Tomomi Marugame

Cancer Incidence and Incidence Rates in Japan in 2004: Based on Data from 14 Population-based Cancer Registries in the Monitoring of Cancer Incidence in Japan (MCIJ) Project

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.

Lung cancer occurrence in never-smokers: an analysis of 13 cohorts and 22 cancer registry studies.

Background Better information on lung cancer occurrence in lifelong nonsmokers is needed to understand gender and racial disparities and to examine how factors other than active smoking influence risk in different time periods and geographic regions. Methods and Findings We pooled information on lung cancer incidence and/or death rates among self-reported never-smokers from 13 large cohort studies, representing over 630,000 and 1.8 million persons for incidence and mortality, respectively. We also abstracted population-based data for women from 22 cancer registries and ten countries in time periods and geographic regions where few women smoked. Our main findings were: (1) Men had higher death rates from lung cancer than women in all age and racial groups studied; (2) male and female incidence rates were similar when standardized across all ages 40+ y, albeit with some variation by age; (3) African Americans and Asians living in Korea and Japan (but not in the US) had higher death rates from lung cancer than individuals of European descent; (4) no temporal trends were seen when comparing incidence and death rates among US women age 40–69 y during the 1930s to contemporary populations where few women smoke, or in temporal comparisons of never-smokers in two large American Cancer Society cohorts from 1959 to 2004; and (5) lung cancer incidence rates were higher and more variable among women in East Asia than in other geographic areas with low female smoking. Conclusions These comprehensive analyses support claims that the death rate from lung cancer among never-smokers is higher in men than in women, and in African Americans and Asians residing in Asia than in individuals of European descent, but contradict assertions that risk is increasing or that women have a higher incidence rate than men. Further research is needed on the high and variable lung cancer rates among women in Pacific Rim countries.

Cancer incidence and incidence rates in Japan in 2002: based on data from 11 population-based cancer registries.

The number of cancer incidences, crude incidence rates, age-standardized incidence rates in 2002 in Japan are estimated. The estimated total number of incidences was 570,598.

Population Attributable Fraction of Mortality Associated with Tobacco Smoking in Japan: A Pooled Analysis of Three Large-scale Cohort Studies

Background Quantitative measures of the burden of tobacco smoking in Asian countries are limited. We estimated the population attributable fraction (PAF) of mortality associated with smoking in Japan, using pooled data from three large-scale cohort studies. Methods In total, 296,836 participants (140,026 males and 156,810 females) aged 40-79 years underwent baseline surveys during the 1980s and early 1990s. The average follow-up period was 9.6 years. PAFs for all-cause mortality and individual tobacco-related diseases were estimated from smoking prevalence and relative risks. Results The prevalence of current and former smokers was 54.4% and 25.1% for males, and 8.1% and 2.4% for females. The PAF of all-cause mortality was 27.8% [95% confidence interval (CI): 25.2-30.4] for males and 6.7% (95% CI: 5.9-7.5) for females. The PAF of all-cause mortality calculated by summing the disease-specific PAFs was 19.1% (95% CI: 16.0-22.2) for males and 3.6% (95% CI: 3.0-4.2) for females. The estimated number of deaths attributable to smoking in Japan in 2005 was 163,000 for males and 33,000 for females based on the former set of PAFs, and 112,000 for males and 19,000 for females based on the latter set. The leading causes of smoking-attributable deaths were cancer (61% for males and 31% for females), ischemic heart diseases and stroke (23% for males and 51% for females), and chronic obstructive pulmonary diseases and pneumonia (11% for males and 13% for females). Conclusion The health burden due to smoking remains heavy among Japanese males. Considering the high prevalence of male current smokers and increasing prevalence of young female current smokers, effective tobacco controls and quantitative assessments of the health burden of smoking need to be continuously implemented in Japan.

