A Review on the Clinical Utility of PSA in Cancer Prostate

Abstract

Prostate cancer has come to share the oncological centrestage among male cancers. The availability of Serum Prostate Specific Antigen, PSA, as a marker has encouraged it's use to diagnose both cancer and cancer recurrence. Some clarity is required about its precise role in clinical practice. The available literature on Prostate Specific Antigen was reviewed; Articles were reviewed for content, applicability to the problem at hand, availability of data about sensitivity and specificity of values, refinements in measurements and finally for impact of screening programmes using these values on survival and quality of life. The data in the literature was critically re-evaluated and analysed to draw reasonable conclusions. Serum PSA measurements show variable reliability when it comes to diagnosis of Prostate cancer, given the dynamics of PSA physiology. Surrogate measures like PSA density, PSA velocity, free-to-complexed PSA ratio, percentage Pro-PSA, etc., have been used to improve the predictive utility of this assay for Prostate cancer. The ability of PSA to detect those cancers that will cost life, and thereby permit early curative treatment, is as yet unclear. It's most definitive role appears to be in diagnosing recurrences after adequate surgical treatment, and in evaluating response to treatment.

Keywords: Prostate Specific Antigen (PSA); Prostate cancer; Prostate cancer diagnosis; Prostate cancer treatment.

Fig. 1

Prostate-specific antigen (PSA) isoforms in cells and blood. ACT: antichymotrypsin, hK-2: human glandular kallikrein, BPSA: benign prostate-specific antigen, iPSA: initial prostate-specific antigen, cPSA: complexed prostate-specific antigen. (Adapted from Partin AW, Gretzer MB. Molecular forms of PSA: what does the future hold? Urology Times 10/2003)