Immuno-analytical characteristics of PSA and derived biomarkers (total PSA, free PSA, p2PSA)

Prostate-specific antigen (PSA) is the recommended tumor marker for individual screening and follow-up of prostate cancer. This paper reviews main structural and physiological data about prostate specific antigen isoforms: total PSA, free PSA, [-2]proPSA (also named p2PSA). It describes the pre-, per- and post-analytical conditions for these different parameters. It presents the interpretation of results and derived calculated indices (free/total PSA ratio, Prostate Health Index or PHI) for the management of prostate cancer (initial diagnosis and follow-up).