Outcomes Following OnabotulinumtoxinA Injection for Storage Symptoms in Patients Who Have Been Treated for Prostate Cancer

PURPOSE: Treatment of prostate cancer (PC) can cause storage symptoms, for which bladder onabotulinumtoxinA (BTXA) is a treatment option. We hypothesized that BTXA is effective and safe in patients treated for PC, regardless of treatment modality, with more favorable outcomes among patients treated with radical prostatectomy (RP) alone. MATERIALS AND METHODS: We identified patients at our institution who underwent RP alone, radiation therapy (RT) alone, or RP + RT and subsequently received BTXA for storage symptoms. Effectiveness was evaluated by the rate of repeat BTXA injection, as patients who experience symptom relief can choose to repeat treatment when effects subside over time. Safety was evaluated by rates of complication of urinary retention or urinary tract infection within 90 days of BTXA injection. RESULTS: Among n = 104 patients identified between 2007 and 2024, 37 had RP-alone, 39 RP and RT, and 28 RT alone. Compared to RP alone, we found lower rates of repeat BTXA in RP + RT (HR 0.42, 95 CI 0.20, 0.86, p = 0.018). The Kaplan-Meier estimated rates at 8-month repeat BTXA rates for the groups were 40% (95 CI 20%-55%), 14% (95 CI 1.8%-24%), and 34% (95 CI 13%-50%), respectively. Compared to RP alone, we found increased 90-day risk of complication in both RP + RT and RT alone (OR 5.41, 95 CI 1.48-20, p = 0.011; OR 7.76; 95 CI 2.03-30; p = 0.003). CONCLUSIONS: Bladder BTXA injection is a viable treatment option for storage symptoms across PC survivors with varying treatment modalities, especially those who have undergone RP alone, but careful patient selection and counseling is necessary.