Clinical implications of free-to-total immunoreactive prostate-specific antigen ratios

Abstract

Our data indicate that the free-to-total PSA ratio, in patients with prostatic disease and with PSA levels in the 2.0-10.0 microg/l range, gives a significant improvement in prediction of cancer over the total immunoreactive PSA value alone. Because of the correlation between a higher tumor grade and a lower free-to-total PSA ratio, this ratio may be helpful in assessing the risk of a poorly differentiated cancer.