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A comprehensive evidence-based cancer prevention recommendation for Japanese was developed. We evaluated the magnitude of the associations of lifestyle factors and infection with cancer through a systematic review of the literature, meta-analysis of published data, and pooled analysis of cohort studies in Japan. Then, we judged the strength of evidence based on the consistency of the associations between exposure and cancer and biological plausibility. Important factors were extracted and summarized as an evidence-based, current cancer prevention recommendation: 'Cancer Prevention Recommendation for Japanese'. The recommendation addresses six important domains related to exposure and cancer, including smoking, alcohol drinking, diet, physical activity, body weight and infection. The next step should focus on the development of effective behavior modification programs and their implementation and dissemination.

Background: Although East Asia is one of the largest tobacco-epidemic regions in the world, only a few prospective studies from Asia have investigated the impact of smoking and cessation of smoking on cancer. We aimed to assess the effect of cessation of smoking on the risk of cancer using eight population-based cohort studies in Japan., Methods: We analyzed pooled data from eight population-based prospective cohort studies in Japan with more than 320,000 participants to assess the effect of smoking cessation on the risk of total cancers and smoking-related cancers., Results: After adjustment for potential confounders, cancer risks in men with >21years of smoking cessation before baseline were found to decrease to the same level as never smokers for total cancer (never smokers: reference; former smokers with ≥21 years since smoking cessation: HR, 1.01; 95%CI: 0.91, 1.11). Even men who are heavy smokers (more than 20 pack-years) reported a reduced risk of total cancer (never smokers: reference; former smokers with ≥21 years since smoking cessation: HR, 1.06; 95%CI: 0.92, 1.23). In women, the risk of total cancer did not differ from that of never smokers after 11 years of smoking cessation before baseline (never smokers: reference; former smokers with ≥11 years since smoking cessation: HR, 0.96; 95%CI: 0.74, 1.23)., Conclusions: Our study suggests that longer duration of smoking cessation may attenuate the risk of cancer in both men and women, and that even heavy smokers (more than 20 pack-years) were found to benefit from quitting smoking., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Evidence regarding stress as a risk factor for cancer onset is inconsistent. In this study, based on the Japan Public Health Center-based Prospective Study, we enrolled 101,708 participants aged 40-69 years from 1990-1994. The self-reported perceived stress level was collected at baseline and updated through 5-year follow-up. The association between perceived stress and cancer risk was measured by Cox proportional hazards regression model, adjusted for all known confounders. During follow-up (mean = 17.8 years), we identified 17,161 cancer cases. We found no association between baseline perceived stress level and cancer incidence. However, by taking account of the dynamic changes in perceived stress, time-varying analyses revealed a slightly (4-6%) increased overall cancer risk for subjects under elevated perceived stress levels compared to the 'low stress level' group. Analyses concerning long-term perceived stress level showed that individuals with constantly high perceived stress level had an 11% (95% confidence interval 1-22%) excess risk for cancer compared to subjects with persistently low stress levels. This association was confined to men (20% excess risk), and was particularly strong among smokers, alcohol drinkers, obese subjects, and subjects without family history of cancer. Therefore, we concluded high perceived stress level might contribute to excess overall cancer incidence among men.

Background: Diet-induced metabolic acidosis has been linked to cardiometabolic abnormalities including hypertension and type 2 diabetes. However, there are limited data on its association with other chronic diseases and mortality. Objective: The present study aimed to examine the association between dietary acid load and total and cause-specific mortality. Design: This study was a large-scale, population-based, prospective cohort study in Japan involving 42,736 men and 49,742 women, aged 45-75 y, who had no history of cancer, stroke, ischemic heart disease (IHD), or chronic liver disease at baseline. Dietary intake was assessed by using a validated 147-item food-frequency questionnaire. Potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores were derived from nutrient intake. Death and cause of death were identified by using the residential registry and death certificates. Cox proportional hazards regression was used to estimate HRs and 95% CIs for total and cause-specific mortality with adjustment for potential confounding variables. Results: During a median follow-up of 16.9 y, 12,993 total deaths occurred. A higher PRAL score was associated with higher total mortality: the multivariable-adjusted HR for total mortality for the highest compared with the lowest quartiles of PRAL scores was 1.13 (95% CI: 1.07, 1.18; P -trend < 0.001). This score was positively associated with mortality from cardiovascular disease (CVD) and particularly from IHD; the HRs (95% CIs) for the highest compared with the lowest quartile of PRAL score were 1.16 (1.06, 1.28) and 1.16 (1.02, 1.33) for CVD and IHD mortality, respectively. There was no association between PRAL score and cancer mortality. Similar associations were observed between NEAP score and total and cause-specific mortality. Conclusion: A high dietary acid load score was associated with a higher risk of total mortality and mortality from CVD, particularly from IHD, in Japanese adults., (© 2017 American Society for Nutrition.)

