A risk-based subgroup analysis of the effect of adjuvant S-1 in estrogen receptor-positive, HER2-negative early breast cancer.

PURPOSE: The Phase III POTENT trial demonstrated the efficacy of adding S-1 to adjuvant endocrine therapy for estrogen receptor-positive, HER2-negative early breast cancer. We investigated the efficacy of S-1 across different recurrence risk subgroups. METHODS: This was a post-hoc exploratory analysis of the POTENT trial. Patients in the endocrine-therapy-only arm were divided into three groups based on composite risk values calculated from multiple prognostic factors. The effects of S-1 were estimated using the Cox model in each risk group. The treatment effects of S-1 in patients meeting the eligibility criteria of the monarchE trial were also estimated. RESULTS: A total of 1,897 patients were divided into three groups: group 1 (≤ lower quartile of the composite values) (N = 677), group 2 (interquartile range) (N = 767), and group 3 (> upper quartile) (N = 453). The addition of S-1 to endocrine therapy resulted in 49% (HR: 0.51, 95% CI: 0.33-0.78) and 29% (HR: 0.71, 95% CI 0.49-1.02) reductions in invasive disease-free survival (iDFS) events in groups 2 and 3, respectively. We could not identify any benefit from the addition of S-1 in group 1. The addition of S-1 showed an improvement in iDFS in patients with one to three positive nodes meeting the monarchE cohort 1 criteria (N = 290) (HR: 0.47, 95% CI: 0.29-0.74). CONCLUSIONS: The benefit of adding adjuvant S-1 was particularly marked in group 2. Further investigations are warranted to explore the optimal usage of adjuvant S-1.

Prognostic impact of adjuvant endocrine therapy for estrogen receptor-positive and HER2-negative T1a/bN0M0 breast cancer.

PURPOSE: Mammography screening has increased the detection of subcentimeter breast cancers. The prognosis for estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative T1a/bN0M0 breast cancers is excellent; however, the necessity of adjuvant endocrine therapy (ET) is uncertain. METHODS: We evaluated the effectiveness of adjuvant ET in patients with ER-positive and HER2-negative T1a/bN0M0 breast cancer who underwent surgery from 2008 to 2012. Standard ET was administrated after surgery. The primary endpoint was the cumulative incidence of distant metastasis. All statistical tests were 2-sided. RESULTS: Adjuvant ET was administered to 3991 (83%) of the 4758 eligible patients (1202 T1a [25.3%] and 3556 T1b [74.7%], diseases). The median follow-up period was 9.2 years. The 9-year cumulative incidence of distant metastasis was 1.5% with ET and 2.6% without ET (adjusted subdistribution hazard ratio [sHR], 0.54; 95% CI, 0.32-0.93). In multivariate analysis, the independent risk factors for distant metastasis were no history of ET, mastectomy, high-grade, and lymphatic invasion. The 9-year overall survival was 97.0% and 94.4% with and without ET, respectively (adjusted HR, 0.57; 95% CI, 0.39-0.83). In addition, adjuvant ET reduced the incidence of ipsilateral and contralateral breast cancer (9-year rates; 1.1% vs. 6.9%; sHR, 0.17, and 1.9% vs. 5.2%; sHR, 0.33). CONCLUSIONS: The prognosis was favorable in patients with ER-positive and HER2-negative T1a/bN0M0 breast cancer. Furthermore, adjuvant ET reduced the incidence of distant metastasis with minimal absolute risk difference. These findings support considering the omission of adjuvant ET, especially for patients with low-grade and no lymphatic invasion disease.

Nuclear grade and comedo necrosis of ductal carcinoma in situ as histopathological eligible criteria for the Japan Clinical Oncology Group 1505 trial: an interobserver agreement study.

