The importance of local control in the treatment of prostatic cancer.

In a retrospective analysis of 946 patients with prostatic carcinoma treated with external beam radiotherapy between 1958 and 1989 at Stanford University Hospital the 15-year actuarial clinical local control rate was 77.8 +/- 3.3% for Stanford stage T1, 61.3 +/- 4.4% for stage T2 and 64.9 +/- 4.8% for stage T3 disease. Overall, there was improvement in disease-specific survival without a significant alteration in survival in patients who achieved clinical local control. For the 50 Stanford stage T1 cases with local control on clinical examination and a positive post-treatment biopsy a decrease in disease-specific survival was observed. There was no difference in disease-specific survival for comparable stage T2 or T3 cases. In an analysis of patients who underwent ultrasound guided prostatic biopsy performed after irradiation the trend of prostate specific antigen was more important than biopsy results in predicting which patients would have relapse.