Breast cancer

In Japan the mortality and incidence rates of breast cancer have been increasing. In 2000, the number of breast cancer deaths in female was 9,171. In 1996, the aged adjusted incidence rate of breast cancer was 38.9, top among all of female cancers and the estimated number of female breast cancer patients was 29,448 in Japan. Therefore, efficient breast cancer screening system is urgently needed. In April 2000, breast screening using biennial mammography in combination with clinical breast examination instead of annual clinical breast examination alone was introduced for women aged 50 and over in Japan. However, the compliance of screening using mammography was less than 1% in the fiscal 2000 year. On the other hand, the compliance of screening with clinical breast examination alone was 6.5% in same period. These compliances were significantly lower than that of about 65% in the USA. Given the importance of the control of quality in screening mammography, a central committee for the quality control of mammographic screening has been established in order to educate doctors and radiographers and to assess image apparatus in each facility. As of April 2002, 1,409 out of 1,978 doctors that participated in the training program had obtained either grade A (instructor level) or grade B (adequate level). Gøtzche and Olsen reassessed previous meta-analyses of screening mammography and concluded that screening for breast cancer with mammography was unjustified. Subsequently, reviews by U. S. Preventive Services Task Forces and the WHO reconfirmed the effectiveness of screening mammography in reducing breast cancer mortality. These controversies show the importance of assessment of screening mammography effectiveness in Japan.