Mobile unit for use in mass screening for breast cancer.

Since 1977, mass screening for breast cancer has been carried out in Miyagi prefecture, Japan. The main activities involve itinerant screening in the communities and group screening at the workplaces. The first step in this screening is the physical examination; the second step, for women with suspicious findings, is examination by mammography and ultrasonography, in a specially equipped mobile unit. The number of subjects screened over a seven-year period ending in March, 1984, was 94,953. Mammography was performed on 4,485 subjects (4.7 per cent) Breast cancer was detected in 116 subjects (0.12 per cent). Since 1980, 2,292 high risk subjects have undergone mammography as the first step screening. The detection rate (0.35 per cent) for this group was higher than for the general subjects examined. Therefore, mammography performed in a mobile unit is a suitable approach for the detecting and diagnosing of breast cancer.