Longitudinal evaluation of the complexed-to-total prostate specific antigen ratio in men with prostate disease.: Effect of treatment

The longitudinal changes in the complexed-to-total prostate specific antigen (PSA) ratio were evaluated in 90 men with benign prostatic hyperplasia (BPH) and 50 men with prostate cancer. The influence of treatment on this ratio was studied in 45 BPH patients and 50 patients with prostate cancer. Using a cut-off of 0.80 for the complexed-to-total PSA ratio, the large majority of prostate cancer patients had a ratio above the cut-off before treatment in serial determinations, whereas most BPH patients had a ratio consistently below that value. However, the few prostate cancer patients who had a ratio less than or equal to 0.80 showed this low ratio in serial determinations, as did BPH patients who had a ratio greater than or equal to 0.80. During treatment, the ratio significantly decreased in 43 of the 50 patients with prostate cancer in parallel with the decrease in total PSA, and 34 of the 41 patients that had a pretreatment ratio > 0.80 showed a ratio less than or equal to 0.80 during hormonal therapy. Our results show that neither the physiological changes in total and complexed PSA nor the treatment of BPH patients change the diagnostic efficacy of the complexed-to-total PSA ratio, whereas in prostate cancer patients under hormonal therapy, the ratio decreased in parallel with the decrease in total PSA. This suggests that, apart from improving the diagnostic efficacy of total PSA, the complexed-to-total PSA ratio could also be used to monitor BPH patients for newly developed tumours or to monitor therapy in patients with prostate cancer. (C) 1998 Elsevier Science Ltd. All rights reserved.