A Finnish study has shown that after surgery (radical prostatectomy) adding adjuvant radiotherapy in men with prostate cancer who had positive margins or extracapsular extension prolonged their biochemical recurrence-free survival compared with just surgery.

The study enrolled 250 men with pT2 prostate tumors and positive surgical margins or pT3aN0M0 cancer without seminal vesicle invasion. Investigators randomly assigned 126 of the men to receive adjuvant radiotherapy (5 of whom declined post-RP radiotherapy following randomization to this study arm) and 124 to have just surgery (observation arm). The radiation dose in the adjuvant group was 66.6 Gy given in 37 fractions.

The median follow-up time for the men who were alive at the end of follow-up was 9.3 years in the adjuvant group compared with 8.6 years in the observation (surgery only) arm.

The 10-year biochemical recurrence-free survival rate was 82% in the adjuvant group compared with 61% in the surgery only arm.

The adjuvant group had a significant 74% decreased the risk of biochemical recurrence compared with the observation arm. The 10-year overall survival rates did not differ significantly between the adjuvant and observation groups (92% and 87%, respectively). Only two men died from prostate cancer; 1 in each group. The 10-year PCa-specific survival rate was 99% in both groups.

The study was reported in European Urology. (Greetta Hackman, MD, of the University of Helsinki, and collaborators reported in European Urology).