OBJECTIVE: The Japan Clinical Oncology Group 1505 trial is a single-arm multicentre prospective study that examined the possibility of non-surgical follow-up with endocrine therapy for patients with low-grade ductal carcinoma in situ. In that study, the eligible criteria included histopathological findings comprising low to intermediate nuclear grade and absence of comedo necrosis, and cases were entered according to the local histopathological diagnosis. Nuclear grade is largely based on the Consensus Conference criteria (1997), whereas comedo necrosis is judged according to the Rosen's criteria (2017). The purpose of this study was to standardize and examine the interobserver agreement levels of these histopathological criteria amongst the participating pathologists. METHODS: We held slide conferences, where photomicrographs of haematoxylin-eosin-stained slides from 68 patients with ductal carcinoma in situ were presented using PowerPoint. The nuclear grade and comedo necrosis statuses individually judged by the pathologists were analysed using κ statistics. RESULTS: In the first and second sessions, where 22 cases each were presented, the interobserver agreement levels of nuclear grade whether low/intermediate grade or high grade were moderate amongst 29 and 24 participating pathologists, respectively (κ = 0.595 and 0.519, respectively). In the third session where 24 cases were presented, interobserver agreement levels of comedo necrosis or non-comedo necrosis were substantial amongst 25 participating pathologists (κ = 0.753). CONCLUSION: Although the concordance rates in nuclear grade or comedo necrosis were not high in a few of the cases, we believe that these results could provide a rationale for employing the present criteria of nuclear grade and comedo necrosis in the clinical study of ductal carcinoma in situ.

Current approach and future perspective for ductal carcinoma in situ of the breast.

Ductal carcinoma in situ (DCIS) has a good prognosis with the current treatment approach, with a 10-year breast cancer-specific survival rate of 97-98%. In ductal carcinoma in situ without micrometastasis, surgery and postoperative adjuvant therapy significantly improve local control, however it has been reported that the selection of the surgical procedure and adjuvant therapy does not influence breast cancer death. On the other hand, owing to widespread mammography screening, the frequency of early breast cancer detection has increased. In early breast cancer, increased incidence of DCIS is remarkable. However, there is not enough reduction of advanced cancer to match it. Problems with overdiagnosis are now being discussed all over the world. It has been reported that surgery for low-grade ductal carcinoma in situ does not contribute to breast cancer-specific survival. However, it is currently impossible to reliably identify a population that does not progress to invasive cancer even without treatment. Recently, a non-surgery clinical trial for low-risk ductal carcinoma in situ was started. There is a possibility of achieving individualized treatment for ductal carcinoma in situ with less treatment intervention, without compromising the good prognosis obtained with the current treatment approach. This review presents an overview of the current treatment approaches, problems with overdiagnosis and potential future management strategies for ductal carcinoma in situ of the breast.

Mentorship as Experienced by Women Surgeons in Japan.

BACKGROUND: Women have accounted for over 30% of new medical students since 1995 in Japan. Establishing support systems for women surgeons to continue their work is a major issue in Japan. Mentorship can be one of the most effective means to help women surgeons to continue their work. The purpose of this study was to clarify the current status of mentorship among Japanese women surgeons and to discuss the role of mentors for women surgeons. METHODS: Invitation letters were sent to all female members of the Japan Association of Women Surgeons in April 2011. An 84-item questionnaire survey was sent to those who agreed to participate in this study via the internet. RESULTS: Fifty-five surgeons participated in this study, a response rate of 48.7%. Sixty-seven percent of respondents found it difficult to continue in their job; 85% thought mentorship was necessary for women surgeons to progress in their careers; and 84% reported that they already had a mentor. Respondents thought that a mentor helped them to advance their clinical career, to stay in their job, and to provide moral support. However, mentors appeared to be less useful in helping them to advance their research career, to network, to increase their status, and to achieve a work-life balance. CONCLUSIONS: This study revealed areas where mentors appeared to be less helpful to women surgeons. The survey gave an indication of how to help improve and develop the career and personal life of women surgeons in Japan.

Prognostic factors of HER2-positive breast cancer patients who develop brain metastasis: a multicenter retrospective analysis.

The clinical course and prognostic factors of HER2-positive breast cancer patients with brain metastases are not well known because of the relatively small population. The aim of this study was to determine prognostic factors associated with HER2-positive patients who develop brain metastases. This retrospective study assessed the largest dataset to date of 432 HER2-positive patients who were diagnosed with brain metastases from 24 institutions of the Japan Clinical Oncology Group, Breast Cancer Study Group. The median age of the 432 patients was 54 years (range, 20-86 years). Of the patients, 162 patients (37.5 %) had ER-positive/HER2-positive (ER+HER2+) breast cancer, and 270 (62.5 %) had ER-negative/HER2-positive (ER-HER2+) breast cancer. The median brain metastasis-free survival period from primary breast cancer was 33.5 months in both groups. The median survival after developing brain metastasis was 16.5 and 11.5 months in the ER+HER2+ and ER-HER2+ groups, respectively, (p = 0.117). Patients with >3 brain metastases had significantly shorter overall survival in both ER+HER2+ (p < 0.001) and ER-HER2+ (p = 0.018) groups. Treatment with trastuzumab before developing brain metastases was not associated with survival duration after developing brain metastases (p = 0.571). However, patients treated with both trastuzumab and lapatinib after developing metastasis had significantly longer survival than patients treated with trastuzumab alone, lapatinib alone, or no HER2-targeting agent (p < 0.001). For HER2-positive patients with brain metastases, regardless of the use of trastuzumab before developing brain metastasis, treatment with both trastuzumab and lapatinib might improve survival.