Objective: A meta-analysis showed an inverse association of a prudent/healthy dietary pattern with all-cause mortality and no association of a western/unhealthy dietary pattern. However, the association of distinctive dietary patterns of Japanese population with mortality remains unclear. We prospectively investigated the association between dietary patterns and all-cause, cancer, and cardiovascular disease mortality among Japanese adults., Methods: Participants were 36,737 men and 44,983 women aged 45-74 years who participated in the second survey of the Japan Public Health Center-based Prospective Study (1995-1998) and who had no history of serious disease. Dietary patterns were derived from principal component analysis of the consumption of 134 food and beverage items ascertained by a food frequency questionnaire. Hazard ratios of death from the second survey to December 2012 were estimated using cox proportional hazard regression analysis., Results: A prudent dietary pattern, which was characterized by high intake of vegetables, fruit, soy products, potatoes, seaweed, mushrooms, and fish, was significantly associated with decreased risk of all-cause and cardiovascular disease mortality. The multivariable-adjusted hazard ratios (95% confidence intervals) of all-cause and cardiovascular disease mortality for the highest versus lowest quartile of the prudent dietary pattern score were 0.82 (0.77 to 0.86) and 0.72 (0.64 to 0.79), respectively (P for trend <0.001 in both). A Westernized dietary pattern, characterized by high intake of meat, processed meat, bread, and dairy products, was also inversely associated with risk of all-cause, cancer, and cardiovascular disease mortality. A traditional Japanese dietary pattern was not associated with these risks., Conclusions: The prudent and Westernized dietary patterns were associated with a decreased risk of all-cause and cardiovascular disease mortality in Japanese adults.

Background: A series of recent reports from large-scale cohort studies involving more than 100,000 subjects reported no or only very small inverse associations between fruit and vegetable intake and overall cancer incidence, despite having sufficient power to do so. To date, however, no such data have been reported for Asian populations., Objective: To provide some indication of the net impact of fruit and vegetable consumption on overall cancer prevention, we examined these associations in a pooled analysis of large-scale cohort studies in Japanese populations., Methods: We analyzed original data from four cohort studies that measured fruit and vegetable consumption using validated questionnaires at baseline. Hazard ratios (HRs) in the individual studies were calculated, with adjustment for a common set of variables, and combined using a random-effects model., Results: During 2,318,927 person-years of follow-up for a total of 191,519 subjects, 17,681 cases of overall cancers were identified. Consumption of fruit or vegetables was not associated with decreased risk of overall cancers: corresponding HRs for the highest versus lowest quartiles of intake for men and women were 1.03 (95% CI, 0.97-1.10; trend p = 1.00) and 1.03 (95% CI, 0.95-1.11; trend p = 0.97), respectively, for fruit and 1.07 (95% CI, 1.01-1.14; trend p = 0.18) and 0.98 (95% CI, 0.91-1.06; trend p = 0.99), respectively, for vegetables, even in analyses stratified by smoking status and alcohol drinking., Conclusions: The results of this pooled analysis do not support inverse associations of fruit and vegetable consumption with overall cancers in the Japanese population., (Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

