BACKGROUND

Unlike many North American and European countries, Japan has observed a continuous increase in cancer incidence over the last few decades. We examined the most recent trends in population-based cancer incidence and mortality in Japan.

METHODS

National cancer mortality data between 1958 and 2018 were obtained from published vital statistics. Cancer incidence data between 1985 and 2015 were obtained from high-quality population-based cancer registries maintained by three prefectures (Yamagata, Fukui, and Nagasaki). Trends in age-standardized rates (ASR) were examined using Joinpoint regression analysis.

RESULTS

For males, all-cancer incidence increased between 1985 and 1996 (annual percent change [APC] +1.1%; 95% confidence interval [CI], 0.7-1.5%), increased again in 2000-2010 (+1.3%; 95% CI, 0.9-1.8%), and then decreased until 2015 (-1.4%; 95% CI, -2.5 to -0.3%). For females, all-cancer incidence increased until 2010 (+0.8%; 95% CI, 0.6-0.9% in 1985-2004 and +2.4%; 95% CI, 1.3-3.4% in 2004-2010), and stabilized thereafter until 2015. The post-2000 increase was mainly attributable to prostate in males and breast in females, which slowed or levelled during the first decade of the 2000s. After a sustained increase, all-cancer mortality for males decreased in 1996-2013 (-1.6%; 95% CI, -1.6 to -1.5%) and accelerated thereafter until 2018 (-2.5%; 95% CI, -2.9 to -2.0%). All-cancer mortality for females decreased intermittently throughout the observation period, with the most recent APC of -1.0% (95% CI, -1.1 to -0.9%) in 2003-2018. The recent decreases in mortality in both sexes, and in incidence in males, were mainly attributable to stomach, liver, and male lung cancers.

CONCLUSION

The ASR of all-cancer incidence began decreasing significantly in males and levelled off in females in 2010.