1. World Health Organization. Globocan. 2020. https://gco.iarc.fr/today/data/factsheets/cancers/39-All-cancers-fact-sheet.pdf Accessed 27 Oct 2023.
2. National Cancer Center. Cancer Statistics, Cancer Information Service (National Cancer Registry and Vital Statistics of Japan, Ministry of Health, Labour and Welfare). 2023. https://ganjoho.jp/reg_stat/statistics/data/dl/index.html#anchor2 Accessed 27 Oct 2023.
3. Ministry of Health, Labor and Welfare. Vital statistics. 2023. https://www.mhlw.go.jp/toukei/saikin/hw/life/life22/index.html Accessed 27 Oct 2023.
4. Wu Q, Gu D. Oldest-Old Adults. In: Gu D, Dupre ME, editors. Encyclopedia of Gerontology and Population Aging. Geneva: Springer; 2022. pp. 3637–53.
5. Japanese Gastric Cancer Association. Japanese classification of gastric carcinoma. 15th ed. Tokyo: Kanehara; 2017. (in Japanese).