Diabetes mellitus constitutes a major disease burden globally, and the prevalence of diabetes continues to increase worldwide. We aimed to estimate the burden of cancer associated with type 2 diabetes mellitus in Japan between 2010 and 2030. In this study, we estimated the population attributable fraction of cancer risk associated with type 2 diabetes in 2010 and 2030 using the prevalence estimates of type 2 diabetes in Japan from 1990 to 2030, summary hazard ratios of diabetes and cancer risk from a pooled analysis of eight large-scale Japanese cohort studies, observed incidence/mortality of cancer in 2010 and predicted incidence/mortality for 2030 derived from the age-period-cohort model. Our results showed that between 2010 and 2030, the total numbers of cancer incidence and mortality were predicted to increase by 38.9% and 10.5% in adults aged above 20 years, respectively. In the number of excess incident cancer cases associated with type 2 diabetes, an increase of 26.5% in men and 53.2% in women is expected between 2010 and 2030. The age-specific analysis showed that the population attributable fraction of cancer will increase in adults aged >60 years over time, but will not change in adults aged 20-59 years. In conclusion, this study suggests a modest but steady increase in cancers associated with type 2 diabetes., (© 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Previous studies have reported associations between diabetes and cancer risk. However, specific association of hemoglobin A1c (HbA1c) levels with cancer risk remains inconclusive. We followed 29,629 individuals (11,336 men; 18,293 women) aged 46-80 years who participated in the Japan Public Health Center-based prospective study who had HbA1c measurements available and were cancer-free at baseline. Cancer incidence was assessed by systemic surveys. We estimated hazard ratios (HRs) for cancer risk with adjustment for age sex, geographic area, body mass index, smoking status, physical activity, alcohol, coffee, vegetable and total energy consumption, and history of cardiovascular disease. After a median follow-up of 8.5 years, 1,955 individuals had developed cancer. Higher HbA1c levels within both the non-diabetic and diabetic ranges in individuals without known diabetes were associated with overall cancer risk. Compared with individuals without known diabetes and HbA1c levels of 5.0-5.4%, the HRs for all cancers were 1.27 (95% confidence interval, 1.07-1.52); 1.01 (0.90-1.14); 1.28 (1.09-1.49); and 1.43 (1.14-1.80) for individuals without known diabetes and HbA1c levels <5.0%, 5.5-5.9%, 6.0-6.4%, and ≥6.5%, respectively, and 1.23 (1.02-1.47) for individuals with known diabetes. The lowest HbA1c group had the highest risk of liver cancer, and HbA1c levels were linearly associated with the risk of all cancers after excluding liver cancer (P for linear trend, 0.004). In conclusion, our findings corroborate the notion that glycemic control in individuals with high HbA1c levels may be important not only to prevent diabetes but also to prevent cancer., (© 2015 The Authors International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Background: Psychological stress is a modifiable risk factor for health outcomes and can be managed through coping mechanisms. Biological and behavioral hypotheses have been proposed to explain the association between stress coping strategies and cancer outcomes., Methods: The Japan Public Health Center-based study asked questions on coping behaviors in its 10-year follow-up survey. 55,130 subjects aged 50-79 without a history of cancer diagnosis and who provided complete answers on coping were included in analyses on cancer incidence and mortality. Hazard Ratios (HR) according to coping style were determined using Cox regression models adjusted for known confounders for cancer., Results: Mean follow-up time was 9.5 years for cancer incidence and 9.8 years for cancer mortality. The utilization of the approach-oriented coping strategy (HR=0.85, 95% CI: 0.72-0.99) and a behavior of positive reappraisal (HR=0.84, 95% CI: 0.72-0.97) was associated with a reduced risk of cancer mortality. The approach-oriented coping strategy was further associated with localized cancer incidence (HR=1.13, 95% CI: 1.01-1.27) and screening-detected cancers (HR=1.35, 95% CI: 1.15-1.58). The avoidance oriented coping strategy was inversely associated with cancer incidence (HR=0.69, 95% CI: 0.50-0.94) only after excluding events occurring in the first three years of follow-up., Conclusion: The results of this study may favor the behavioral hypothesis to explain associations between premorbid coping styles and cancer outcomes., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Despite the rising consumption of coffee worldwide, few prospective cohort studies assessed the association of coffee intake with mortality including total and major causes of death., Objective: We aimed to investigate the association between habitual coffee drinking and mortality from all causes, cancer, heart disease, cerebrovascular disease, respiratory disease, injuries, and other causes of death in a large-scale, population-based cohort study in Japan., Design: We studied 90,914 Japanese persons aged between 40 and 69 y without a history of cancer, cerebrovascular disease, or ischemic heart disease at the time of the baseline study. Subjects were followed up for an average of 18.7 y, during which 12,874 total deaths were reported. The association between coffee intake and risk of total and cause-specific mortality was assessed by using a Cox proportional hazards regression model with adjustment for potential confounders., Results: We showed an inverse association between coffee intake and total mortality in both men and women. HRs (95% CIs) for total death in subjects who consumed coffee compared with those who never drank coffee were 0.91 (0.86-0.95) for <1 cup/d, 0.85 (0.81-0.90) for 1-2 cups/d, 0.76 (0.70-0.83) for 3-4 cups/d, and 0.85 (0.75-0.98) for >5 cups/d (P-trend < 0.001). Coffee was inversely associated with mortality from heart disease, cerebrovascular disease, and respiratory disease., Conclusion: With this prospective study, we suggest that the habitual intake of coffee is associated with lower risk of total mortality and 3 leading causes of death in Japan., (© 2015 American Society for Nutrition.)

