Breast cancer screening and the changing population pyramid of Japan.

Background: Breast cancer has been the most prevalent cancer in Japan since the 1990s. The mortality from breast cancer is increasing in Japan, whereas in other industrialized countries it has been decreasing since 1990. On the other hand, Japan faces unparalleled growth in its aging population. The aim of this study was to report the mammography screening among Japanese women and the related upcoming changes in the population pyramid of Japan.

Data Sources And Methods: The reference data for our study were obtained from the Center for Cancer Control and Information Services, Japan Ministry of Internal Affairs and Communications, Ministry of Health, Labour and Welfare, the Japanese Cancer Society, and the National Institute of Population and Social Security. The survey data were obtained from breast cancer and mammography screenings in the Tokyo Prefecture in 2008. The following parameters were analyzed: annual breast cancer incidence, current screening rates, average life-span, and predicted demographic statistics.

Results: Our results showed that breast cancer incidence and mortality have been increasing annually in Japan. The average age of breast cancer patients increased to 58.40 years in 2010. The incidence of breast cancer in women aged 65 years and older increased from 25.3 to 32.9 % in the last 10 years and is expected to continue to increase in the future. The check-up rate was 16.0-20.0 % for women aged 65-74 years and 43.0-46.0 % for women aged 40-54 years. According to our questionnaire survey, concerns about breast cancer and mammography screening were high in the young and low in the elderly women. The Japanese population aged 65 years and older was 30,740 (24.1 %) in 2012 and is estimated to increase by 40 % over the next 20 years despite Japan's declining population size.

Conclusion: Breast cancer incidence has increased in Japan, even among patients aged 65 years and older. Breast cancer has become increasingly prevalent in older Japanese women. As the population pyramid of Japan changes, women aged 65 years and older, who think that there is no longer need to receive mammography screening and are not educated regarding self-examinations, should be encouraged to receive regular check-ups for breast cancer.