To update the effect of immediate androgen suppression in conjunction with standard external-beam irradiation versus radiation alone on a group of histologically lymph node-positive patients with adenocarcinoma of the prostate.

A national prospective randomized trial (Radiation Therapy Oncology Group 85-31) of standard external-beam irradiation plus immediate androgen suppression versus external-beam irradiation alone was initiated in 1985 for patients with locally advanced adenocarcinoma of the prostate. One hundred seventy-three patients in this trial had histologically involved lymph nodes. Ninety-eight patients received radiation plus immediate androgen suppression (luteinizing hormone-releasing hormone [LHRH] agonist), whereas 75 patients received radiation alone with hormonal manipulation instituted at the time of relapse.

With a median follow-up of 6.5 years for all patients and 9.5 years for living patients, estimated progression-free survival with prostate-specific antigen (PSA) level less than 1.5 ng/mL at 5 and 9 years was 54% and 33%, respectively, for patients who received immediate LHRH agonist versus 10% [corrected] and 4% for patients who received radiation alone with hormonal manipulation instituted at time of relapse (P < .0001). Multivariate analysis revealed radiation therapy and immediate hormonal manipulation as having a statistically significant impact on all end points analyzed: absolute survival, disease-specific failure, metastatic failure, and biochemical control with PSA less than 4 ng/mL and less than 1.5 ng/mL.

Pending the results of randomized trials, patients with adenocarcinoma of the prostate who have pathologically involved pelvic lymph nodes (pathologic node-positive or clinical stage D1) should be considered for external-beam irradiation plus immediate hormonal manipulation rather than radiation alone with hormone manipulation at the time of relapse.