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

Annual report of National Clinical Database-Breast Cancer Registry in 2021: characteristics categorized by body mass index and menopause status

The Japanese Breast Cancer Society initiated the breast cancer registry in 1975 and migrated the registry to the National Clinical Database-Breast Cancer Registry (NCD-BCR) in 2012. This annual report presents 2021 data on the NCD-BCR. We analyzed data from 98,540 breast cancer (BC) cases registered in 2021. In 2021, 99.4% of BC cases were females with a median age of 61. Most (57.5%) were diagnosed at early stages (Stage 0 or I). Breast-conserving surgery was performed in 42.8% of cases. Sentinel lymph node biopsy was performed in 67.8%, followed by radiotherapy in 71.0% of those post-conserving surgery. Regarding postoperative systemic therapy, 63.1% received endocrine therapy, 28.2% received chemotherapy, and 14.9% received molecular-targeted therapy. ER positivity was observed in 75.2%, HER2 in 13.6%, and Ki67 ≥30% in 29.1% of cases. The median age of premenopausal cases was 46 (interquartile range, 42-49) years and the median BMI was 21.5 (19.7-24.2) kg/m2 whereas the median age of postmenopausal cases was 69 (61-76) years and the median BMI was 23.0 (20.6-25.9) kg/m2. In premenopausal cases, cases with normal BMI were more likely to be found at checkups without subjective symptoms and in the early stage than those with high BMI. The tendency of ER, PgR, HER2, and Ki67 status on BMI differed by menopause status; premenopausal cases with a lower BMI showed higher proportions of ER- and PgR-positive cancer and lower proportions of cancer with high Ki67. These nationwide descriptive statistics would help clinical explanation and further research on breast cancer.

Breast cancer statistics for Japan in 2022: annual report of the national clinical database-breast cancer registry-clinical implications including chemosensitivity of breast cancer with low estrogen receptor expression

This is an annual report by the Japanese Breast Cancer Society, which provides statistics on the clinical data on breast cancer in Japan, extracted from the National Clinical Database-Breast Cancer Registry (NCD-BCR). This report includes an update of 102,453 breast cancer cases at 1339 institutions registered in the NCD-BCR in 2022. Among the 101,793 female patients, the median age at cancer diagnosis was 62 years (interquartile range, 50-73 years), and 29.4% of the patients were premenopausal. Of these patients, 15,437 (15.2%) and 42,936 (42.2%) were diagnosed with stage 0 and I disease, respectively. Estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) were positive in 78.7%, 69.4%, and 12.8% of the patients, respectively. Of the 97,154 patients without distant metastasis, 40,521 (41.7%) underwent breast-conserving surgery, and 5780 (5.9%) patients underwent some form of breast reconstruction procedures at the time of mastectomy. A total of 66,894 (68.9%) patients were treated with sentinel lymph node biopsy and 7155 (7.4%) patients were treated with sentinel lymph node biopsy followed by axillary node dissection. In the group of patients treated with breast-conserving surgery (n = 40,521), 29,500 (72.8%) received whole-breast irradiation. In the group of patients who underwent mastectomy (n = 54,476), 6226 (11.4%) received radiation therapy to the chest wall. Of the 13,950 patients receiving preoperative chemotherapy with or without molecular targeted therapy, 4308 (30.9%) achieved a pathological complete response, with the highest rate of 60.5% in patients with the hormone receptor-negative/HER2-positive subtype.

Global, regional, and national burden of male breast cancer in 204 countries and territories: a systematic analysis from the global burden of disease study, 1990-2021

Background

Male breast cancer (MBC) is a rare malignancy that has been under-investigated, with limited global epidemiological research dedicated to it. A comprehensive estimate of the global, regional, and national burden of MBC is valuable for policy planning. This study aims to evaluate the burden of MBC across 204 countries and territories.

Methods

MBC data were collected from the 2021 Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study estimates spanning from 1990 to 2021. The global incidence, prevalence, deaths, and disability-adjusted life-years (DALYs) attributed to MBC, as well as corresponding age-standardized rates, were calculated. Temporal trends, projections of incidence and mortality to 2050, lifetime risk, and risk factors of MBC were also estimated according to regions and countries.

