Prostate cancer screening markers

Prostate cancer is the most frequent new cancer diagnosis in the Western world. Prostate-specific antigen (PSA) was shown to be an adequate tool in prostate cancer screening. However, in men with a PSA level between 4.0 and 10 ng/ml its predictive value is low. PSA serum levels are poorly correlated with grade and stage of prostate cancer, and clinically significant prostate cancers have been found in patients with serum PSA levels lower than 4.0 ng/ml. The widespread use of PSA screening programs led to over-diagnosis and unnecessary biopsies. Consequently, there is a need for new instruments that are likely to improve the specificity of serum PSA levels between 4.0 and 10 ng/ml and the screening for prostate cancer in subjects with low PSA. Potential biomarkers related to conventional PSA, such as free PSA, PSA density, PSA velocity and complexed PSA, intact PSA, nicked PSA, benign PSA and pro PSA, as well as insulin-like growth factor 1 and its binding protein, and human glandular kallikrein 2 are reviewed. Promising urinary markers for the early detection of prostate cancer, such as glutathione-S transferase P1 gene (GSTP-1), 8-hydroxydeoxyguanosine (8-OHdG), differential display code 3 (DD3), uPM3, and telomerase, which have been described during the last years are reviewed in this article. The advantages and limitations of screening markers for prostate cancer are discussed.