This present study was conducted among the nine centers of Akita prefectural Welfare Federation of Agricultural Cooperatives. This applied to women over 30 years of age, and carried out following to the standard method of the Japan Cancer Society.
The total of women examined by the first screening from April 1983 to January 1985 amounted to 15903, of which the number of women over 60 years of age was only 7 per cent of the total. According to the type of screening, the number of women slightly more in the center screening than in the local screening. However, in both types of screening, the number of women examined by the combination method, for example, anemia or uteric cancer, was much higher than that of the mass screening for breast cancer alone.
The second screening rates indicaded a marked difference of 0.4 to 21.7 per cent depending on the location of the center. The over-all average for the second screening was 3.8 per cent. As a result of the second screening, breast cancers were detected in 12 cases (0.07%). The breast cancer detection rate increased with age. It is notable that the breast cancer detection rate for women over 60 years of age was 5 times higher than for women over 40 years of age. Among other diseases detected in the second screening were mastpathy (233 cases), fibroadenoma (15 cases), mastitis (40 cases) and others.
As far the stage distribution and screening history for detected breast cancers, 60 per cent of all cancer cases were diagnosed as stage I, and 70 per cent were the initial screening. Seven out of 12 cases were aware the breast lump themselves before the first screening. From this point of view, it was suggested that every women should be educated in order to perform selfexamination.