Findings

In 2021, there were 38,827 (95% uncertainty interval [UI], 24,650-47,846) new cases, 320,459 (95% UI, 220,533-384,317) prevalent cases, 13,274 (95% UI, 9074-16,240) deaths, and 380,917 (95% UI, 252,922-476,417) DALYs attributed to MBC worldwide, with the highest disease burden observed in the Eastern Sub-Saharan Africa region. From 1990 to 2021, the age-standardized incidence and mortality rates of MBC significantly increased, but they are projected to decrease over the next 30 years. High-middle Socio-demographic Index (SDI) quintile had the highest lifetime risk of developing MBC, while the low SDI quintile had the highest lifetime risk of dying from MBC. Dietary risk and alcohol use were identified as important risk factors for MBC deaths and DALYs globally.

Interpretation

The global burden of MBC significantly increased from 1990 to 2021, with notable geographic disparities. Efforts aimed at MBC prevention and control strategies should take into account the inequities in its global distribution.

Funding

This study was supported by the National Natural Science Foundation of China (grant numbers 82372996 and 82202913) and the Chongqing Natural Science Foundation (grant number CSTB2023NSCQ-MSX0480).

Unveiling the comorbidity burden of male breast cancer

Male breast cancer (MBC) is a rare condition with unique characteristics compared to female breast cancer (FBC). Despite its scarceness, there is growing evidence that MBC should not be studied and treated as FBC due to factors like later diagnosis stage and distinct genetic makeup. Retrospective observational study in the EpiChron Cohort, selecting all the prevalent patients with breast cancer between 2010 and 2019. Logistic models were used to determine associated comorbidities. Between 2010 and 2019, 105 MBC and 11,657 FBC patients were found in the EpiChron Cohort. MBC patients had a high mean age at diagnosis and number of comorbidities. Paying attention to comorbidity prevalences in breast cancer patients, it was clear that MBC patients tended to be prone to cardio-metabolic coexisting diseases, while FBC patients were more prone to hormone-, bone- and mental diseases. There were nine chronic conditions associated to MBC patients, but after a year-by-birth matching only four associations remained. Two of them were associated previously [odds ratio (95% confidence interval)]: "Disorder of lipid metabolism" [1.65 (1.03-2.64)] and "Genitourinary symptoms and ill-defined conditions" [2.03 (1.07-3.87)]; and the other two were new, "Anxiety disorders" [2.05 (1.09-3.87)] and "Osteoporosis" [3.58 (1.26-10.14)]. After comparing associated comorbidities in FBC with those in MBC, it seems MBC patients share some of them, but they have their own particular set of coexisting diseases. In fact, once a year-by-birth matching was performed in MBC patient cohort, it was more obvious MBC comorbidities behave more similar to none-Breast-Cancer male population than to FBC patients. These findings highlight the distinct characteristics of the MBC patient population and the need for a tailored approach of managing MBC.

The features of male breast cancer in China: A real-world study

BACKGROUND

Male breast cancer (MBC) is a rare disease. Although several large-scale studies have investigated MBC patients in other countries, the features of MBC patients in China have not been fully explored. This study aims to explore the features of Chinese MBC patients comprehensively.

METHODS

We retrospectively collected data of MBC patients from 36 centers in China. Overall survival (OS) was evaluated by the Kaplan-Meier method, log-rank test, and Cox regression analyses. Multivariate Cox analyses were used to identify independent prognostic factors of the patients.

RESULTS

In total, 1119 patients were included. The mean age at diagnosis was 60.9 years, and a significant extension over time was observed (P < 0.001). The majority of the patients (89.1 %) received mastectomy. Sentinel lymph node biopsy was performed in 7.8 % of the patients diagnosed in 2009 or earlier, and this percentage increased significantly to 38.8 % in 2020 or later (P < 0.001). The five-year OS rate for the population was 85.5 % [95 % confidence interval (CI), 82.8 %-88.4 %]. Multivariate Cox analysis identified taxane-based [T-based, hazard ratio (HR) = 0.32, 95 % CI, 0.13 to 0.78, P = 0.012] and anthracycline plus taxane-based (A + T-based, HR = 0.47, 95 % CI, 0.23 to 0.96, P = 0.037) regimens as independent protective factors for OS. However, the anthracycline-based regimen showed no significance in outcome (P = 0.175).

