Prostate-specific antigen relapse-free survival in patients with localized prostate cancer treated by brachytherapy

OBJECTIVE To report the clinical outcome after permanent implantation of (125)iodine seeds (brachytherapy) for early prostate cancer, after 8.2 years of follow-up. PATIENTS AND METHODS Between March 1995 and December 2001, 667 men (mean age 63 years, range 42-77) were treated with brachytherapy at the one cancer centre; 346 (51.9%) had a short course of neoadjuvant hormone therapy. The prescribed minimum peripheral dose was 145 Gy. No patient received external beam radiation. RESULTS The median (range) follow-up was 31 (18-98.2) months; 41 patients were lost to follow-up. The actuarial biochemical relapse-free survival was 74.9%; 100 patients had biochemical relapse (international definition). In all, 20 patients had clinical relapse, and 24 died (10 from prostate cancer). The prostate-specific antigen (PSA) relapse-free survival was 78.3%, 66.5% and 56.4% for patients with Gleason scores of <7, 7 and >7, respectively, and was 81.4%, 69.8% and 36.3% for those with PSA levels of <10, 10-20 and >20 ng/mL, respectively (both P< 0.001). There was a strong cohort effect depending on year of implant, with progressive annual improvements in relapse-free survival (P < 0.001). Hormone therapy, tumour stage, prostate volume before implantation, age and D90 dose had no significant effect on the outcome. CONCLUSION The overall relapse-free survival for all patients was 75%; the initial PSA, Gleason score and risk group were significant factors predicting the outcome. Increasing clinical experience was associated with a better outcome but neoadjuvant hormone therapy had no effect.