About 20 years ago a blood test called prostate specific antigen (PSA) was developed with the hope that it would help in the diagnosis of prostate cancer.  Since then, countless healthy men have been tested for prostate cancer with a PSA and a digital rectal exam despite the fact that there has never been convincing evidence that diagnosing prostate cancer saves lives. The reason for the controversy about prostate cancer screening is that prostate cancer is a very slowly growing cancer which us...