PSA in benign prostatic hyperplasia and prostatic intraepithelial neoplasia.

Prostate specific antigen has become an important adjunct to the digital rectal examination in screening for prostate cancer. The clinician should be familiar with interpretation of this test. Many men with BPH have elevated serum PSA concentrations; however, the majority of these men will have other pathologic processes such as occult cancer, PIN, or acute inflammation that may account for the elevations in serum PSA. Certainly, serial increases in serum PSA should increase concern that occult carcinoma is present. Patients with PIN may also have elevated PSA concentrations. When PIN is associated with elevated PSA, a high incidence of invasive carcinoma is noted on subsequent biopsy. Further investigation into the associations will further refine the clinical utility of this powerful tumor marker.