Time-series blood cytokine profiles correlate with treatment responses in triple-negative breast cancer patients

BACKGROUND

Triple-negative breast cancer (TNBC) is the most heterogeneous breast cancer subtype. Partly due to its heterogeneity, it is currently challenging to stratify TNBC patients and predict treatment outcomes.

METHODS

In this study, we examined blood cytokine profiles of TNBC patients throughout treatments (pre-treatment, during chemotherapy, pre-surgery, and 1 year after the surgery in a total of 294 samples). We analyzed the obtained cytokine datasets using weighted correlation network analyses, protein-protein interaction analyses, and logistic regression analyses.

RESULTS

We identified five cytokines that correlate with good clinical outcomes: interleukin (IL)-1α, TNF-related apoptosis-inducing ligand (TRAIL), Stem Cell Factor (SCF), Chemokine ligand 5 (CCL5 also known as RANTES), and IL-16. The expression of these cytokines was decreased during chemotherapy and then restored after the treatment. Importantly, patients with good clinical outcomes had constitutively high expression of these cytokines during treatments. Protein-protein interaction analyses implicated that these five cytokines promote an immune response. Logistic regression analyses revealed that IL-1α and TRAIL expression levels at pre-treatment could predict treatment outcomes in our cohort.

CONCLUSION

We concluded that time-series cytokine profiles in breast cancer patients may be useful for understanding immune cell activity during treatment and for predicting treatment outcomes, supporting precision medicine.

TRIAL REGISTRATION

The study has been registered with the University Hospital Medical Information Network Clinical Trials Registry ( http://www.umin.ac.jp/ctr/index-j.htm ) with the unique trial number UMIN000023162. The association Japan Breast Cancer Research Group trial number is JBCRG-22. The clinical outcome of the JBCRG-22 study was published in Breast Cancer Research and Treatment on 25 March 2021. https://doi.org/10.1007/s10549-021-06184-w .

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.

Current Challenges and Perspectives in Breast Cancer in Elderly Women: The Senologic International Society (SIS) Survey

Objective

Mammographic screening and management of breast cancer (BC) in elderly women are controversial and continue to be an important health problem. To investigate, through members of the Senologic International Society (SIS), the current global practices in BC in elderly women, highlighting topics of debate and suggesting perspectives.

Materials and Methods

The questionnaire was sent to the SIS network and included 55 questions on definitions of an elderly woman, BC epidemiology, screening, clinical and pathological characteristics, therapeutic management in elderly women, onco-geriatric assessment and perspectives.

Results

Twenty-eight respondents from 21 countries and six continents, representing a population of 2.86 billion, completed and submitted the survey. Most respondents considered women 70 years and older to be elderly. In most countries, BC was often diagnosed at an advanced stage compared to younger women, and age-related mortality was high. For this reason, participants recommended that personalized screening be continued in elderly women with a long life expectancy.In addition, this survey highlighted that geriatric frailty assessment tools and comprehensive geriatric evaluations needed to be used more and should be developed to avoid undertreatment. Similarly, multidisciplinary meetings dedicated to elderly women with BC should be encouraged to avoid under- and over-treatment and to increase their participation in clinical trials.

Conclusion

Due to increased life expectancy, BC in elderly women will become a more important field in public health. Therefore, screening, personalized treatment, and comprehensive geriatric assessment should be the cornerstones of future practice to avoid the current excess of age-related mortality. This survey described, through members of the SIS, a global picture of current international practices in BC in elderly women.

Abstract P5-09-01: Neoadjuvant hormonal therapy plus palbociclib versus hormonal therapy plus placebo in women with operable, hormone sensitive and HER2-negative primary breast cancer

Background: Early biologic response to endocrine therapy, such as changes in Ki67 labeling index (LI), has been suggested to predict long-term outcomes in hormone sensitive breast cancer. The addition of a CDK4/6 inhibitor to endocrine therapy has been shown to augment biological response in breast cancer. Pre-operative Endocrine Prognostic Index (PEPI) scores, generated based on post-treatment Ki67 LI, have been shown to predict patient outcomes. EndoPredict® is a multigene assay that predicts the risk of distant recurrence in patients with operable estrogen receptor (ER)-positive HER2-negative breast cancer. This study was conducted to evaluate the efficacy of the neoadjuvant endocrine therapy plus palbociclib versus neoadjuvant endocrine therapy plus placebo. Patients and Methods: This is a phase III randomized, double-blind study of neoadjuvant hormonal therapy plus palbociclib versus neoadjuvant hormonal therapy plus placebo in untreated pre/peri- and post-menopausal women with operable, hormone receptor-positive (ER and/or progesterone receptor), HER2-negative breast cancer. The other major inclusion criteria included tumor size ≥ 15mm, T1c-3N0-1, Ki67 LI ≥14% by central assessment, and no previous history of radiotherapy or systemic therapy for breast cancer. Patients were randomly assigned 1:1 to receive 16 weeks of hormonal therapy plus palbociclib or hormonal therapy plus placebo. Hormonal therapy consisted of letrozole for post-menopausal patients and tamoxifen plus LH-RH agonist for pre/peri-menopausal patients. The co-primary endpoints included PEPI score and EPclin Risk Score, a score combining EndoPredict® molecular score with clinical factors. These scores were sequentially analyzed on a modified intent-to-treat basis according to the gatekeeping procedure: if statistical significance was detected on the PEPI score, the statistical significance of EPclin Risk Score would be assessed. The sample size was 100 patients in each arm, which was calculated with < 5% type I error rate (two sided) and 80% power. Results: Between 16 July 2019 – 7 July 2021, 141 eligible patients were randomized from 25 participating institutes in Japan, Korea, Taiwan, Hong Kong and Australia. One hundred twenty-six patients completed the treatment duration and surgical samples were collected to evaluate endpoints. All randomized patients were evaluable for safety assessment. Randomization was well-balanced in terms of age, menopausal status and cancer stage. The proportion of patients who had a low, moderate, or high PEPI score was 15.2%, 50.0% and 34.8% in the hormonal therapy plus palbociclib arm and 13.3%, 55.0% and 31.7% in the hormonal therapy plus placebo arm, respectively. There was no statistically significant difference in PEPI score between two arms (one-sided p-value=0.563). The proportion of patients who had a high risk EPclin Risk Score seemed lower in the palbociclib arm than in the placebo arm (62.1% vs 68.3%) although hypothesis testing was not performed on EPclin Risk Score because statistical significance was not detected on the PEPI score. No new safety signals were found in the study. Permanent discontinuation from the study in association with adverse events was reported for 7 (9.7%) patients in the hormonal therapy plus palbociclib arm and for 0 patients in the hormonal therapy plus placebo arm. Conclusions: The addition of palbociclib to neoadjuvant hormonal therapy did not improve efficacy measured by PEPI score. In palbociclib arm, the rate of patients who had a high risk EPclin Risk Score after treatment was lower than in placebo arm. Translational researches are ongoing to analyze molecular changes by treatments. The role of chemotherapy after neoadjuvant therapy is under investigation. Clinical trial identification: NCT03969121 Funding: Pfizer Inc.

Citation Format: Takayuki Ueno, Louis W.C. Chow, Wonshik Han, Chiun Sheng Huang, G Bruce Mann, Satoshi Morita, Hironori Haga, Elham Fakhrejahani, Takayuki Kobayashi, Kenichi Inoue, Mariko Tokiwa, Hirofumi Suwa, Tomoyuki Aruga, Sachiko Minamiguchi, Yosuke Yamada, Yuko Tanabe, Masahiro Takada, Toshinari Yamashita, Hiroji Iwata, Chi-Feng Chung, Sachiko Takahara, Eriko Tokunaga, Shigeru Imoto, Eun Sook Lee, Yasuaki Sagara, Jee Hyun Kim, Richard H DeBoer, Hyun-Ah Kim, Hung Wen Lai, Ming-Feng Hou, Michelle White, Yoshiko Umeyama. Neoadjuvant hormonal therapy plus palbociclib versus hormonal therapy plus placebo in women with operable, hormone sensitive and HER2-negative primary breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-09-01.

Abstract P1-05-06: Establishment of the breast ultrasound support system using deep-learning system

Although the categorization of ultrasound using the Breast Imaging Reporting and Data System (BI-RADS) has become widespread worldwide, the problem of inter-observer variability remains. To maintain uniformity in diagnostic accuracy, we have developed a novel artificial intelligence (AI) system in which AI can distinguish whether a static image obtained using a breast ultrasound represents BI-RADS3 or lower, or BI-RADS4a or higher, to determine the medical management that should be performed on a patient whose breast ultrasound shows abnormalities. To establish and validate the AI system, a training dataset consisting of 4,028 images containing 5,014 lesions and a test dataset consisting of 3,166 images containing 3,656 lesions were collected and annotated. We selected a setting that maximized the area under the curve (AUC) and minimized the difference in sensitivity and specificity by adjusting the internal parameters of the AI system, achieving an AUC, sensitivity, and specificity of 0.95, 90.0%, and 88.5%, respectively. Furthermore, based on 30 images extracted from the test data, the diagnostic accuracy of 20 clinicians and the AI system was compared, and the AI system was found to be significantly superior to the clinicians (McNemar test, p < 0.001). Then, we conducted a trial to introduce the system for use in clinical practice. Physicians reviewed the images and determined whether they were BI-RADS3 or lower, or BI-RADS4a or higher. Next, the classification was performed again for the same images concerning the AI diagnosis. At this time, the initial judgment was allowed to be overturned. We checked whether there was any difference in the diagnostic accuracy, sensitivity, and specificity before and after reviewing to the AI diagnosis. Reviews by 24 physicians were evaluated: 4 Japanese Breast Cancer Society breast specialists, 5 non-specialists and physicians with experience treating more than 40 cases of breast cancer, and 15 non-specialists and physicians with no experience treating more than 40 cases of breast cancer. The average rate of accuracy before confirming the AI diagnosis increased to 73.1% after confirming the AI diagnosis (p=0.00548), compared to 69.3% on average before the AI diagnosis. Compared to practice experience, the accuracy increased from an average of 77.1% to 79.6% for the 9 physicians who were breast specialists or who had treated 40 or more cases of breast cancer. For the 15 physicians with less than 40 breast cancer cases, the average rate of accuracy increased from 64.7% to 69.2%. Furthermore, sensitivity increased significantly to an average of 99.7% after reviewing of the AI diagnosis from an average of 88.8% prior to reviewing the AI-diagnosis.(p< 0.01). Specificity increased from an average of 62.4% to 63.8% (p=0.433) after reviewing AI diagnosis. We showed that our AI system, when applied to clinical practice and used by physicians, contributes to the improvement of diagnostic accuracy. Our results indicated that our AI diagnostic system was sufficiently accurate to be used in the clinical practice.

Citation Format: Erina Odani, Tetsu Hayashida, masayuki kikuchi, Aiko Nagayama, tomoko seki, maiko takahashi, Akiko Matsumoto, Takeshi Murata, Rurina Watanuki, Takamichi Yokoe, Ayako Nakashoji, Hinako Maeda, Tatsuya Onishi, Sota Asaga, Takashi Hojo, Hiromitsu Jinno, Keiichi Sotome, Akira Matsui, Akihiko Suto, Shigeru Imoto, Yuko Kitagawa. Establishment of the breast ultrasound support system using deep-learning system [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-05-06.

