastasis., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Surgical biopsy of metastatic lesions followed by pathological confirmation for the investigation of biomarkers is occasionally proposed as an effective strategy in the treatment of metastatic breast cancer. However, few reports have examined Ki-67 immunohistochemical expression in distant metastatic lesions of breast cancer patients. This study aimed to investigate the clinicopathological significance of subtypes and Ki-67 immunohistochemical expression in metastatic breast cancer lesions., Methods: We retrospectively studied surgical specimens of primary breast cancer tumors and their corresponding metastatic lesions from patients (n = 68) who underwent surgery for primary breast cancer tumors between December 1977 and March 2013. Tissue microarrays were constructed using primary and metastatic lesions, and were stained with antibodies against estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and Ki-67. We also examined the clinicopathological characteristics and outcome measures of patients with metastatic breast cancer using primary and paired metastatic lesions., Results: Compared with the primary lesions, there was no significant difference in subtypes in the metastatic lesions according to metastatic sites. Metastatic lesions of the brain, viscera, and bone exhibited slightly higher levels of Ki-67 immunohistochemical expression compared with primary lesions. A Cox proportional hazards model using multivariate analysis demonstrated that high Ki-67 immunohistochemical expression in distant metastatic lesions was associated with poorer overall survival outcomes after biopsy of recurrence lesion (hazard ratio 2.307; 95% confidence interval 1.207-4.407, P = 0.011)., Conclusions: High Ki-67 immunohistochemical expression levels in distant metastatic lesions were independently associated with poorer overall survival outcomes after biopsy of recurrence lesion in breast cancer patients.

Background: For premenopausal women with breast cancer, information on the effects of chemotherapy and the risk of infertility is important. In this study, the effect of chemotherapy on the ovarian function in premenopausal women with hormone receptor-positive breast cancer was investigated, with an age-stratified analysis of the appearance of amenorrhea and the resumption of menstruation after the use of chemotherapy with anthracyclines or taxanes., Patients and Methods: Premenopausal women diagnosed with operable Stage I-III hormone receptor-positive breast cancer and underwent neoadjuvant or adjuvant chemotherapy with the standard regimen of anthracyclines and/or taxanes were included. The patients were classified into age groups in 5-year increments, and the rates of chemotherapy-induced amenorrhea (CIA), resumption of menstruation, and duration of CIA after chemotherapy were analyzed., Results: The subjects consisted of 101 patients (median age 45 years). CIA occurred in 97 (96%) patients and 40 patients resumed menstruation. In all patients aged ≤39 years menstruation restarted, whereas in all patients aged ≥50 years, menstruation did not restart. For the patients who resumed menstruation, the younger the patients, the sooner menstruation tended to restart. The resumption of menstruation occurred within 1 year for younger patients aged around 30 years, but for those aged ≥35 years, 60% of cases took around 2-3 years for resumption., Conclusions: The incidence of CIA, the resumption of menstruation and duration of CIA after chemotherapy depend greatly on the patient's age.

Background: Estrone (E1), the major circulating estrogen in postmenopausal women, promotes estrogen-receptor positive (ER+) breast tumor growth and proliferation. Two major reactions contribute to E1 plasma concentrations, aromatase (CYP19A1) catalyzed E1 synthesis from androstenedione and steroid sulfatase (STS) catalyzed hydrolysis of estrone conjugates (E1Cs). E1Cs have been associated with breast cancer risk and may contribute to tumor progression since STS is expressed in breast cancer where its activity exceeds that of aromatase., Methods: We performed genome-wide association studies (GWAS) to identify SNPs associated with variation in plasma concentrations of E1Cs, E1, and androstenedione in 774 postmenopausal women with resected early-stage ER+ breast cancer. Hormone concentrations were measured prior to aromatase inhibitor therapy., Results: Multiple SNPs in SLCO1B1, a gene encoding a hepatic influx transporter, displayed genome-wide significant associations with E1C plasma concentrations and with the E1C/E1 ratio. The top SNP for E1C concentrations, rs4149056 (p = 3.74E-11), was a missense variant that results in reduced transporter activity. Patients homozygous for the variant allele had significantly higher average E1C plasma concentrations than did other patients. Furthermore, three other SLCO1B1 SNPs, not in LD with rs4149056, were associated with both E1C concentrations and the E1C/E1 ratio and were cis-eQTLs for SLCO1B3. GWAS signals of suggestive significance were also observed for E1, androstenedione, and the E1/androstenedione ratio., Conclusion: These results suggest a mechanism for genetic variation in E1C plasma concentrations as well as possible SNP biomarkers to identify ER+ breast cancer patients for whom STS inhibitors might be of clinical value.

