Switching Cancers: A Systematic Review Assessing the Role of Androgen Suppressive Therapy in Bladder Cancer

Abstract

Context: Bladder cancer demonstrates striking gender-based differences in incidence, with a role for androgens possibly implicated in the development and progression of the disease. Emerging preclinical and clinical evidence suggests that there may be a role for antiandrogen therapy in bladder cancer.

Objective: This systematic review assessed the current clinical evidence evaluating androgen suppressive therapy (AST) for the treatment or prevention of bladder cancer.

Evidence acquisition: Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, MEDLINE was searched for full-text articles detailing clinical outcomes or incidence of bladder cancer among patients who received AST, defined as gonadotropin-releasing hormone agonists or equivalent, androgen receptor antagonists, or 5-alpha reductase inhibitors.

Evidence synthesis: A total of 12 studies were included. Five studies focused on prostate cancer patients, with one study in men with lower urinary tract symptoms. Among these studies, a lower incidence of bladder cancer was observed in five, with adjusted risk reduction estimates ranging from 7% to 47%. Six studies evaluating 11 820 bladder cancer patients investigated clinical outcomes among men who received a form of AST. Three out of four studies evaluating recurrence-free survival found a benefit for AST, with adjusted hazard ratios for recurrence of non-muscle-invasive cancer ranging from 0.29 to 0.53. Limitations included large variability in data sources and methodologies, as well as no data on tolerability.

Conclusions: Current evidence indicates that antiandrogen therapies exert a favorable influence on bladder tumors. Further prospective studies are needed to assess their therapeutic potential.

Patient summary: Androgen suppressive therapy is commonly prescribed for the treatment of prostate-related problems. Prior research indicates that there may be a role for these treatments in patients with bladder cancer. In this review, we evaluate the current evidence that strongly suggests that these agents may be effective against bladder cancer.

Keywords: Androgen suppression therapy; Androgens; Bladder cancer; Incidence; Recurrence; Systematic review.