Abstract P1-01-05: Adjuvant S-1 plus endocrine therapy for estrogen receptor-positive, HER2-negative, primary breast cancer: updated overall survival analysis from the POTENT trial

Background: The Phase III POTENT trial demonstrated an improvement in invasive disease-free survival (IDFS) by the addition of S-1, an oral fluoropyrimidine, to adjuvant endocrine therapy in patients with ER-positive/HER2-negative early breast cancer. Because the trial was terminated at the interim analysis as the primary endpoint was met, the result of the overall survival (OS) remains immature. Methods: This multicenter observational study aimed to investigate the survival outcomes of patients who participated in the POTENT trial, in which patients with stage I to IIIB ER-positive, HER2-negative breast cancer without protocol-defined low-risk features received adjuvant endocrine therapy alone or with S-1 for 1 year. Of the full analysis set (FAS) of the POTENT trial (N=1930), patients who withdrew the consent or whose institutions terminated the contract were excluded from this study. The primary endpoint was OS. Secondary endpoints were IDFS and distant recurrence-free survival (DRFS). Results: A total of 337 patients (17%) in the POTENT study were excluded from this analysis (eight patients withdrew consent and 329 patients for institutions whose contract had been terminated). A total of 1593 patients were included in this study (803 in the endocrine therapy alone group and 790 in the endocrine therapy plus S-1 group). The median follow-up was 77.5 months (IQR: 68.8–86.0). The median duration of endocrine therapy was 71 and 69 months in the endocrine therapy alone and endocrine therapy plus S-1 groups, respectively. The patient characteristics were well balanced between the treatment groups, except for the number of lymph nodes involved. The endocrine therapy alone group included more patients with four or more positive nodes than the endocrine therapy plus S-1 group (12% vs. 9%, P=0.01). 58 (7%) patients in the endocrine therapy alone group and 51 (6%) in the endocrine therapy plus S-1 group died (HR 0.89, 95%CI: 0.61–1.30, P=0.54). The 5-year overall survival estimate was 94.7% (95%CI: 92.9–96.1%) in the endocrine therapy alone group and 95.6% (95%CI: 93.8–96.8%) in the endocrine therapy plus S-1 group. IDFS events were observed in 166 patients (21%) in the endocrine therapy alone group and in 135 patients (17%) in the endocrine therapy plus S-1 group (HR 0.80, 95%CI: 0.64–1.01). DRFS events occurred in 123 patients (15%) in the endocrine therapy alone group and in 91 patients (12%) in the endocrine therapy plus S-1 group (HR 0.74, 95%CI: 0.56–0.97). Conclusions: In this observational study, data from 337 patients (17%) were missing from the FAS of the POTENT trial. Both the endocrine therapy alone group and endocrine therapy plus S-1 groups showed favorable OS, and OS was similar between the treatment groups. The benefit of IDFS and DRFS by the addition of S-1 to endocrine therapy were maintained.

Citation Format: Masahiro Takada, Shigehira Saji, Takayuki Ueno, Norikazu Masuda, Hiroshi Ishiguro, Takanori Ishida, Toshiaki Saeki, Shigeru Imoto, Shinji Ohno, Hiroji Iwata, Tomoharu Sugie, Kenjiro Aogi, Hirofumi Mukai, Shin Takayama, Nobuaki Sato, Yuichiro Kai, Masahiro Kitada, Rikiya Nakamura, Yutaka Matsuyama, Masakazu Toi. Adjuvant S-1 plus endocrine therapy for estrogen receptor-positive, HER2-negative, primary breast cancer: updated overall survival analysis from the POTENT trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-01-05.

Abstract P4-02-25: Analysis of prognosis in different subtypes of invasive lobular carcinoma using a National Cancer Database Breast Cancer Registry of Japan

[Introduction] Invasive lobular carcinoma (ILC) has different pathological and clinical features from invasive ductal carcinoma (IDC). ILC has more likely to be hormone receptor (HR) positive, and several studies reported that the prognosis of ILC was better than IDC. However, ILC also has different prognosis according to the subtypes as IDC does, and better prognosis of ILC might depend on their high HR positivity. Additionally, there are many reports that chemotherapy (CT) does not improve the prognosis of ILC due to the high positivity of HR. Therefore, we compared the prognosis of ILC and IDC in the same subtypes and considered necessity of CT for luminal ILC. ILC usually constitutes small population of invasive breast cancer. Thus, we have planed the analysis by using the Breast Cancer Registry (BCR) run on the National Cancer Database (NCD) in Japan. [Methods] 318,338 breast cancer patients were registered in BCR between 2004 and 2012. We selected 250,736 patients who were diagnosed as ILC or IDC. Patients with distant metastasis, those who did not receive surgery, and those who received preoperative therapy, and those who had bilateral breast cancer were excluded, and it resulted in 207,428 patients. Of these cases, the cases with 10-year follow-up data were 136,654, and we examined 5,705 ILC and 130,949, IDC. Because it was presumed that there are differences in pathological and clinical characteristics between ILC and IDC, we have planned to make the matched cohorts by using exact matching for comparing their prognosis. To evaluate the prognosis of each subtype, we compared DFS and OS for IDC and ILC in each subtype. To evaluate the effect of CT in luminal ILC, we corrected the data of luminal ILC with pT2N0M0 or pT1-2N1M0 patients and compared DFS and OS between endocrine therapy (ET) only group and ET+CT group. DFS was defined as the time from surgery to local or distant recurrence or death from any cause. OS was defined as the time between the surgery and the death from any cause. Peason’s Chi squared test was used to identify the characteristics. Survival curves were constructed by Kaplan-Meier method and were compared by log-rank test. [Results] We made the matched cohort by using exact matching and we identified 5,633 ILC and 5,633 IDC for prognosis analysis. In overall subtypes, the 10-year DFS of ILC was poor than those of IDC (76.56% vs 79.14%, p=0.04). In the analysis by each subtype, there was no statistical difference in DFS for luminal HER2, HER2, and TN cohorts, however luminal ILC had statistically significant poor DFS than luminal IDC (78.04% vs 81.17%, p< 0.01). The analysis of 10-year OS showed similar results, and there were no differences in the OS of luminal HER2, HER2 and TN cohorts between ILC and IDC. However, ILC had worse OS than IDC in luminal cohort (85.95% vs 89.13%, p< 0.01). To evaluate the effect of CT in luminal ILC, we made the matched cohort and we identified 95 luminal IDC and 95 luminal ILC in pT2N0 cohort, and 83 luminal IDC and 83 luminal ILC in pT1-2N1 cohort for the analysis. In pT2N0 cohort, the 10-year DFS was 82.12% in ET+CT group and 87.35% in ET only group (p=0.99). The OS of the ET+CT and the ET only group was 93.48% and 94.04% (p=0.88). In pT1-2N1 cohort, the ET only group had 54.17% and the ET+CT group had 77.03% of DFS (p=0.34). The OS in the ET only group and the ET+CT group was 61.96% and 94.81% (p=0.01). [Discussion] Although luminal HER2, HER2 and TN cohorts had no differences in prognosis between ILC and IDC, luminal ILC had a poor prognosis than luminal IDC. Therefore, luminal ILC needs stronger approach to improve their prognosis. And it was suggested that chemotherapy is effective for recurrent high-risk luminal ILC such as those with positive lymph node metastasis. [Conclusion] ILC had worse prognosis than IDC in luminal cohort, however it was comparable in luminal HER2, HER2, TN cohorts. A new strategy of treatments for luminal ILC might be needed to improve their prognosis.

Citation Format: Yayoi Adachi, Sota Asaga, Hiraku Kumamaru, Yutaka Yamamoto, Shigeru Imoto, Hiromitsu Jinno. Analysis of prognosis in different subtypes of invasive lobular carcinoma using a National Cancer Database Breast Cancer Registry of Japan [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-02-25.

Survival advantage of locoregional and systemic therapy in oligometastatic breast cancer: an international retrospective cohort study (OLIGO-BC1)

BACKGROUND

An international retrospective cohort study was conducted to clarify the survival advantage of combination therapy with locoregional and systemic therapy (ST) in oligometastatic breast cancer (BC).

METHODS

Patients with oligometastatic BC diagnosed from 2007 to 2012 were enrolled in center hospitals in China, Korea and Japan. It was defined as a low-volume metastatic disease at up to five sites and not necessarily in the same organ. Cases with brain, pleural, peritoneal and pericardial metastases were excluded. The primary endpoint was overall survival (OS) from the initial diagnosis of oligometastases. OS was summarized using the Kaplan-Meier method. A multivariable Cox regression model was used to estimate the hazard ratio (HR) for clinicopathological factors.

RESULTS

Among 1,295 cases registered from February 2018 to May 2019, 932 remained for analysis after the exclusion of unavailable cases and locoregional recurrence. One metastatic site was found in 400 cases, 2 in 243, 3 in 130, 4 in 86 and 5 in 73. At the median follow-up of 4.5 years, 5-year OS was 54.7% and 39.7% for 321 cases in the combination therapy group and 611 cases in the ST group, respectively. An adjusted HR was 0.66 (95% confidence interval: 0.55, 0.79). Some types of ST without chemotherapy alone, younger age, ECOG performance status 0, early-stage BC, non-triple negative subtype, fewer metastatic sites and longer duration of surgery to relapse were significantly favorable prognostic factors.

CONCLUSION

Combination therapy may be considered for longer survival under some conditions in oligometastatic BC.

Characteristics of female breast cancer in japan: annual report of the National Clinical Database in 2018

Information regarding patients who were treated for breast cancer in 2018 was extracted from the National Clinical Database (NCD), which is run by Japanese physicians. This database continues from 1975, created by the Japanese Breast Cancer Society (JBCS). A total of 95,620 breast cancer cases were registered. The demographics, clinical characteristics, pathology, surgical treatment, adjuvant chemotherapy, adjuvant endocrine therapy, and radiation therapy of Japanese breast cancer patients were summarized. We made comparisons with other reports to reveal the characteristics of our database. We also described some features in Japanese breast cancer that changed over time. The unique characteristics of breast cancer patients in Japan may provide guidance for future research and improvement in healthcare services.

