BCL2 expression in invasive breast carcinoma varies across molecular subtypes, suggesting prognostic utility.
Background
Breast cancer (BC) remains the most common cancer and a leading cause of death in women, characterized by significant molecular heterogeneity. Despite advances in treatment, identifying reliable prognostic markers is crucial for guiding individualized therapeutic strategies. Current standard-of-care relies on markers like ER, PR, HER2/neu, and Ki67, but additional markers are needed to refine risk stratification and treatment selection. The BCL2 protein, known for its anti-apoptotic functions, has been implicated in various cancers, making its expression a potential prognostic indicator in BC.
Study Design
Researchers analyzed 50 cases of invasive breast carcinoma diagnosed between 2015 and 2020. A manual tissue microarray technique was employed to assess the expression of several IHC markers, including BCL2, ER, PR, Her2/neu, Ki67, CK5/6, and EGFR. The study aimed to correlate BCL2 expression with established clinicopathological parameters such as histological grade, tumor size, lymph node status, and molecular subtypes. Results were then subjected to statistical analysis to identify significant associations.
Results
BCL2 positivity was detected in 36% of the breast cancer cases studied. The distribution of BCL2 expression varied significantly across different molecular subtypes: 22.22% of HER2 enriched cases, 33.33% of hormone receptor positive cases, 38.89% of triple negative breast cancer (TNBC) non-classifiable cases, and 5.56% of basal-like breast cancer (BLBC) cases showed BCL2 positivity. Specifically, BCL2 was positive in 35.29% of hormone receptor positive BC cases (34% of total cases), 36.36% of TNBC cases (44% of total cases), and 10% of BLBC cases (20% of total cases).
Key Findings
- BCL2 expression was observed in 36% of invasive breast carcinoma cases.
- BCL2 positivity was seen in 33.33% of hormone receptor positive breast cancer cases.
- Triple negative breast cancer (TNBC) cases showed BCL2 positivity in 38.89% of non-classifiable cases and 36.36% of total TNBC cases.
- Basal-like breast cancer (BLBC) cases exhibited BCL2 positivity in 5.56% of non-classifiable cases and 10% of total BLBC cases.
- Loss of BCL2 expression showed a statistically insignificant association with higher tumor grade and stage, and lymph node positivity.
Why It Matters
The findings suggest that BCL2 expression could serve as a valuable prognostic marker in breast cancer, meriting its inclusion in routine IHC panels. This could significantly impact personalized therapeutic strategies, especially given its varied expression across molecular subtypes like TNBC and BLBC, which often have limited targeted treatment options. Integrating BCL2 into diagnostic workups may help clinicians better stratify patient risk and tailor treatment plans, potentially improving outcomes. While this study provides correlative data, further research is needed to establish its predictive value for treatment response and to develop BCL2-targeted therapies for specific patient subsets.
breast-cancer
bcl2
prognostic-marker
immunohistochemistry
molecular-subtypes
tnbc