CHEK2 is considered to be involved in homologous recombination repair (HRR). Individuals who have germline pathogenic variants (gPVs) in CHEK2 are at increased risk to develop breast cancer and likely other primary cancers. PARP inhibitors (PARPi) have been shown to be effective in the treatment of cancers that present with HRR deficiency-for example, caused by inactivation of BRCA1/2. However, clinical trials have shown little to no efficacy of PARPi in patients with CHEK2 gPVs. Here, we show that both breast and non-breast cancers from individuals who have biallelic gPVs in CHEK2 (germline CHEK2 deficiency) do not present with molecular profiles that fit with HRR deficiency. This finding provides a likely explanation why PARPi therapy is not successful in the treatment of CHEK2-deficient cancers.

A 77-year-old transgender man (assigned female sex at birth, gender identity male, i.e. female-to-male) was referred for a palpable mass of the right chest wall. Biopsies revealed invasive lobular breast carcinoma. After discussion by a multidisciplinary tumour board meeting, the patient was treated with total mastectomy, adjuvant hypofractionated radiation therapy, and hormone therapy. At 1.5-year follow-up, there was no sign of recurrence or long-term radiation side effects. To our knowledge, this is the first reported case of adjuvant hypofractionated radiation therapy in a transgender patient with breast cancer.

Breast cancer in men is a rare and understudied disease. Until recently, prospective studies and clinical trials on breast cancer treatments often excluded men. Treatment recommendations were generally extrapolated from the results of clinical trials that included only women. Significant efforts have been made to better understand the biological characteristics, the most effective treatments, and the outcomes of breast cancer in men, as well as to identify clinically relevant differences of this disease. This article reviews the current data on the epidemiology, pathological and clinical characteristics, as well as the treatment of breast cancer in men.
Le cancer du sein chez l’homme est une maladie rare et peu étudiée. Jusqu’à récemment, les études prospectives et les essais cliniques sur les traitements du cancer du sein excluaient souvent les hommes. Les recommandations de traitement étaient généralement extrapolées à partir des résultats d’essais cliniques incluant uniquement des femmes. Des efforts significatifs ont été déployés pour mieux comprendre les caractéristiques biologiques, les traitements les plus efficaces et les résultats du cancer du sein chez les hommes, ainsi que pour identifier les différences cliniquement pertinentes de cette maladie. Cet article passe en revue les données actuelles sur l’épidémiologie, les caractéristiques pathologiques et cliniques, ainsi que le traitement du cancer du sein chez l’homme.

The number of men undergoing breast imaging has increased in recent years, according to some reports. Most male breast concerns are related to benign causes, most commonly gynecomastia. The range of abnormalities typically encountered in the male breast is less broad than that encountered in women, given that lobule formation rarely occurs in men. Other benign causes of male breast palpable abnormalities with characteristic imaging findings include lipomas, sebaceous or epidermal inclusion cysts, and intramammary lymph nodes. Male breast cancer (MBC) is rare, representing up to 1% of breast cancer cases, but some data indicate that its incidence is increasing. MBC demonstrates some clinical features that overlap with those of gynecomastia, including a propensity for the subareolar breast. Men with breast cancer tend to present at a later stage than do women. MBC typically has similar imaging features to those of female breast cancer, often characterized by an irregular mass that may have associated calcifications. Occasionally, however, MBC has a benign-appearing imaging phenotype, with an oval shape and circumscribed margins, and therefore most solid breast masses in men require tissue diagnosis. Histopathologic evaluation may alternatively reveal other benign breast masses found in men, including papillomas, myofibroblastomas, and hemangiomas. Radiologists must be familiar with the breadth of male breast abnormalities to meet the rising challenge of caring for these patients. ©RSNA, 2024 Supplemental material is available for this article.

