Salvage radiotherapy after radical prostatectomy: functional outcomes in the LAPPRO trial after 8-year follow-up

Radical prostatectomy reduces mortality among patients with localized prostate cancer, however up to 35% of patients will experience biochemical recurrence, often treated with salvage radiotherapy. The objective of the study was to investigate long-term effects of salvage radiotherapy. A prospective, controlled, non-randomized trial at 14 Swedish center's including 4,003 patients scheduled for radical prostatectomy 2008-2011. A target trial emulation approach was used to identify eligible patients that was treated with salvage radiotherapy. The control group received no salvage radiotherapy. Outcomes were assessed by patient questionnaires on ordinal scales and statistical group comparisons were made using ordered logit regression with adjustment for baseline outcome and confounding factors. The primary endpoints were bowel, urinary and sexual function and bothering due to dysfunction at 8 years. Eleven percent (330/3,139) of the analyzed study population received salvage radiotherapy. Fecal leakage, leakage of mucus and hematochezia were more common after receiving salvage radiotherapy compared with the control group; 4.5% versus 2.6% odds ratio (95% confidence interval [CI]): (1.90 [1.38; 2.62]), 6.8% versus 1.5% 4.14 (2.98; 5.76) and 8.6% versus 1.2% 4.14 (2.98; 5.76), respectively. Urinary incontinence, erectile dysfunction and hematuria were more common after receiving salvage radiotherapy, 34% versus 23% 2.23 (2.65; 3.00), 65% versus 57% 1.65 (1.18; 2.29) and 16% versus 1.6% 11.17 (5.68; 21.99), respectively. Salvage radiotherapy was associated with increased risk for fecal leakage, hematochezia, urinary incontinence and hematuria. Our results emphasize the importance of selecting patients for salvage radiotherapy to avoid overtreatment and to give high quality pre-treatment information to ensure patients' preparedness for late side-effects.