Screening for carcinoma of the prostate: efficacy of available screening tests.

Despite the high prevalence and mortality from carcinoma of the prostate, very few prospective, controlled, population-based studies are available to assess the impact of early diagnosis programs. Three screening modalities have been suggested for this tumor: rectal examination, serum tumor markers, and transrectal ultrasound. Prostatic acid phosphatase and prostatic specific antigen have proven to be insensitive and nonspecific in large trials and generally, when elevated, allow diagnosis of metastatic disease. Transrectal ultrasound also suffers from poor specificity. Rectal examination, although insensitive to small tumors (less than 1 ml in volume), has the advantage of possibly detecting tumors of a higher biologic activity. An improved survival has been demonstrated in populations undergoing routine rectal examinations. Further prospective, population-based trials comparing early detection techniques are necessary before mass screening for carcinoma of the prostate can be recommended.