FINAL REPORT OF MULTICENTER CANADIAN PHASE III RANDOMIZED TRIAL OF 3 VERSUS 8 MONTHS OF NEOADJUVANT ANDROGEN DEPRIVATION THERAPY BEFORE CONVENTIONAL-DOSE RADIOTHERAPY FOR CLINICALLY LOCALIZED PROSTATE CANCER

Purpose: To evaluate the effect of 3 vs. 8 months of neoadjuvant hormonal therapy before conventional-dose radiotherapy (RT) on disease-free survival for localized prostate cancer. Methods and Materials: Between February 1995 and June 2001, 378 men were randomized to either 3 or 8 months of flutamide and goserelin before 66 Gy RT at four participating centers. The median baseline prostate-specific antigen level was 9.7 ng/mL (range, 1.3-189). Of the 378 men, 26% had low-, 43% intermediate-, and 31% high-risk disease. The two arms were balanced in terms of age, Gleason score, clinical T category, risk group, and presenting prostate-specific antigen level. The median follow-up for living patients was 6.6 years (range, 1.6-10.1). Of the 378 patients, 361 were evaluable, and 290 were still living. Results: The 5-year actuarial freedom from failure rate for the 3- vs. 8-month arms was 72 % vs. 75 %, respectively (p = 0.18). No difference was found in the failure types between the two arms. The median prostate-specific antigen level at the last follow-up visit for patients without treatment failure was 0.6 ng/mL in the 3-month arm vs. 0.50 ng/mL in the 8-month arm. The disease-free survival rate at 5 years was improved for the high-risk patients in the 8-month arm (71 % vs. 42 %, p = 0.01). Conclusion: A longer period of NHT before standard-dose RT did not alter the patterns of failure when combined with 66-Gy RT. High-risk patients in the 8-month arm had significant improvement in the 5-year disease-free survival rate. (c) 2009 Elsevier Inc.