Significance of Bcl-2 and Ki-67 Expression in Breast Carcinoma and their Correlation with Histologic Grade

Background: ER, PR, HER2, and Ki-67 are established prognostic markers in breast carcinoma. The anti-apoptotic factor B-cell lymphoma 2 (Bcl-2) is emerging as an additional prognostic indicator. This study aimed to assess the correlation of Bcl-2 expression with Ki-67 scores and histological grading. Material and Methods: A hospital-based, prospective observational study was conducted on 52 mastectomy specimens after applying exclusion criteria. Gross examination and routine histopathology with Hematoxylin and Eosin staining were followed by immunohistochemistry for ER, PR, HER2, Ki-67, and Bcl-2. Cases were graded using the Nottingham Histologic Score. Bcl-2 expression was correlated with Ki-67 scores and histological grades, and statistical analysis was performed. Results: Out of 52 cases, 50 (98.1%) were invasive ductal carcinoma and 2 (1.9%) were lobular carcinoma. Histologic Grade 3 tumors constituted 57.7% of cases. A Ki-67 score ≥20% was significantly associated with higher grades (p = 0.0285770). Bcl-2 expression was inversely correlated with histological grade (p = 0.004302). Low Bcl-2 expression was significantly associated with a high Ki-67 score (p = 0.03708). Conclusion: Strong Bcl-2 expression correlates with lower-grade, less aggressive tumors and is inversely related to high Ki-67 expression. Bcl-2 combined with Ki-67 may enhance prognostic assessment in breast carcinoma.