Background: In many developed countries, socioeconomic status is associated with cancer incidence and survival. However, research in Japan is sparse. We examined the association between neighborhood deprivation based on the Japanese Deprivation Index and the risk of incidence, mortality and survival from total and major cancers in the Japan Public Health Center-based Prospective Study., Methods: 86,112 participants were followed through the end of 2009. A total of 10,416 incident cases and 5,510 deaths from cancer were identified among 1,348,437 person-years of follow-up (mean follow-up: 15.7 years). The Japanese deprivation index was used to access neighborhood deprivation. Hazard ratios and 95% confidence intervals were calculated by Cox regression analysis., Results: We found no associations between neighborhood deprivation index and the incidence of total and major cancers. In some cancer risks or deaths, however, we found positive or inverse associations with a higher deprivation index, such as a decreased risk of colorectal cancer incidence and an increased risk of liver cancer incidence and deaths in women., Conclusion: Although some positive or inverse associations were detected for specific sites, the neighborhood deprivation index has no substantial overall association with the risk of incidence, mortality and survival from cancer in the Japanese population.

Objective: The present work aims to provide 10-year estimates of the probability of cancer occurrence in the Japanese population based on age, sex, and the pattern of adherence to five healthy lifestyle habits., Methods: The study population consisted of 74,935 participants in the Japan Public Health Center-Based Prospective Study (aged 45 to 74 years) who answered a 5-year follow-up questionnaire about various lifestyle habits between 1995 and 1999. The relationship between five previously identified healthy lifestyle habits (never smoking, moderate or no alcohol consumption, adequate physical activity, moderate salt intake, and appropriate body mass index) and cancer occurrence was assessed using a sex-specific parametric survival model., Results: Compared to individuals not adhering to any of the five habits, never-smoking men had a nearly 30% reduction in the 10-year probability of cancer occurrence (e.g., 20.5% vs. 28.7% at age 70), and never-smoking women had a 16% reduction (e.g., 10.5% vs. 12.5% at age 70). Adherence to all five habits was estimated to reduce the 10-year probability of cancer occurrence by 1/2 in men and 1/3 in women., Conclusion: By quantifying the impact of lifestyle habits on the probability of cancer occurrence, this study emphasizes the importance of lifestyle improvement., (© 2013.)

Although a growing body of evidence suggests a link between diabetes and cancer, it is not clear whether diabetes independently increases the risk of cancer. We conducted a comprehensive assessment of the association between pre-existing diabetes and total and site-specific cancer risk based on a pooled analysis of eight cohort studies in Japan (>330 000 subjects). We estimated a summary hazard ratio by pooling study-specific hazard ratios for total and site-specific cancer by using a random-effects model. A statistically increased risk was observed for cancers at specific sites, such as colon (hazard ratio; HR = 1.40), liver (HR = 1.97), pancreas (HR = 1.85) and bile duct (HR = 1.66; men only). Increased risk was also suggested for other sites, and diabetes mellitus was associated with an overall 20% increased risk in total cancer incidence in the Japanese population. The association between these two diseases has important implications for reiterating the importance of controlling lifestyle factors and may suggest a possible strategy for cancer screening among patients with diabetes. Studies continuously investigating the risk factors for diabetes are also important., (© 2013 Japanese Cancer Association.)