CONCLUSION

As the most extensive MBC study in China, we described the characteristics, treatment and prognosis of Chinese MBC population comprehensively. T-based and A + T-based regimens were protective factors for OS in these patients. More research is required for this population.

Survival trends and patient characteristics between 2004 and 2016 for breast cancer in Japan based on the National Clinical Database-Breast Cancer Registry

This is a prognostic report by the Japanese Breast Cancer Society on breast cancer extracted from the National Clinical Database-Breast Cancer Registry of Japan. Here, we present a summary of 457,878 breast cancer cases registered between 2004 and 2016. The median follow-up duration was 5.6 years. The median age at the start of treatment was 59 years (5-95%: 38-82 years) and increased from 57 years between 2004 and 2008 to 60 years between 2013 and 2016. The proportion of patients with Stage 0-II disease increased from 74.5% to 78.3%. The number of cases with estrogen and progesterone receptor positivity increased from 74.8% to 77.9% and 60.5% to 68.1%, respectively. Regarding (neo-)adjuvant chemotherapy, the taxane (T) or taxane-cyclophosphamide (C) regimen increased by 2.4% to 8.2%, but the (fluorouracil (F)) adriamycin (A)-C-T/(F) epirubicin (E)C-T and (F)AC/(F)EC regimens decreased by 18.6% to 15.2% and 13.5% to 5.0%, respectively. Regarding (neo-)adjuvant anti-human epidermal growth factor-2 (HER2)-targeted therapy, the use of trastuzumab increased from 4.6% to 10.5%. The rate of sentinel lymph node biopsy increased from 37.1% to 60.7%, while that of axillary dissection decreased from 54.5% to 22.6%. Improvements in disease-free and overall survival were observed in patients with HER2-positive breast cancer, but there was no apparent trend in patients with hormone receptor-positive, HER2-negative, or triple-negative breast cancers.

2020 Annual Report of National Clinical Database-Breast Cancer Registry: 10-year mortality of elderly breast cancer patients in Japan

The Japanese Breast Cancer Society initiated the breast cancer registry in 1975, which transitioned to the National Clinical Database-Breast Cancer Registry in 2012. This annual report presents data from 2020 and analyzes the ten-year mortality rates for those aged 65 and older. We analyzed data from 93,784 breast cancer (BC) cases registered in 2020 and assessed 10-year mortality rates for 36,279 elderly patients diagnosed between 2008 and 2012. In 2020, 99.4% of BC cases were females with a median age of 61. Most (65%) were diagnosed at early stages (Stage 0 or I). Breast-conserving surgery rates varied with stages: 58.5% at cStage I, 30.8% at cStage II, and 13.1% at cStage III. Sentinel lymph node biopsy was done in 73.6% of cases, followed by radiotherapy in 70% of those post-conserving surgery and chemotherapy in 21.1% post-surgery. Pathology showed that 63.4% had tumors under 2.0 cm, 11.7% had pTis tumors, and 77.3% had no axillary lymph node metastasis. ER positivity was seen in 75.1%, HER2 in 14.3%, and 30% had a Ki67 positivity rate above 30%. Across all stages and subtypes, there was a trend where the 10-year mortality rates increased for individuals older than 65 years. In Stage I, many deaths were not directly linked to BC and, for those with HER2-type and triple-negative BC, breast cancer-related deaths increased with age. Within Stage II, patients older than 70 years with luminal-type BC often experienced deaths not directly linked to BC, whereas patients below 80 years with HER2-type and triple-negative BC, likely had breast cancer-related deaths. In Stage III, breast cancer-related deaths were more common, particularly in HER2 and triple-negative BC. Our prognostic analysis underscores distinct mortality patterns by stage, subtype, and age in elderly BC patients. It highlights the importance of personalized treatment strategies, considering subtype-specific aggressiveness, age-related factors, and comorbidities.