Establishment of a deep-learning system to diagnose BI-RADS4a or higher using breast ultrasound for clinical application

Although the categorization of ultrasound using the Breast Imaging Reporting and Data System (BI‐RADS) has become widespread worldwide, the problem of inter‐observer variability remains. To maintain uniformity in diagnostic accuracy, we have developed a system in which artificial intelligence (AI) can distinguish whether a static image obtained using a breast ultrasound represents BI‐RADS3 or lower or BI‐RADS4a or higher to determine the medical management that should be performed on a patient whose breast ultrasound shows abnormalities. To establish and validate the AI system, a training dataset consisting of 4028 images containing 5014 lesions and a test dataset consisting of 3166 images containing 3656 lesions were collected and annotated. We selected a setting that maximized the area under the curve (AUC) and minimized the difference in sensitivity and specificity by adjusting the internal parameters of the AI system, achieving an AUC, sensitivity, and specificity of 0.95, 91.2%, and 90.7%, respectively. Furthermore, based on 30 images extracted from the test data, the diagnostic accuracy of 20 clinicians and the AI system was compared, and the AI system was found to be significantly superior to the clinicians (McNemar test, p < 0.001). Although deep‐learning methods to categorize benign and malignant tumors using breast ultrasound have been extensively reported, our work represents the first attempt to establish an AI system to classify BI‐RADS3 or lower and BI‐RADS4a or higher successfully, providing important implications for clinical actions. These results suggest that the AI diagnostic system is sufficient to proceed to the next stage of clinical application.

Prognostic impact of postoperative radiotherapy in patients with breast cancer and with pT1-2 and 1-3 lymph node metastases: A retrospective cohort study based on the Japanese Breast Cancer Registry

AIM

Postmastectomy radiotherapy (PMRT) is the standard treatment for locally advanced breast cancer. However, the effectiveness of PMRT in patients with pT1-2 and N1 tumours remains controversial. Therefore, this study aimed to determine the prognostic impact of PMRT in patients with breast cancer and with pT1-2 and 1-3 lymph node metastases.

METHODS

Using data from the Japanese National Clinical Database from 2004 to 2012, we evaluated the association of PMRT with locoregional recurrence (LRR), any recurrence, and mortality. We enrolled patients who had undergone mastectomy and axillary node dissection and were diagnosed with pT1-2 and N1. We compared clinicopathological factors and prognosis between patients who received (PMRT group) and those who did not receive (No-PMRT group) PMRT.

RESULTS

Among 8914 patients enrolled, 492 patients belonged to the PMRT group and 8422 to the No-PMRT group. The median observation time was 6.3 years. There was no significant difference in the incidences of LRR (4.0% versus 5.0%, P = 0.61), recurrence (13.8% versus 11.8%, P = 0.23) and breast cancer death (6.0% versus 4.3%, P = 0.08) at 5 years between the groups. Multivariable analysis revealed that LRR was significantly associated with tumour size, number of node metastases and triple-negative subtype but not with PMRT.

CONCLUSIONS

The LRR rate in the No-PMRT group was 5.0% at 5 years among patients with T1-2 and N1. PMRT did not significantly influence LRR in patients with T1-2 and N1. However, PMRT administration should be tailored considering the individual risks of tumour size, 3 node metastases and triple-negative subtype.

Observational study of axilla treatment for breast cancer patients with 1 to 3 positive micrometastases or macrometastases in sentinel lymph nodes

e12576

Background: From the results of ACOSOG Z0011, IBCSG23-01 and AMAROS trials, axilla surgery in node-positive breast cancer (BC) tends to be less invasive with sentinel node biopsy (SNB) followed by adjuvant therapy and regional node irradiation (RNI). However, optimized axilla treatment including SNB without RNI is still debated. The Japanese Society for Sentinel Node Navigation Surgery conducted a multi-institutional prospective cohort study to compare SNB with SNB followed by axillary lymph node dissection (ALND) in cases with positive-sentinel lymph nodes (SLN)(UMIN No. 000011782, Jpn J Clin Oncol, p.876-9, 2014). Methods: Female BC patients with cT1-3N0-1M0 were eligible. When 1 to 3 positive micrometastases or macrometastases in SLN were confirmed by histological or molecular diagnosis, SNB alone or additional ALND had been decided by physician’s discretion. Primary chemotherapy before or after SNB was acceptable for registration. Lymph node sampling was also allowed in the SNB group. Cases with bilateral BC, isolated tumor cells only in SLN, past history of invasive cancer within 5 years at the registration were ineligible. The primary endpoint was the 5-year recurrence rate of regional node (RN) in the SNB group. The secondary endpoint was overall survival (OS). We planned to collect 240 patients to reject that the 5-year recurrence rate of RN was more than 10% assuming the rate 5%. To compare the SNB group and ALND group, the propensity score matching (PSM) was performed. Matching variables were initial treatment, metastatic size and numbers of SLN, clinical stage, age, body mass index, menopausal status, family history, past history of invasive cancer, breast surgery. Results: Eight-hundred eighty cases had been registered between 2013 and 2016. In the 871 eligible cases, 308 cases were the SNB group. At the median follow-up of 6.3 years, 5-year recurrence rate of RN was 2.7% [95% confidence interval, 1.4% to 5.4%] and 5-year OS was 97.6% [94.9% to 98.8%]. After PSM, 209 cases were matched in the SNB and ALND group. Among them, 343 cases (82%) received operation at initial treatment. Partial and total mastectomy was performed in 225 (54%) and 193 cases (46%), respectively. One-positive SLN was recorded in 366 cases (88%), 2 in 48 (11%) and 3 in 4 (1%). Macrometastases and micrometastases in SLN were diagnosed in 271 (65%) and 147 cases (35%), respectively. Three-hundred seventy-six cases (90%) belonged to luminal-like subtype. RNI was underwent in 42 cases (20%) of the SNB group and 13 cases (6%) of the ALND group. Five-year recurrence rate of RN was 2.1% [0.8% to 5.5%] and 2.0% [0.8% to 5.3%] for the SNB and ALND group, respectively. Conclusions: Our series suggests that RNI is not necessary for regional control in cases with 1 to 3 positive SLN. In conclusion, SNB alone is acceptable in cases with fewer metastatic SLN. Clinical trial information: UMIN No. 000011782.

Abstract P3-19-27: Prognostic impact of postmastectomy radiation therapy in breast cancer patients with T1, 2 and 1-3 lymph nodes from Japan Breast Cancer Registry

Background: The effectiveness of postmastectomy radiation therapy (PMRT) in patients with pT1-2 and 1-3 lymph node metastases remains controversial in the current clinical practice. Patients and Methods: Using data from the Japanese National Clinical Database (NCD) between 2004 and 2012, we evaluated the association of PMRT with recurrence and breast cancer mortality. Patients who underwent mastectomy and axillary node dissection and were diagnosed as pT1-2 with 1-3 node metastases were enrolled. Patients who received presurgical treatment were excluded. We compared clinicopathological factors and prognosis between patients with PMRT (PMRT group) and without PMRT (No-PMRT group). The primary endpoint was the locoregional recurrence (LRR) rate. We also assessed the impact of PNRT according to the number of node metastasis. We considered death as a competing event.Results: Among 8,914 enrolled patients, PMRT group included 492 patients (5.5%), and No-PMRT group did 8,422 patients (94.5%). Patients of PMRT group were younger, had a larger tumor and more node metastases than patients of No-PMRT group. There is no difference in breast cancer subtype between two groups. A median observation time was 6.3 years (arnge 5.0- 9.7 years). There was no significant difference between PMRT group and No-PMRT group in LRR rate (4.0% v.s. 5.0%, P=0.61), any recurrence rate (13.8% v.s. 11.8%, P=0.23), and breast cancer mortality rate (6.0% v.s. 4.3%, P=0.08) at 5 years. Multivariate analysis revealed no significant association between PMRT and LRR while LRR is significantly associated with tumor size larger than 2cm (hazard ratio [HR] 1.48, 95%confidence interval [CI] 1.21-1.82 in 2.1-3.5cm, HR 1.97, 95%CI 1.53-2.53 in 3.6-5.0cm) 2 (HR1.25 95%CI 1.02-1.52) or 3 node metastases (HR 1.40. 95%CI 1.10-1.79), triple-negative subtype (HR 1.64, 95%CI 1.21-2.23). According to the number of node metastasis, LRR in PMRT group was significantly lower than that of No-PMRT group among patients with 3 node metastases (2.6% v.s. 7.0%, P=0.03) while there was no significant difference between two groups among patients with 1 or 2 node metastases. In multivariate analysis, HR was relatively lower in patients with 3 node metastases (HR 0.37, 95%CI 0.11 -1.19) comparing to the patients with 1 (HR 0.97, 95%CI 0.53- 1.77) or 2 node metastases (HR 1.06, 95%CI 0.53-2.09). Tumor size was significantly associated with LRR in patients with 1 (HR 1.51, 95%CI 1.13- 2.02) or 2 node metastases (HR 1.45, 95%CI 1.02-2.07). Chemotherapy was significantly associated with LRR among the patients with 2 (HR 0.57, 95%CI 0.40-0.82) or 3 node metastases (HR 0.4, 95%CI 0.25-0.65).Conclusions: Among the patients with T1-2 and 1-3 node metastases, PMRT was not associated with a reduced risk of LRR in the latest Japanese cohort. Advances in systemic therapy might the main reason to reduce the LRR rate rather than PMRT in this population. The administration of PMRT should be tailored considering the individual risks of LRR, such as 3 node metastases.

Citation Format: Akimitsu Yamada, Naoki Hayashi, Hiraku Kumamaru, Masayuki Nagahashi, Shiori Usune, Hiroaki Miyata, Takashi Ishikawa, Kazutaka Narui, Itaru Endo, Shigeru Imoto, Shinji Ohno, Hiromitsu Jinno. Prognostic impact of postmastectomy radiation therapy in breast cancer patients with T1, 2 and 1-3 lymph nodes from Japan Breast Cancer Registry [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-27.

Living with COVID-19: mass gatherings and minimizing risk

During the COVID-19 pandemic, it has been important to both minimize the risk of infection and restore daily life. As a typical example, mass gathering events, such as sporting events, are gradually becoming more common, thanks to the measures taken to contain COVID-19. Some pilot studies have been launched at governments' initiative to investigate the risk of infection without measures such as face masks and physical distancing at mass gathering events, but the ethics of these studies should be carefully considered. On the other hand, it is still beneficial to implement infection control measures at mass gathering events and, in parallel, to estimate the risk of infection with measures in place, especially under a lack of vaccination progress or the spread of mutant strains possibly resistant to vaccines. To help improve compliance with measures taken by spectators and organizers and to ensure their effectiveness, we have conducted quantitative evaluations of the implementation of such measures by monitoring CO2 concentrations, assessing the proportion of people wearing face masks and analysing human flow at the event. This approach allows us to share our observations with stakeholders and participants, enabling us to protect the culture of mass gathering events, minimize the risk of infection and restore a sense of well-being in daily life.

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.