Population-based Survival of Cancer Patients Diagnosed Between 1993 and 1999 in Japan: A Chronological and International Comparative Study

OBJECTIVE The purpose of the present study was to collect data from population-based cancer registries and to calculate relative 5-year survival of cancer patients in Japan. We also sought to determine time trends and to compare the results with international studies. METHODS We asked 11 population-based cancer registries to submit individual data for patients diagnosed from 1993 to 1999, together with data on outcome after 5 years. Although all these registries submitted data (491 772 cases), only six met the required standards for the quality of registration data and follow-up investigation. The relative 5-year survival calculated by pooling data from 151 061 cases from six registries was taken as the survival for cancer patients in Japan. RESULTS Relative 5-year survival (1997-99) was 54.3% for all cancers (males: 50.0%, females: 59.8%). Survival figures for all sites changed slightly over the 7-year period, from 53.2% for the first 4 years of the study (1993-96) to 54.3% for the last 3 years (1997-99), however, a major improvement was observed in several primary sites. Some overall survival was lower in Japan than in the USA, but similar to that in European countries. Specifically, survival for uterine cancer, prostate cancer, testis cancer, lymphoma and leukemia was much lower in Japan than in other countries. However, survival was better in Japan mainly for cancers of the esophagus, stomach, colon, liver and gallbladder. CONCLUSION The study suggests an improvement in cancer survival in several primary sites in Japan, which is consistent with the development of treatments and early detection.

A Joinpoint regression analysis of long‐term trends in cancer mortality in Japan (1958–2004)

Cancer is one of the major targets of disease control programs in Japan. A Joinpoint regression model was used to analyze the long‐term trends of mortality related to overall cancer and the 15 most common cancers based on published data from the National Vital Statistics of Japan between 1958 and 2004. Since 1996, a decline has been seen in overall cancer for both sexes in Japan. Most of the common sites, including cancers of the stomach, colon, liver, gallbladder and lung and leukemia in both sexes, cancer of esophagus in men and rectal and ovarian cancers in women showed a decreasing trend, and cancers of the rectum, pancreas, prostate and urinary bladder and malignant lymphoma in men and cancers of the esophagus and uterus in women leveled off during the most recent period. However, an increasing trend was confirmed for cancers of the pancreas, breast and urinary bladder and malignant lymphoma in women. An effective cancer control program including prevention, early detection and treatment should be implemented to further reduce the cancer mortality, particularly for cancer sites that show higher mortality rates or increasing trends.

Lung cancer death rates by smoking status : Comparison of the Three-Prefecture Cohort study in Japan to the Cancer Prevention Study II in the USA

Cigarette smoking is an established risk factor for lung cancer. However, the magnitude of the relative risk (RR) on lung cancer mortality in relation to cigarette smoking is reported to be lower in Japan than in Western countries. We investigated whether this discrepancy could be explained by differences in the exposure to cigarettes smoked, by differences in sensitivity to smoking, or by differences in lung cancer mortality among non‐smokers. We examined the 10‐year follow‐up data on 88 153 participants in a Japanese population‐based prospective study conducted in three prefectures. Data used as a Western counterpart was retrieved from a published report of the US Cancer Prevention Study (CPS)‐II. Although there was a significant increased risk of lung cancer death among current smokers compared with non‐smokers, the observed RR in the Three‐Prefecture Study were much lower than RR reported in the CPS‐II. Lung cancer mortality of our Japanese sample was lower among current smokers and higher among non‐smokers regardless of age and sex. Current smokers in our sample had initiated smoking at an older age and smoked fewer cigarettes per day for shorter durations than those in the CPS‐II sample. The Poisson regression model (controlling for age, number of cigarettes smoked per day and duration of smoking) showed that male current smokers in our sample had a lower risk of lung cancer compared with those in the CPS‐II sample (rate ratio 0.34 [95%CI 0.27–0.43]). These findings might explain why Japanese risks of lung cancer are lower than those observed in Western countries. (Cancer Sci 2005; 96: 120–126)

