Yoshifumi Komoike

Effects of lifestyle and single nucleotide polymorphisms on breast cancer risk: a case–control study in Japanese women

BackgroundLifestyle factors, including food and nutrition, physical activity, body composition and reproductive factors, and single nucleotide polymorphisms (SNPs) are associated with breast cancer risk, but few studies of these factors have been performed in the Japanese population. Thus, the goals of this study were to validate the association between reported SNPs and breast cancer risk in the Japanese population and to evaluate the effects of SNP genotypes and lifestyle factors on breast cancer risk.MethodsA case–control study in 472 patients and 464 controls was conducted from December 2010 to November 2011. Lifestyle was examined using a self-administered questionnaire. We analyzed 16 breast cancer-associated SNPs based on previous GWAS or candidate-gene association studies. Age or multivariate-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were estimated from logistic regression analyses.ResultsHigh BMI and current or former smoking were significantly associated with an increased breast cancer risk, while intake of meat, mushrooms, yellow and green vegetables, coffee, and green tea, current leisure-time exercise, and education were significantly associated with a decreased risk. Three SNPs were significantly associated with a breast cancer risk in multivariate analysis: rs2046210 (per allele OR = 1.37 [95% CI: 1.11-1.70]), rs3757318 (OR = 1.33[1.05-1.69]), and rs3803662 (OR = 1.28 [1.07-1.55]). In 2046210 risk allele carriers, leisure-time exercise was associated with a significantly decreased risk for breast cancer, whereas current smoking and high BMI were associated with a significantly decreased risk in non-risk allele carriers.ConclusionIn Japanese women, rs2046210 and 3757318 located near the ESR1 gene are associated with a risk of breast cancer, as in other Asian women. However, our findings suggest that exercise can decrease this risk in allele carriers.

A phase I dose-escalation study of eribulin and S-1 for metastatic breast cancer

Background:We evaluated the safety, maximum-tolerated dose (MTD), pharmacokinetics, recommended dose for phase II (P2RD), and preliminary anticancer activity of a combination eribulin and S-1 therapeutic in metastatic breast cancer patients pretreated with anthracycline and taxane.Method:Patients aged 20–74 years were recruited. In level 1, patients received S-1 (65 mg m−2) from day 1 to 14, and eribulin (1.1 mg m−2) on day 1 and 8 in a 21-day cycle. In level 2, eribulin was increased to 1.4 mg m−2. In level 3, S-1 was increased to 80 mg m−2.Results:Twelve patients were enrolled into three cohorts. Planned dose escalation was completed, with one case exhibiting dose-limiting toxicity (grade 3 hypokalaemia) at level 3, without reaching the MTD. The P2RD was determined to be level 2 (eribulin 1.4 mg m−2 and S-1 65 mg m−2). The most common grade 3 or 4 toxicity was neutropenia (83.3%), followed by febrile neutropenia (25.0%). Five of eleven patients (41.7%) with measurable disease had a partial response. Pharmacokinetics were characterised by dose-dependent elimination and nonlinear exposure.Conclusion:Dose level 3 was not tolerated owing to febrile neutropenia development. Thus, intermediate dose level 2 was recommended for further evaluation. Preliminary antitumour activity warrants further investigation in this setting.

Phase I study of weekly nab‐paclitaxel combined with S‐1 in patients with human epidermal growth factor receptor type 2‐negative metastatic breast cancer

We conducted a phase I study of a weekly nab‐paclitaxel and S‐1 combination therapy in patients with human epidermal growth factor receptor type 2‐negative metastatic breast cancer. The primary objective was to estimate the maximum tolerated and recommended doses. Each treatment was repeated every 21 days. Levels 1, 2a, 2b, and 3 were set depending on the S‐1 dose (65 or 80 mg/m2) and nab‐paclitaxel infusion schedule (days 1 and 8 or days 1, 8, and 15). Fifteen patients were enrolled. Dose‐limiting toxicity was observed in one patient at Level 3 (100 mg/m2 nab‐paclitaxel on days 1, 8, and 15 with 80 mg/m2 S‐1 daily for 14 days, followed by 7 days of rest). Although the maximum tolerated dose was not reached, the recommended dose was determined to be Level 3. Neutropenia was the most frequent grade 3–4 treatment‐related adverse event. For patients with measurable lesions, the response rate was 50.0% and the median time to treatment failure and median progression‐free survival was 13.2 and 21.0 months, respectively. The present results show the feasibility and potential for long‐term administration of this combination therapy.