Favorable prognostic factors of oligometastatic breast cancer: A subset analysis of OLIGO-BC1

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Background: The Federation of Asian Clinical Oncology (FACO) conducted an international retrospective cohort study of oligometastatic breast cancer (BC) (OLIGO-BC1) (UMIN No.000030047). At ASCO2020, we demonstrated that locoregional and systemic therapy prolonged overall survival (OS) for patients with oligometastatic BC, especially for cases with some type of systemic therapy, younger age, ECOG performance status 0, stage I BC, non-triple negative subtype, fewer metastatic sites, local recurrence and longer disease-free interval from a multivariate analysis (#1025). Although BC is heterogeneous and a retrospective dataset has many kinds of bias, we attempted a subset analysis based on intrinsic subtype and several prognostic factors. Methods: Oligometastatic BC patients diagnosed from 2007 to 2012 were registered from CSCO, KSMO and JSCO. OS period was measured from the diagnosis of oligometastases to the latest follow-up. ER, PgR and HER2 status were determined by immunohistochemistry and/or in situ hybridization. A hazard ratio (HR) of OS was calculated by using a univariate analysis. Results: In 1200 eligible cases, one oligometastatic site was found in 578 cases, two in 289, three in 154, four in 102 and five in 77. Bone metastases were recorded in 301 cases, visceral metastases in 387, locoregional recurrence in 25, local recurrence in 83 and multiple metastatic sites in 404. Luminal subtype was recorded in 526 cases (44%), luminal-HER2 in 189 (16%), HER2 in 154 (13%), triple-negative in 166 (14%) and others in 165 (13%). In any subtype, locoregional and systemic therapy and ECOG performance status 0 were beneficial for OS. Stage I BC, one oligometastatic site and longer disease-free interval were also related to favorable prognosis in luminal and HER2 subtype. However, triple-negative subtype had no survival advantage with these 3 factors. On the other hand, pathological negative or micrometastatic lymph nodes at primary BC and one oligometastatic site of lymph node, lung, liver and bone were favorable prognostic factors. In addition, cases treated locally with surgical resection and conventional radiation therapy were expected to prolong OS. Discussions: Locoregional therapy for oligometastatic BC may be considered in luminal and HER2 subtype with some conditions. As reported in ASCO2020, triple-negative BC should be managed with systemic therapy. Conclusions: Oligometastatic BC is diagnosed by chance, but some cases seem to survive with multidisciplinary treatment. It is worthwhile to consider locoregional therapy in oligometastatic BC after evaluating favorable prognostic factors.

Long-term results of fluorescence and indigo carmine blue dye-navigated sentinel lymph node biopsy

BACKGROUND

Sentinel lymph node biopsy is widely applied for the management of clinically node-negative breast cancer, and a radioisotope with a blue dye are most often used as tracers. Fluorescence of indocyanine green could also potentially be used as tracer. This study aimed to demonstrate the long-term survival results of fluorescence-guided sentinel lymph node biopsy.

PATIENTS AND METHODS

Patients with clinically node-negative breast cancer who underwent surgery as initial treatment were included in this study. Both fluorescence of indocyanine green and indigo carmine blue dye were used as tracers. Axillary lymph node dissection was omitted unless metastasis was pathologically proven in sentinel nodes. Breast cancer recurrence and death were recorded and prognostic factors were identified using disease-free survival and overall survival data.

RESULTS

A total of 565 patients were analyzed. There were 14 (2.5%) patients whose sentinel nodes could not be identified, yielding an identification rate of 97.5%. Axillary dissection was performed in 90 patients. Forty-three recurrences including 6 ipsilateral axilla recurrence and 13 deaths were observed during the median 83 months of follow-up period. Seven-year disease-free and overall survival were 92.4% and 97.3%, respectively. Multivariate analyses demonstrated that pre-menopausal status and invasive lobular carcinoma were significant unfavorable prognostic factors of disease-free survival. Half of ipsilateral axilla recurrences occurred within 5 years after surgery and these recurrences were correlated with inappropriate adjuvant therapy.

CONCLUSION

Fluorescence-guided sentinel lymph node biopsy demonstrated favorable prognostic results and could be alternative to the radioisotope for clinically node-negative breast cancer.

Breast Cancer Management During the COVID-19 Pandemic: The Senologic International Society Survey

Objective

In early 2020, the spread of coronavirus disease-2019 (COVID-19) led the World Health Organization to declare this disease a pandemic. Initial epidemiological data showed that patients with cancer were at high risk of developing severe forms of COVID-19. National scientific societies published recommendations modifying the patients' breast cancer (BC) management to preserve, in theory, quality oncologic care, avoiding the increased risk of contamination. The Senology International Society (SIS) decided to take an inventory of the actions taken worldwide. This study investigates COVID-19-related changes concerning BC management and analyzes the will to maintain them after the pandemic, evaluating their oncological safety consequences.

Materials and Methods

SIS network members participated in an online survey using a questionnaire (Microsoft^® Forms) from June 15^th to July 31^st, 2020.

Results

Forty-five responses from 24 countries showed that screening programs had been suspended (68%); magnetic resonance imagines were postponed (73%); telemedicine was preferred when possible (71%). Surgeries were postponed: reconstructive (77%), for benign diseases (84%), and in patients with significant comorbidities (66%). Chemotherapy and radiotherapy protocols had been adapted in 28% of patients in both. Exception for telemedicine (34%), these changes in practice should not be continued.

Conclusion

The SIS survey showed significant changes in BC's diagnosis and treatment during the first wave of the COVID-19 pandemic, but most of these changes should not be maintained. Indeed, women have fewer severe forms of COVID-19 and are less likely to die than men. The risk of dying from COVID-19 is more related to the presence of comorbidities and age than to BC. Stopping screening and delaying treatment leads to more advanced stages of BC. Only women aged over 65 with BC under treatment and comorbidities require adaptation of their cancer management.

Abstract PS7-79: Clinicopathological characteristics of male breast cancer in Japan from the national clinical database

Background: Male breast cancer is a rare cancer. According to the Japanese Breast Cancer Society's Breast Cancer Registry, there were 613 cases of male breast cancer in 2016. It is only 0.6% of all cases of breast cancer incidence. Because of its rarity, there have been no comprehensive studies on characteristics of male breast cancer in Japan. Therefore, there has been few specific treatments developed for male breast cancer. In this study, we investigated the prevalence and clinicopathological characteristics of male breast cancer in Japan, using the most reliable domestic data, the National Clinical Database (NCD). NCD is a database that collects medical information on diseases, treatments, and surgeries in Japan. In collaboration and cooperation with academic societies and academic organizations, NCD maintain and manage the collected data. The data are used in domestic research to evaluate the standards of medical care and support clinical research. This study conducted with a collaboration with NCD and the registration committee of Japan Breast Cancer Society. Materials and Methods: Clinicopathological data were collected from all breast cancer patients in NCD between 2012 and 2018. We compared the male and female breast cancer patients on age, stage, surgical technique, estrogen receptor (ER) status, progesterone receptor (PgR) status, HER2 expression, family history, comorbidities, and systemic treatment history. Results: 3,780 male and 590,636 female breast cancers were enrolled in the study. The median age was 71 years for men (56-87 years, 5-95 percentile) and 61 years for women (40-83 years). The clinical stage in males was 7.2% in stage 0, 36.3% in stage I, 33.4% in stage II, 12.4% in stage III, 1.4% in Stage IV and 4.5% in unknown, respectively. In females, 13.0%, 41.6%, 31.4%, 6.6%, 1.3% and 2.3%, respectively. Breast conserving surgery (BCS) was performed for 14.6% in men 46.2% in women. BCS rate in men is more frequent in Japan compared to in western countries (Ann Oncol. 2018 Feb 1;29(2):405-417). Hormone receptor-positive (HR+; ER+ and/or PgR+) HER2-negative (HER2-) was 88%, HR+HER2-positive (HER2+) was 8%, HR-HER2+ was 1% and HR-HER2- was 3% in men. 74%, 10%, 6% and 10% in women, respectively. The distribution of subtypes in men is similar to western countries. Comorbidity was reported in 42.3% of men and 66.8% of women. Hypertension, diabetes, cardiac disorder and cerebrovascular disorder were more common in men. Conclusion: Male breast cancer is 0.6% of all breast cancer in Japan. Stage III and HR+ is more frequent in male and its tendency is similar to data from western countries. BCS is underwent more frequent in Japan than in western countries.

Citation Format: Akihiko Shimomura, Masayuki Nagahashi, Hiraku Kumamaru, Yutaka Yamamoto, Hiromitsu Jinno, Shigeru Imoto, Registration Committee of Japan Breast Cancer Society. Clinicopathological characteristics of male breast cancer in Japan from the national clinical database [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-79.

Adjuvant S-1 plus endocrine therapy for oestrogen receptor-positive, HER2-negative, primary breast cancer: a multicentre, open-label, randomised, controlled, phase 3 trial

BACKGROUND

Oral fluoropyrimidines, such as S-1, have been shown to have a role in controlling disease progression in metastatic breast cancer. We examined adjuvant treatment with S-1 in patients with oestrogen receptor (ER)-positive and HER2-negative primary breast cancer.

METHODS

We did a multicentre, open-label, randomised, controlled, phase 3 trial in 139 sites (137 hospitals and two clinics). Eligible patients were women aged 20-75 years with histologically diagnosed stage I to IIIB invasive breast cancer (intermediate to high risk of recurrence). Patients were temporarily registered at participating institutions and biopsy or surgical samples were collected and sent for central pathological assessment. Patients received 5 years of standard adjuvant endocrine therapy (selective oestrogen receptor modulators with or without ovarian suppression and aromatase inhibitors) with or without 1 year of S-1. Oral S-1 80-120 mg/day was administered twice a day for 14 days with 7 days off. Randomisation (1:1) using the minimisation method was done with six stratification factors (age, axillary lymph node metastasis at surgery or sentinel lymph node biopsy, preoperative or postoperative (neoadjuvant or adjuvant) chemotherapy, preoperative endocrine therapy, proportion of ER-positive cells, and study site). The primary endpoint was invasive disease-free survival, in the full analysis set (all randomly assigned patients, excluding those with significant protocol deviations). The safety analysis set consisted of all patients who received at least one dose of study treatment. Here, we report the results from the interim analysis at the data cutoff date Jan 31, 2019. This trial is registered with Japan Registry of Clinical Trials, jRCTs051180057, and the University hospital Medical Information Network, UMIN000003969.

FINDINGS

Between Feb 1, 2012, and Feb 1, 2016, 1930 patients were enrolled in the full analysis set, 957 (50%) received endocrine therapy plus S-1 and 973 (50%) received endocrine therapy alone. Median follow-up was 52·2 months (IQR 42·1-58·9). 155 (16%) patients in the endocrine therapy alone group and in 101 (11%) patients in the endocrine therapy plus S-1 group had invasive disease-free survival events (hazard ratio 0·63, 95% CI 0·49-0·81, p=0·0003). As the primary endpoint was met at interim analysis, the trial was terminated early. The most common grade 3 or worse adverse events were decreased neutrophil count (72 [8%] of 954 patients in the endocrine therapy plus S-1 group vs seven [1%] of 970 patients in the endocrine therapy alone group), diarrhoea (18 [2%] vs none), decreased white blood cells (15 [2%] vs two [<1%]), and fatigue (six [<1%] vs none). Serious adverse events were reported in nine (1%) of 970 patients in the endocrine therapy alone group and 25 (3%) of 954 patients in the endocrine therapy plus S-1 group. There was one (<1%) possible treatment-related death in the endocrine therapy plus S-1 group due to suspected pulmonary artery thrombosis.

INTERPRETATION

These data suggest that this combination of S-1 with endocrine therapy could be a potential treatment option for this intermediate and high-risk group of patients with ER-positive, HER2-negative primary breast cancer.

