Radiotherapy for prostatic carcinoma: post-irradiation prostatic biopsy and recurrence patterns with long-term followup.

From 1968 through 1975, 159 patients with stages A, B and C adenocarcinoma of the prostate were treated with supervoltage radiation therapy. A median dose of 7,200 rad was given. The influence upon survival of grade, stage and a positive biopsy result after irradiation is analyzed. Over-all survival is a patently imprecise test of local treatment because patients die of intercurrent disease and are alive with metastases for significant intervals. The classification of survival with no evidence of recurrent disease excluded those patients dying of intercurrent disease. Therefore, the rate of survival free of disease always will be greater than the over-all survival rate in these patients, and a certain percentage of the patients without evidence of cancer will harbor subclinical disease. The 5 and 10-year survival rates free of disease were 80 and 69 per cent, respectively, in 51 patients with stages A and B cancer, and 66 and 47 per cent, respectively, in 108 with stage C disease. The 5 and 10-year over-all survival rates were 72 and 56 per cent, respectively, in the former and 68 and 39 per cent, respectively, in the latter patients. Survival free of disease and death of prostatic carcinoma were influenced adversely by advancing grade and stage (p less than 0.05), while over-all survival was influenced adversely by grade (p equals 0.02) but not by stage (p greater than 0.05). A positive biopsy result after irradiation did not predict survival free of disease, over-all survival or death of prostatic cancer in patients followed for 10 years (p greater than 0.05).