Predictive analysis of breast cancer response to neoadjuvant chemotherapy through plasma metabolomics.

PURPOSE: Preoperative chemotherapy is a critical component of breast cancer management, yet its effectiveness is not uniform. Moreover, the adverse effects associated with chemotherapy necessitate the identification of a patient subgroup that would derive the maximum benefit from this treatment. This study aimed to establish a method for predicting the response to neoadjuvant chemotherapy in breast cancer patients utilizing a metabolomic approach. METHODS: Plasma samples were obtained from 87 breast cancer patients undergoing neoadjuvant chemotherapy at our facility, collected both before the commencement of the treatment and before the second treatment cycle. Metabolite analysis was conducted using capillary electrophoresis-mass spectrometry (CE-MS) and liquid chromatography-mass spectrometry (LC-MS). We performed comparative profiling of metabolite concentrations by assessing the metabolite profiles of patients who achieved a pathological complete response (pCR) against those who did not, both in initial and subsequent treatment cycles. RESULTS: Significant variances were observed in the metabolite profiles between pCR and non-pCR cases, both at the onset of preoperative chemotherapy and before the second cycle. Noteworthy distinctions were also evident between the metabolite profiles from the initial and the second neoadjuvant chemotherapy courses. Furthermore, metabolite profiles exhibited variations associated with intrinsic subtypes at all assessed time points. CONCLUSION: The application of plasma metabolomics, utilizing CE-MS and LC-MS, may serve as a tool for predicting the efficacy of neoadjuvant chemotherapy in breast cancer in the future after all necessary validations have been completed.

Efficacy and safety of dose-dense neoadjuvant chemotherapy with nab-paclitaxel followed by epirubicin and cyclophosphamide for operable breast cancer.

OBJECTIVE: Dose-dense chemotherapy has shown a better prognosis than standard interval chemotherapy in adjuvant settings for high-risk breast cancer. This study aimed to evaluate the efficacy and safety of dose-dense nanoparticle albumin-bound paclitaxel followed by dose-dense epirubicin and cyclophosphamide as neoadjuvant chemotherapy for human epidermal growth factor 2 (HER2)-negative operable breast cancer. METHODS: Patients with histologically confirmed stage I-III HER2-negative breast cancer were enrolled in this study. Patients received nanoparticle albumin-bound paclitaxel (260 mg/m2) followed by epirubicin (90 mg/m2) and cyclophosphamide (600 mg/m2) every 2 weeks with pegfilgrastim. The primary endpoint was the pathological complete response rate. Patients also underwent prophylactic management for peripheral neuropathy, which involved a combination of cryotherapy, compression therapy using elastic stockings and medications including goshajinkigan. RESULTS: Among the 55 patients enrolled in this study, 13 (23.6%) achieved pathological complete response, of whom 10/26 (38.5%) patients had triple-negative disease and 3/29 (10.3%) had luminal disease. The objective response was observed in 46 (83.6%) patients. Of the 36 patients who were initially planned for mastectomy, 11 (30.6%) underwent breast-conserving surgery after neoadjuvant chemotherapy. The most common grade 3-4 adverse events were myalgia (14.5%), fatigue (12.7%) and elevated transaminase levels (9.1%). No patients experienced febrile neutropenia. Eight (14.5%) patients discontinued treatments due to adverse events. CONCLUSIONS: Neoadjuvant dose-dense biweekly nanoparticle albumin-bound paclitaxel followed by dose-dense epirubicin and cyclophosphamide was effective, especially in patients with triple-negative disease, and feasible with pegfilgrastim support.

Analysis of prognosis in different subtypes of invasive lobular carcinoma using the Japanese National Cancer Database-Breast Cancer Registry.

