Male Breast Cancer

Area of Science:

• Oncology
• Pathology

Background:

• Male breast cancer is rare, and its clinicopathologic and immunohistochemical features are less understood compared to female breast cancer.
• Understanding these characteristics is crucial for accurate diagnosis, prognosis, and treatment strategies.

Purpose of the Study:

• To present a clinicopathologic study of male invasive breast cancers.
• To emphasize the tumor immunohistochemical profile in this cohort.
• To compare the findings with those of female breast cancers.

Main Methods:

• A retrospective study of 61 cases of male invasive breast cancer.
• Analysis of tumor immunohistochemical markers including GATA-binding protein 3, androgen receptor, progesterone receptor, and human epidermal growth factor receptor 2.
• Survival analysis correlating tumor stage, receptor status, and Nottingham prognostic index.

Main Results:

• The cohort's median age was 65 years.
• Tumors were predominantly estrogen receptor-positive (97%) and rarely human epidermal growth factor receptor 2-positive (10%).
• High positivity rates were observed for GATA-binding protein 3 (98%), androgen receptor (95%), and progesterone receptor (90%). The immunohistochemistry profile was similar to female breast cancers. Overall survival was 70%, with breast cancer-specific survival at 92%. 33% developed second malignancies.

Conclusions:

• The immunohistochemistry profile of male breast cancer is similar to that of female breast cancer.
• Second malignancies significantly affected overall survival in this cohort.
• The findings suggest potential germline mutations, possibly beyond BRCA2, in male breast cancer patients.