Prediction of response to radiotherapy for localised prostatic cancer

Fifty-one patients with TO-4 NX MO carcinoma of the prostate were treated by external beam radiotherapy. Comparison with 40 patients with TO-3 NX MO disease, whose treatment was deferred initially, showed a higher incidence of local progression in the untreated patients. Age at presentation and initial T category did not have a significant influence upon the probability of disease progression after radiotherapy, whereas all but one of the irradiated patients with Gleason sum scores greater than or equal to 6 progressed. Treatment-related morbidity was appreciable and prolonged proctitis occurred in 31 patients. There was one treatment-related death. Biopsy 1 year after treatment did not yield information of prognostic significance. It is recommended that the selection of patients with localised carcinoma of the prostate for treatment by radiotherapy is based on histological grade. The Gleason score is a practical method for identifying those who would best be treated by other methods.