Elevated prostatic acid phosphatase: a prognostic factor for stage C adenocarcinoma of the prostate.

The clinical course of 25 patients with clinical stage C adenocarcinoma of the prostate who had pre-treatment elevations of the prostatic acid phosphatase (Roy test) was analyzed retrospectively. All patients were treated with definitive external beam radiation therapy at our hospital between 1974 and 1980. Of the 25 patients 17 (68 per cent) have had disease progression. The median time to treatment failure for this group was 27 months (range 10 to 101 months), and the over-all median survival for these patients has not been reached (range 16 to 120 months). Local control of disease was achieved in 84 per cent (21 of 25) of the patients. The control group consisted of 75 consecutive age-matched patients with normal pre-treatment prostatic acid phosphatase levels whose disease was identically staged and treated at our hospital from July 1977 to January 1979. The median time to disease progression in this group has not yet been reached. Of these 75 patients 24 (32 per cent) have had disease progression within a median time of 38 months. Therefore, an elevated pre-treatment prostatic acid phosphatase value is a harbinger of systemic disease and indicates that radiotherapy will be significantly (p equals 0.002) less effective as a definitive local therapeutic modality.