Purpose: CYP2D6 is the key enzyme responsible for the generation of the potent active metabolite of tamoxifen, "endoxifen." There are still controversial reports questioning the association between CYP2D6 genotype and tamoxifen efficacy. Hence, we performed a prospective multicenter study to evaluate the clinical effect of CYP2D6 genotype on tamoxifen therapy. Experimental Design: We enrolled 279 patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative, invasive breast cancer receiving preoperative tamoxifen monotherapy for 14 to 28 days. Ki-67 response in breast cancer tissues after tamoxifen therapy was used as a surrogate marker for response to tamoxifen. We prospectively investigated the effects of allelic variants of CYP2D6 on Ki-67 response, pathological response, and hot flushes. Results: Ki-67 labeling index in breast cancer tissues significantly decreased after preoperative tamoxifen monotherapy ( P = 0.0000000000000013). Moreover, proportion and Allred scores of estrogen receptor-positive cells in breast cancer tissues were significantly associated with Ki-67 response ( P = 0.0076 and 0.0023, respectively). Although CYP2D6 variants were not associated with pathologic response nor hot flushes, they showed significant association with Ki-67 response after preoperative tamoxifen therapy ( P = 0.018; between two groups, one with at least one wild-type allele and the other without a wild-type allele). Conclusions: This is the first prospective study evaluating the relationship between CYP2D6 variants and Ki-67 response after tamoxifen therapy. Our results suggest that genetic variation in CYP2D6 is a key predictor for the response to tamoxifen in patients with breast cancer. Clin Cancer Res; 23(8); 2019-26. ©2016 AACR ., (©2016 American Association for Cancer Research.)

Background: Breast cancer is currently the most common type of cancer in Japanese females. Unlike most other types of cancer, breast cancer develops more frequently in middle-aged females than in elderly females., Methods: Of all Japanese female breast cancer patients aged ≥20 years whom the BioBank Japan Project originally enrolled between 2003 and 2008, 2034 were registered within 90 days after their diagnosis. We described the lifestyle and clinical characteristics of these patients at study entry. Furthermore, we examined the effect of these characteristics on all-cause mortality., Results: In the female patients registered within 90 days after diagnosis, the frequency of stage 0 or unclassified, stage I, II, III and IV were 11.4%, 47.9%, 37.0%, 2.9% and 0.8%, respectively. The proportion of histological types was 12.9% for non-invasive carcinoma (ductal carcinoma and lobular carcinoma), 81.0% for invasive carcinoma (papillotubular carcinoma, solid tubular carcinoma, scirrhous carcinoma and special types), 0.2% for Paget's diseases and 5.8% for others. Those positive for the estrogen and progesterone receptors accounted for 75.8% and 62.1% of all patients, respectively. Among 1860 female participants registered within 90 days, 218 participants died during 144,54 person-years of follow-up. More advanced stage, elevation of serum carcinoembryonic antigen and carbohydrate antigen 15-3 levels and absence of the estrogen receptor at study entry were crudely associated with an increased risk of all-cause mortality after adjustment for age., Conclusions: This study showed the association of several clinical characteristics with all-cause mortality in female breast cancer patients., (Copyright © 2017. Production and hosting by Elsevier B.V.)

Background: In metastatic breast cancer, the status of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), as well as the Ki-67 index sometimes change between primary and metastatic lesions. However, the change in expression levels of enhancer of zeste homolog 2 (EZH2) between primary and metastatic lesions has not been determined in metastatic breast cancer., Methods: Ninety-six metastatic breast cancer patients had biopsies or resections of metastatic lesions between September 1990 and February 2014 at the Kanagawa Cancer Center. We evaluated ER, PR, HER2, Ki-67, and EZH2 in primary lesions and their corresponding metastatic lesions using immunohistochemistry. We examined the change in expression of EZH2 between primary and metastatic lesions, the correlation between the expression of EZH2 and the expression of other biomarkers, and the relationship between EZH2 expression and patient outcome in metastatic breast cancer., Results: EZH2 expression was significantly higher in metastatic lesions compared with primary lesions. EZH2 expression was highly correlated with Ki-67 expression in primary and metastatic lesions. High-level expression of EZH2 was associated with poorer disease-free survival (DFS) outcomes in patients with primary lesions (P < 0.001); however, high-level expression of EZH2 was not associated with poorer DFS outcomes in patients with metastatic lesions (P = 0.063). High-level expression of EZH2 was associated with poorer overall survival (OS) postoperatively in patients with primary (P = 0.001) or metastatic lesions (P = 0.005). High-level expression of EZH2 was associated with poorer OS outcomes after recurrence in patients with metastatic lesions (P = 0.014); however, high-level expression of EZH2 was not associated with poorer OS outcomes after recurrence in patients with primary lesions (P = 0.096). High-level expression of EZH2 in metastatic lesions was independently associated with poorer OS outcomes after recurrence., Conclusions: EZH2 expression was significantly increased in metastatic lesions compared with primary lesions. High-level expression of EZH2 in metastatic lesions was associated with poorer OS outcomes after primary surgery and recurrence.

