Acceptance and efficacy of recommended adjuvant radiotherapy in patients with positive lymph nodes at radical prostatectomy: a preference-based study

Purpose To investigate acceptance and efficacy of recommended adjuvant radiotherapy in patients with positive lymph nodes at radical prostatectomy. Methods Among 495 patients with positive lymph nodes who consecutively underwent radical prostatectomy between 2007 and 2017, we investigated 347 patients who were recommended to undergo adjuvant radiotherapy by a multidisciplinary post-therapeutic tumor board and in whom information whether such treatment was eventually given was available. The median follow-up for censored patients was 5.4 years. Univariate analyses were performed using Kaplan–Meier curves, Mantel–Haenszel hazard ratios and log rank tests. Proportional hazard models for competing risks were used for multivariable analyses. Results Adjuvant radiotherapy was independently associated with lower overall mortality and in high-risk patients (Gleason score 8–10 or three or more involved lymph nodes) also with lower prostate cancer-specific mortality. In patients with a Gleason score of 8–10 or three or more involved lymph nodes, the hazard ratio for adjuvant radiotherapy was 0.455 (95% confidence interval 0.257–0.806, p = 0.0069) for overall and 0.426 (95% confidence interval 0.201–0.902, p = 0.0259) for prostate cancer-specific mortality. Among patients receiving adjuvant radiotherapy, there was a trend to lower mortality when such treatment was combined with adjuvant androgen deprivation. Conclusion Adjuvant radiotherapy decreased mortality in patients with positive lymph nodes at radical prostatectomy with further disease factors but not in patients with low-risk disease. Simultaneous androgen deprivation might increase efficacy. Multidisciplinary recommendations may possibly increase the use of adjuvant radiotherapy in this setting.