Purpose: Arsenic is a known human carcinogen and has been linked to adverse health outcomes, including cancer. However, the effects of arsenic exposure from food on health are still unknown. We researched to examine the association between arsenic exposure from food and incidence of cancer in a Japanese population., Methods: We conducted a population-based prospective study in 90,378 Japanese men and women aged 45-74 years. Participants responded to a validated questionnaire that included 138 food items. We estimated dietary arsenic intake from 12 food groups (75 items) based on the questionnaire data. During 11 years of follow-up, 7,002 cancer cases were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer were calculated by Cox proportional hazards modeling., Results: Total arsenic and inorganic arsenic showed no association with the risk of total cancer in both men and women. Total arsenic and inorganic arsenic intake tended to be associated with an increased risk of lung cancer in men. In particular, these positive associations were strengthened in currently smoking men, with HRs (95% CI) in the highest categories of arsenic and inorganic arsenic intake compared with the lowest of 1.29 (95% CI = 1.03-1.61) and 1.36 (95% CI = 1.09-1.70), respectively. We also detected an interaction between arsenic and inorganic arsenic intake and smoking status in men (p(interaction) < 0.01 and 0.07, respectively)., Conclusion: A significant dose-response trend was seen in the association of arsenic and inorganic intake with lung cancer risk in currently smoking men.

Background: To contribute to evidence-based policy decision making for national cancer control, we conducted a systematic assessment to estimate the current burden of cancer attributable to known preventable risk factors in Japan in 2005., Methods: We first estimated the population attributable fractions (PAFs) of each cancer attributable to known risk factors from relative risks derived primarily from Japanese pooled analyses and large-scale cohort studies and the prevalence of exposure in the period around 1990. Using nationwide vital statistics records and incidence estimates, we then estimated the attributable cancer incidence and mortality in 2005., Results: In 2005, ≈ 55% of cancer among men was attributable to preventable risk factors in Japan. The corresponding figure was lower among women, but preventable risk factors still accounted for nearly 30% of cancer. In men, tobacco smoking had the highest PAF (30% for incidence and 35% for mortality, respectively) followed by infectious agents (23% and 23%). In women, in contrast, infectious agents had the highest PAF (18% and 19% for incidence and mortality, respectively) followed by tobacco smoking (6% and 8%)., Conclusions: In Japan, tobacco smoking and infections are major causes of cancer. Further control of these factors will contribute to substantial reductions in cancer incidence and mortality in Japan.

Background: Cadmium, a ubiquitous environmental pollutant, is classified as a carcinogenic substance. Several laboratory and epidemiologic studies of workers and subjects in polluted areas have suggested a positive association between cadmium exposure and risk of several cancers. However, data from general populations are sparse. We prospectively examined the association between cadmium exposure and incidence of cancer in a Japanese population with a relatively high dietary intake of cadmium., Methods: We conducted a population-based prospective study in 90,383 Japanese men and women 45-74 years of age. Participants responded to a validated questionnaire that included 138 food items. We estimated dietary cadmium intake from 6 food groups, based on the questionnaire data. During 9 years of follow-up, 5849 cancer cases were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer were calculated by Cox proportional hazards modeling., Results: There was no evidence of an association of cadmium consumption and total cancer, with HRs in the highest versus lowest cadmium intake group of 0.94 (95% CI = 0.82 to 1.08; test for trend, P = 0.46) for men and 0.96 (0.81 to 1.15; 0.60) for women. No site-specific cancers were associated with cadmium intake in men or women., Conclusion: We found no associations of cancer with cadmium, at least at the exposure levels observed in a general population in Japan.

