Despite the introduction of screening procedures and an increased public awareness of prostate cancer, a substantial number of patients present with locally advanced prostate cancer. Traditional therapies (such as radiation therapy or radical prostatectomy) applied either alone or in combination fail to control local disease in a large number of cases and have no effect on disseminated disease. Recent advances in molecular oncology and genetics have led to such novel therapies as p53 gene therapy, which we are currently evaluating in a clinical protocol in patients with locally advanced (nonmetastatic) prostatic cancer. Ad5CMVp53 (RPR/INGN 201) has previously shown promise in both patients with lung cancer and those with head and neck cancer. The traditional end points used to appraise prostate cancer preclude rapid evaluation of the patient's disease and prevent modification of the therapeutic strategy, and we suggest that the pathologic stage after therapy be evaluated as an intermediate end point.