Prostate-specific antigen (PSA) is a protein produced by the cells of the prostate gland. Levels of PSA in the blood are used to detect early prostate cancer (which is usually asymptomatic) as higher PSA levels are associated with a greater likelihood of prostate cancer.[1]
However, the PSA test has poor specificity. Infection, trauma, inflammation (i.e., prostatitis), and benign prostatic hyperplasia can all increase PSA levels. A PSA level ≥ 4.0 ng/mL is generally the threshold for which further evaluation for prostate cancer should occur,[2] but prostate cancer has been detected in men with PSA levels as low as 1.1 ng/mL[3] and not every man with very high PSA levels will have prostate cancer.
Although PSA testing appears to have a small potential benefit on reducing the risk of death from prostate cancer,[4] there are potential harms of testing due to frequent occurrence of false-positive results,[5] including psychological distress, additional testing and prostate biopsy, and treatment complications (e.g., incontinence, erectile dysfunction).[6] Many men with prostate cancer never become symptomatic and wouldn’t know they have the disease if they weren’t screened for it. In these cases, treatment would only result in harm without benefit.
For these reasons, it’s recommended that, in men aged 55–69, undergoing PSA testing should be a personal choice, rather than a blanket recommendation.[6]