OBJECTIVE: To determine the characteristics and risk factors of breast cancer patients in a tertiary care setting.
METHODS: The retrospective, cross-sectional study was conducted at the Sindh Institute of Urology and Transplantation, Karachi, and comprised data of all patients diagnosed with breast cancer from March 2017 to December 2021. Demographic characteristics, clinical presentation, stage of the disease and histopathological characteristics were noted. Data related to all the variables was not available in all cases. Data was analysed using SPSS 23.
RESULTS: Of the 690 patients, 683(99%) were females and 7(1%) were males. The mean age at presentation was 49.3±13.5 years, while the mean duration of symptoms was 10.24±17.64) months. Most of the females were married 642(93%) and multiparous 484(70.9%), while 293(42.5%) had breastfed their children for >1 year, and 412(59.7%) had no history of contraception use. The most common stage at presentation was stage II (48.6%), and most patients had grade II 395(57.2%) invasive ductal carcinoma, with Luminal A molecular subtype noted in 287(41.6%) cases.
CONCLUSIONS: The characteristics of breast cancer in the sample had certain distinctions compared to other populations. It is important to integrate all datasets and develop guidelines appropriate to Pakistani population.

Breast cancer in men accounts for around 1 % of all cases of the disease. The study aimed to identify histopathological parameters and selected biomarkers in men with breast cancer.
Retrospective study of archival material from 53 men diagnosed with breast cancer at the department of pathology, Haukeland University Hospital, in the period 1996-2020. The prevalence of the oestrogen receptor (ER), progesterone receptor (PGR) and Human Epidermal Growth Factor (HER2) biomarkers was examined.
Median age at time of diagnosis was 72 years. Median tumour diameter was 24 mm. Forty-nine tumours were classified histologically as invasive carcinoma of no special type (NST), 29 tumours were histologic grade 2 and 18 were grade 3. Fifty-two tumours were ER positive, 39 were PGR positive and four were HER2 positive. Twenty-five patients had lymph node metastases.
Our findings indicate that men with breast cancer are diagnosed at an older age than women, and that men have a more advanced stage than women at the time of diagnosis. The histopathology and expression of biomarkers of breast cancer differ between men and women.

Germline genetic testing is a vital component of guideline-recommended cancer care for males with pancreatic, breast, or metastatic prostate cancers. We sought to determine whether there were racial disparities in germline genetic testing completion in this population.
This retrospective cohort study included non-Hispanic White and Black males with incident pancreatic, breast, or metastatic prostate cancers between January 1, 2019, and September 30, 2021. Two nationwide cohorts were examined: (1) commercially insured individuals in an administrative claims database, and (2) Veterans receiving care in the Veterans Health Administration. One-year germline genetic testing rates were estimated by using Kaplan-Meier methods. Cox proportional hazards regression was used to test the association between race and genetic testing completion. Causal mediation analyses were performed to investigate whether socioeconomic variables contributed to associations between race and germline testing.
Our cohort consisted of 7,894 males (5,142 commercially insured; 2,752 Veterans). One-year testing rates were 18.0% (95% CI, 16.8%-19.2%) in commercially insured individuals and 14.2% (95% CI, 11.5%-15.0%) in Veterans. Black race was associated with a lower hazard of testing among commercially insured individuals (adjusted hazard ratio [aHR], 0.73; 95% CI, 0.58-0.91; P=.005) but not among Veterans (aHR, 0.99; 95% CI, 0.75-1.32; P=.960). In commercially insured individuals, income (aHR, 0.90; 95% CI, 0.86-0.96) and net worth (aHR, 0.92; 95% CI, 0.86-0.98) mediated racial disparities, whereas education (aHR, 0.98; 95% CI, 0.94-1.01) did not.
Overall rates of guideline-recommended genetic testing are low in males with pancreatic, breast, or metastatic prostate cancers. Racial disparities in genetic testing among males exist in a commercially insured population, mediated by net worth and household income; these disparities are not seen in the equal-access Veterans Health Administration. Alleviating financial and access barriers may mitigate racial disparities in genetic testing.

