J Epidemiol. 2026 Mar 21. doi: 10.2188/jea.JE20250559. Online ahead of print.
ABSTRACT
BACKGROUND: Long-term trends in cancer incidence were reported until 2015 in Japan, but recent data have been limited since the launch of the National Cancer Registry (NCR) in 2016. We analyzed 30-year trends in cancer incidence and mortality, emphasizing the NCR’s establishment.
METHODS: Cancer incidence data were obtained from high-quality population-based cancer registries in three prefectures (Yamagata, Fukui, and Nagasaki) from 1985 to 2015, and the NCR extracted data from these prefectures between 2016 and 2021. National cancer mortality data from 1979 to 2023 were obtained from published vital statistics. Trends in age-standardized rates (ASR) calculated using the 1985 Japan Standard Population were examined using joinpoint regression analysis.
RESULTS: The ASR incidence in 2016 (the first year of the NCR) was the highest ever recorded. All-cancer incidence (for both sexes) increased between 1985 and 2021 (annual percentage change, 0.9%; 95% confidence interval [95% CI]: 0.8 to 1.0). For males, all-cancer incidence stabilized after increasing until 2017, whereas for females, it increased after 2002 (1.7%; 95% CI: 1.4 to 2.3). All-cancer mortality (for both sexes) declined between 1997 and 2023 (-1.5%; 95% CI: -1.5 to -1.4), mainly due to decreases in stomach, lung, and liver cancers.
CONCLUSIONS: The NCR’s launch and the sharp rise in incidence in 2016 may have influenced trend interpretation and should be considered with caution. A longer observation period is needed before clear secular trends can be established under the NCR data system.
PMID:41866192 | DOI:10.2188/jea.JE20250559
