Irradiation of carcinoma of the prostate localized to the pelvis: analysis of tumor response and prognosis.

Abstract A group of 195 patients with histologically proven adenocarcinoma of the prostate limited to pelvis were treated with definitive irradiation between 1967 and December 1976. In 42 patients with Stage B adenocarcinoma, the tumor free actuarial five year survival was 80%; for 141 with Stage C it was 56%; there were no long term survivors in 12 patients with Stage D1 (extensive tumor limited to the pelvis, without distant metastasis). The pelvic failure rate was 7% in Stage B, 17% in Stage C and 25% in Stage D1. Histological differentiation of the tumor had no significant impact in survival of patients with Stage B. However, in Stage C, patients with well or moderately differentiated tumor had a five year survival of 70% in contrast to 25% in those with poorly differentiated lesions. In this group of patients 60% of the failures resulted from distant metastasis. In Stage C, 38% of the patients who were treated with doses between 5500 and 6000 rad developed pelvic failures, as opposed to 20% of those treated with a mean dose of 6500 rad and 12% in patients receiving 7000 rad or greater dose. The addition of hormonal therapy, usually castration and diethylstilbestral (DES) (5 mg daily), did not significantly affect the prognosis of patients with Stage B or C. Major complications of therapy occurred in 11% of the patients. The most common problem was urinary incontinence which was observed in 13.3% of 60 patients who had a transurethral resection (TUR) as opposed to 4.4% in 135 patients on whom this procedure was not performed. Less severe complications were noted in 18% of the patients and treated with conservative management. Leg edema developed in three of 14 patients on whom a staging laparotomy was performed (21.4%) in contrast to only three of 181 patients without such a procedure (1.6%). At the present time external irradiation is a viable alternative to radical prostatectomy in the treatment of Stage B and the modality of choice in patients with Stage C adenocarcinoma of prostate. It is important to identify prognostic factors that may optimize the effectiveness of irradiation in the management of this tumor. In order to improve the prognosis of carcinoma of the prostate, effective systemic therapy will be necessary to control micrometastasis in patients with poorly differentiated lesions.