Safety and feasibility of adjuvant chemotherapy with S-1 in Japanese breast cancer patients after primary systemic chemotherapy: a feasibility study.

BACKGROUND: Advanced breast cancer patients have a higher risk of postoperative recurrence than early-stage breast cancer patients. Recurrence is believed to be caused by the increase in micrometases, which were not eradicated by preoperative or postoperative chemotherapy. Therefore, a new therapeutic strategy that can improve treatment efficacy is mandatory for advanced breast cancer. S-1 was shown to be effective and safe in Japanese metastatic breast cancer patients treated with previous chemotherapy, including anthracyclines. Thus, in this study, we evaluated S-1 as adjuvant chemotherapy in breast cancer patients after standard primary systemic chemotherapy. METHODS: The treatment consisted of 18 courses (a 2-week administration and a 1-week withdrawal; one year) administered at 80-120 mg/body/day. In cases judged to require postoperative radiotherapy, it was concurrently initiated on Day 1 of the study. If the estrogen receptor and/or human epidermal growth factor receptor 2 were positive, endocrine therapy and/or trastuzumab were permitted, concurrently. RESULTS: Of the 45 patients enrolled between September 2007 and September 2009 from 3 institutions, 43 patients were eligible. Thirty-two of the 43 (74.4%) patients received concurrent radiotherapy. Twenty-two of the 43 (51.2%) patients completed the scheduled courses of chemotherapy. The most common reasons for withdrawal of treatment were subjective symptoms, such as nausea, anorexia, or general fatigue during the first 9 courses of treatment in 9/43 (20.9%) patients, recurrence in 7/43 (16.3%) patients, and adverse events in 5/43 (11.6%) patients. The cumulative percentage of administration for 365 days was 66.4% (95% confidence interval: 50.8-79.1%). Although grade 3 neutropenia (9.3%), leukopenia (4.7%), and diarrhea (4.7%) were observed, they were manageable. No grade 4 adverse effects were observed. CONCLUSIONS: The percentage of Japanese breast cancer patients completing the 18-course treatment and the cumulative percentage of administration for 365 days using S-1 after standard primary systemic chemotherapy were similar with the results of another study of adjuvant chemotherapy for the Japanese gastric cancer patients with no severe adverse effects. A phase III trial investigating the usefulness of adjuvant S-1 is now ongoing in Japan, and it is expected that S-1 will have a significant survival benefit in breast cancer patients. UMIN000013469.

Treatment outcomes and prognostic factors for patients with brain metastases from breast cancer of each subtype: a multicenter retrospective analysis.

To define prognostic factors for breast cancer patients with brain metastases, compare their clinical courses and prognoses according to breast cancer subtypes, and analyze the causes of death in such patients. We retrospectively analyzed 1,466 patients diagnosed with brain metastases between April 1, 2001 and December 31, 2012, from 24 institutions of the Japan Clinical Oncology Group. Overall, 1,256 patients with brain metastases were included. The median overall survival (OS) was 8.7 months (95 % confidence interval [CI] 7.8-9.6 months). Univariate and multivariate analyses revealed that patients diagnosed with brain metastasis within 6 months of metastatic breast cancer diagnoses, asymptomatic brain disease, or HER2-positive/estrogen receptor-positive tumors had increased OS. Median OS after the development of brain metastases was 9.3 months (95 % CI 7.2-11.3) for the luminal type, 16.5 months (95 % CI 11.9-21.1) for the luminal-HER2 type, 11.5 months (95 % CI 9.1-13.8) for the HER2 type, and 4.9 months (95 % CI 3.9-5.9) for the triple-negative type. Luminal-HER2 type patients had significantly longer OS than patients with the luminal type (hazard ratio [HR] = 1.50, P < 0.0001) and triple-negative type (HR = 1.97, P < 0.0001); no significant differences were noted compared to HER2-type patients (HR = 1.19, P = 0.117). The prognosis and clinical course of patients with brain metastasis from breast cancer before and after developing brain metastases vary according to subtype. Focusing on the subtypes of breast cancer can optimize the prevention, early detection, and improved treatment of brain metastases.

