Prostate cancer (PCa) is the most common newly diagnosed cancer among men in the United States today. With the advent of the prostate-specific antigen (PSA) test, the number of newly diagnosed cases has increased tremendously. The rates of PCa have increased so dramatically over the last decade that the age-adjusted incidence rate of PCa is now greater than that for any other cancer among men in the United States. Although PCa rates have risen steadily since 1973, there has been a dramatic acceleration in the late 1980s which has been associated with the introduction and use of PSA for screening and early detection. There is now some evidence that the rates may be leveling off and even decreasing in some areas.