The introduction of prostate-specific antigen (PSA) testing has resulted in increased diagnoses of early-stage disease. Less is known about the role of short-term ADT in men receiving radiotherapy for these cancers. Accordingly, in 1994, the RTOG opened a large, randomized trial, RTOG 94-08, to evaluate whether adding short-term ADT to radiotherapy would improve survival among patients with nonbulky localized prostate adenocarcinomas and an initial PSA level of 20 ng per milliliter or less.

Patients
Patients with histologically confirmed prostate adenocarcinoma, stage T1b, T1c, T2a, or T2b (according to the 1992 classification of the American Joint Committee on Cancer), and a PSA level of 20 ng per milliliter or less were eligible for this international phase 3 study. Pretreatment evaluation included a digital rectal examination and bone scan. The regional lymph nodes were evaluated surgically by means of lymph-node sampling or clinically by means of lymphangiography or pelvic computed tomography. The Gleason score (the sum of the two most common histologic patterns or grades in a prostate tumor, each of which is graded on a scale of 1 to 5, with 5 indicating the most aggressive pattern) was determined, and tumors were also classified as well differentiated, moderately differentiated, or poorly differentiated. Eligibility criteria included a Karnofsky performance score of 70 or more (on a scale of 0 to 100, with higher scores indicating better performance status), an alanine aminotransferase level that was no more than twice the upper limit of the normal range, no evidence of regional lymph-node involvement or distant metastatic disease, and no previous chemotherapy, radiotherapy, hormonal therapy, cryosurgery, or definitive surgery for prostate cancer. Patients with previous basal-cell or squamous- cell skin carcinomas who had been diseasefree for 2 years or more before study entry, and patients with invasive cancers who had been disease- free for 5 years or more, were eligible if their participation was approved by the study cochairs. The institutional review boards of the participating institutions approved the study protocol, and all patients provided written informed consent. The National Cancer Institute sponsored the study. The drugs were purchased from vendors. No commercial support was provided for this study.

Study Design
After stratification according to PSA level (<4 vs. 4 to 20 ng per milliliter), tumor grade (well differentiated, moderately differentiated, or poorly differentiated), and surgical versus clinical documentation of negative regional nodal status, patients were randomly assigned to receive either radiotherapy plus short-term ADT or radiotherapy alone, according to the permuted-block randomization method described by Zelen. The RTOG carried out this trial and was responsible for data collection, statistical analysis, study design, and preparation of the manuscript.