Evaluation of BCL-2 expression in 33 consecutive cases of serous ovarian carcinoma

Abstract

Introduction: Serous ovarian carcinoma, the most frequent subtype, exhibits aggressive behavior and late diagnosis. The BCL-2 protein, with its anti-apoptotic role, promotes tumor cell survival. BCL-2 expression is heterogeneous and, although clinicopathological correlations are not consistent, it remains a potential therapeutic target. Materials and Methods: The study had a retrospective, cross-sectional design, including 33 consecutive cases of serous ovarian carcinoma diagnosed between 2021–2025 at the Oncology Institute. BCL-2 expression was evaluated immunohistochemically on paraffin-embedded sections, with antigen retrieval by boiling at elevated pH for 20 minutes and incubation for 25 minutes with monoclonal BCL-2 antibody, clone 124. Detection was performed using the BioSB, highlighting a brown cytoplasmic reaction. Expression was quantified using the immunoreactive score (IRS), determined according to staining intensity (score 0–3) and the proportion of positive tumor cells, with emphasis on intratumoral heterogeneity. Statistical analysis included descriptive methods and inferential tests (Spearman, Chi-square), with a significance threshold of p<0.05 Results: Of the 33 analyzed cases, 78.8% were high-grade serous ovarian carcinoma, while 21.2% were low-grade. Advanced stages predominated, with stage III identified in 63.6% of cases. Immunohistochemical expression of BCL-2 was heterogeneous: absence of expression (score 0) was observed in 36.4% of cases, weak expression (score 1) in 15.2%, moderate expression (score 2) in 27.3%, and strong expression (score 3) in 21.2%. The proportion of positive tumor cells ranged from 0% to 80%, with a mean of 26% and a median of 20%. Analysis of the immunoreactive score (IRS) revealed a median of 2, with values ranging from 0 to 12. Most cases (79%) showed low BCL-2 expression, while high expression was observed in 21%. Statistical analysis did not reveal significant associations between IRS score and tumor stage (Spearman r = –0.33; p = 0.063) or between BCL-2 expression level (low/high) and disease stage (χ², p = 0.55). Conclusions: In the analyzed cohort, BCL2 expression did not demonstrate statistically significant associations with the evaluated clinicopathological parameters. However, the presence of high expression in a subgroup of cases may reflect activation of anti-apoptotic mechanisms, with possible implications for tumor biological behavior.