Molecular subtypes predict the prognosis of male breast cancer: a retrospective cohort study

Area of Science:

• Oncology
• Genetics
• Epidemiology

Background:

• Male breast cancer is a rare condition with distinct characteristics compared to female breast cancer.
• The molecular subtypes and their prognostic implications in male breast cancer remain poorly understood due to a lack of large-scale studies.

Purpose of the Study:

• To investigate the characteristics and survival outcomes of male breast cancer patients.
• To analyze the distribution and prognostic significance of molecular subtypes in male breast cancer.

Main Methods:

• A retrospective analysis of 1,597 male breast cancer cases from the Surveillance, Epidemiology, and End Results (SEER) database (2010-2014).
• Molecular subtypes were defined by estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status.
• Survival analysis, including overall survival and cause-specific survival (CSS), was performed using Cox regression.

Main Results:

• Significant differences in age, race, grade, tumor size, and AJCC stage were observed across molecular subtypes.
• Five-year CSS rates varied significantly: 89.2% for HR+/HER2-, 78.4% for HR+/HER2+, 72.6% for HR-/HER2+, and 43.2% for triple-negative (TN).
• Independent prognostic factors for poorer CSS included older age, negative ER/PR status, TN subtype, advanced AJCC stage, larger tumor size, distant metastasis, and Black race.

Conclusions:

• Molecular subtypes are diverse in male breast cancer, similar to female breast cancer.
• These subtypes serve as crucial predictors of survival.
• Understanding molecular subtypes can enhance clinical strategy development and improve patient management.