Role of androgen receptor expression in non-muscle-invasive bladder cancer: a systematic review and meta-analysis

In order to evaluate the potential prognostic/predictive role of androgen receptor (AR) expression in non-muscle-invasive bladder cancer (NMIBC), and whether it may represent a therapeutic target, we conducted a systematic search of the literature using 'androgen receptor or AR', 'testosterone', 'bladder cancer' and 'non-muscle invasive bladder cancer or NMIBC' as keywords. Eleven studies met the inclusion/exclusion criteria. No significant association was found between AR status and patients' gender (p=0.232), tumor size (p=0.975), tumor stage (p=0.237), tumor grade (p=0.444), tumor multicentricity (p=0.397), concomitant CIS (p=0.316) and progression of disease (p=0.397). On the other hand, relative lack of AR expression was significantly correlated to recurrent disease (p=0.001). Evidence for a direct correlation between AR expression and recurrence-free survival of patients with NMIBC indicate ARs as potential markers of BC behavior; moreover, the finding of a role of androgen blockade therapy in improving survival highlights the potential clinical application of this pathway, which deserves to be further explored.