PURPOSE: Many studies have shown that the prognosis of invasive lobular carcinoma (ILC) is better than that of invasive ductal carcinoma (IDC). However, both disorders exhibit different prognoses according to molecular subtype, and the prognosis of ILC subtypes might depend on their hormone receptor positivity rate. This study clarified the prognosis of ILC and IDC in each subtype and examined the effectiveness of adjuvant chemotherapy (CT) in luminal ILC. METHODS: We planned the analysis using data from the Breast Cancer Registry in Japan. Because it was presumed that there are differences in characteristics between ILC and IDC, we created matched cohorts using exact matching to compare their prognoses. We compared the prognosis of ILC and IDC for each subtype. We also compared the prognosis of luminal ILC between the CT and non-CT groups. RESULTS: For all subtypes, the disease-free survival (DFS) and overall survival (OS) of ILC were poorer than those of IDC. In the analysis by each subtype, no statistically significant difference was found in DFS and OS in luminal human epidermal growth factor 2 (HER2), HER2, and triple-negative cohorts; however, luminal ILC had significantly poorer DFS and OS than luminal IDC. The CT effects on the prognosis of luminal ILC were greater in more advanced cases. CONCLUSION: Luminal ILC had a poorer prognosis than luminal IDC, contributing to the worse prognosis of ILC than that of IDC in the overall cohort. Different therapeutic approaches from luminal IDC are essential for a better prognosis of luminal ILC.

Solitary fibrous tumor of the breast: A case report.

INTRODUCTION: Solitary fibrous tumors (SFTs) are uncommon mesenchymal neoplasms that comprise <2 % of all soft tissue tumors. They are a diagnostically challenging group of neoplasms that can occur essentially anywhere. Molecular or genetic testing of soft tissue tumors will increasingly add to the foundation of distinctive histologic features, as accurate diagnosis is critical for appropriate treatment. CASE PRESENTATION: A 28-year-old woman was referred to our hospital for a left breast mass. Ultrasonography showed an oval hypoechoic mass with partially obscured boundaries. Surgical specimens revealed spindle tumor cells surrounding the mammary ducts and were immunoreactive for both CD34 and STAT6, suggesting SFTs. However, the infiltration of spindle tumor cells into the surrounding fat, and the storiform-like pattern made us consider dermatofibrosarcoma protuberans (DFSP) as a differential diagnosis. Lack of amplification of the COL1A1-PDGFB fusion gene, a characteristic feature of DFSP, led to our definitive diagnosis of breast SFT. DISCUSSION: The presence of STAT6 in tumor cell nuclei is a highly sensitive immunohistochemical marker for SFT. In our case, morphological features evoked the differential diagnosis of DFSP and we investigated the COL1A1-PDGFB fusion gene. The diagnostic process of reliably performing careful morphological examination and immunohistochemical marker test, and then obtain conviction by molecular cytogenetic technique is more and more important for soft tissue tumors. CONCLUSIONS: We report a quite uncommon case of breast SFT and excluded DFSP as a differential diagnosis. If it is difficult to distinguish between these diseases, molecular cytogenetic analysis would be required for accurate diagnosis.

Acute arterial occlusive disease due to tumor thrombus from lung metastasis of breast cancer with cartilaginous and osseous metaplasia: a case report.

BACKGROUND: Tumor embolization due to venous infiltration of breast cancer pulmonary metastases is very rare. CASE PRESENTATION: A 72-year-old female was diagnosed with triple-negative breast cancer. Neoadjuvant chemotherapy was discontinued because of progressive disease, and a right mastectomy with sentinel lymph node biopsy was performed. The pathological analysis of surgical specimens revealed carcinoma with cartilaginous and/or osseous metaplasia. At 22 months after surgery, lung metastasis was observed, and 6 months after initiating treatment for lung metastases, she complained of sudden numbness in the left-lower limb with trouble walking. Ultrasonography showed an embolism in the left popliteal artery, and contrast computed tomography showed enlarged lung metastases and infiltration of the left-upper lobe disease into the left superior pulmonary vein and left atrium. Acute arterial occlusive disease in the left-lower limb caused by the tumor embolism was suspected, so an endovascular thrombectomy was performed. Tumor emboli were removed by embolectomy catheter. CONCLUSION: This report of lung metastasis from breast cancer with cartilaginous and/or osseous metaplasia and acute lower-limb artery occlusion due to a tumor thrombus adds useful information to the literature on these extremely rare cases.

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.

[A Case of Triple Negative Breast Cancer with Successful Control of Recurrent Disease Activity for More than Ten Years].