Projection of lung cancer mortality in Japan

According to the National Vital Statistics data, age‐standardized mortality rates (ASRs) of lung cancer have shown slightly declining trends in Japan for both men and women. In order to evaluate whether this tendency will continue, a Bayesian age‐period‐cohort (APC) model was applied using the National Vital Statistics data from 1952 to 2001. In the projection, a Gaussian autoregressive prior model was applied to smooth age, period, and cohort effects from its 2 immediate predecessors by extrapolation. Posterior distributions from which we drew inferences on mortality rates were derived from 15,000 iterations using 5000 burn‐in iterations. We defined the median of the iterated values as the overall summary mortality rate of the iterated results. Our results suggest that the number of deaths due to lung cancer will double for men and women during the next 3 decades due to the aging of the baby‐boomer generation (individuals who were born between 1947 and 1951). Currently declining trends in some age groups will reverse and start to increase again in the next decades. However, for recent birth cohorts, the results of the projection varied according to whether the data set included early age group mortality or not. Lung cancer mortality in the future depends on the risk factors engaged in by todays young people, especially smoking. Strong promotion of anti‐smoking measures and careful surveillance for lung cancer are needed.

Decrease in risk of lung cancer death in Japanese men after smoking cessation by age at quitting: Pooled analysis of three large‐scale cohort studies

To evaluate the impact of smoking cessation on individuals and populations, we examined the decrease in risk of lung cancer death in male ex‐smokers by age at quitting by pooling the data from three large‐scale cohort studies in Japan. For simplicity, subjects were limited to male never smokers and former or current smokers who started smoking at ages 18–22 years, and 110 002 men aged 40–79 years at baseline were included. During the mean follow‐up of 8.5 years, 968 men died from lung cancer. The mortality rate ratio compared to current smokers decreased with increasing attained age in men who stopped smoking before age 70 years. Among men who quit in their fifties, the cohort‐adjusted mortality rate ratios (95% confidence interval) were 0.57 (0.40–0.82), 0.44 (0.29–0.66) and 0.36 (0.13–1.00) at attained ages 60–69, 70–79 and 80–89 years, respectively. The corresponding figures for those who quit in their sixties were 0.81 (0.44–1.48), 0.60 (0.43–0.82) and 0.43 (0.21–0.86). Overall, the mortality rate ratio for current smokers, relative to non‐smokers, was 4.71 (95% confidence interval 3.76–5.89) and those for ex‐smokers who had quit smoking 0–4, 5–9, 10–14, 15–19, 20–24 and ≥25 years before were 3.99 (2.97–5.35), 2.55 (1.80–3.62), 1.87 (1.23–2.85), 1.21 (0.66–2.22), 0.76 (0.33–1.75) and 0.67 (0.34–1.32), respectively. Although earlier cessation of smoking generally resulted in a lower rate of lung cancer mortality in each group of attained age, the absolute mortality rate decreased appreciably after stopping smoking even in men who quit at ages 60–69 years. (Cancer Sci 2007; 98: 584–589)

Comparison of Time Trends in Lung Cancer Mortality (1990–2006) in the World, from the WHO Mortality Database

Mortality data, abstracted from the World Health Organization (WHO) database, are available for various countries. We used lung cancer mortality (ICD-10: C33–C34) in 11 countries during the period 1990–2006. These countries were Japan, China (Hong Kong) and the Republic of Korea (Asian countries); the United States of America (USA); Australia; the Russian Federation, the United Kingdom (UK), Italy, Spain, France and Germany (European countries). For the USA, Spain and France, data were available only for 1990–2005; and for Australia and Italy, for 1990–2003. The world population was used for age standardization. Age-standardized rates for lung cancer mortality (ICD-10: C33–C34) in the 11 selected countries between 1990 and 2006 are shown for males (Fig. 1) and for females (Fig. 2). Lung cancer mortality rates were higher for males than for females (note that Figure 1 and 2 use different vertical scales). For males, mortality rates in eight countries [China (Hong Kong), USA, Australia, Russian Federation, UK, Italy, France and Germany] decreased throughout the period, whereas in other three countries, a downward trend started in the mid-1990s in Japan and Spain and in 2000 in Republic of Korea. The mortality rate in Japan was the lowest in the 11 countries and that in Russian Federation was the highest. Time trends in mortality rates for females were different from those for males. Out of 11 countries, only 2 [China (Hong Kong) and the Russian Federation] showed decreasing trends in mortality rates throughout the period. Mortality rates in five