Prognostic significance of high androgen receptor expression in prostatic acinar adenocarcinoma

Background: Quantitative immunohistochemical expression of Androgen receptor (AR) has not been evaluated as a prognostic biomarker of prostate cancer in our population, therefore in the current study we aimed to evaluate the association of AR expression in prostatic acinar adenocarcinoma with various prognostic parameters like tumor quantification, Gleason score, WHO grade group and perineural invasion. Methods: Total 121 cases of biopsy proven prostatic acinar adenocarcinoma were selected from records of pathology department archives from January 2013 till December 2017. Hematoxylin and eosin stained slides and paraffin blocks were retrieved and new sections were cut where necessary. Slides of all cases were reviewed by two senior histopathologists and pathologic characteristics like Gleason score, WHO grade, tumor quantification, perineural and lymphovascular invasion were evaluated. Androgen receptor immunohistochemistry was applied on all cases. Results: Low AR expression was noted in 53 cases (43.8%) while high AR expression was seen in 68 cases (56.2%). Significant association of AR expression was noted with total Gleason score, WHO grade and percentage of tissue involvement (tumor quantification). Univariate binary logistic regression showed patients with low Gleason scores (scores 6,7 or 8) and low WHO grade (grade 1, 2 or 3) were less likely to express high AR expression in comparison to high Gleason score (score 9) and high WHO grade group (grade 5) respectively. Similarly, cases with low tissue involvement by carcinoma (< 50%) were less likely to show high AR expression in comparison to cases with > 50% tissue involvement by carcinoma. Conclusion: Significant association of AR expression was noted with total Gleason score, WHO grade and percentage of tissue involvement (tumor quantification) which are among the most important markers of tumor progression; therefore we suggest that AR expression should be performed in patients with prostatic adenocarcinoma for prognostic stratification of the patients.