This article presents the current reports of complexed prostate-specific antigen (PSA) aimed for the enhancement of prostate cancer detection. Further studies are needed to ascertain the variability of complexed PSA. Comparisons of percent free PSA, potential additive value of alpha(1)-antichymotripsin-bound PSA (PSA-ACT) and Bayer complexed PSA (cPSA) remains controversial in men with intermediate elevated total PSA concentration. Volume-referenced complexed PSA (PSA-ACT and cPSA) can enhance prostate cancer detection. Preliminary results show that PSA-alpha(2)-macrobloblin (PSA-a(2)M) and PSA-alpha(1)-protease inhibitor (PSA-API) are promising assays for improving cancer detection.