PSA: What is it?

PSA is used to screen for prostate cancer. Learn more about PSA.

By Mayo Clinic Staff

Prostate-specific antigen (PSA) is a protein in a man's body that is sometimes used to screen for prostate cancer.

What is PSA?

PSA is a protein produced by both cancerous (malignant) and noncancerous (benign) prostate tissue.

PSA helps liquefy the semen. A small amount of PSA normally enters the bloodstream.

Mar. 22, 2014 See more In-depth