[Screening examination for prostate cancer. Early detection and mass screening]

The significance of symptoms, digital rectal examination (DRE), transrectal ultrasonography (TRUS) and prostatic specific antigen (PSA) as aids in the early detection of prostate cancer was investigated. In number of studies, sensitivity of DRE is lower than that of TRUS but specificity of DRE is adversely higher than that of TRUS. PSA was an excellent means to observe clinical course of prostate cancer patients but have proven to be insensitive and nonspecific to detect early stage prostate cancer. There is certainly no single test that can be applied reliable to detect the presence of prostate cancer at present. The use of three screening modalities must be recommended to improve the detection rate. Mass screening program in Gunma Prefecture has been being studied since 1981. In this paper, we demonstrated that this screening program is successful to detect early prostate cancer with high detection rate (0.8%), improves the survival rates comparing to those of patients detected by outpatient clinics and the tests applied in this program prove relatively high specificity and sensitivity. To prove the significance of mass screening program, pilot studies in well executed randomized prospective protocols are urgently needed. To achieve this purpose, it is necessary to organize a cooperative study group since approximate 50,000 to 100,000 subjects should be examined in this protocol.