REDUCTION OF SERUM PROSTATE-SPECIFIC ANTIGEN DURING ENDOCRINE OR CYTOTOXIC TREATMENT OF HORMONE-RESISTANT CANCER OF THE PROSTATE - A PRELIMINARY-REPORT

During the years 1988-1991 sequential serum prostate-specific antigen (PSA) determinations were performed during systemic treatment of hormo ne-resistant prostate cancer. The following drugs were used: prednison e (5 mg 4 times per os daily, 8 patients); flutamide (250 mg 3 times p er os daily, 13 patients); estramustine phosphate (280 mg 2-3 times pe r os daily, 12 patients), and epirubicin (100 mg/m(2) i.v. every 3rd w eek, 18 patients). In 3, 3, 4 and 6 patients, respectively, a PSA redu ction of greater than or equal to 50% was observed during treatment, w hich in 12 patients was combined with pain relief and improvement in t he performance status. Though the exact mechanism of PSA reduction and its clinical significance are not completely understood, the findings suggest that hormone-resistant prostate cancer still contains hormone -sensitive tumor cells. The 4 drugs used in this study seem to be equa lly effective in achieving a PSA reduction of greater than or equal to 50%.