FUNDING

Public Health Research Foundation (Japan), Taiho Pharmaceutical.

Breast cancer survival among Japanese individuals and US residents of Japanese and other origins: a comparative registry-based study

BACKGROUND

Breast cancer survival outcomes vary across different ethnic groups. We clarified the differences in clinicopathological and survival characteristics of breast cancer among Japanese, US residents with Japanese origin (USJ), and US residents with other origins (USO).

METHOD

Using Surveillance, Epidemiology, and End Results (SEER) 18 dataset and Japanese Breast Cancer Society (JBCS) registry, we included patients first diagnosed with breast cancer between 2004 and 2015. We categorized the patients into three groups based on the database and the recorded ethnicity: Japanese (all those from the JBCS registry), USJ (those from SEER with ethnicity: Japanese), and USO (those from SEER with ethnicity other than Japanese). Excluding patients diagnosed after 2012, stage 0, and 4 patients, we examined the overall survival (OS) and breast cancer-specific survival (BCSS) using the Kaplan-Meier method and Cox proportional hazards models, adjusting for age, sex, cancer stage, and hormone receptor (HR) status.

RESULTS

We identified 7362 USJ, 701,751 USO, and 503,013 Japanese breast cancer patients. The proportion of HR-positive breast cancer was the highest among USJ (71%). OS was significantly longer among Japanese and USJ than USO (Hazard ratio 0.46; 95% Confidence Interval [CI] 0.45-0.47 for Japanese and 0.66 [95% CI 0.59-0.74] for USJ) after adjusting for baseline covariates. BCSS was also significantly higher in the two groups (HR 0.53 [95% CI 0.51-0.55] for Japanese and 0.53 [95% CI 0.52-0.74] for USJ).

CONCLUSIONS

In stage I-III breast cancer, Japanese and US residents with Japanese origin experienced significantly longer survival than US residents with non-Japanese origins.

Estimation of absolute benefit of S-1 postoperative therapy for ER-positive, HER2-negative breast cancer: Exploratory analysis of the phase III potent trial

532

Background: Estimation of risk of recurrence is critical for adjuvant therapy decision making in patients with primary breast cancer. The POTENT trial examined outcomes associated with standard postoperative endocrine therapy with/without S-1 in patients with estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative primary breast cancer (Toi et al, San Antonio Breast Cancer Symposium 2019). The aim of this study was to investigate absolute treatment effect across recurrence risk score to individualize indication for the concurrent administration of standard postoperative endocrine therapy with S-1. Methods: The POTENT trial included 1930 patients with ER-positive and HER2-negative breast cancer. The primary end point was invasive disease-free survival (iDFS). A continuous, composite measure of recurrence risk for each patient was determined from a Cox model incorporating age, tumor size, nodal status, grade, estrogen receptor, and Ki-67 expression levels. Absolute treatment effect of S-1 was estimated in each risk group defined by the composite risk score. Results: Of 1930 patients, we included the data from 1897 patients without unavailable data. Tumor grade, ER expression, and Ki-67 expression were available from central assessment. A Cox proportional hazards model for iDFS was estimated in standard endocrine therapy only group (N = 954). Age was excluded from the model because it did not add prognostic information. 5-year iDFS estimates were 91.6%, 82.0%, and 67.2% for low, intermediate, and high composite risk group, respectively. Absolute improvement in 5-year iDFS by the addition of S-1 to standard endocrine therapy were 0.9%, 6.7%, and 8.1% for low, intermediate, and high composite risk group, respectively. Hazard ratio for S-1 in each risk group were 0.86 (95%CI: 0.45-1.63, P = 0.642), 0.51 (95%CI: 0.34-0.78, P = 0.001), and 0.71 (95%CI: 0.49-1.02, P = 0.064), respectively. Continuous value of composite risk was also prognostic in a Cox proportional hazards model stratified by S-1 and neoadjuvant/adjuvant chemotherapy use (HR 2.58, 95%CI: 2.13-3.11, P < 0.0001). Conclusions: Patients with ER-positive and HER2-negative disease, and intermediate to high risk, defined by clinicopathological factors, experienced absolute improvement of about 7-8% in 5-year iDFS with addition of S-1 to standard endocrine therapy, while improvement was minimal in those at low risk. Clinical trial information: 000003969 .

International retrospective cohort study of locoregional and systemic therapy in oligometastatic breast cancer (OLIGO-BC1)

1025

Background: Systemic therapy is the standard care in metastatic breast cancer (BC). However, retrospective studies demonstrated survival benefits of locoregional and systemic (combination) therapy in oligometastatic BC. To clarify it, the Federation of Asian Clinical Oncology conducted an international retrospective cohort study (OLIGO-BC1) (UMIN No.000030047). Methods: Oligometastatic BC patients diagnosed from 2007 to 2012 were registered. “Oligometastases” is defined as low volume metastatic disease with limited number and size of metastatic lesions up to five and not necessarily in the same organ by the ABC guidelines. Overall survival (OS) from the diagnosis of oligometastases was the primary endpoint and compared between combination and systemic therapy using a log-rank test. Assuming the 5-year OS of 50% and 40%, respectively, 698 patients were required to achieve 80% power to detect the superiority of combination therapy, at a two-sided significance level. A multivariable Cox regression model with stratification by country was performed to estimate hazard ratio (HR) for therapy and other risk factors. Results: While 1,262 cases had been registered from February 2018 to May 2019, 1,200 remained for analysis after exclusion of unavailable cases. Among them, 573, 529 and 98 cases were registered from China, Japan and Korea, respectively. Luminal BC was recorded in 526 cases (44%), luminal-HER2 BC in 189 (16%), HER2 BC in 154 (13%), triple-negative BC in 166 (14%) and others in 165 (13%). One oligometastatic BC was found in 578 cases, 2 in 289, 3 in 154, 4 in 102 and 5 in 77. Bone metastases were recorded in 301 cases, visceral metastases in 387, locoregional recurrence in 25, local recurrence in 83 and multiple metastatic sites in 404. Combination therapy was performed in 595 cases and systemic therapy in 404. At median follow-up of 4.9 years, 5-year OS was 59.6% and 41.9%, respectively (p < 0.01). An adjusted HR was 0.61 (95% CI: 0.51, 0.74). Type of systemic therapy, younger age, ECOG performance status 0, stage I BC, non-triple negative subtype, fewer metastatic sites, local recurrence and longer disease-free interval were significantly favorable prognostic factors. Discussions: Oligometastatic BC under some conditions seems to be curable. Taken together with recent molecular targeted therapy, locoregional therapy will be advantageous to conquer it. Conclusions: Combination therapy is a promising strategy for patients with oligometastatic BC.

Annual report of the Japanese Breast Cancer Society registry for 2016

The Japanese Breast Cancer Society (JBCS) registry began data collection in 1975, and it was integrated into National Clinical Database in 2012. As of 2016, the JBCS registry contains records of 656,896 breast cancer patients from more than 1400 hospitals throughout Japan. In the 2016 registration, the number of institutes involved was 1422, and the total number of patients was 95,870. We herein present the summary of the annual data of the JBCS registry collected in 2016. We analyzed the demographic and clinicopathologic characteristics of registered breast cancer patients from various angles. Especially, we examined the registrations on family history, menstruation, onset age, body mass index according to age, nodal status based on tumor size and subtype, and proportion based on ER, PgR, and HER2 status. This report based on the JBCS registry would support clinical management for breast cancer patients and clinical study in the near future.

Ki-67 response-guided preoperative chemotherapy for HER2-positive breast cancer: results of a randomised Phase 2 study

BACKGROUND

The effectiveness of a therapeutic strategy that switches chemotherapy, based on Ki-67 tumour expression after initial therapy, relative to that of standard chemotherapy, has not been evaluated.

METHODS

Patients were randomly assigned to the control arm or the Ki-67 response-guided arm (Ki-67 arm). Primary tumour biopsies were obtained before treatment, and after three once-weekly doses of paclitaxel and trastuzumab to assess the interim Ki-67 index. In the control arm, paclitaxel and trastuzumab were continued for a total of 12 doses, regardless of the interim Ki-67 index. In the Ki-67 arm, subsequent treatment was based on the interim Ki-67 index. Ki-67 early responder is defined as the absolute Ki-67 value that was <10%, and the percentage of Ki-67-positive tumour cells was reduced by >30% compared with before treatment. Early Ki-67 responders continued to receive the same treatment, while early Ki-67 non-responders were switched to epirubicin plus cyclophosphamide. The primary endpoint was the pathological complete response (pCR) rate.

RESULTS

A total of 237 patients were randomised. There was almost linear correlation between the Ki-67 reduction rate at interim assessment and the pCR rate. The pCR rate in Ki-67 early non-responders in the Ki-67 arm was inferior to that in the control arm (44.1%; 31.4-56.7; P = 0.025).

CONCLUSIONS

The standard chemotherapy protocol remains as the recommended strategy for patients with HER2-positive breast cancer.

CLINICAL TRIAL REGISTRATION

Clinical Trial Registration: UMIN-CTR as UMIN000007074.

A double-blind, randomized, multicenter phase 3 study of palonosetron vs granisetron combined with dexamethasone and fosaprepitant to prevent chemotherapy-induced nausea and vomiting in patients with breast cancer receiving anthracycline and cyclophosphamide

Purpose

To investigate whether palonosetron is better than granisetron in preventing chemotherapy‐induced nausea and vomiting (CINV) in a three‐drug combination with dexamethasone and fosaprepitant (Fos) in patients with breast cancer who are placed on anthracycline and cyclophosphamide (AC‐based regimen).

Patients and Methods

Chemo‐naive women with primary breast cancer were randomly administered either palonosetron 0.75 mg (day 1) or granisetron 1 mg (day 1) combined with dexamethasone (12 mg at day 1, 8 mg at day 2 and day 3) and Fos 150 mg (day 1) before receiving AC‐based regimen in a double‐blind study. The primary endpoint was the complete response (CR) rate of emesis in cycle 1 in the delayed phase. This was defined as neither vomiting nor rescue drug usage for emesis at >24‐120 hours after chemotherapy. Secondary endpoints were the CR in the acute/overall phase (0‐24/0‐120 hours, respectively, after chemotherapy), no nausea and vomiting, Patient‐Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO‐CTCAE), and safety.

Results

From December 2012 to October 2014, 326 patients were treated and evaluated (164/162 evaluable patients in granisetron/palonosetron arm, respectively). The CR during the delayed phase was 60.4% in the granisetron regimen and 62.3% in the palonosetron regimen. The CR during acute phase (73.2% vs 75.9%, respectively) and the CR during overall phase (54.9% in both regimens) were very identical. A significantly higher number of patients in the palonosetron arm were free from nausea during the delayed phase (28% vs 40.1%; P = .029). Adverse events were also identical, although infusion site reactions (ISR) were higher (20.3%‐23.3%) than preceding studies in both regimens.

Conclusion

In combination with dexamethasone and Fos, this study suggests that palonosetron is not better than granisetron in chemo‐naive patients with primary breast cancer receiving AC‐based regimen. Administration of Fos in peripheral veins after AC‐based regimen increased ISR.