Japan Breast Cancer Society clinical practice guideline for surgical treatment of breast cancer

From 1972 to 1989, 6 randomized controlled trials (RCT) of breast-conserving surgery followed by radiotherapy and radical mastectomy were performed. The two groups did not significantly differ in long-term survival rate after 20 years [1, 2]. Breast-conserving therapy is now a standard of care for Stage I and II breast cancer. As for ductal carcinoma in situ (DCIS), no RCTs compared breast-conserving therapy with mastectomy, but many published case series, reviews and meta-analyses showed good local control rates and high overall survival (OS) results [3]. Most Stage 0–II breast cancers are candidates for breastconserving therapy, but as the EBCTCG’s meta-analysis showed that local recurrence adversely affected survival rates [4], caution is warranted regarding indication or contraindication for breast-conservation therapy and extent of resection.

O6‑methylguanine‑DNA methyltransferase as a prognostic and predictive marker for basal‑like breast cancer treated with cyclophosphamide‑based chemotherapy

The O6-methylguanine-DNA methyltransferase (MGMT) protein protects cells from alkylating agents by removing alkyl groups from the O6-position of guanine. However, its effect on DNA damage induced by cyclophosphamide (CPM) is unclear. The present study investigated whether MGMT expression was correlated with prognosis in patients with breast cancer that was managed according to a common therapeutic protocol or treated with CPM-based chemotherapy. The intrinsic subtypes and MGMT protein expression levels were assessed in 635 consecutive patients with breast cancer using immunohistochemistry. In total, 425 (67%) luminal A, 95 (15%) luminal B, 47 (7%) human epidermal growth factor receptor-2+/estrogen receptor− (HER2+/ER−) and 48 (8%) basal-like subtypes were identified. Of these, MGMT positivity was identified in 398 (63%) of 635 breast cancers; 68% of luminal A, 67% of luminal B, 30% of HER2+/ER− and 46% of basal-like subtypes were positive. The overall survival (OS) and disease-free survival (DFS) rates did not significantly differ according to the MGMT status among patients with luminal A, luminal B or HER2+/ER− subtypes, and patients with MGMT-negative basal-like cancers tended to have a longer DFS, but not a significantly longer OS time. CPM-containing chemotherapy was administered to 26%, 40%, 47% and 31% of patients with luminal A, luminal B, HER2+/ER− and basal-like tumors, respectively. Although the MGMT status and clinical outcomes of patients with the luminal A, luminal B or HER2+/ER− subtypes treated with CPM were not significantly correlated, the patients with MGMT-negative basal-like tumors who received CPM exhibited significantly improved DFS and OS compared with the CPM-treated patients with MGMT-positive tumors. MGMT may be a useful prognostic and predictive marker for CPM-containing chemotherapy in basal-like breast cancer.

HER2 genomic amplification in circulating tumor DNA and estrogen receptor positivity predict primary resistance to trastuzumab emtansine (T-DM1) in patients with HER2-positive metastatic breast cancer

BackgroundTrastuzumab emtansine (T-DM1) is approved for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (ABC), and has high efficacy. However, some patients exhibit primary resistance to T-DM1, and thus methods that can predict resistance in clinical practice are needed. Genomic analysis of circulating tumor DNA (ctDNA) in plasma is a non-invasive and reproducible method. This study aimed to predict primary resistance to T-DM1 by combining genomic analysis of ctDNA and other clinicopathological features of patients with HER2-positive ABC.MethodsThe study population comprised 34 patients with HER2-positive ABC who had been treated with T-DM1. Correlations between clinicopathological characteristics of patients and primary resistance to T-DM1 were examined, and HER2 gene copy number and PIK3CA gene mutations were analyzed using plasma ctDNA samples obtained from 16 patients before T-DM1 administration.ResultsAmong the 34 patients, nine (26.5%) had progressive disease at the first efficacy analysis; these patients were considered to have primary resistance to T-DM1. No significant difference was found in the rate of primary resistance to T-DM1 between groups. Among 16 patients whose ctDNA was analyzed, four showed primary resistance to T-DM1. These four patients showed negative HER2 gene amplification in ctDNA and were ER-positive and/or PR-positive by immunohistochemistry.ConclusionsHER2 gene amplification in ctDNA and ER and PR status may predict primary resistance to T-DM1. A liquid biopsy before the initiation of T-DM1 treatment could be a non-invasive way to predict whether a patient would exhibit primary resistance to T-DM1.

Increased risk of SSEs in bone-only metastatic breast cancer patients treated with zoledronic acid

