Immunohistochemical Expression Status of HER2/neu and E-cadherin in Prostate Adenocarcinoma: A Cross-sectional Study

Abstract

Introduction: Prostate cancer is a common tumour, accounting for 92% of malignancies in the male genital tract. Due to the high recurrence rate, it is important to identify prognostic markers in prostate cancer. Human Epidermal Growth Factor Receptor 2 (HER2) and Epithelial cadherin (E-cadherin) are speculated to be associated with carcinogenesis, but the literature has provided controversial results. Aim: To investigate the expression of HER2/neu and E-cadherin in prostatic adenocarcinoma and its correlation with clinicopathological parameters. Materials and Methods: A retrospective cross-sectional study was conducted at the Department of Pathology, SDM University, Dharwad, Karnataka, India. The study duration was one year and five months, from October 2020 to March 2022. A total of 45 cases diagnosed as prostatic adenocarcinoma between October 2016 and September 2019 were included. Clinicopathological parameters such as age, Prostate- Specific Antigen (PSA) levels, metastasis, perineural invasion, Gleason score, Gleason grade, and two-year survival were retrieved from hospital records and through telephone interviews. Immunohistochemistry (IHC) staining for HER2 and E-cadherin was performed and assessed by pathologists. Statistical analysis was conducted using Statistical Package for Social Sciences (SPSS) version 20.0, and the Chi-square test was applied. Results: The mean age of the study participants was 69.6 years, ranging from 52 to 95 years. The rates of HER2/neu overexpression/positivity and reduced E-cadherin expression were 25 (55.5%) and 14 (31.1%), respectively. No statistically significant associations were found between HER2 and E-cadherin expression and age, PSA levels, perineural invasion, Gleason score, Gleason grade, and two-year survival (p>0.05). However, a statistically significant association was observed between HER2 expression and distant metastasis (p-value=0.006), whereas no significant association was found with E-cadherin (p-value=0.81). Conclusion: The study demonstrated a significant association between HER2/neu overexpression and tumour metastasis, suggesting that HER2/neu could serve as a prognostic parameter to assist surgeons. In contrast, E-cadherin showed no association with clinicopathological parameters, raising questions about its involvement in the progression of prostatic adenocarcinoma.