Prostate specific antigen and human glandular kallikrein 2 in early detection of prostate cancer

Purpose: Several tumor markers have recently been applied for prostate cancer screening. We analyze the effectiveness of prostate specific antigen (PSA), age specific PSA, PSA velocity, volume adjusted PSA densities, change in PSA level following antibacterial therapy, free-to-total PSA ratio, alpha1-antichymotrypsin bound PSA, alpha2-macroglobulin bound PSA, alpha1-protease inhibitor bound PSA and human glandular kallikrein 2 in detecting prostate cancer. Materials and Methods: We conducted a review of the literature between September 2000 and February 2001. A total of 7,250 abstracts and articles published during the previous 12 years were retrieved from MEDLINE using the key words PSA and human glandular kallikrein 2. Of these reports 135 are included in this review. Results: We analyzed and systematized data from studies regarding the effectiveness of PSA and human glandular kallikrein 2 and their derivatives in the detection of prostate cancer. Conclusions: Improvement in the specificity and sensitivity of PSA is imperative. Free-to-total PSA ratio, transition zone PSA density and change in PSA level increase the specificity of PSA to some extent. Protocols investigating the effectiveness of different combinations of these 3 measurements seem necessary for improving the effectiveness of prostate cancer screening among men within the diagnostic "gray zone." PSA velocity, age adjusted PSA levels and PSA density might be used in limited cases. alpha1-Antichymotrypsin, alpha2-macroglobulin and alpha1-protease inhibitor bound PSA, and human glandular kallikrein 2 are promising experimental methods.