Background Bone represents one of the most common sites to which breast cancer cells metastasize. Patients experience skeletal related adverse events (pathological fractures, spinal cord compressions, and irradiation for deteriorated pain on bone) even during treatment with zoledronic acid (ZA). Therefore, we conducted a retrospective cohort study to investigate the predictive factors for symptomatic skeletal events (SSEs) in bone-metastasized breast cancer (b-MBC) patients. Methods We retrospectively collected data on b-MBC patients treated with ZA. Patient characteristics, including age, subtype, the presence of non-bone lesions, the presence of multiple bone metastases at the commencement of ZA therapy, duration of ZA therapy, the time interval between breast cancer diagnosis and the initiation of ZA therapy, and type of systemic therapy, presence of previous SSE were analyzed using multivariable logistic regression analysis. Results The medical records of 183 patients were reviewed and 176 eligible patients were analyzed. The median age was 59 (range, 30–87) years. Eighty-seven patients were aged ≥60 years and 89 patients were aged < 60 years. The proportions of patients with estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2-positive disease were 81.8%, 63.1%, and 17.6%, respectively. Fifty-three patients had bone-only MBC at the commencement of ZA therapy. SSEs were observed in 42 patients. In the multivariable logistic regression analysis, bone-only MBC but not a breast cancer subtype was an independent risk factor for an SSE during ZA therapy (odds ratio: 3.878, 95% confidence interval: 1.647–9.481; p = 0.002). Conclusions Bone-only MBC patients are more likely to experience an SSE even after treatment with ZA.

Abstract P3-10-07: Phase I trial of eribulin in combination with S-1 for advanced and recurrent breast cancer patients

Introduction: Eribulin is a non-taxane microtubule dynamics inhibitor that has been proved to prolong overall survival in patients with advanced and recurrent breast cancer compared to treatment of physician’s choice. S-1 is an oral fluoropyrimidine anticancer agent that combines tegafur as the effector drug with two modulators, gimeracil, and oteracil potassium, and has shown promising antitumor activity as a single agent for the treatment of advanced breast cancer. In the basis of these results, we aimed to assess the efficacy of the combination of these two drugs in patients with advanced and recurrent breast cancer. In this trial, we determined maximum tolerated dose (MTD) and phase II recommended dose of Eribulin and S-1 combination therapy. Methods: A traditional 3+3 dose escalation design was implemented. 12 patients pre-treated with anthracycline and taxane were enrolled. As an initiation level, patients received s-1 50 mg/m2 from day1 to day14, and Eribulin 1.1mg/m2 on day1, and day8. In level 2, Eribulin dose was increased to 1.4mg/m2. In level 3, S-1 dose was increased to 80 mg/m2. Results: In level 1 or 2, no dose limiting toxicity (DLT) was observed. In level 3, grade 3 hypokalemia occurred in 1 case. The level 3 dose level was determined as phase II recommended dose. Neutropenia was observed in all cases, 3 of which was grade 3 febrile neutropenia. However, other non-hematological toxicity was mild, and the toxicity of the both drugs was not enhanced by the combination. Partial response is confirmed in 5/11 patients with measurable lesions. Conclusion: We have shown that treatment with Eribulin and S-1 is active and well tolerated in patients with advanced and recurrent breast cancer, suggesting that this combination therapy may have potential as a new treatment option. A phase II study is being conducted to evaluate the efficacy and safety. Citation Format: Tsutomu Iwasa, Junji Tsurutani, Satomi Nishida, Yoshifumi Komoike, Kazuhiko Nakagawa. Phase I trial of eribulin in combination with S-1 for advanced and recurrent breast cancer patients [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-10-07.

Abstract OT3-1-04: A phase 2 study of eribulin in combination with pertuzumab and trastuzumab for advanced or recurrent human epidermal growth factor receptor 2 (HER2)-positive breast cancer (SONG-02)

