Association of Androgen Receptor (AR) and HER-2/Neu Expression in prostate adenocarcinoma using immunohistochemistry

Abstract

Objective: To assess the frequency of androgen receptor (AR) and HER-2/Neu expression across different Gleason Grade Groups among patients with prostate adenocarcinoma.

Methodology: This cross-sectional study was conducted in Department of Histopathology, Allama Iqbal Medical College, Lahore, over a period of six months (July 12, 2025 to January 12, 2026). A total of 78 histopathologically confirmed cases of prostate adenocarcinoma were included using non-probability purposive sampling. Formalin-fixed paraffin-embedded tissue sections were evaluated for AR and HER-2/Neu expression by immunohistochemistry using standardized staining protocols. AR expression was assessed based on nuclear staining intensity, whereas HER-2/Neu expression was evaluated according to ASCO/CAP immunohistochemical criteria. Data analysis was done using SPSS v24.

Results: Strong AR expression was observed in 48.7% of cases, moderate expression in 39.7%, weak expression in 10.3%, and negative staining in 1.3%. HER-2/Neu expression was negative (score 0) in 84.6% of cases, while 15.4% showed only 1+ staining; no cases demonstrated 2+ or 3+ expression. AR expression showed significant association with increasing Gleason Grade Group (p < 0.001), whereas HER-2/Neu expression showed no significant association (p = 0.477).

Conclusion: AR expression was preserved in the majority of prostate adenocarcinomas and demonstrated a significant positive association with higher Gleason Grade Groups, suggesting its potential role as a marker of tumor aggressiveness. In contrast, HER-2/Neu expression was infrequent and showed no significant association with tumor grade.