Abstract GS1-09: Addition of S-1 to endocrine therapy in the post-operative adjuvant treatment of hormone receptor-positive and human epidermal growth factor receptor 2-negative primary breast cancer: A multicenter, open-label, phase 3 randomized trial (POTENT trial)

BACKGROUND: Although long-term prognostic outcomes of primary breast cancer (PBC) patients have been improved remarkably in recent years, the disease recurrence remains a serious problem. We have previously investigated a role for oral fluoropyrimidines in postoperative adjuvant treatments.In this study, we aimed to verify the usefulness of S-1 in combination with adjuvant endocrine therapy for PBC patients having luminal disease.

PATIENTS AND METHODS: This open-label, randomized, phase 3 trial was carried out in 139 centers in Japan. StageI-IIIPBC patients, who had hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negativestatus and intermediate or higher risk of recurrence were randomly assigned (1:1) to receive standard endocrine therapy alone (control arm) or endocrine therapy plus S-1 (S-1 arm). Recurrence risk assessment was performed using anatomical stage, pathological findings such as histologic grade, and centrally confirmed proliferative marker status. S-1 was administered postoperatively in combination with standard endocrine therapy. For patients who underwent multi-drug postoperative adjuvant or preoperative neoadjuvant chemotherapy, S-1 was administered following the multi-drug chemotherapy. Cases having no residual cancer in the breast and axillary node after the preoperative chemotherapy were excluded from this study. The S-1 dosage was chosen among 80 mg/day, 100 mg/day, and 120 mg/day according to the body surface area of each patient, and S-1 was administered for one year with a 2 weeks on/1 week off administration schedule. The primary endpoint was invasive disease-free survival (iDFS), defined as time from randomization to invasive disease recurrence, occurrence of second invasive cancer event, or death, and was analyzed on an intent-to-treat basis. Secondary endpoints included DFS, distant DFS, overall survival, and safety profile.

RESULTS: From Feb 2012 to Feb 2016, 1959 patients were enrolled and 1932 patients were included in the full analysis set (control arm, 973; S-1 arm, 959). The results of the prespecified interim analysis met the primary end point, and this trial was terminated early. Median follow-up was 51.4 months. S-1 significantly reduced invasive events; 153 iDFS events were reported in the control arm and 99 iDFS events were reported in the S-1 arm [hazard ratio, 0.63 (95%CI, 0.49-0.81); p-value, 0.0003]. The 5-year iDFS estimate was 81.5% in the control arm and 86.9% in the S-1 arm. Distant recurrence as the first disease event was observed in 6.8% of patients in the S-1 arm and in 9.5% of those in the control arm. The safety data in patients treated with S-1 was consistent with the known profile of S-1. The S-1 treatment was well tolerated and manageable.

CONCLUSIONS: It was concluded that the postoperative adjuvant use of an oralfluoropyrimidine S-1 significantly reduced iDFS events and improved 5-year iDFS estimate in PBC patients having HR-positive and HER2-negative disease, in the combination with standard endocrine therapy, with a feasible safety profile.

Funding: This study was funded by the Comprehensive Support Project (CSP) of the Public Health Research Foundation. The research fund was provided to CSP by Taiho Pharmaceutical Co., Ltd. This trial was conducted as a study of ‘Advanced Medical Care,’ the Ministry of Health, Labour and Welfare, Japan. JRCT ID: jRCTs051180057, UMIN000003969

Citation Format: Masakazu Toi, Shigeru Imoto, Takanori Ishida, Yoshinori Ito, Hiroji Iwata, Norikazu Masuda, Hirofumi Mukai, Shigehira Saji, Akira Shimizu, Takafumi Ikeda, Hironori Haga, Toshiaki Saeki, Kenjiro Aogi, Tomoharu Sugie, Takayuki Ueno, Takayuki Kinoshita, Yuichiro Kai, Masahiro Kitada, Yasuyuki Sato, Kenjiro Jimbo, Nobuaki Sato, Hiroshi Ishiguro, Masahiro Takada, Yasuo Ohashi, Shinji Ohno. Addition of S-1 to endocrine therapy in the post-operative adjuvant treatment of hormone receptor-positive and human epidermal growth factor receptor 2-negative primary breast cancer: A multicenter, open-label, phase 3 randomized trial (POTENT trial) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr GS1-09.

A population-based recurrence risk management study of patients with pT1 node-negative HER2+ breast cancer: a National Clinical Database study

Purpose

Recurrence risk management of patients with small (≤ 2 cm), node-negative, human epidermal growth factor receptor 2 (HER2)-positive breast cancer remains challenging. We studied the effects of adjuvant chemotherapy and/or trastuzumab and survival outcomes among these patients, using data from the population-based Japanese National Clinical Database (NCD).

Methods

We identified a cohort of 2736 breast cancer patients with HER2+ pT1N0 disease: 489 pT1a, 642 pT1b, and 1623 pT1c. The median observation period was 76 months, and the 5-year follow-up rate was 48.2%. The number of events was 212 for disease-free survival (DFS), 40 for breast cancer-specific survival, and 84 for overall survival (OS).

Results

There were 24.5% of pT1a, 51.9% of pT1b, and 63.3% of pT1c patients who were treated systemically after surgery. OS in pT1b (logrank test; p = 0.03) and DFS in pT1c (logrank test; p < 0.001) were significantly improved in treated compared with untreated patients. In the Cox proportional hazards model, treated patients had significantly longer OS than untreated patients in pT1b (hazard ratio (HR) 0.20) and pT1c (HR 0.54) groups. Estrogen receptor-negative tumors was also a significant predictor of survival in pT1c (HR 2.01) but not pT1ab patients. Furthermore, HR was greater in patients aged ≤ 35 years (3.18) compared to that in patients aged 50–69 years in the pT1b group.

Conclusions

NCD data revealed that systemic treatment improved OS in pT1bc but not in pT1a node-negative HER2+ breast cancer patients. Future observational research using big-sized data is expected to play an important role in optimizing treatment for patients with early-stage breast cancer.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05413-7) contains supplementary material, which is available to authorized users.

Risk Factors for Skin Flap Necrosis in Breast Cancer Patients Treated with Mastectomy Followed by Immediate Breast Reconstruction

BACKGROUND

Skin-sparing mastectomy (SSM) and nipple-sparing mastectomy (NSM) are the standard techniques for achieving a cosmetic outcome, but necrosis of a cutaneous flap including the nipple-areolar complex (NAC) is a serious complication. To analyze the risk factors for skin flap necrosis, we retrospectively evaluated a clinical database of breast cancer patients treated with mastectomy followed by immediate breast reconstruction.

METHODS

Four hundred and twelve cases were consecutively recorded between 2006 and 2016. Body weight (BW), body mass index (BMI), distance from NAC to referent tumor, distance from overlying skin to the tumor and weight of breast resection (WBR) as measured in the operating theater were included in the statistical analysis.

RESULTS

NSM, SSM and total mastectomy were performed in 123 (30%), 96 (23%) and 193 cases (47%), respectively. A tissue expander was used in 379 cases (92%), a silicone implant in 8 (2%) and autologous breast reconstruction in 25 (6%). Skin flap necrosis was found in 7% of all cases and NAC necrosis in 13% of NSM cases. In a univariate analysis, BW, NSM and WBR were risk factors for skin flap necrosis, and BW, BMI and WBR were risk factors for NAC necrosis. In a multivariate analysis, NSM and WBR remained significant risk factors for skin flap necrosis, and WBR was a significant risk factor for NAC necrosis.

CONCLUSIONS

WBR is an important risk factor for skin flap necrosis. Especially, NAC necrosis should be considered for patients with large-volume breasts who undergo NSM and immediate breast reconstruction.

Relation between dexamethasone (DEX) usage, preventive trimetprim/sulfametoxazole (ST), and pneumocystis pneumonia (PCP) for patients with breast cancer receiving dose-dense AC followed by dose-dense paclitaxel (ddAC-ddP): Preplanned analysis of WJOG9016B

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Background: PCP is rare complication of ddAC-ddP. DEX is plausible risk factor for PCP. Dose and duration of DEX against CINV is changing over time as other anti-emetic drugs (5HT3 RA, NK1 RA, and olanzapin) became available. Then DEX usage varies widely in each hospitals. ASCO/IDSA guideline recommends preventive ST for patients receiving 20 mg or more predonisone equivalents daily for more than one month, although evidence is lacking in patients receiving ddAC-ddP. This study is to investigate relation between DEX usage, preventive ST, and risk of PCP for patients receiving ddAC-ddP. Methods: This study is preplanned analysis of WJOG9016B (UMIN000024992) which investigated relative dose intensity of ddAC-ddP supported by 3.6 mg (approved dose in Japan) of pegfilgrastim. Eligible pts were HER2 negative PBC with stage I to IIIc, going to start ddAC-ddP and younger than 65 y.o.. DEX usage and preventive ST usage were discrete to treating physicians. Results: From Jan. 2017 to Jan. 2018, 92 pts were registered and 91 pts were in the FAS set, because one patients turned out be ineligible after registration. All patients received DEX for prevention of delayed CINV. Median total dose of DEX during ddAC was 112 mg (range; 80 to 212 mg), which was equal to 13.3 mg (9.52 mg–24.76 mg) predonisone equivalents daily. Only five of them (5.4%) received more than 20 mg predonisone equivalents daily. Twenty patients received preventive ST. Three patients developed PCP. None of them with preventive ST developed PCP (0%), whereas three of patients without ST developed PCP (4.2%). These three patients received total DEX dose during ddAC at 80 mg, 112 mg, and 112 mg, respectively. Conclusions: ST was highly effective for PCP prevention for patients receiving ddAC-ddP, if DEX used against delayed CINV. Without ST prevention, the risk of PCP was 4.2 %, which was higher than threshold (3.5%) proposed in ASCO/ IDSA guidelines. The threshold of steroid dose leading to the risk of PCP might be lower than 20 mg or more predonisone equivalents daily in patients receiving ddAC-ddP. Clinical trial information: UMIN000024992.

Progesterone receptor expression in proliferating cancer cells of hormone-receptor-positive breast cancer

Breast cancer has been suggested to have two distinct driving mechanisms: the hormone receptor and the growth factor receptor pathways. We hypothesized that each driving system produces a different expression pattern of estrogen-regulated genes, such as progesterone receptor, in proliferating cells. Progesterone receptor and Ki67 expressions were assessed by dual-fluorescence immunohistochemistry in estrogen-receptor-positive breast cancer tissues. Two distinct proliferating cell populations were observed: progesterone-receptor-positive and progesterone-receptor-negative. In the training cohort, tissues with progesterone-receptor-positive proliferating cells were associated with lower grade and better disease-free survival (p = 0.0055 and 0.0026, respectively). These associations were confirmed in the validation cohort from the neoadjuvant endocrine trial JFMC34 (p = 0.033 and 0.0003, respectively). In the validation cohort, patients with progesterone-receptor-positive proliferating cells responded better to endocrine therapy and had a lower Oncotype DX Recurrence Score. In the multivariate analysis, progesterone receptor status of proliferating cells, but not progesterone receptor or Ki67 alone, was an independent predictor of disease-free survival in both cohorts (p = 0.0043 and 0.0026). In conclusion, the progesterone receptor status of proliferating cancer cells was associated with histological grade and Recurrence Score, and a potent prognostic factor in estrogen-receptor-positive breast cancers. Results suggest that different driving systems generate different expression patterns of progesterone receptor in proliferating cancer cells. Further studies are warranted to validate the findings.