A woman in her 70s underwent mastectomy plus axillary lymph node excision(Bt plus Ax)in December 2011 for left breast cancer classified as pT2N1M0, pStage ⅡB. The tumor was identified as an invasive ductal carcinoma(IDC), neural/ glial antigen 2(NG2), pT2(35 mm), INF γ, ly2, v0, g+, f+, s+, extensive intraductal component(EIC)-negative, ICT- positive, NCAT-positive, n(4/18), estrogen receptor(ER)-negative, progesterone receptor(PgR)-negative, human epidermal growth factor receptor 2(HER2)-negative, Ki-67 30-40%. Postoperative adjuvant fluorouracil plus epirubicin HCl plus cyclophosphamide(FEC)plus paclitaxel(PTX)therapy was administered. The patient refused to undergo postoperative radiation therapy. Two years after the surgery, she was diagnosed as having a lung metastasis and local disease recurrence. Biopsy of the local recurrent lesion revealed the same histopathological diagnosis as before. Capecitabine was selected for treatment of the recurrent lesion. After 2 years of capecitabine treatment, the response was rated as progressive disease (PD). At this time, eribulin mesylate was selected, along with intensity-modulated radiation therapy(IMRT). This resulted in disappearance of the tumor on imaging. However, considering that the histological findings did not suggest complete response(CR)and that the tumor was triple-negative(TN), we adopted a strategy of continuing the drug therapy at reduced dose level. With this strategy, the disease activity could be successfully controlled for 6.5 years. Subsequently, liver metastasis was detected, and the drug was switched to vinorelbine ditartrate(a drug with less non-hematological toxicity). Meanwhile, a breast cancer susceptibility gene(BRCA)analysis was performed in January 2021, which was negative. Subsequently, in September 2021, we obtained a positive result for PDL1-SP142 and negative result for 22C3. About half a year later, ie, in October 2021(11 years after the surgery), we detected an increase in the size of the liver metastasis and selected atezolizumab and nab-PTX for treatment. Applicable regimens of drug therapy are still available at present and drug therapy has been continued based on a discussion and mutual understanding of the adverse reactions, etc. with the patient. Few reports have been published concerning long-term survivors among TN breast cancer cases.

Prognosis and effectiveness of chemotherapy for medullary breast carcinoma.

PURPOSE: We aimed to determine the prognosis and potential benefit of postoperative chemotherapy according to subtype of medullary breast carcinoma (MedBC), a very rare invasive breast cancer. METHODS: A cohort of 1518 female patients with unilateral MedBC and 284,544 invasive ductal carcinoma (IDC) cases were enrolled from the Japanese Breast Cancer Registry. Prognosis of MedBC was compared to IDC among patients with estrogen receptor (ER)-negative and HER2-negative subtype (553 exact-matched patients) and ER-positive and HER2-negative subtype (163 MedBC and 489 IDC patients via Cox regression). Disease free-survival (DFS) and overall survival (OS) were compared between propensity score-matched adjuvant chemotherapy users and non-users with ER-negative and HER2-negative MedBC. RESULTS: Among ER-negative and HER2-negative subtype patients, DFS (hazard ratio (HR) 0.45; 95% confidence interval (95% CI), 0.30-0.68; log-rank P < 0.001) and OS (HR 0.51; 95% CI 0.32-0.83; log-rank P = 0.004) were significantly better in MedBC than IDC. Patients treated with postoperative chemotherapy showed better DFS (HR 0.27; 95% CI 0.09-0.80; log-rank P = 0.02) and OS (HR 0.27; 95% CI 0.09-0.80; log-rank P = 0.02) compared to those without. For the ER-positive and HER2-negative subtype, the point estimate for HR for DFS was 0.60 (95% CI 0.24-1.22) while that for OS was 0.98 (95% CI 0.46-1.84) for MedBC. CONCLUSION: In ER-negative and HER2-negative MedBC, the risk of recurrence and death was significantly lower than that of IDC, about half. Postoperative chemotherapy reduced recurrence and mortality. ER-positive and HER2-negative MedBC may have a lower risk of recurrence compared to IDC.

Management of Crohn's disease relapse during neoadjuvant chemotherapy for bilateral breast cancer: a case report.

Diagnosis of breast cancer in a patient with Crohn's disease (CD) is uncommon. However, cytotoxic chemotherapy might help control CD during the treatment period. Here, we report a case of CD relapse during treatment with neoadjuvant chemotherapy (NAC) for bilateral breast cancer. A 39-year-old woman with CD controlled by infliximab and mesalazine was diagnosed with bilateral breast cancer. Infliximab treatment was discontinued temporarily so that the patient could receive NAC. However, her CD symptoms intensified during chemotherapy, and after her symptoms improved after a one-time administration of infliximab, the remainder of NAC was completed with a corticosteroid. Bilateral breast conservation surgery was performed. Histopathological examination revealed partial response of the left breast cancer and no residual cancer in the right breast. Breast irradiation and hormone therapy were added and no signs of recurrence have been observed for 5 years. CD has been well controlled with adalimumab and mesalazine.