The Japanese breast cancer society clinical practice guidelines for breast cancer screening and diagnosis, 2022 edition.

This article provides updates to readers based on the newly published Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer Screening and Diagnosis, 2022 Edition. These guidelines incorporate the latest evaluation of evidence from studies of diagnostic accuracy. For each clinical question, outcomes for benefits and harms were established, and qualitative or quantitative systematic reviews were conducted. Recommendations were determined through voting by a multidisciplinary group, and guidelines were documented to facilitate shared decision-making among patients and medical professionals. The guidelines address screening, surveillance, and pre- and postoperative diagnosis of breast cancer. In an environment that demands an integrated approach, decisions are needed on how to utilize modalities, such as mammography, ultrasound, MRI, and PET/CT. Additionally, it is vital to understand the appropriate use of new technologies, such as tomosynthesis, elastography, and contrast-enhanced ultrasound, and to consider how best to adapt these methods for individual patients.

Alopecia neoplastica: A manifestation of metastatic breast cancer.

We herein report a typical case of alopecia neoplastica secondary to breast cancer. Alopecia neoplastica is a rare form of alopecia resulting from metastasis of a primary tumour to the scalp and is often misdiagnosed as alopecia areata.

Copy number alteration is an independent prognostic biomarker in triple-negative breast cancer patients.

BACKGROUND: Next-generation sequencing (NGS) has enabled comprehensive genomic profiling to identify gene alterations that play important roles in cancer biology. However, the clinical significance of these genomic alterations in triple-negative breast cancer (TNBC) patients has not yet been fully elucidated. The aim of this study was to clarify the clinical significance of genomic profiling data, including copy number alterations (CNA) and tumor mutation burden (TMB), in TNBC patients. METHODS: A total of 47 patients with Stage I-III TNBC with genomic profiling of 435 known cancer genes by NGS were enrolled in this study. Disease-free survival (DFS) and overall survival (OS) were evaluated for their association to gene profiling data. RESULTS: CNA-high patients showed significantly worse DFS and OS than CNA-low patients (p = 0.0009, p = 0.0041, respectively). TMB was not associated with DFS or OS in TNBC patients. Patients with TP53 alterations showed a tendency of worse DFS (p = 0.0953) and significantly worse OS (p = 0.0338) compared with patients without TP53 alterations. Multivariable analysis including CNA and other clinicopathological parameters revealed that CNA was an independent prognostic factor for DFS (p = 0.0104) and OS (p = 0.0306). Finally, multivariable analysis also revealed the combination of CNA-high and TP53 alterations is an independent prognostic factor for DFS (p = 0.0005) and OS (p = 0.0023). CONCLUSIONS: We revealed that CNA, but not TMB, is significantly associated with DFS and OS in TNBC patients. The combination of CNA-high and TP53 alterations may be a promising biomarker that can inform beyond standard clinicopathologic factors to identify a subgroup of TNBC patients with significantly worse prognosis.

[Protocol for administration of trastuzumab based on cardiac function].

We analyzed 7 patients with breast cancer who suffered from trastuzumab-associated cardiac dysfunction. Left ventricular ejection fraction (EF) was calculated by M-mode echocardiography. We propose a protocol for the administration of trastuzumab based on EF in the clinical courses of the 7 patients and the literatures concernig trastuzumab. If the EF is ≥60%, an echocardiography is performed every 3 months during trastuzumab therapy. If the EF is ≥53% and ≤60%, an echocardiography is performed every 2 months. If the EF is ≤53%, an echocardiography is performed more frequently. If the EF decreases by ≥10% from its previous level, an echocardiography is performed after 3 weeks. Also, trastuzumab is withheld when the EF falls to ≤45%. When the EF falls to ≤40%, the standard treatment for congestive heart failure is initiated. An echocardiography is performed every 2 weeks after trastuzumab is withheld. Trastuzumab therapy can be resumed if the EF improves to ≥50%.

Trends in adjuvant therapy after breast-conserving surgery for ductal carcinoma in situ of breast: a retrospective cohort study using the National Breast Cancer Registry of Japan.

