[Characteristics of screening-detected prostate cancer on health checkup]

Prostate cancer has the highest incidence and the second most common cause of death in U.S. men. In Japanese men, prostate cancer is not so common but is the most increasing neoplasm. Detection of early-stage cancer and early curative treatment are the most effective ways to reduce mortality from this disease. Therefore the mass screening system for prostate cancer to reduce mortality has become an important issue in recent years in Japan. The screening project for prostate cancer was conducted using only the prostate specific antigen (PSA) levels of primary screening with the cut off level of 4.0 ng/ml for candidates undergoing a medical checkup every 2 years. Totally, 20,338 men had health checkups every 2 years and 899 men requested the screening checkup for prostate cancer and their serum PSA level. Fifty (5.6%) men showed abnormal PSA level, 41 men had a second screening, 27 men underwent needle biopsy of prostate, and finally 14 cases of prostate cancer were detected. The detection rate calculated for prostate cancer was 1.56%. Thirteen cases out of 14 (92.9%) were clinically diagnosed as localized cancer. In 10 cases, total prostatectomy was performed and the pathological findings showed none of them to be clinically insignificant cancers. In conclusion, from our result the screening of prostate cancer using PSA only is considered to be very useful to detect early clinically significant prostate cancer.