Outcomes after adjuvant radiation therapy for prostate cancer at a comprehensive cancer center

Abstract

Objectives: Randomized trials have shown that adjuvant radiation therapy improves prostate cancer control for men with adverse surgical pathology. We report cancer control outcomes for men who received adjuvant radiation at The University of Texas MD Anderson Cancer Center (MDACC). Methods: We identified men who received adjuvant radiation within 12 months of prostatectomy from 1987 through 2010. All men had PSA <0.2 ng/mL at time of RT. Failure was defined as either a rising post-radiation PSA of at least 0.2 ng/mL; or local, nodal, or distant recurrence; or the initiation of salvage treatment. Results: A total of 137 men received adjuvant radiation. Most men had positive margins (N = 127, 92.7 %) and extraprostatic extension (N = 98, 71.5 %). Thirty-eight percent had Gleason 8–9 disease (N = 52) at prostatectomy. Median radiation dose was 60 Gy (IQR 60–66 Gy). Few men (N = 24, 17.5 %) received concurrent hormone therapy with radiation. Five-year failure for the entire cohort was 11.9 % and 10-year failure was 16 %. Gleason score was the only factor significantly associated with failure. Five- and 10-year failure for men with Gleason 8–9 disease were 18.4 and 20.8 %, while 5- and 10-year failure for men with Gleason <8 disease were 6.7 and 11.9 % (p = 0.013). Radiation dose (<66 Gy versus ≥66 Gy), margin status, and receiving hormone therapy were not associated with failure. Conclusions: At MDACC, men referred for adjuvant radiation often have margin involvement and/or extraprostatic extension. Patients did well overall, with high 5- and 10-year freedom from failure. Gleason 8–9 disease was associated with increased failure after adjuvant radiation.