Send a comment on this item to LII: Send a comment on this item to LII staff, who on weekdays will usually reply within 24 hours. The Prostate-Specific Antigen (PSA) Test Fact sheet about this test measuring levels in the blood of prostate-specific antigen (PSA), "a protein produced by cells of the prostate gland." Includes details about why and how the test is performed, some of the limitations of the PSA test, why "using the PSA test to screen men for prostate cancer is controversial," research to improve the test, and other prostate cancer detection methods under study. Also in Spanish. From the National Cancer Institute. http://www.cancer.gov/cancertopics/factsheet/detection/PSA Asterisk * indicates required field. Your Name Your Email Address * We will not sell or provide your email address to anyone else. Comment * Enter the verification code as it is shown in the box below. This helps prevent automated submissions. *