Abstract
Mass screening to detect both breast and thyroid cancer at the same time was conducted between April 1980 and March 1990 in Gunma Prefecture with the cooperation of the Gunma Cancer Society. The total number of subjects during these ten years on the first screening with physical examination alone was 273, 964. Of these, 24, 587 women (9.0%) were advised to undergo a second examination. Breast cancer was detected in 218 women, a detection rate of 0.08% and thyroid cancer in 276 women (0.10%). The detection rate for breast cancer was approximately twice as high at the initial screening than at the subsequent screening. The breast cancer detected by mass screening was in an earlier stage of disease and showed better prognosis than that of ordinary outpatients in our hospital. The 10-year survival rate was 95. 3% for the mass screening group and 76.8% for the outpatients group. Interval breast cancer was found in 24 cases and the prognosis was very favorable. Each physician obtained a different rate at the second examination. This mass screening program is a useful means for the early discovery and treatment of breast cancer. Hereafter, the number of initial examinees and women aged 60 or more should be increased. Mammography and ultrasonography should be introduced into the first examination. It is important to train physicians participating in the screening and to educate women about practicing breast self-examination.
