Post-prostatectomy radiotherapy adversely affects urinary continence irrespective of radiotherapy regime.

Purpose: To investigate the influence of different postoperative radiotherapy (RT) regimes on post-prostatectomy continence and QoL.
Methods: Men after prostatectomy (RP) and RT were assigned in adjuvant (ART), early salvage (ESRT) and salvage radiotherapy (SRT) groups depending on time of initiation, indication and pre-RT-PSA (≤/>0.5 ng/ml). Continence and QoL outcomes were evaluated by validated questionnaire. Statistical analysis included students t test, Chi square, Fisher's test, ROC- and McNemar-Bowker-Analyses.
Results: The mean follow-up was 5.1 years. 33.5, 38.2 and 28.3% received ART, ESRT and SRT, respectively. Mean time to RT was 0.3 (±0.4), 1.8 (±2.5) and 3.3 (±3.6) years respectively. Differences in age at RP (p = 0.54) and RT (p = 0.47) between groups were not significant. Mean-RT-dose was similar (p = 0.70). Differences in continence distribution between groups before (p = 0.56) and after RT (p = 0.38) were not significant. No significant differences were observed for frequency (p = 0.58) or amount (p = 0.88) of urine loss, impact on QoL (p = 0.13) and ICIQ-SF scores (p = 0.69) between groups. Even though no significant difference in post-RT-continence (p = 0.89) was observed in the direct comparison between groups, a significant worsening of long-term continence was observed in all groups (p < 0.001). We found no cutoff and no time-point after RP at which this negative effect of RT on continence became insignificant (AUC = 0.474). A subgroup with apparent local recurrence showed no differences for ICIQ-SF-score (p = 0.155), QoL (0.077), incontinence grade (p = 0.387), frequency (p = 0.182) and amount (p = 0.415) of urine loss. Proportionally more men in this subgroup remembered deterioration of continence after RT (p = 0.029).
Conclusion: Postoperative RT adversely affects long-term continence; this negative effect is irrespective of time of initiation or indication for RT. These results suggest a need for innovative strategies of prostate cancer therapy with lasting oncological, functional and QoL outcomes.