Patient Reported Urinary Incontinence and Sexual Impotency Following Multimodality Radical Therapy for Prostate Cancer: An Untold Story of Compound Toxicity?

Abstract Purpose: To evaluate urinary continence and sexual potency following radical prostatectomy and adjuvant radiotherapy.Materials/Methods: Expanded Prostate Cancer Index Composite (EPIC) surveys of patients with localized prostate cancer treated with surgery followed by adjuvant/salvage pelvic radiotherapy (S+RT) were analyzed. A control cohort was primary radiotherapy (RT). Reverse "bifecta" was defined as a score less than 60 in both incontinence and sexual domains. Superior urinary function was defined as a score above 90. The clinically important difference was calculated using a distribution approach.Results: Surveys at least 1 year after treatment were available for 130 S+RT and 374 RT patients. For S+RT vs. RT, the mean urinary incontinence score was 68 [6.25 -100] versus 86.4 [CI-95 39.5-100] (p<0.001), confirming 6.5 points of clinically significant difference. The adjusted odds ratio for superior urinary function was 2.67 (1.7-4.1, p<0.001) for primary radiotherapy. The odds ratio of having both poor urinary and sexual performance (reverse " bifecta") was 0.29 in RT arm (0.14-0.58, p<0.001) when adjusted for age and Androgen Deprivation Therapy (ADT) , group risk stratification, comorbidities and smoking status.Conclusion: In this cross sectional study, Surgery with adjuvant/salvage RT was associated with significantly worse patient reported urinary continence outcomes at 1-year post treatment, lower odds of achieving perfect urinary continence and a threefold risk of reverse ‘bifecta’ with inferior urinary continence and sexual performance. Longitudinal studies of evolving toxicity are required to validate these findings. Patients referred for surgery with a high probability of requiring adjuvant or salvage radiotherapy should be informed regarding the potential composite toxicity of both surgery and radiotherapy.