Prostate-specific antigen and detection of prostate cancer: What have we learned and what should we recommend for screening?

Prostate-specific antigen (PSA) has become one of the most commonly used cancer clinical tests, and routine PSA-based screening has led to a dramatic increase in prostate cancer detection. A significant downward stage migration has resulted, and a decrease in prostate cancer mortality has also been observed. However, PSA screening remains controversial because there is no definitive proof that it decreases prostate cancer death rates, and there is concern that it may detect a significant number of clinically insignificant cancers. Screening age and interval have been recently questioned, and the best threshold to recommend biopsy has been complicated by new data showing that prostate cancer exists at all PSA levels, even those thought to be "normal" in the past. It is hoped that ongoing prospective screening trials will determine the value of PSA screening. However, until these results are available the controversy will continue, and men will continue to be screened.