Current status of breast cancer screening in the world.

The mortality associated with breast cancer is decreasing in Europe and the United States. There are various reasons for these trends, including an increase in detection of early-stage breast cancers due to increased use of mammographic screening and the establishment of standardized systemic treatments based on evidence-based medicine. However, in Japanese women, both the morbidity and the mortality of breast cancer are increasing. In this manuscript, we describe the current status of mammographic screening in Europe and the United States, and the status of breast cancer screening in Japan. Quality control systems are also introduced, and the need for practical measures, such as implementation of quality control systems aimed at improving the cancer screening rate (with a target of 50%) and population-based screening (organized screening), based on the Cancer Control Act, is described. Current countermeasures for dense breasts in women in their 40s, both overseas and in Japan, are also described, together with discussions of the diagnostic capability of digital mammography, the usefulness of screening combined with computer-aided diagnosis, and the current status of screening using MRI in Europe and the United States.