Comparative analysis of genitourinary toxicity following bladder outlet obstruction procedures in patients before...

Prior studies have reported genitourinary toxicity associated with transurethral resection of the prostate after radiation therapy (XRT) for localized prostate cancer (PCa). However, treatment options for benign prostatic hyperplasia have expanded exponentially within the last decade. Using a more contemporary cohort and analyzing newer bladder outlet obstruction procedures (BOOP), this study aims to compare the rates of genitourinary toxicity in men who have undergone BOOP after versus before XRT for PCa.

We conducted a retrospective cohort study using the TriNetX network. We identified 447 patients receiving BOOP after XRT (Cohort A) and 1 504 patients receiving BOOP before XRT (Cohort B). Cohorts were propensity-score matched for demographic, comorbidities and relevant medications. We stratified the analysis by type of procedure-minimally invasive surgical techniques (MISTs) or resective surgery (RS). Statistical analysis reporting risk ratios (RR) and 95% confidence intervals (95% CI) was conducted.

Each cohort consisted of 411 matched patients who were well balanced after PSM (SMD < 0.1). Patients in Cohort A had an increased risk of stress urinary incontinence [RR 4.29, 95% CI (2.19, 8.41)], urge urinary incontinence[RR 2.09, 95% CI (1.25, 3.49)], mixed urinary incontinence[RR 2.49, (1.21, 5.11)], urinary retention [RR 2.38, 95% CI (1.54, 3.68)], bladder neck contracture [RR 2.56, 95% CI(1.39, 4.68)] and urethral strictures [RR 3.28, 95% CI (1.83-5.88)] compared to patients in Cohort B. Outcomes for MISTs after versus before XRT were limited by small sample size but suggested no difference in the risk of genitourinary toxicity. Compared to RS before XRT, RS after XRT was associated with an increased risk of stress incontinence, urinary retention, bladder neck contracture, and urethral strictures.

Men with a history of BOOP undergoing XRT have less genitourinary toxicity than those undergoing XRT after. To limit such toxicity, urologists should evaluate concomitant benign prostatic hyperplasia and consider BOOP before patients undergo XRT.