Population-based referrals for adjuvant radiotherapy after radical prostatectomy in men with prostate cancer: impact of randomized trials.

INTRODUCTION To examine the impact of published randomized controlled trial (RCT) data on referrals for adjuvant radiotherapy (RT) in patients who had high-risk pathologic features after radical prostatectomy (RP). METHODS In this population-based, retrospective Canadian study, all patients who received a diagnosis of prostate adenocarcinoma and underwent RP from 2003-2008 were identified through the Manitoba Cancer Registry. Manual review of pathology reports was performed, and patients who had high-risk pathologic features of extracapsular extension, seminal vesicle invasion, or positive surgical margins were included. Referrals for adjuvant RT were examined before and after publication of RCT data to determine their influence on practice. Multivariable logistic regression was used to identify factors related to referral. RESULTS Of the 1080 identified patients, 546 (50.6%) had ≥ 1 high-risk pathologic feature. Only 78 (14.3%) of the 546 patients were referred for adjuvant RT within 6 months of RP. Year of diagnosis, in relation to the publication of the RCT, was not significantly associated with referral (P =.60). Higher pT stage (P < .0001), Gleason score (P =.035), and increased distance from cancer center (P =.004) were associated with referral. CONCLUSION In patients who had high-risk pathologic features after RP, referral rates for adjuvant RT were low and did not increase after presentation of RCT. Men who had higher pT stage, Gleason score, and rural residence were more likely to be referred.