Akiko Shibata

The Japan Cancer Surveillance Research Group aimed to estimate the cancer incidence in Japan in 2009 based on data collected from 32 of 37 population-based cancer registries, as part of the Monitoring of Cancer Incidence in Japan (MCIJ) project. The incidence of only primary invasive cancer in Japan for 2009 was estimated to be 775 601. Stomach cancer and breast cancer were the leading types of cancer in males and females, respectively.

The Japan Cancer Surveillance Research Group aimed to estimate the cancer incidence in Japan in 2008 based on data collected from 25 of 34 population-based cancer registries, as part of the Monitoring of Cancer Incidence in Japan project. The incidence in Japan for 2008 was estimated to be 749 767 (C00-C96). Stomach cancer and breast cancer were the leading types of cancer in males and females, respectively.

The incidence of a malignant disease reflects the genetic and cumulative exposure to the environment of a population. Therefore, evaluation of the incidence and trends of a disease in different populations may provide insights into its aetiology and pathogenesis. To evaluate the incidence of haematological malignancies according to specific subtypes, we used population-based registry data in Japan (N = 125 148) and the United States (US; N = 172 925) from 1993 to 2008. The age-adjusted incidence of haematological malignancies in Japan was approximately one-half that in the US but has been increasing significantly, whereas no significant change was seen in the US [annual percent change (95% C confidence interval): Japan, +2·4% (1·7, 3·1); US, +0·1% (-0·1, 0·2)]. Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) showed the largest differences in incidence, with the most remarkable differences observed for chronic lymphocytic leukaemia, HL-nodular sclerosis, mycosis fungoides and cutaneous T-cell lymphoma. HL and NHL are increasing substantially in Japan but not in the US, suggesting that environmental exposures, such as Westernization of the life style may be causing this increase. Differences in the incidence and trends for specific subtypes also showed a marked contrast across subtypes, which, in turn, may provide significant new insights into disease aetiology in the future.

The analysis of cancer trends in Japan requires periodic updating. Herein, we present a comprehensive report on the trends in cancer incidence and mortality in Japan using recent population-based data. National cancer mortality data between 1958 and 2013 were obtained from published vital statistics. Cancer incidence data between 1985 and 2010 were obtained from high-quality population-based cancer registries of three prefectures (Yamagata, Fukui and Nagasaki). Joinpoint regression analysis was performed to examine the trends in age-standardized rates of cancer incidence and mortality. All-cancer mortality decreased from the mid-1990s, with an annual percent change of -1.3% (95% confidence interval [CI]: -1.4, -1.3). During the most recent 10 years, over 60% of the decrease in cancer mortality was accounted for by a decrease in stomach and liver cancers (63% for males and 66% for females). The long-term increase in female breast cancer mortality, beginning in the 1960s, plateaued in 2008. All-cancer incidence continuously increased, with annual percent changes of 0.6% (95% CI: 0.5, 0.8) between 1985 and 2005, and 1.8% (95% CI: 0.6, 2.9) between 2005 and 2010. During the most recent 10 years, almost half of the increase in cancer incidence was accounted for by an increase in prostate cancer (60%) in males and breast cancer (46%) in females. The cancer registry quality indices also began to increase from ∼2005. Decreases in stomach and liver cancers observed for incidence and mortality reflect the reduced attribution of infection-related factors (i.e. Helicobacter pylori and hepatitis virus). However, it should be noted that cervical cancer incidence and mortality rates began to increase from ∼1990.

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.