Background: Pertuzumab, an anti-HER2 humanized monoclonal antibody that inhibits receptor dimerization, has a mechanism of action that is complementary to that of trastuzumab, and the combination of pertuzumab plus trastuzumab plus taxanes, when used as first-line treatment for HER2-positive metastatic breast cancer, significantly prolonged progression-free survival (PFS). However, in the second and later line treatment of HER2-positive advanced or recurrent breast cancer, it has not settled whether it should be treated with pertuzumab plus trastuzumab plus chemotherapy or with trastuzumab plus chemotherapy. Eribulin mesylate is a non-taxane microtubule dynamics inhibitor that has been proved to prolong the overall survival of advanced or recurrent breast cancer patients compared with the treatment of physician9s choice. The benefit of eribulin in combination with trastuzumab for patients with locally recurrent or metastatic HER2-positive breast cancer has been reported. However, the efficacy and safety of eribulin in combination with pertuzumab and trastuzumab for advanced or recurrent HER2-positive breast cancer patients has not been reported. The purpose of this study is to evaluate the efficacy and safety of eribulin in combination with pertuzumab and trastuzumab as second and later line therapy for patients with advanced or recurrent HER2-positive breast cancer. Trial Design: This is a multicenter single arm phase 2 study for advanced or recurrent HER2-positive breast cancer patients who have experienced progression with anti-HER2 therapy. Patients received eribulin mesylate 1.4mg/m2 administered via intravenous (IV) infusion over 2 to 5 minutes on Days 1 and 8 each 21-day cycle and pertuzumab 840mg/kg IV and trastuzumab 8mg/kg IV over 90 minutes on Day 1 of Cycle 1. Thereafter eribulin mesylate 1.4mg/m2 and pertuzumab 420mg/kg and trastuzumab 6mg/kg was infused each 21-day cycle until disease progression or the appearance of toxic effects that could not be effectively managed. The primary endpoint is PFS of the combination therapy, based on local assessment of response using RECIST 1.1 criteria. Secondary endpoints are overall response rate (ORR), safety and tolerability. In addition, we examine PFS and safety according to the most recent treatment regimen. The study was conducted in accordance with the Declaration of Helsinki (2008), and the protocol and informed consent forms were submitted for approval to institutional review boards by the primary investigators. All patients provided written informed consent before undergoing any study-related procedures Statistical Method: All efficacy analyses were based primarily on the full analysis set (FAS), which included all patients who received over 1 dose(s) of study treatment. The PFS and ORR were calculated 95% confidence intervals (CIs). Treatment of 39 evaluable patients with the identified phase 2 doses will detect this difference with a power of 80% and alpha=5% (one-sided test). Accounting for a 10% invaluable rate and lead-in patients, a total of 43 patients will be enrolled on the study. Clinical trial information UMIN000014107. Citation Format: Hajime Abe, Shunji Kamigaki, Yoshifumi Komoike, Nobuki Matsunami, Yoshiaki Nakano, Kenji Tezuka, Junji Tsurutani, Jun Yamamura, Keiichi Yamazaki. A phase 2 study of eribulin in combination with pertuzumab and trastuzumab for advanced or recurrent human epidermal growth factor receptor 2 (HER2)-positive breast cancer (SONG-02) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT3-1-04.

Abstract P3-13-08: A phase I study of weekly nab-paclitaxel in combination with S-1 in patients with metastatic breast cancer

Background: S-1 is an oral, fixed dose combination product comprised of tegafur, a fluoropyrimidine prodrug of 5-fluorouracil (5-FU), and modulators of 5-FU metabolism, 5-chloro-2.4-dihydrooxypyridine and oteracil potassium. S-1 is designed to provide oral delivery of 5-FU, a pyrimidine analog antimetabolite antineoplastic agent, while reducing the rate of degradation of 5-FU and its conversion in the gastrointestinal tract to its toxic phosphorylated metabolite. S-1 is active in breast cancer and a variety of solid tumors. nab™-Paclitaxel (nab-P) is a treatment option in metastatic breast cancer (MBC) (approved 260 mg/m2 q3w dosing schedule), and high activity of nab-P with single-agent weekly administration at 100 mg/m2 has been investigated in MBC as well as other disease states. Since these two agents differed in their mechanisms of action and toxicity profiles, we sought to test their combined activity in a phase I study of nab-P/S-1 for HER2-negative MBC. The primary objectives of this study was to determine the maximum tolerated dose (MTD) and recommended dose (RD) of nab-P/S-1 in patients with HER-2 negative MBC. The secondary objective of this study was to evaluate pharmacokinetic (PK) parameters of both agents. Methods: Patients received treatment on 3 week cycles. S-1 was administered orally at a twice-daily dose of 65 mg/m2 (dose level 1 and 2b) or 80 mg/m2 (dose level 2a and 3) for 14 days and nab-P was administered as a 30-minute IV infusion at a dose of 100 mg/m2 on days 1 and 8 (dose level 1 and 2b) or 100 mg/m2 on days 1, 8 and 15 (dose level 2a and 3). Results: Fifteen patients were enrolled in this study; nab-P/S-1 was given as first-line chemotherapy for MBC in 9 patients, and as second-line therapy subsequent to an anthracycline-containing therapy in 6 patients. At dose level 3, one patient experienced a DLT. The observed DLT was delay of initiation of next cycle, G4 neutropenia had not recovered to G1/G0 in a period defined on the protocol. No cases of febrile neutropenia were observed. Judged from the status of dose reduction and the extension of drug holidays (cycle start delay), and the occurrence of non-severe adverse events after 2 cycles, the dose level was not increased above level 3. Seven patients were able to be treated 10 cycles or more. Additionally, three patients were able to be treated 20 cycles or more. Among of the 12 patients who had a measurable lesion which was evaluable by RECISTv1.1, the overall response rate was 50%, with 1 CR, 5 PR, 4 SD, and 1 PD. Pharmacokinetics of Paclitaxel and 5-FU in the combination therapy were comparable to those after single-agent administration of nab-P and S-1, respectively. Conclusion: Based on the results of this study, the RD was determined to be dose level 3 (S-1 80 mg/m2 twice daily plus nab-P 100 mg/m2 on days 1, 8, and 15). Since this combination therapy was generally well tolerated even with prolonged treatment, it is suggested that this combination therapy may be a promising treatment regimen in HER-2 negative MBC and merits further evaluation. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-13-08.