Teletherapy for stage C adenocarcinoma of the prostate.

From 1967 to 1977, 22 patients with clinical stage C adenocarcinoma of the prostate received external beam radiation therapy with curative intent. The crude rate of survival was 100 per cent at 2 years and 64 per cent (14 of 22) at 5 years post-radiation. Metastatic disease developed in 14 patients (64 per cent) 1 to 5 years after radiation therapy, 5 of whom (23 per cent) died of the disease. Eight patients (36 per cent) who were followed 5 to 14 years after radiation therapy achieved a status free of disease. When results were analyzed according to grade 100 per cent of the patients with grade 1 (well differentiated) carcinoma survived free of disease 7 to 14 years post-radiation and 40 per cent with grade 2 (moderately differentiated) carcinoma survived free of disease 5 to 7 years. Of those patients with grade 3 (poorly differentiated) carcinoma none became free of disease and 63 per cent died of cancer 3 to 5 years after radiotherapy. Local control was achieved in 100 per cent of the patients with grade 1 tumors, in 70 per cent with grade 2 disease and in 50 per cent with grade 3 cancer. We conclude that the degree of tumor differentiation is a major determinant in the response of stage C adenocarcinoma of the prostate to external beam radiation therapy.