PURPOSE: Radiotherapy (RT) and endocrine therapy (ET) are standard treatment options after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS). We investigated the national patterns of adjuvant therapy use after BCS for DCIS in Japan. METHODS: We obtained relevant data of patients diagnosed with DCIS undergoing surgery and treated with BCS between 2014 and 2016 from the Japanese Breast Cancer Registry database. The relationship between the clinicopathologic, institutional, and regional factors, and adjuvant treatment was examined using multivariable analyses. RESULTS: We identified 9516 patients who underwent BCS for DCIS. Overall, 23% received no adjuvant treatment, 71% received RT, 32% received ET, and 26% received combination therapy. The percentages of patients who received ET and combination therapy in 2016 were significantly lower [odds ratio (OR): 0.71, 0.77, respectively] than in 2014. The proportion of RT was low among young or elderly patients (OR: 0.75, 0.44, respectively) and in non-certified facilities (OR: 0.56). The proportion of ET was high in non-certified facilities (OR: 1.58) and among patients with positive margins (OR: 1.62). Combination therapy was higher among patients with positive margins (OR: 1.53). CONCLUSIONS: Our study found a distinct adjuvant treatment pattern after BCS for DCIS depending on clinicopathologic factors, year, age, which indicate that physicians provide individualized treatment according to the background of the patients and the biology of DCIS. The facilities and regions remain significant factors of influencing adjuvant treatment pattern.

Clinicopathological predictors of postoperative upstaging to invasive ductal carcinoma (IDC) in patients preoperatively diagnosed with ductal carcinoma in situ (DCIS): a multi-institutional retrospective cohort study.

BACKGROUND: We conducted a prospective study with the intention to omit surgery for patients with ductal carcinoma in situ (DCIS) of the breast. We aimed to identify clinicopathological predictors of postoperative upstaging to invasive ductal carcinoma (IDC) in patients preoperatively diagnosed with DCIS. PATIENTS AND METHODS: We retrospectively analyzed patients with DCIS diagnosed through biopsy between April 1, 2010 and December 31, 2014, from 16 institutions. Clinical, radiological, and histological variables were collected from medical records. RESULTS: We identified 2,293 patients diagnosed with DCIS through biopsy, including 1,663 DCIS (72.5%) cases and 630 IDC (27.5%) cases. In multivariate analysis, the presence of a palpable mass (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.2-2.6), mammography findings (≥ category 4; OR 1.8; 95% CI 1.2-2.6), mass formations on ultrasonography (OR 1.8; 95% CI 1.2-2.5), and tumor size on MRI (> 20 mm; OR 1.7; 95% CI 1.2-2.4) were independent predictors of IDC. Among patients with a tumor size on MRI of ≤ 20 mm, the possibility of postoperative upstaging to IDC was 22.1%. Among the 258 patients with non-palpable mass, nuclear grade 1/2, and positive for estrogen receptor, the possibility was 18.1%, even if the upper limit of the tumor size on MRI was raised to ≤ 40 mm. CONCLUSION: We identified four independent predictive factors of upstaging to IDC after surgery among patients with DCIS diagnosed by biopsy. The combined use of various predictors of IDC reduces the possibility of postoperative upstaging to IDC, even if the tumor size on MRI is larger than 20 mm.

[Trastuzumab-associated cardiac dysfunction].

We analyzed 127 consecutive patients who received trastuzumab-based chemotherapy from December, 2003 to February, 2009 in our hospital. Of 127 patients, cardiac dysfunction appeared in 6 patients(4. 7%). Cardiac dysfunction was defined as a decline in left ventricular (LV) ejection fraction (EF) < or =55% with absolute reduction of at least 10% from baseline. Among the 6 patients with cardiac dysfunction, one patient suffered symptomatic heart failure. Other patients were asymptomatic. The 4 patients of the 5 patients recovered their cardiac dysfunction after withdrawal of trastuzumab. Patients with trastuzumab-associated cardiac dysfunction had a history of administration of epirubicin or taxane, lower registration LVEF, and larger LV end-diastolic dimension (> or =49 mm). We recommend that LV function be assessed by echocardiography or multigated radionuclide angiography scans prior to instituting trastuzumab therapy and at three-month intervals during therapy. Trastuzumab should be discontinued in patients who develop a decrease in LVEF below 45% or congestive heart failure.

Prognostic factors for radical resection of middle and distal bile duct cancer.

