Management of Male Breast Cancer: The Journey so Far and Future Directions

Outcomes of the patients with metastatic male breast cancer

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.

Asynchronous bilateral male breast cancer. A rare case report

We describe a rare case of asynchronous bilateral carcinoma of the mammary glands in a 66-year-old man. The patient was admitted to the Department of Dermatology and Venereology due to exacerbation of chronic eczema. During the examination, a 3×2-cm tumor with retraction of the mammilla was found in the right mammary gland. Mastectomy and regional lymphatic dissection were performed. Histological examination showed invasive ductal carcinoma, ER (+) 70%, PR (-), HER2 (-). Treatment included chemotherapy, radiotherapy, and hormone therapy. Three years later, the patient reported a lump in the left breast. The presence of a tumor formation was confirmed by mammography and ultrasound examination. A radical mastectomy with regional lymphatic dissection was performed. Histological examination showed invasive ductal carcinoma of the mammary gland, ER (3+) 80%, PP (2+) 60%, HER2 (+++), and Ki67 (+) 80%. Treatment with chemotherapy and radiation therapy was carried out. Five years after diagnosis of the second carcinoma, the patient is in a good general condition. Regardless of its rarity, the described case should draw doctors' attention to this pathology. Assessment of risk factors and periodic breast examination in men would allow early diagnosis, timely treatment, and better prognosis of the disease.

A Prospective Population-Based Study of Cardiovascular Disease Mortality following Treatment for Breast Cancer among Men in the United States, 2000-2019

Male breast cancer is rare but its incidence and mortality are increasing in the United States, with racial/ethnic disparities in survival reported. There is limited evidence for cardiotoxicity of cancer treatment among men with breast cancer. We evaluated the relation between breast cancer treatment and cardiovascular disease (CVD) mortality among men and investigated the salient roles that race/ethnicity play on this relation. Data were from 5216 men with breast cancer aged ≥ 40 years from the Surveillance, Epidemiology, and End Results program who were diagnosed from 2000 to 2019 and underwent surgery. Competing risk models were used to estimate hazards ratios (HR) and 95% confidence intervals (CI). During a median follow-up of 5.6 years, 1914 deaths occurred with 25% attributable to CVD. In multivariable-adjusted models, men who received chemotherapy had elevated risk for CVD (HR: 1.55, 95%CI: 1.18-2.04). This risk was higher among Hispanic men (HR: 3.96, 95%CI: 1.31-12.02) than non-Hispanic Black and non-Hispanic White men. There was no significant association between radiotherapy and CVD deaths. In this population-based study, treatment with chemotherapy was associated with elevated risk of CVD mortality in men with breast cancer. Racial/ethnic disparities in the association of chemotherapy and CVD mortality were observed.

Cancer Progression Is not Different in Mice of Different Gender Inoculated With Cells of the Triple-Negative 4T1 Breast Cancer Model

BACKGROUND

Breast cancer in men is a rare and poorly studied disease, and its treatment is based on women breast cancer studies. However, clinical outcome is not the same in men and women. Basic studies and clinical trials in animal models provide detailed information on cancer, origin, development, cell signaling pathways, sites of metastasis, and target molecules. It is necessary to explore the biology of breast cancer in male animal models that allow observing their similarity.

METHODS

The triple-negative 4T1 breast cancer model was developed in both male and female mice and studied weekly during 4 weeks. For that, twenty 8-week-old female and male BALB/c mice were used. Sixteen mice (eight males and eight females) were inoculated into the second left thoracic mammary pad with 20,000 4T1 cells, resuspended in 20 µL phosphate-buffered saline (PBS). All samples were processed for immunodetection, characterized histopathologically and immunohistochemically.

RESULTS

In this work, we describe the development of a triple-negative 4T1 breast cancer model in male BALB/c mice. Breast tumors were characterized histopathologically at different time points and corresponded to a moderately differentiated invasive ductal carcinoma, estrogen receptor ER-/progesterone receptor PR-/human epidermal growth factor receptor 2 HER2-/Ki67+, with histological grade II (moderately differentiated; a solid mass with occasional duct formation and moderate to severe nuclear pleomorphism), infiltrating the adipose and muscular tissue, and metastasis to lungs. From the results, we did not observe differences in the time of tumor development, necrosis, color change of tumor tissue, and lung metastasis between male and female mice. Even though we did not find histological differences, response to treatment and molecular signaling may be different.

CONCLUSIONS

The histogenesis of male breast tumors was similar to that of female BALB/c mice. The histological and immunohistochemical characteristics of male tumors also match the features reported for stage IV human breast cancer of men and women. The murine male breast cancer model described here can be a significant tool to explore the molecular mechanisms involved in male breast cancer tumorigenesis and metastasis and may bring new approaches for clinical treatment of triple-negative breast cancer in men.