Abstract OT2-05-02: International retrospective cohort study of locoregional and systemic therapy in oligometastatic breast cancer (OLIGO-BC1)

Breast cancer (BC) is so-called “systemic disease”, because disseminated cancer cells in bone marrow and blood are detected even in early BC patients. Despite adjuvant therapy and postoperative radiation therapy, patients with triple negative BC and Luminal B-like BC often relapse early and systemic therapy is the only way to control disease progression. On the other hand, some BC patients relapse several years later. In such patients, oligometastases are occasionally diagnosed, because metastatic cancer cells are slowly growing and indolent. Oligometastatic BC is defined as low volume metastatic disease with limited number and size of metastatic lesions (up to five and not necessarily in the same organ). This definition is proposed in the Advanced Breast Cancer guidelines that are developed as a joint effort from European School of Oncology and European Society of Medical Oncology. Several retrospective studies demonstrated survival benefit of locoregional therapy in addition to systemic therapy. Locoregional therapy consisted of surgical resection, radiation therapy, ablation therapy, etc. However, it remains unclear about survival benefit of combined therapy in oligometastatic BC. To improve the standard of cancer treatment through the cooperate studies on more effective therapeutic strategies based on drugs, surgery and/or radiotherapy, Federation of Asian Clinical Oncology (FACO) was established in 2012 by Chinese Society of Clinical Oncology (CSCO), Korean Society of Medical Oncology (KSMO) and Japan Society of Clinical Oncology (JSCO). Thus, FACO conducted a retrospective cohort study on oligometastatic BC. The primary endpoint is to compare the estimated 5-year overall survival (OS) of oligometastatic BC patients treated with combined therapy and systemic therapy alone. To hypothesize that combined therapy has more advantage of OS in oligometastatic BC, the 5-year OS rates are expected to be 50% and 40%, respectively. The estimated sample size is calculated to be the number of 698 cases (349 cases in each group) needed to prove the superiority of survival with a two-sided type I error rate of 5% and a statistical power of 80%. Case registry opened in February 2018 and will close in January 2019. We planned to register 700 cases, i.e., 234 cases each from investigators of CSCO, KSMO and JSCO. Update information will be discussed.

Citation Format: Imoto S, Futamura M, Toi M, Fujiwara Y, Ueno T, Im Y-H, Im S-A, Ahn SG, Lee JE, Park YH, Wang K, Kitagawa Y, Nishiyama M. International retrospective cohort study of locoregional and systemic therapy in oligometastatic breast cancer (OLIGO-BC1) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-05-02.

Abstract OT2-01-01: Observational study of axilla treatment for breast cancer patients with 1 to 3 positive micrometastases or macrometastases in sentinel lymph nodes

[Background] Axilla surgery in node-positive breast cancer is dramatically changing from axillary lymph node dissection (ALND) to sentinel node biopsy (SNB). From the results of ACOSOG Z0011, IBCSG23-01 and AMAROS trials, adjuvant therapy and regional node irradiation could reduce regional lymph node recurrence for sentinel node-positive breast cancer patients. However, optimal indication of SNB alone remains uncertain. Trial design: To evaluate the outcome of sentinel node-positive breast cancer patients, the Japanese Society for Sentinel Node Navigation Surgery (SNNS) conducted a prospective cohort study in 2013 (UMIN000011782, Jpn J Clin Oncol, p.876-9, 2014). [Eligibility criteria] For eligible patients, SNB was performed or scheduled after 1 January 2012. Then 1 to 3 positive micrometastases or macrometastases in sentinel lymph nodes are confirmed by histological or molecular diagnosis. Primary chemotherapy before or after SNB is also acceptable for registration. [Specific aims] The primary endpoint is the 5-year recurrence rate of regional lymph node in patients treated with SNB alone. The secondary endpoint is the 5-year overall survival rate of this cohort. Patients treated with SNB followed by ALND are also registered simultaneously to compare the prognosis. The propensity score matching (PSM) is used to make the distributions of baseline risk factors comparable. [Statistical method] Based on an estimated recurrence rate of 5% at 5 years among patients treated with SNB alone, 240 patients are needed to give a 80% power to reject the null hypothesis that the recurrence rate is 10% with a one-sided type I error rate of 2.5%. If we consider that some patients will be lost to follow-up or become ineligible, a total of 250 patients will be needed to comprise the sample. [Present accrual] Eight hundred and eighty patients who underwent SNB alone or SNB followed by ALND were registered from 27 participating institutes between 2013 and 2016. Data cleaning is being performed. Patient's background and PSM will be reported.

Citation Format: Imoto S, Saito Oba M, Masuda N, Nagashima T, Wada N, Takashima T, Kitada M, Kawada M, Hayashida T, Taguchi T, Aihara T, Miura D, Toh U, Yoshida M, Sugae S, Yoneyama K, Matsumoto H, Jinno H, Sakamoto J. Observational study of axilla treatment for breast cancer patients with 1 to 3 positive micrometastases or macrometastases in sentinel lymph nodes [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-01-01.

Phase II study on radiofrequency ablation in stage 0 and I breast cancer without extensive intraductal components

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Background: We reported about a multi-center registration study on radiofrequency ablation (RFA) in early breast cancer (BC) (ASCO2012 #1119). Although various devices and ablation procedure were used, 5-year’s recurrence-free survival was 96% in 425 cases of T1BC treated with RFA alone. To validate complete pathological ablation in BC, we started a non-randomized phase II study in 2013 (UMIN000013836). Methods: Unilateral BC patients with stage 0 (TisN0M0) or I (T1N0M0 or T1N1miM0) were eligible. Tumor diameter of 2cm or less should be diagnosed by ultrasound and MR mammography. RFA was performed by Cool-tip RF ablation system (Covidien, USA). One month later, ablated tissue was collected by core needle biopsy or vacuum-assisted breast biopsy. Cell viability was determined by central review of independent pathologists using tumor specimens stained with hematoxylin–eosin and nicotinamide adenine dinucleotide (NADH) diaphorase. In case of complete ablation, breast irradiation and adjuvant therapy was planned. In case of incomplete ablation, partial mastectomy was recommended. The primary endpoint is complete ablation rate. The secondary endpoints are breast deformity after RFA, relapse-free survival and overall survival for 10 years. Two-step design consisting of 9 cases at 1st step and 20 cases at 2nd step was used for statistical evaluation. We expected complete ablation rate of 95% and 29 cases were needed to reject the null hypothesis that complete ablation rate would be less than 80% at lower threshold. Thus, 32 cases were required. Results: Thirty-six patients were enrolled between February 2013 and May 2016. The mean tumor size was 1.3 cm measured by MR mammography. Two patients were ineligible because of macrometastasis in a sentinel node. Of 34 eligible patients, one patient had viable cancer cells with NADH diaphorase staining in ablated specimens. Finally, complete ablation rate was 97%. As of January 2017, one patient, who refused adjuvant therapy and breast irradiation, had in-breast tumor recurrence adjacent to previously ablated lesion. Conclusions: Long-term follow-up should be needed, but RFA in early BC is a promising strategy instead of breast-conserving surgery. Clinical trial information: UMIN000013836.

Abstract 4138: Immunological profile of metastatic or recurrent breast cancer patients

Background: We previously reported about immune suppression in breast cancer patients at this meeting. In brief, tumor tissue specimens and peripheral blood mononuclear cells (PBMC) were analyzed in 50 early or advanced breast cancer (BC) patients. To compare between 38 early and 12 advanced BC cases, CD163-positive tumor cells and CCR4-positive tumor cells were detected more frequently in advanced cases than in early cases. Regulatory T (Treg) cells in PBMC significantly increased in percentage of the population in 37 BC patients than in 21 healthy volunteers (AACR 2011). In addition, several cytokines were examined in that cohort and plasma IL-17A had significantly higher levels in early BC than in advanced BC (AACR 2013). Then, we examined their prognosis and immunological profile.

Patients and methods: Treg cells were examined by counting CD4+CD25highCD127low/-cells in PBMC with flow cytometry analysis. Immunohistochemical evaluation of tumor specimens was performed with monoclonal antibodies of HLA-ABC and DR, CD56, CD68, CD83, CD163 and CCR4. The number of stained cells was analyzed using a semiquantitative ordinal scale ranging from 0 to 3 (0, +/-, ++, +++). Human IL-2, IL-4, IL-6, IL-10, TNF, INFγ and IL-17A were measured using cytometric beads array system. Most patients received chemotherapy, hormonal therapy, and/or anti-HER2 therapy on the basis of intrinsic subtype and breast irradiation after breast-conserving surgery.

Results and discussions: At the median follow-up of 7 years after blood sample collection, only 2 operable patients relapsed and 3 patients including 2 cases of stage IV died of disease. Of 5 cases of stage IV or recurrent BC, CD163 and/or CCR4 were strongly stained positive in tumor cells. There were significant differences of staining intensity in CD163 and CCR4-positive tumor cells between those cases and the rest 45 cases (p&lt;0.01 at Chi-square test). However, other immune cell profiles, Treg cells in PBMC and cytokines in plasma had no trend between them. Several reports demonstrated that cancer patients with CD163-positive tumor-infiltrating macrophages and CD163-positive tumor cells had poor prognosis due to tumor-associated macrophage. Phenotypic macrophage traits in cancer cells, like CD163 expression, may be explained by heterotypic cell fusion between monocytes/macrophages and cancer cells.

Conclusion: Targeted therapy against M2 macrophage or CCR4 is considered as a promising strategy of advanced breast cancer.

Citation Format: Shigeru Imoto, Takayuki Ueno, Hirotsugu Isaka, Hiroki Ito, Kaisuke Miyamoto, Tomohiro Chiba, Hiroshi Kamma. Immunological profile of metastatic or recurrent breast cancer patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4138.

Abstract 3484: Analysis of in situ expression of hormone receptors and proliferation marker at a single cell level in breast cancer tissues

Background: Hormone receptors and proliferation markers are critical parameters for treatment selection of breast cancer patients. The expression of different parameters are currently assessed separately in different tissue sections but it is unclear how different parameters are co-expressed in a single cell in breast cancer tissues.

Samples and Methods: Breast cancer tissues from fifty-one patients with ER-positive HER2-negative breast cancer were analyzed. Expressions of ER and PgR were assessed in association with Ki67 using dual fluorescence immunohistochemistry with specific antibodies: SP-1 (abcam, Tokyo), 1E2 (Roche Diagnostics GmBH, Germany), and MIB1 (Dako Japan, Tokyo), respectively. More than 500 cancer cells were assessed in each tissue. Expression levels of each marker in a single cell were semi-quantitatively assessed by MetaMorph image analyzer (Molecular Devices Japan, Tokyo). All statistical analyses were performed using JMP ver.8.01 (SAS Institute Japan, Tokyo).

