Recent trends in population-based cancer registries in Japan: the Act on Promotion of Cancer Registries and drastic changes in the historical registry.

Cancer registration in Japan has a long history spanning over 60 years; the first population-based cancer registry was established in Miyagi prefecture in 1951. The progress made in the regional population-based cancer registries in terms of standardization and quality improvement during the 10 years of the third comprehensive strategy for cancer control was highlighted in the history of cancer registration in Japan. However, there were still weak points regarding local government-oriented cancer registries that remained, e.g., the reporting of cancer cases to the population-based cancer registries was not a mandatory task for medical institutions. After the Cancer Control Act in 2006, the Act on Promotion of Cancer Registries was finally enacted in Japan on December 6, 2013. According to that Act, hospital managers must report information on any primary cancer that was first diagnosed in their institutions from January 1, 2016 to the prefectural governors. Given the increasing number of cases and amount of information recorded, it would have been almost impossible to maintain our cancer registries using the same system, and changes were required to obtain reliable cancer statistics. This was particularly important in Japan, because the country is facing a hyper-aging society, with two to three million cancer patients requiring entry of detailed information. We appreciate the long history of the Japanese cancer registry, but it is necessary to make dramatic changes to bring the registry up to date and to be able to track the increasing amount of information.