International trends in cancer mortality revisited: Japan’s site-specific progress and remaining challenges until 2024

This study examined recent international trends in age-standardized mortality for all cancers combined and major cancer types, comparing Japan with selected countries (Australia, Canada, the Republic of Korea (Korea), the United Kingdom, and the United States of America) using the latest available national data (from 1980 through the early 2020s). Overall cancer mortality in Japan continued to decline at a pace similar to that of other high-income countries. Marked reductions were observed for stomach and liver cancers in Japan, which historically had high mortality. These declines narrowed international differences, and mortality from female liver cancer in Japan has now fallen below levels in Western countries. Stomach cancer mortality rates have been continuously decreasing in Japan, while the pace was slower than that of Korea. In contrast to those decreasing cancers, Japan showed persistently high mortality for colorectal, pancreatic, and cervical cancers. Mortality from male lung cancer and female breast cancer in Japan declined only slowly or continued to rise, resulting in levels approaching those in Western countries. The decline in liver cancer is considered an effect of measures against hepatitis B and C, and could serve as an international model. The decrease in stomach cancer is also one of Japan's progressive movements, but comparisons with Korea indicate challenges remain in secondary prevention. Strengthened primary and secondary prevention are urgently needed for colorectal, lung, female breast, and cervical cancers, which have not shown a clear decreasing tendency in Japan.