Does 5-alpha Reductase Inhibitor Use Improve The Efficacy of Intravesical Bacille Calmette-Guerin (BCG) for Non-muscle Invasive Bladder Cancer?

BACKGROUND: Prior research implicates the androgen receptor pathway as important in bladder cancer progression and recurrence. In particular, use of 5-alpha reductase inhibitors (5-ARIs) appears to improve bladder cancer outcomes. This study aims to determine if concomitant use of 5-ARIs with intravesical Bacille Calmette-Guerin (BCG) decreases recurrences in patients with non-muscle invasive bladder cancer (NMIBC). MATERIALS & METHODS: This retrospective analysis included male patients diagnosed with NMIBC who were treated with induction intravesical BCG at our institution from 2013 to 2018. Patients were excluded who received prior induction BCG. Recurrence and progression-free survival were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using Cox proportional hazards and Poisson events models. RESULTS: We identified 206 male patients, of whom 39 received 5-ARIs and 167 did not. Most patients (72.8%) received >6 instillations of BCG, with 20.4% completing all induction and maintenance treatments during a median follow up of 3.31 years. There were no significant differences in recurrence or progression-free survival between 5-ARI users or non-users (59% vs 55.7%; p = 0.72 and 97.4% vs 98.2%; p = 1.00, respectively) Similarly, no differences in the number of recurrences between groups was observed (p = 0.78). However, the proportion of patients who completed all prescribed BCG installations was higher among 5-ARI users (39.7% vs 17.9 %, p = 0.07). CONCLUSIONS: In contrast to prior reports, our study does not suggest that 5-ARI use decreases the recurrence rate in men receiving induction BCG for NMIBC. However, our results suggest 5-ARI use may improve patient tolerance to BCG.