Urinary and sexual function do not mediate psychological distress reduction in the PC-PEP randomized controlled trial A secondary mediation analysis.

INTRODUCTION

Psychological distress is common among men treated for localized prostate cancer and is often presumed to stem from treatment-related urinary and sexual sequelae. The Prostate Cancer-Patient Empowerment Program (PC-PEP), a six-month, comprehensive, digital intervention, reduces psychological distress and improves patient-reported urinary and sexual function. This secondary analysis tested whether improvements in urinary incontinence, urinary irritative/obstructive symptoms, or sexual function explain PC-PEP's effect on psychological distress.

METHODS

In a randomized controlled trial, 128 men with localized prostate cancer were assigned to PC-PEP (n=66) or standard care (n=62) for six months. Psychological distress was measured using the Kessler psychological distress scale (K10), and urinary and sexual function were assessed using the expanded prostate cancer index composite (EPIC) at baseline and six months. Mediation models adjusted for age, relationship status, use of medications for anxiety or depression, Charlson comorbidity index, treatment modality, time from randomization to treatment, and baseline K10 and EPIC scores.

RESULTS

PC-PEP produced significant improvements in urinary incontinence and urinary irritative/obstructive symptoms across the full cohort and attenuated postoperative declines in sexual function; however, none of these urinary or sexual outcomes mediated the program's effect on psychological distress.

CONCLUSIONS

While PC-PEP enhances key urinary and postoperative sexual outcomes, these functional gains do not account for its mental health benefits. This challenges the assumption that psychological distress in prostate cancer survivorship is predominantly driven by urinary or sexual sequelae and highlights the importance of addressing broader psychosocial and behavioral determinants of mental health in survivorship care.