Tumor Markers For Prostatic Cancer (Is there a screening test for Prostatic Cancer?)

Prostatic-Specific Antigen (PSA) is a low-molecular weight glycoprotein, that is uniquely associated with prostatic tissue. It has considerable diagnostic specificity for prostatic disease. Concentrations of PSA in serum correlate well with the stage of disease, and response to treatment in patients with prostatic cancer. It is, therefore, a good tumor marker for prostatic cancer. However, it has been reported to be elevated in benign prostatic hypertrophy, after prostatic massage, after biopsy procedures and other benign conditions, therefore, this test has not been recommended as a screening test for prostatic cancer. It has a positive predictive value of only 0.41%, that is one out of every 241 positive tests would be a true positive test. In symptomatic males over the age of 55 there is good evidence suggesting the importance of using this test along with other procedures in the diagnostic workup of such patients.