How cancer patterns in humans compare to those of other species remains largely unknown and there is an even bigger knowledge gap for rare cancers like male breast cancer. One Health is a convergence of human and animal healthcare that encourages cross-pollination of medical research uniting human and veterinary medicine. Recognising that breast cancer occurs spontaneously in other male species (e.g. primates, canines, felines), and knowing that no laboratory models exist for male breast cancer, which limits our ability to perform functional studies, we explored the feasibility of applying One Health to breast cancer in men by conducting a narrative review of the topic. Spontaneous development of breast cancer was reported in captive male primates and in companion canines and felines. Some parallels in tumour biology of human male breast cancer with canines and primates were found. The age distribution, pattern of biomarker expression and metastasis were similar, with mammary tumours typically detected after two-thirds of average lifespan. However, instances of triple negative and inflammatory breast cancer, which are rarely observed in human male breast cancer, were found in canines and histological classification was inconsistent between species. These disparities need redressing to enable full exploration of the One Health paradigm in rare cancers.

OBJECTIVE: This study aimed to examine the relative risk of risk factor in male and female breast cancer (BC) deaths in China and analyzed the changing trends in BC mortality rates from 1990 to 2019.
METHODS: Open data from the Global Burden of Disease database from 1990 to 2019 were analyzed to assess the number of BC deaths and age-standardized mortality rates (ASMR) in China. The age-period-cohort model was employed to study age effects, period effects, cohort effects, as well as local drift and net drift of the data, determining the impact of changing risk factors on crude mortality rates and ASMR of BC.
RESULTS: In 2019, the number of BC deaths across all age groups in China increased by 130.38% compared to 1990, with an increase of 125.68% in females and 648.80% in males. The ASMR for BC and male BC increased in 2019, while female BC ASMR declined. Overall, alcohol consumption and smoking as risk factors contributed to increased mortality rates of BC with advancing age. Over the entire study period, the net drift of alcohol consumption in females for BC was 0.06% (95% confidence interval [CI]: -0.24% to 0.36%), while for smoking it was -0.64% (95% CI: -0.83% to -0.45%). For males, the net drift of alcohol consumption for BC was 6.75% (95% CI: 5.55% to 7.96%), and for smoking, it was 6.09% (95% CI: 2.66% to 9.64%).
CONCLUSIONS: Hence, improving awareness of BC-related risk factors and implementing prevention strategies are necessary to alleviate future BC burdens.

BACKGROUND: The goal of this research is to investigate the clinical characteristics and prognosis of men with metastatic breast cancer (mMBC).
METHODS: A retrospective analysis of the data of 28 patients was conducted. Kaplan-Meier and Cox regression analyses were used to assess overall survival (OS) and prognostic variables.
RESULTS: At the time of diagnosis, the median age was 57 years (range 26-86). The most prevalent pathological subtype was invasive ductal carcinoma (92.6%). HER2 positivity was 21.6% in patients, with estrogen and progesterone receptor positivity at 96.4% and 71.4%, respectively. Bone-75%, lung-39.3%, brain-21.4%, and adrenal gland-10.7% were the most prevalent metastatic sites. Trastuzumab-based chemotherapy was given to six patients. During the study period, 14 patients (or half) died. All patients had a median OS of 42.6 months (range: 21.6-63.7). The OS rates after 1, 3, and 5 years were 95.7%, 54.2%, and 36.6%, respectively. The number of metastatic locations (P = 0.045), brain metastasis (P = 0.033), and a history of regular alcohol intake (P = 0.008) were all shown to be statistically significant factors affecting OS in univariate analysis. However, multivariate analysis did not support the findings. In addition, we discovered that trastuzumab-based therapy and de-novo metastatic disease had no effect on OS for mMBC.
CONCLUSIONS: The data on mMBC is restricted because of its rarity. The prognosis of mMBC was shown to be poor in this investigation. Despite the small number of patients, we discovered that in univariate analysis, having brain metastases, the number of metastatic locations, and a history of alcohol intake may be prognostic factors.