BACKGROUND/AIMS: Prognostic factors after radical operation for middle and distal bile duct cancer are not fully understood. The aim of this study is to identify prognostic factors for patients undergoing radical operation for middle and distal bile duct cancer. METHODOLOGY: The records of 57 patients with middle (n=22) and distal (n=35) bile duct cancer who had undergone radical surgery were reviewed (pancreaticoduodenectomy in 46 patients, extrahepatic bile duct resection in 6, and major hemihepatectomy in 5). The clinicopathological prognostic factors affecting survival were examined. RESULTS: The 5 years survival rate was 36% (median survival time, 34 months). Significant prognostic factors according to univariate analysis include pT classification, papillary type, number of metastatic lymph node, positive radial margin, pancreatic invasion, lymphatic invasion, venous invasion, common hepatic node metastasis, paraaortic node metastasis, and combined vascular resection. Independent significant prognostic factors according to multivariate analysis include the number of metastatic lymph nodes (5 or more), positive radial margin, and common hepatic node metastasis. CONCLUSIONS: The number of metastatic lymph nodes, common hepatic node metastasis, and positive radial margin are independent prognostic factors for middle and distal bile duct cancer. The surgical treatment of middle and bile duct cancer should achieve a negative radial margin for a favorable outcome.

Distinct gene expression profiles between primary breast cancers and brain metastases from pair-matched samples.

Our objectives were to determine whether clinic-pathological markers and immune-related gene signatures in breast cancer exhibit any change upon brain metastasis and whether previously reported genes significantly associated with brain metastases and the epithelial-mesenchymal transition (EMT) were reproducible and consistent in our dataset. Sixteen pair-matched samples from primary breast cancers and brain metastases diagnosed were collected from the Japan Clinical Oncology Group Breast Cancer Study Group. Gene expression profiles for immune-, brain metastases-, and EMT-related genes were compared between primary breast cancers and brain metastases. Potential therapeutic target genes of 41 FDA-approved or under-investigation agents for brain metastases were explored. Immune-related signatures exhibited significantly lower gene expression in brain metastases than in primary breast cancers. No significant differences were detected for the majority of genes associated with brain metastases and EMT in the two groups. Among 41 therapeutic target candidates, VEGFA and DNMT3A demonstrated significantly higher gene expression in brain metastases. We found that distinct patterns of gene expression exist between primary breast cancers and brain metastases. Further studies are needed to explore whether these distinct expression profiles derive from or underlie disease status and compare these features between metastases to the brain and other sites.

Neoadjuvant exemestane or exemestane plus docetaxel and cyclophosphamide tailored by clinicopathological response to 12 weeks' exemestane exposure in patients with estrogen receptor-positive breast cancer: A multicenter, open-label, phase II study.

Our aim was to investigate the efficacy and safety of initial neoadjuvant endocrine therapy with exemestane alone followed by tailored treatment, either continued exemestane monotherapy or exemestane plus docetaxel-cyclophosphamide (TC) combination therapy, in postmenopausal patients with primary invasive estrogen receptor-positive, human epidermal growth factor receptor 2-negative, stage I-IIIA breast cancer and Ki67 labeling index ≤30%. In this open-label phase II study, patients initially received exemestane 25 mg/d for 12 weeks. Responders were defined as patients who achieved complete response (CR), partial response (PR) with Ki67 labeling index ≤5% after treatment, or stable disease with Ki67 labeling index ≤5% both before and after treatment. For the subsequent 12 weeks, exemestane monotherapy was continued for responders (group A), whereas nonresponders received exemestane plus four cycles of TC (docetaxel 75 mg/m2 and cyclophosphamide 600 mg/m2 every 3 weeks) (group B). Clinical response rate (ie the proportion of patients with CR or PR) at 24 weeks was the primary endpoint. Of 64 patients provisionally enrolled between December 2010 and May 2016, 58 (median age 60 years) started the study treatment. Five patients discontinued treatment in the initial exemestane monotherapy period, and 39 completed the study treatment. Clinical response rates at 8-12 and 24 weeks were 71% (10/14, 95% confidence interval [CI] 41.9%-91.6%) and 57% (8/14, 95% CI 28.9%-82.3%), respectively, in group A, and 16% (4/25, 95% CI 4.5%-36.1%) and 56% (14/25, 95% CI 34.9%-75.6%), respectively, in group B. Grade ≥3 adverse events were reported in 8% (1/15) and 53% (20/38) in group A and group B, respectively. The tailored treatment maintained the favorable clinical response to exemestane alone in responders and improved clinical response in nonresponders. TRIAL NUMBER: UMIN000004752 (UMIN Clinical Trials Registry).