The Expression of Androgen Receptor and Its Variants in Human Prostate Cancer Tissue according to Disease Status, and Its Prognostic Significance

ABSTRACT

PURPOSE: To evaluate changes in the expression of androgen receptor (AR) and its variants (ARVs) in human prostate cancer (PCa) tissues according to disease status, and its prognostic significance following radical prostatectomy (RP). MATERIALS AND METHODS: A total of 282 PCa cases were evaluated, which included 252 localized PCa, 8 metastatic castration resistant prostate cancer (CRPC), and 22 benign prostatic hyperplasia (BPH) cases. Samples were collected from patients who underwent RP or transurethral resection and were stored in ethically approved tissue banks. Quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry were performed for AR and ARVs. Each tissue was confirmed as cancerous (greater than 80%) using hematoxylin and eosin staining. AR and ARVs expression was compared according to disease status. The biochemical recurrence free survival (BCRFS) rates in men with localized PCa was analyzed according to AR and ARV7 expression using the Kaplan-Meier curve. RESULTS: Only 58 of the 252 localized PCa were included in the analysis because of insufficient cancer tissue. AR and ARV7 mRNA expression was higher in the CRPC tissue than in the localized PCa tissue (p=0.025, p=0.002, respectively). In localized PCa tissue, high AR mRNA and protein level was associated with a low BCRFS rate (log-ranked, p=0.019, p < 0.001, respectively). CONCLUSIONS: Overall AR and ARV7 mRNA expression levels were increased in CRPC tissues compared to localized PCa and BPH tissues. High AR protein and mRNA expression in the tumor tissue may be considered a predictive factor of BCRFS following RP.