The two tests available to screen for prostate cancer are the prostate-specific antigen (PSA) blood test and digital rectal exam (DRE). Prostate-specific antigen (PSA) is a protein produced by the cells of the prostate gland. The PSA test measures the level of PSA in the blood. A DRE involves a physician inserting a gloved, lubricated finger into the rectum to feel the prostate for any irregularities or firm areas. The DRE is recommended in conjunction with the PSA to detect abnormalities in the prostate.