Impact of androgen deprivation therapy with postoperative radiotherapy after radical prostatectomy on health-related quality of life.

133 Background: There is an ongoing debate on the use and duration of androgen deprivation therapy (ADT) with postoperative radiotherapy (RT) following radical prostatectomy (RP). While there have been conflicting results regarding oncological outcome, the effect of concomitant ADT on health-related quality of life (HRQOL) remains elusive. We aimed to assess the impact of adding ADT to postoperative RT on long-term HRQOL by providing PROM data from a large contemporary cohort of patients undergoing RT following RP with a systematic follow-up of up to 10 yrs. Methods: n=1124 patients who underwent RT after previous RP at a large tertiary care center between 2010 and 2021 were identified within a prospective institutional database. Patients with previous post-op ADT were excluded. Patients were stratified by concomitant ADT (no ADT n=682; ADT n=436). PROMs were prospectively assessed preoperatively, prior and post RT and at a maximum follow-up of up to 120mo, applying the validated EORTC QLQ-C30- and the prostate cancer-specific QLQ-PR25-questionnaires. Correlation analysis and multivariable regression models were used to estimate the impact of ADT with postoperative RT on HRQOL. Results: Median duration of ADT received within the ADT-cohort was 21mo. Prior RT, no significant difference in general HRQOL assessed by the global health status domain (GHS) was found between the ADT cohort (69.6) and the no ADT cohort (68.9; p=0.88). Post RT (65.1 vs. 69.9; p=0.038) and after median follow-up of 59 months (62.8 vs. 68.1; p<0.001) patients in the ADT cohort reported significantly worse general HRQOL. In multivariable regression analysis stratified by age, BMI, pT-stage, urinary continence and erectile functioning, concomitant ADT was confirmed as an independent predictor for worse general HRQOL (OR 0.68, 95% CI 0.47-0.96, p=0.03). Correlation analysis revealed a significant correlation between longer duration of ADT and worse long-term general HRQOL (p<0.001). In line, multivariable linear regression analysis revealed longer duration of ADT to independently predict worse general HRQOL (p=0.041) (Table). Conclusions: In patients with postoperative RT, concomitant ADT yields worse long-term general HRQOL. A longer duration of ADT furthermore leads to worse long-term general HRQOL. Those results support careful patient selection for ADT with postoperative RT after RP. Multivariable linear regression for HRQOL. Variable B [regression coefficient] Beta [standardized regression coefficient] SE [standard error] p value Duration of ADT -0.272 -0.191 0.132 0.041 Age -0.127 -0.043 0.294 0.667 BMI -0.588 -0.120 0.444 0.188 ICIQ-SF-Score 0.914 0.012 6.729 0.892 IIEF5-Score 0.661 0.165 0.403 0.103 R² 0.341 Adjusted R² 0.336