Results: To validate the system, Ki67 LI in breast cancer tissues were compared between this system and the regular DAB system. The two systems showed a good concordance (p &lt; 0.0001). All cancer tissues expressed ER. There were two distinct populations among Ki67-positive proliferating cells according to PgR expression status: PgR-positive proliferating cells and PgR-negative proliferating cells. Since cell proliferation is regulated in cancer cells by at least two different drivers including hormone receptor and growth factor, it is conceivable that these two populations depend on different driving systems. Indeed, tissues with dominantly PgR-positive proliferating cells showed mostly histological grade 1 (15/20, 75%), while most of tissues with PgR-negative proliferating cells showed grade 2 and 3 (22/31, 71%) (p = 0.0025 by chi square test). Moreover, the multivariate analysis using the ordered logistic regression analysis showed that PgR status in proliferating cells is an independent factor associated with histological grade (p = 0.003) while PgR expression rate and Ki67 LI were not (p = 0.3 and 0.25, respectively).

Conclusion: PgR status in Ki67-positive proliferating cells is associated with histological grade in ER positive HER2-negative breast cancers. Our results suggest that different driving systems give different expression patterns of PgR and Ki67 at a single cell level, which may distinguish between luminal A and luminal B cancers.

Citation Format: Takayuki Ueno, Hirotsugu Isaka, Hiroki Itoh, Kaisuke Miyamoto, Manami Kitamura, Shigeru Imoto. Analysis of in situ expression of hormone receptors and proliferation marker at a single cell level in breast cancer tissues. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3484.

The hnRNP-Htt axis regulates necrotic cell death induced by transcriptional repression through impaired RNA splicing

In this study, we identify signaling network of necrotic cell death induced by transcriptional repression (TRIAD) by α-amanitin (AMA), the selective RNA polymerase II inhibitor, as a model of neurodegenerative cell death. We performed genetic screen of a knockdown (KD) fly library by measuring the ratio of transformation from pupa to larva (PL ratio) under TRIAD, and selected the cell death-promoting genes. Systems biology analysis of the positive genes mapped on protein-protein interaction databases predicted the signaling network of TRIAD and the core pathway including heterogeneous nuclear ribonucleoproteins (hnRNPs) and huntingtin (Htt). RNA sequencing revealed that AMA impaired transcription and RNA splicing of Htt, which is known as an endoplasmic reticulum (ER)-stabilizing molecule. The impairment in RNA splicing and PL ratio was rescued by overexpresion of hnRNP that had been also affected by transcriptional repression. Fly genetics with suppressor or expresser of Htt and hnRNP worsened or ameliorated the decreased PL ratio by AMA, respectively. Collectively, these results suggested involvement of RNA splicing and a regulatory role of the hnRNP-Htt axis in the process of the transcriptional repression-induced necrosis.

Clinical significance of the expression of autophagy-associated marker, beclin 1, in breast cancer patients who received neoadjuvant endocrine therapy

Background

Neoadjuvant endocrine therapy (NAE) has been employed to improve surgical outcomes for hormone receptor-positive breast cancers in postmenopausal women. Endocrine responsiveness is estimated by expressions of hormone receptors, but its heterogeneity has been recognized. Autophagy is an evolutionally conserved process associated with cell survival and cell death and has been implicated in cancer treatment.

Methods

In order to examine the possible association between autophagy and response to endocrine therapy, we evaluated the status of autophagy-associated markers, beclin 1 and LC3, and apoptosis-associated markers, TUNEL and M30, in pre- and post-treatment specimens from 71 patients in a multicenter prospective study of neoadjuvant exemestane (JFMC34-0601).

Results

Immunoreactivity of the autophagy-associated markers, beclin 1 and LC3, in carcinoma cells increased in 14 % and 52 % of the patients, respectively, following the exemestane treatment. These increases were statistically significant (beclin 1, p = 0.016, N = 49; LC3, p < 0.0001, N = 33). The status of M30 immunoreactivity decreased (p = 0.008, N = 47) and TUNEL remained unchanged (N = 53). In addition, tumors with pre-treatment stromal beclin 1 immunoreactivity revealed poor clinical and pathological responses compared with those without stromal beclin 1 immunoreactivity (25 % vs 67 % for clinical response, p = 0.011, N = 51; 0 % vs 41 % for pathological response, p = 0.0081, N = 49). Tumors with positive pre-treatment stromal beclin 1 had a higher baseline Ki-67 labeling index (both hot spot and overall average) than those without (p = 0.042 and 0.0075, respectively, N = 53). Results of logistic regression analyses revealed that stromal beclin 1 was a predictor for clinical and pathological responses while ER, PR, Ki-67, and stromal LC3 expressions were not.

Conclusions

Results of our present study demonstrated that beclin 1 and LC3 immunoreactivity increased in carcinoma cells following exemestane treatment and that the status of pre-treatment stromal beclin 1 is associated with higher carcinoma cell proliferation and poor clinical and pathological responses to NAE.

Trial registration

UMIN C000000345 (2006/03/06)

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2270-9) contains supplementary material, which is available to authorized users.

Abstract P3-13-07: Radiofrequency ablation (RFA) is a promising treatment option for primary breast cancer: Experience in 386 Japanese breast cancer patients

Background. Radiofrequency ablation (RFA) is used for the treatment of various solid tumors. Several small experiences have reported as a primary treatment for breast cancer using RFA. However, the clinical benefits remain uncertain. We retrospectively studied 386 patients and analyzed their RFA-related complications and outcomes.

Methods. A clinical database was constructed from 10 institutions. RFA was performed using an electrical generator connected to a single cooled-tip electrode or multiple electrodes. Adjuvant systemic therapy and whole breast radiation were administered according to the clinicopathological background of each patient. Follow-up periods ranged from 1 to 90 months (mean 45.4 months). RFA-related complications and risk factors for in-breast recurrence after RFA were evaluated. Variables evaluated included patient characteristics, pre- and post-operative imaging modalities, tissue sampling modalities, and RFA-related factors.

Results. Skin burns were observed in 7 patients (1.8 %) and RFA-induced damage to the nipple-areolar complex in 7 patients (1.8 %). Persistent induration of the breast after RFA was observed in 137 patients (35.5 %). Eleven patients (2.8 %) developed in-breast recurrence. In-breast recurrence was more frequent in patients with tumor size &gt;2.0 cm, ER-negative tumor, HER2-positive tumor, positive nodes, no breast irradiation and adjuvant chemotherapy.

Conclusions. Skin burns were a major problem after RFA, but the frequency of burns was relatively low. Breast induration was also developed, but it did not bring harmful effect to the patients with this complication. We conclude that RFA is a promising treatment option for solid T1 breast cancer without malignant potential.

Citation Format: Takahashi M, Ito T, Oura S, Nagamine S, Yamamoto N, Yamamichi N, Earashi M, Doihara H, Imoto S, Mitsuyama S, Akazawa K. Radiofrequency ablation (RFA) is a promising treatment option for primary breast cancer: Experience in 386 Japanese breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-13-07.

One-step nucleic acid amplification assay for intraoperative prediction of advanced axillary lymph node metastases in breast cancer patients with sentinel lymph node metastasis

The one-step nucleic acid amplification (OSNA) assay is used to semiquantitatively measure the cytokeratin (CK)19 mRNA copy numbers of each sentinel lymph node (SLN) in breast cancer patients. The aim of the present study was to evaluate whether the diagnosis of ≥4 LN metastases is possible using the OSNA assay intraoperatively. Between May, 2010 and December, 2014, a total of 134 patients who underwent axillary lymph node dissection (ALND) of positive SLNs were analyzed. The total tumor load (TTL) was defined as the total CK19 mRNA copies of all positive SLNs. The correlation between TTL and ≥4 LN metastases was evaluated. Of the 134 patients, 31 (23.1%) had ≥4 LN metastases. TTL ≥5.4×10⁴ copies/µl evaluated by receiver operator characteristic curve analysis was examined along with other clinicopathological variables. In the multivariate analysis, only TTL ≥5.4×10⁴ copies/µl was correlated with ≥4 LN metastases (odds ratio = 2.95, 95% confidence interval: 1.17-7.97, P=0.022). Therefore, TTL assessed by the OSNA assay has the potential to be a predictor of ≥4 LN metastases and it may be useful for the selection of patients with positive SLNs in whom ALND may be safely omitted.

Taxanes versus S-1 as the first-line chemotherapy for metastatic breast cancer (SELECT BC): an open-label, non-inferiority, randomised phase 3 trial

BACKGROUND

Oral fluoropyrimidines are used for the first-line treatment of metastatic breast cancer to avoid severe adverse effects, although firm supporting evidence is lacking. We aimed to establish whether S-1 is non-inferior to taxanes in this setting.

METHODS

We did an open-label, non-inferiority, phase 3 trial at 154 hospitals in Japan. We enrolled individuals who had HER2-negative metastatic breast cancer who had received no chemotherapy for advanced disease, and who were resistant to endocrine treatment. Patients were randomly assigned (1:1) either to taxane (docetaxel 60-75 mg/m(2) at intervals of 3-4 weeks; paclitaxel 80-100 mg/m(2) weekly for 3 of 4 weeks; or paclitaxel 175 mg/m(2) at intervals of 3-4 weeks) or to S-1 (40-60 mg twice daily for 28 consecutive days, followed by a 14-day break). Randomisation was done centrally with the minimisation method, with stratification by institution, liver metastasis, oestrogen and progesterone receptor status, previous treatment with taxanes or oral fluorouracil, and time from surgery to recurrence. The primary endpoint was overall survival, with a prespecified non-inferiority margin of 1·333 for the hazard ratio (HR). The primary efficacy analysis was done in the full analysis set, which consisted of all patients who took at least one study treatment and who had all data after randomisation. This trial is registered with the University Hospital Medical Information Network, Japan (protocol ID C000000416).

FINDINGS

Between Oct 27, 2006, and July 30, 2010, we enrolled 618 patients (309 assigned to taxane; 309 assigned to S-1). The full analysis set consisted of 286 patients in the taxane group and 306 in the S-1 group. Median follow-up was 34·6 months (IQR 17·9-44·4). Median overall survival was 35·0 months (95% CI 31·1-39·0) in the S-1 group and 37·2 months (33·0-40·1) in the taxane group (HR 1·05 [95% CI 0·86-1·27]; pnon-inferiority=0·015). The most common grade 3 or worse adverse events were neutropenia (20 [7%] of 307 patients in the S-1 group vs nine [3%] of 290 patients in the taxane group), fatigue (ten [3%] vs 12 [4%]), and oedema (one [<1%] vs 12 [4%]). Treatment-related deaths were reported in two patients in the taxane group.

INTERPRETATION

S-1 is non-inferior to taxane with respect to overall survival as a first-line treatment for metastatic breast cancer. S-1 should be considered a new option for first-line chemotherapy for patients with HER2-negative metastatic breast cancer.

FUNDING

Comprehensive Support Project for Oncology Research of the Public Health Research Foundation, Japan; Taiho.