[Detection of early prostatic cancer in mass screening program]

Since 1975 up to 1988, we have performed a mass screening program (MS) for prostatic diseases using transrectal ultrasonography (TRS) in the primary study. In our study, 42 cases of prostatic cancer (0.6%) was detected among 6,674 examinees. Out of 42 cases of cancer, 24 (57.1%) were diagnosed as early prostatic cancer (Stage A 1, Stage B 23). The detection rate of cancer in MS and the ratio of early stage of cancer among them were higher than those in the outpatient clinic of our department. Diagnostic accuracy of TRS, palpation and tumor markers in MS were studied respectively through our series of MS. TRS was useful for MS especially in low false negative rate. On the other hand, palpation was characteristic in low false positive rate. Prostatic specific antigen (PSA) among tumor markers was effective to detect early prostatic cancer. However, there were some problems about distinguishing early prostatic cancer from BPH, because of the high false positive rate.