Prognostic significance of prostate-specific antigen in endocrine treatment for prostatic carcinoma.

We have studied the prognostic significance of prostate-specific antigen (PSA), monitored monthly, in 24 patients with prostatic cancer (5 D1, 19 D2) on endocrine therapy. The pretreatment levels of PSA were high in all patients (mean value 41 ng/ml). It was found that PSA levels at the end of the first and sixth months of treatment were reliable prognostic indicators. At the first month evaluation PSA had decreased more than 50% from the initial values in the 16 patients with stable disease, while it had decreased less than 50% in those with progressing disease. At the end of 6 months, patients with stable disease had PSA levels within the normal range, while 8 of the patients who had progressing disease had levels higher than 10 ng/ml. Respectively 6 and 2 patients had also had increases in PSA levels at 3 and 6 months before scintigraphic demonstration of increased bone metastases.