Long-term biochemical control and cause-specific survival in men with Gleason grade Group 4 and 5 prostate cancer treated with brachytherapy and external beam irradiation.

Abstract Purpose Men with Gleason grade Group (GG) 4 and 5 prostate cancer have high failure rates when treated by conventional therapy. We investigated the effect of higher radiation doses on freedom from biochemical failure (FBF) and prostate cancer mortality (cause-specific survival [CSS]) in men treated with a combination of permanent implant and external beam irradiation (EBRT). Methods and Materials Three hundred twenty men with GG4 (n = 186) and 5 (n = 134) prostate cancer were treated with I-125 or Pd-103 implant followed by 45 Gy of EBRT. Radiation doses were converted to the biological equivalent dose (BED). The median age, prostate-specific antigen (PSA), time on hormone therapy, BED, and followup were 69 years, 9.0 ng/mL, 9 months, 210 Gy, and 6.5 years, respectively. FBF and CSS were calculated by Kaplan–Meier method with associations determined by log rank and Cox regression. Results Ten-year FBF for GG4 vs. 5 was 77.8 vs. 61.3% (p = 0.015), and CSS was 94 vs. 79.3% (p = 0.001). Men with lower PSA had improved FBF and CSS (p Conclusions Survival rates for high-grade prostate cancer are favorable when diagnosed in men with lower PSA and treated with doses of BED > 200 Gy. Higher BED is achieved with a combination of I-125 (110 Gy) or Pd-103 (100 Gy) and 45 Gy EBRT.