Comparative Survival Outcomes of High-risk Prostate Cancer Treated with Radical Prostatectomy or Definitive Radiotherapy Regimens

Abstract

BackgroundObservational data has indicated improved survival after radical prostatectomy (RP) compared with definitive radiotherapy (RT) in men with high-risk prostate cancer (PCa). ObjectiveTo compare PCa-specific mortality (PCSM) and overall mortality (OM) in men with high-risk PCa treated with RP or RT, providing information on target doses and fractionations. Design, setting, and participantsThis is an observational study from the Cancer Registry of Norway. Patients were diagnosed with high-risk PCa during 2006–2015, treated with RP ≤12 mo or RT ≤15 mo after diagnosis, and stratified according to RP or RT modality; external beam radiotherapy (EBRT; 70–<74, 74–<78, or 78 Gy), hypofractionated RT or EBRT combined with brachytherapy (BT-RT). Outcome measurements and statistical analysisCompeting risk and Kaplan-Meier methods estimated PCSM and OM, respectively. Multivariable Cox regression models evaluated hazard ratios (HRs) for PCSM and OM. Results and limitationsIn total, 9254 patients were included (RP 47%, RT 53%). RT patients were older, had poorer performance status and more unfavorable disease characteristics. With a median follow-up time of seven and eight yrs, the overall 10-yr PCSM was 7.2% (95% confidence interval [CI] 6.4–8.0) and OM was 22.9% (95% CI 21.8–24.1). Compared with RP, EBRT 70–<74 Gy was associated with increased (HR 1.88, 95% CI 1.33–2.65, p < 0.001) and BT-RT with decreased (HR 0.49, 95% CI 0.24–0.96, p = 0.039) 10-yr PCSM. Patients treated with EBRT 70–78 Gy had higher adjusted 10-yr OM than those treated with RP. ConclusionsIn men with high-risk PCa, treatment with EBRT <74 Gy was associated with increased adjusted 10-yr PCSM and OM, and BT-RT with decreased 10-yr PCSM, compared with RP. Patient summaryIn this study, we compared mortality after radical prostatectomy (RP) and radiotherapy (RT) in men with high-risk prostate cancer (PCa); the results suggest that men receiving lower-dose RT have higher, and patients receiving brachytherapy may have lower, risk of death from PCa than patients treated with prostatectomy.