Early detection of prostate cancer

Prostate cancer is the second most common malignancy in American males and the third leading cause of cancer deaths in this population. There are no symptoms that are unique to early prostate cancer, and nearly one-half of patients will have metastatic disease at diagnosis. Because of its tremendous impact upon the health and well-being of the American male population, and the importance of early diagnosis in curability, there is keen interest in the development of effective screening procedures that are highly sensitive, specific, and cost-effective. Rectal examination serves as the historical control. The serum tumor markers of prostate cancer, prostatic acid phosphatase (PAP), and prostate-specific antigen (PSA), are sensitive but relatively nonspecific in the diagnosis of prostate cancer. The use of transrectal ultrasound as a screening tool is highly controversial but suffers from a similar lack of specificity. As yet, no diagnostic tests, alone or in combination, have proven to be of practical value in screening for prostate cancer. Fundamental but unanswered questions about the natural history and the high incidence of "latent" disease also obscure the issue of early diagnosis of prostate cancer and its impact on survival.