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.

Clinicopathological features of male patients with breast cancer based on a nationwide registry database in Japan.

BACKGROUND: Male breast cancer (MBC) is rare; however, its incidence is increasing. There have been no large-scale reports on the clinicopathological characteristics of MBC in Japan. METHODS: We investigated patients diagnosed with breast cancer in the Japanese National Clinical Database (NCD) between January 2012 and December 2018. RESULTS: A total of 594,316 cases of breast cancer, including 3780 MBC (0.6%) and 590,536 female breast cancer (FBC) (99.4%), were evaluated. The median age at MBC and FBC diagnosis was 71 (45-86, 5-95%) and 60 years (39-83) (p < 0.001), respectively. MBC cases had a higher clinical stage than FBC cases: 7.4 vs. 13.3% stage 0, 37.2 vs. 44.3% stage I, 25.6 vs. 23.9% stage IIA, 8.8 vs. 8.4% stage IIB, 1.9 vs. 2.4% stage IIIA, 10.1 vs. 3.3% stage IIIB, and 1.1 vs. 1.3% stage IIIC (p < 0.001). Breast-conserving surgery was more frequent in FBC (14.6 vs. 46.7%, p = 0.02). Axillary lymph node dissection was more frequent in MBC cases (32.9 vs. 25.2%, p < 0.001). Estrogen receptor(ER)-positive disease was observed in 95.6% of MBC and 85.3% of FBC cases (p < 0.001). The HER2-positive disease rates were 9.5% and 15.7%, respectively (p < 0.001). Comorbidities were more frequent in MBC (57.3 vs. 32.8%) (p < 0.001). Chemotherapy was less common in MBC, while endocrine therapy use was similar in ER-positive MBC and FBC. Perioperative radiation therapy was performed in 14.3% and 44.3% of cases. CONCLUSION: Japanese MBC had an older age of onset, were more likely to be hormone receptor-positive disease, and received less perioperative chemotherapy than FBC.

Feasibility study on collecting patient-reported outcomes from breast cancer patients using the LINE-ePRO system.

Due to the increasing complexity of cancer treatment, ensuring safety and maintaining the quality of life during treatment are important issues. Patient-reported outcomes (PROs) in oncology are essential for assessing patient symptoms. A feasibility study was undertaken on breast cancer patients by building a PRO data collection system based on LINE, one of the most popular social network service applications in Japan. In this study, one or more predefined PRO questions for each breast cancer patient's clinical situation were sent to the patient's LINE application daily. The patient selected a predefined answer by tapping the screen, but no free-text answers were allowed. Seventy-three patients were enrolled. The median observation period was 435 days (84-656 days), and the total number of PROs collected was 16,417, with a mean of 224.9 reports per patient. Patients on adjuvant endocrine therapy were notified of 2.5 questions per week, and the median number of responses per week and response rate were 2.387 (1.687-11.627) and 95.5%, respectively. Analyzing the results by age group, the number of responses from those aged 60 and above was equal to or higher than that of the younger age group. It was also possible to track each patient's PROs accurately. These results suggested that the design of the system, based on an application used daily, instead of using specifically prepared applications for collecting electronic PROs, was the reason for the favorable acceptance from patients and the satisfactory response rate from all age groups, including the elderly.

Surgical treatment trends and identification of primary breast tumors after surgery in occult breast cancer: a study based on the Japanese National Clinical Database-Breast Cancer Registry.