Trends and Age-Period-Cohort Effect on Incidence of Male Breast Cancer from 1980 to 2019 in Taiwan and the USA

Although male breast cancer (MBC) is globally rare, its incidence significantly increased from 1990 to 2017. The aim of this study was to examine variations in the trends of MBC incidence between populations in Taiwan and the USA from 1980 to 2019. The Taiwan Cancer Registry database and the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute of the USA were used. The age-standardized incidence rate was calculated using the world standard population in 2000. The long-term trends of the age, time period, and birth cohort effect on MBC incidence rates were estimated using the SEER Age-Period-Cohort Web Tool. The results revealed that the incidence of MBC in both countries increased from 2010 to 2019 (Taiwan: average annual percentage change (AAPC) = 2.59%; USA: AAPC = 0.64%). The age and period effects on the incidence rates in both countries strengthened, but the cohort effect was only identified in Taiwan (Rate ratio: 4.03). The identified cohort effect in this study bears resemblance to that noted in a previous investigation on female breast cancer in Taiwan. This suggests the possible presence of common environmental factors influencing breast cancer incidence in both genders, such as a high fat diet and xenoestrogen.

Annual report of the Japanese Breast Cancer Registry for 2019

This is an annual report by the Japanese Breast Cancer Society regarding the clinical data on breast cancer extracted from the National Clinical Database-Breast Cancer Registry (NCD-BCR) of Japan. Here, we present an updated summary of 98,300 breast cancer cases registered in 2019. The median age at cancer diagnosis was 61 years (interquartile range 49-72 years), and 30.6% of the breast cancer patients were premenopausal. Of the 93,840 patients without distant metastases, 14,118 (15.0%) and 42,047 (44.8%) were diagnosed with stage 0 and I disease, respectively. Breast-conserving surgery was performed in 42,080 (44.8%) patients. Regarding axillary procedures, 62,677 (66.8%) and 7371 (7.9%) patients underwent sentinel node biopsy and axillary node dissection after biopsy, respectively. Whole breast irradiation was administered to 29,795 (70.8%) of the 42,080 patients undergoing breast-conserving surgery. Chest wall irradiation was administered to 5524 (11.1%) of the 49,637 patients who underwent mastectomy. Of the 6912 clinically lymph node-negative patients who received preoperative therapy, 5250 (76.0%) and 427 (6.2%) underwent sentinel node biopsy and axillary node dissection after biopsy, respectively; however, 602 (8.7%) patients initially underwent axillary node dissection without biopsy.

Clinicopathological features, genetic alterations, and BRCA1 promoter methylation in Japanese male patients with breast cancer

PURPOSE

Male breast cancer (MBC) is a rare cancer accounting for only 1% of all male cancers and is, therefore, poorly studied. We aimed to characterize the subtypes of MBC in Japanese patients based on genetic profiling, the presence of tumor-infiltrating cells, and the expression of immunohistochemical markers.

METHODS

This retrospective study included 103 patients with MBC diagnosed between January 2009 and December 2019 at various hospitals in Japan. Clinicopathological patient characteristics were obtained from medical records, and formalin-fixed paraffin-embedded tissue specimens were analyzed for histological markers, mutations of 126 genes, BRCA1 methylation, and stromal tumor-infiltrating lymphocytes.

RESULTS

The median patient age was 71 (range 31-92) years. T1-stage tumors were the most frequent (47.6%), and most were node negative (77.7%). The majority of tumors were positive for estrogen receptor (98.1%), progesterone receptor (95.1%), and androgen receptor (96.1%), and BRCA2 was the most frequently mutated gene (12.6%). The most common treatment was surgery (99.0%), either total mastectomy (91.1%) or partial mastectomy (7.0%). Survival analysis showed a 5-year recurrence-free survival rate of 64.4% (95% confidence interval [CI] 46.7-88.8) and a 5-year overall survival rate of 54.3% (95% CI 24.1-100.0).

CONCLUSION

Japanese MBC is characterized by a high rate of hormonal receptor positivity and BRCA2 somatic mutation. Due to the observed clinicopathological differences in MBC between the Western countries and Japan, further prospective studies are needed to evaluate the most suitable treatment strategies.