Breast cancer patients have a generally increased risk of developing second cancers. The object of this study was to clarify the increased as well as decreased incidence of cancers in breast cancer patients using autopsy cases. 164 211 autopsy cases in the Annual of Pathological Autopsy Cases in Japan from 2002 to 2010 were analyzed for multiple primary cancer (MPC). Female MPC cases (4222 cases) were selected. We investigated the cancer incidence observed in breast cancer associated MPC. The Chi-squared test was used for analysis. All P-values were two-sided, and differences at P < 0.05 were considered significant. Breast cancer associated MPC showed a significantly increased incidence of ovarian, pancreatic, and skin cancer (Odds Ratio [95 % confidence interval (CI)]) = 1.464 [1.03, 2.08], 1.414 [1.08, 1.85] and 2.092 [1.28, 3.41]), and a decreased incidence of colorectal and cervical cancer (OR [95 % CI]) = 0.732 [0.60, 0.90], 0.605 [0.38, 0.96]). Our findings of an increased incidence of malignancies in breast cancer associated MPC cases were consistent with the results of previous population-based studies. This study is the first study to analyze massive autopsy data on MPC which provide new evidence clinically and pathologically., (© 2016 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

We identified phosphatidylinositol glycan anchor biosynthesis, class X (PIGX), which plays a critical role in the biosynthetic pathway of glycosylphosphatidylinositol (GPI)-anchor motif, to be upregulated highly and frequently in breast cancer cells. Knockdown of PIGX as well as reticulocalbin 1 (RCN1) and reticulocalbin 2 (RCN2), which we found to interact with PIGX and was indicated to regulate calcium-dependent activities, significantly suppressed the growth of breast cancer cells. We also identified PIGX to be a core protein in an RCN1/PIGX/RCN2 complex. Microarray analysis revealed that the expression of two putative tumor suppressor genes, Zic family member 1 (ZIC1) and EH-domain containing 2 (EHD2), were upregulated commonly in cells in which PIGX, RCN1, or RCN2 was knocked down, suggesting that this RCN1/PIGX/RCN2 complex could negatively regulate the expression of these two genes and thereby contribute to human breast carcinogenesis. Our results imply that PIGX may be a good candidate molecule for development of novel anticancer drugs for breast cancer.

The immune microenvironment of tumor plays a critical role in therapeutic responses to chemotherapy. Cancer tissues are composed of a complex network between antitumor and pro-tumor immune cells and molecules; therefore a comprehensive analysis of the tumor immune condition is imperative for better understanding of the roles of the immune microenvironment in anticancer treatment response. In this study, we performed T cell receptor (TCR) repertoire analysis of tumor infiltrating T cells (TILs) in cancer tissues of pre- and post-neoadjuvant chemotherapy (NAC) from 19 breast cancer patients; five cases showed CR (complete response), ten showed PR (partial response), and four showed SD/PD (stable disease/progressive disease) to the treatment. From the TCR sequencing results, we calculated the diversity index of the TCRβ chain and found that clonal expansion of TILs could be detected in patients who showed CR or PR to NAC. Noteworthy, the diversity of TCR was further reduced in the post-NAC tumors of CR patients. Our quantitative RT-PCR also showed that expression ratio of CD8/Foxp3 was significantly elevated in the post-NAC tumors of CR cases (p=0.0032), indicating that antitumor T cells were activated and enriched in these tumors. Collectively, our findings suggest that the clonal expansion of antitumor T cells may be a critical factor associated with response to chemotherapy and that their TCR sequences might be applicable for the development of TCR-engineered T cells treatment for individual breast cancer patients when their tumors relapse.

