Performance of total prostate specific antigen and free prostate specific antigen ratio for screening prostate cancer in a Turkish population

The aim of the study was to report the diagnostic performance of total prostate-specific antigen (tPSA) and free prostate-specific antigen ratio (%fPSA). The diagnostic performances of tPSA and %fPSA were evaluated in 3 4 men by ROC curves, sensitivity, specificity and diagnostic odds ratio calculations. One hundred and sixty-two patients were diagnosed as prostate cancer (PCa) and 202 as normal. The median tPSA levels and %fPSA ratios differed significantly, 11.1 ng/mL and 11 versus .51 ng/mL and 20 in PCa and normal groups, respectively. At tPSA levels between 4-10 ng/mL; area under curve (AUC)%fPSA was greater than AUCtPSA. 1 as a cut off value of %fPSA was the optimum choice revealing a sensitivity of 0.703, a specificity of 0. 5 and diagnostic odds ratio of 4.254(95% CI 2.1578.39 ). %fPSA ratio is an expedient screening marker in PCa. In our laboratory, at tPSA levels between 410 ng/mL, %fPSA ratio of 1 offers a preferable diagnostic performance. [Turk J Cancer 2009;39(1):18-25]