BCL2 as a Subtype-Specific Prognostic Marker for Breast Cancer

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• B-cell lymphoma 2 (BCL2) is an antiapoptotic protein and a prognostic marker in breast cancer.
• Its clinical significance may be influenced by estrogen receptor (ER) status and molecular subtypes.

Purpose of the Study:

• To investigate the relationship between BCL2 expression and prognostic outcomes across different breast cancer molecular subtypes.
• To determine if BCL2 serves as a prognostic marker in specific breast cancer subtypes.

Main Methods:

• Retrieved data from 1,356 newly diagnosed breast cancer patients.
• Assessed BCL2 expression using immunohistochemistry, alongside ER, HER2, Ki-67, and progesterone receptor.
• Classified tumors into five molecular subtypes: luminal A, luminal B (HER2-negative), luminal B (HER2-positive), HER2-overexpression, and triple-negative.

Main Results:

• BCL2 expression was observed in 53.8% of cases and correlated with younger age, lower grade, low Ki-67, hormone receptor positivity, HER2 negativity, and luminal subtypes.
• BCL2 positivity was associated with improved 5-year relapse-free survival (RFS) and disease-specific survival (DSS) overall.
• Significantly favorable RFS and DSS were observed for BCL2-positive luminal A breast cancer, but not other subtypes.

Conclusions:

• The prognostic value of BCL2 in breast cancer is subtype-dependent.
• BCL2 expression is a favorable prognostic marker exclusively in luminal A breast cancer.