A high level of prostate-specific antigen, or PSA, in the blood sometimes indicates the presence of prostate cancer, according to the National Cancer Institute. Other conditions, such as a urinary tract infection, inflammation of the prostate or benign prostatic hyperplasia sometimes elevate PSA levels as well.
Because PSA levels are often elevated in men who have prostate cancer, in 1986 the U.S. Food and Drug Administration approved the PSA blood test as a tool to follow the progression of prostate cancer in men who already had the disease, the National Cancer Institute reports. In 1994, the FDA approved the test, along with digital rectal exams, as a screening tool for prostate cancer in men between the ages of 40 and 45.
Since 1994, research indicates that the PSA test is not as accurate in diagnosing prostate cancer as the FDA once believed, explains the National Cancer Institute. False-positive results, over-diagnosis and over-treatment are relatively common, which means that the test detects high PSA levels in men who either don't have prostate cancer or who are not at risk of dying of the disease if left untreated. Additionally, the test sometimes detects normal PSA levels in men who have prostate cancer, and drugs that treat benign prostatic hyperplasia lower PSA levels artificially. Most importantly, two large studies did not show that routine screening reduces overall prostate cancer deaths.
As of 2015, some professional organizations recommend that men over 45 get routine PSA screening, but others do not, states the National Cancer Institute. Medicare and many private insurers still cover routine screening for men over the age of 50.