prostatic acid phosphatase
[pros-tat-ick a-sid fos-fuh-tace]
also called PAP. A substance made by the prostate gland which can be found on a blood test. The PAP test is not useful for prostate cancer screening because it can be elevated due to many factors, but the test is sometimes used in men who are known to have prostate cancer. (This not the same as the Pap screening test for cervical cancer; for that, see Pap test.) See also prostate, prostate-specific antigen, screening.