Germline mutations in the PTEN gene, which cause Cowden syndrome, are known to be one of the genetic factors for primary thyroid and breast cancers; however, PTEN mutations are found in only a small subset of research participants with non-syndrome breast and thyroid cancers. In this study, we aimed to identify germline variants that may be related to genetic risk of primary thyroid and breast cancers. Genomic DNAs extracted from peripheral blood of 14 PTEN WT female research participants with primary thyroid and breast cancers were analyzed by whole-exome sequencing. Gene-based case-control association analysis using the information of 406 Europeans obtained from the 1000 Genomes Project database identified 34 genes possibly associated with the phenotype with P < 1.0 × 10(-3). Among them, rare variants in the PARP4 gene were detected at significant high frequency (odds ratio = 5.2; P = 1.0 × 10(-5)). The variants, G496V and T1170I, were found in six of the 14 study participants (43%) while their frequencies were only 0.5% in controls. Functional analysis using HCC1143 cell line showed that knockdown of PARP4 with siRNA significantly enhanced the cell proliferation, compared with the cells transfected with siControl (P = 0.02). Kaplan-Meier analysis using Gene Expression Omnibus (GEO), European Genome-phenome Archive (EGA) and The Cancer Genome Atlas (TCGA) datasets showed poor relapse-free survival (P < 0.001, Hazard ratio 1.27) and overall survival (P = 0.006, Hazard ratio 1.41) in a PARP4 low-expression group, suggesting that PARP4 may function as a tumor suppressor. In conclusion, we identified PARP4 as a possible susceptibility gene of primary thyroid and breast cancer., Competing Interests: Declaration of interest The authors have nothing to disclose, (© 2016 Society for Endocrinology.)

Aims: Although 8-73 % of breast cancer patients who receive adjuvant endocrine therapy discontinue it, discontinuation is little studied in Asian breast cancer patients., Materials and Methods: To determine frequency and reasons for discontinuation at a single institution, we reviewed records and database information for women with hormone receptor-positive breast cancer who were treated at the National Kyushu Cancer Center 2001-2006, defining "persistence" as continued endocrine treatment (even when physicians decided to stop because of recurrent disease or severe adverse effects), and "discontinuation" as ending therapy due to patient's wishes., Results: Among 686 patients who started adjuvant endocrine therapy, 607 patients (88 %) persisted, 79 patients (12 %) discontinued. Of the 79 patients who discontinued, 37 (46 %) did so because of side effects, 26 (33 %) stopped appointments, 11 (14 %) stopped for "no particular reason", 4 (5 %) to get pregnant, and 1 (1 %) for economic reasons. The rate of persistence was higher in patients with lymph node involvement than in those without lymph node involvement (92 vs. 87 %; P = 0.03)., Conclusions: Clinicians should discuss side effects with patients, both as part of informed consent and to prepare them to continue therapy, and should be aware that over time, patients' reasons for discontinuation change.

Background: Thymidylate synthase (TS) is an enzyme involved in DNA synthesis, and it is a target for 5-fluorouracil. Previous studies have demonstrated that TS is a potent estrogen-induced gene in breast carcinoma cells, suggesting the importance of TS in estrogen-receptor (ER)-positive breast carcinoma. TS immunolocalization has been reported previously, but the clinicopathological significance of TS in ER-positive breast carcinoma still remains unclear., Patients and Methods: We immunolocalized TS in 178 breast carcinoma tissues in total, and examined its significance according to the ER-status., Results: TS status was positive in 58% of ER-positive ductal carcinoma in situ (DCIS) cases, and it was significantly associated with the Ki-67 and progesterone receptor (PR). Moreover, in ER-positive DCIS patients who received aromatase inhibitor (AI) before surgery, TS immunoreactivity was significantly decreased after AI treatment. In ER-positive invasive ductal carcinoma (IDC) cases, TS status was significantly associated with PR, and it turned out an independent favorable prognostic factor for recurrence of the patients by multivariate analysis. On the other hand, TS status was positively correlated with pathological T factor in ER-negative IDC cases, and tended to have a worse prognosis for disease-free survival of the patients., Conclusion: These results suggest that TS expression is mainly regulated by estrogen in ER-positive breast carcinoma and is associated with estrogen-mediated proliferation. TS status is a favorable prognostic factor in ER-positive IDC patients, which is different from the ER-negative cases.

Prostaglandins are a group of lipid compounds involved in inflammation and cancer. We focused on PGF2α and its stereoisomer 11β-PGF2α and examined the expression and functions of their cognate receptor (FP receptor) and metabolizing enzymes (AKR1B1 and AKR1C3 respectively) in breast cancer. In immunohistochemical analysis FP receptor status associated with adverse clinical outcome only in the AKR1C3 positive cases. Therefore, we studied FP receptor-mediated functions of 11β-PGF2α using FP receptor expressed MCF-7 cell line (MCF-FP). 11β-PGF2α treatment phosphorylated ERK and CREB and induced Slug expression through FP receptor in MCF-FP, and MCF-FP cells demonstrated decreased chemosensitivity compared to parental controls. Finally, the correlation between FP receptor and Slug was also confirmed immunohistochemically in breast cancer cases. Overall these results indicated that the actions of AKR1C3 can produce FP receptor ligands whose activation results in carcinoma cell survival in breast cancer., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)