[Trial of early detection of breast cancer by mass screening in Miyagi Prefecture].

Mass screening for breast cancer which was commenced by Miyagi Cancer Society in 1977 has been carried out on 94953 examinees. The main activities comprise itinerant screening in the communities and group screening at the workplaces. In addition to two types of mass screening, examination was also performed at the detection center. The overall breast cancer detection rate was 0.12% in mass screening. In contrast it was 3.1% at the center. Early breast cancer, however, was more frequently found in mass screening than at the center examination. The cytologic studies of nipple discharge were performed on 14314 subjects as first screening. Positive finding was seen in 5 (0.005%). In high risk group, which also underwent mammography at first screening, the detection rate was higher than that among general examinees. Method for effective procedures for detecting early breast cancer are now under study.