BACKGROUND: Occult breast cancer (OBC) is classified as carcinoma of an unknown primary site, and the adequate therapy for OBC remains controversial. This retrospective study aimed to reveal the transition in breast cancer therapy and the frequency of primary breast tumors after resection in clinical OBC (cT0N+) patients using the Japanese Breast Cancer Registry database. METHODS: We enrolled OBC patients with cT0N+ from the registry between 2010 and 2018. On the basis of the period of diagnosis, OBC patients were divided into the following two groups: 2010-2014 and 2015-2018. We described the transition in treatments and tumor characteristics. After breast resection, the frequency of pathological identification of primary tumors and tumor sizes was assessed. RESULTS: Of the 687,468 patients registered, we identified 148 cT0N+ patients with a median age of 61 years. Of these patients, 64.2% (n = 95) received breast surgery (2010-2014: 79.1%, 2015-2018: 50.0%). Axillary lymph node dissection was performed in 92.6% (n = 137, 2010-2014: 91.6%, 2015-2018: 93.4%). The breast tumor size in the resected breast was 0-7.0 cm (median: 0 cm, 2010-2014: 0-7.0 cm [median: 0 cm], 2015-2018: 0-6.2 cm [median: 0 cm]). The pathological identification rate of the primary tumor was 41.1% (n = 39, 2010-2014: 40.4%, 2015-2018: 42.1%). CONCLUSIONS: Breast surgery for cT0N+ decreased between 2010 and 2018. Despite the high identification rate of primary tumors, most tumors were small, and there was no significant change in the identification rate or invasive diameter of the identified tumors after 2010.

Large Nipple Volume as a Risk Factor of Nipple-areola Complex Necrosis Following Nipple-sparing Mastectomy.

BACKGROUND: Nipple-areola complex (NAC) necrosis, which is caused by local ischemia, remains one of the complications associated with nipple-sparing mastectomy. Obesity, smoking, diabetes mellitus, and immediate breast reconstruction have been identified as risk factors of NAC necrosis. The current study examined the correlation between NAC necrosis and nipple volume. MATERIALS AND METHODS: A total of 83 patients who underwent NSM for primary breast cancer from January 2016 to December 2019 were retrospectively analyzed. Nipple volume was determined using the formula: volume (cc) = length × width × height (mm), with measurements determined using contrast-enhanced magnetic resonance imaging. Total and partial NAC necrosis was defined as full-thickness necrosis requiring surgical procedures and epidermal necrosis managing local wound care, respectively. RESULTS: NAC necrosis was observed in 30 patients (36%), with 3 and 27 patients having total and partial necrosis, respectively. Large nipple volume (56% vs. 24%, p = 0.006), as well as smoking and immediate breast reconstruction (57 vs. 28%, p = 0.017; 48% vs. 20%, p = 0.009, respectively), were significantly correlated with NAC necrosis. Multivariate analysis identified nipple volume as an independent risk factor for NAC necrosis (OR, 3.75; 95% CI, 1.23-11.44; p = 0.02). Smoking (OR, 4.68; 95% CI, 1.37-15.94; p = 0.014) and immediate breast reconstruction (OR, 3.43; 95% CI, 1.05-11.23; p = 0.042) were also independently associated with NAC necrosis. CONCLUSIONS: This study suggested that a large nipple volume could be one of the risk factors for NAC necrosis following NSM.

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.

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.

Annual report of the Japanese Breast Cancer Registry for 2017.

BACKGROUND: The Japanese Breast Cancer Society Registry started in 1975; it was transferred to the registry platform of the National Clinical Database in 2012. We provide the annual data and an analysis of the Breast Cancer Registry for 2017. METHODS: Patients' characteristics and pathological data of the 95,203 registered Japanese breast cancer patients from 1,427 institutes in 2017 were obtained. Trends in age at diagnosis and pathological stage were determined during the most recent 6 years (2012-2017). RESULTS: The mean onset age was 60.2 years with bimodal peaks at 45-49 years and 65-69 years. A short-term trend of the most recent 6 years of data caused the second, older peak. At diagnosis, 32.4% of breast cancer patients were premenopausal. The distribution of stages revealed that the proportion of early stage breast cancer (stage 0-I) increased up to 60%. At the initial diagnosis, 2.2% of patients presented with metastatic disease. Sentinel node biopsy without axillary node dissection was performed without neoadjuvant chemotherapy (NAC) in 68.8%, and with NAC in 31.1%, of patients. For patients without NAC, lymph node metastasis was less than 3% if the tumor size was less than 1 cm. The proportion of node-negativity decreased to 79.5% when tumor size was 2.1-5 cm. CONCLUSIONS: This analysis of the registry provides new information for effective treatment in clinical practice, cancer prevention, and the conduct of clinical trials. Further development of the registry and progress in collecting prognostic data will greatly enhance its scientific value.