Prostate Specific Antigen (PSA) Test

PSA detection flowchart

Prostate-specific  antigen (PSA) is a protein produced and secreted by prostate cells. The protein is a tumor marker that is frequently be found at higher concentrations in the blood of those with prostate cancer. It was created as a possible diagnostic method for prostate cancer by Kuriyama et al.1  The use of PSA tests to screen normal men for prostate cancer is controversial for several reasons. Some prostate cancers do not produce the protein and would be missed. PSA levels can also increase in the blood when cancer is not present  (i.e. as a response to infection or inflammation). Patients with elevated levels of PSA under these circumstances could be subjected to unnecessary medical tests and stress.

  • 1Kuriyama, M., et al. "Quantitation of Prostate-specific Antigen in Serum by a Sensitive Enzyme Immunoassay." Cancer Research. 40 (1980): 4568-4662.