Objective: To evaluate whether 5 combined healthy lifestyle factors (not smoking, moderate drinking, eating minimum salt-preserved foods, being physically active, and having appropriate body mass index) are associated with reduced risk of cancer., Methods: Participants were enrolled in the Japan Public Health Center Study and responded to the 5-year follow-up questionnaire covering lifestyle factors in 1995-1999 at ages 45-74 years. During follow up through December 31, 2006, 3451 and 2125 cases of cancer were newly identified in men and women, respectively. For men and women, a factor-dependent risk reduction was observed for healthy lifestyles and cancer development. Compared to 0-1 healthy lifestyle factors, the adjusted RRs and 95% CIs for adherence to 2, 3, 4, and 5 healthy factors were 0.86 (0.78-0.95), 0.72 (0.65-0.80), 0.61 (0.54-0.69), and 0.57 (0.45-0.72), respectively, for men (P for trend<0.0001) and 0.86 (0.53-1.40), 0.73 (0.46-1.16), 0.68 (0.42-1.08), and 0.63 (0.39-1.01), respectively, for women (P for trend=0.0003). Risk was reduced 14% and 9% by each one healthy lifestyle for men and women, respectively. Risk reduction was more pronounced among elderly women., Conclusion: These combined lifestyle factors have a considerable impact on preventing cancer., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Despite the popular use of vitamin supplements and several prospective cohort studies investigating their effect on cancer incidence and cardiovascular disease (CVD), scientific data supporting their benefits remain controversial. Inconsistent results may be partly explained by the fact that use of supplements is an inconsistent behavior in individuals. We examined whether vitamin supplement use patterns affect cancer and CVD risk in a population-based cohort study in Japan., Methods: A total of 28,903 men and 33,726 women in the Japan Public Health Center-based Prospective Study cohort, who answered questions about vitamin supplement use in the first survey from 1990-1994 and the second survey from 1995-1998, were categorized into four groups (never use, past use, recent use, and consistent use) and followed to the end of 2006 for cancer and 2005 for CVD. Sex-specific hazard ratios (HRs) and 95% confidence intervals (95% CIs) were used to describe the relative risks of cancer and CVD associated with vitamin supplement use., Results: During follow-up, 4501 cancer and 1858 CVD cases were identified. Multivariate adjusted analysis revealed no association of any pattern of vitamin supplement use with the risk of cancer and CVD in men. In women, consistent use was associated with lower risk of CVD (HR 0.60, 95% CI 0.41-0.89), whereas past (HR 1.17, 95% CI 1.02-1.33) and recent use (HR 1.24, 95% CI 1.01-1.52) were associated with higher risk of cancer., Conclusions: To our knowledge, this is the first prospective cohort study to examine simultaneously the associations between vitamin supplement use patterns and risk of cancer and CVD. This prospective cohort study demonstrated that vitamin supplement use has little effect on the risk of cancer or CVD in men. In women, however, consistent vitamin supplement use might reduce the risk of CVD. Elevated risk of cancer associated with past and recent use of vitamin supplements in women may be partly explained by preexisting diseases or unhealthy background, but we could not totally control for this in our study.

The recent tendency of Japanese towards greater acceptance of being informed that they have cancer, along with the growing understanding and use of informed consent, appears to have improved the accuracy of self-reported cancer. To clarify the recent validity of self-reports, we measured the sensitivity and positive predictive value of self-reported cancer among a Japanese population. Using a 10-year follow-up questionnaire conducted in 2000-2004 and the cancer registry of the JPHC Study cohort (n=93,680), we calculated the sensitivity and positive predictive value of self-reported cancer diagnoses over 10 years. Sensitivity and positive predictive value of total self-reported cancer diagnoses were 53% and 60%, respectively, but varied by site, at 62% and 52% for stomach, 38% and 47% for colorectum, 57% and 46% for lung, 34% and 31% for liver, 82% and 58% for breast, and 59% and 22% for uterus, respectively. Sensitivity was considerably improved from that in the previous report (36%), which tested for 1990-1995, but was still not considered satisfactory. Self-reported diagnoses of cancer do not provide sufficient accuracy for the detection and classification of incident cancers. Our findings may be extrapolated to other Japanese populations., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: We pooled data from 7 ongoing cohorts in Japan involving 353 422 adults (162 092 men and 191 330 women) to quantify the effect of body mass index (BMI) on total and cause-specific (cancer, heart disease, and cerebrovascular disease) mortality and identify optimal BMI ranges for middle-aged and elderly Japanese., Methods: During a mean follow-up of 12.5 years, 41 260 deaths occurred. The Cox proportional hazards model was used to estimate hazard ratios (HRs) for each BMI category, after controlling for age, area of residence, smoking, drinking, history of hypertension, diabetes, and physical activity in each study. A random-effects model was used to obtain summary measures., Results: A reverse-J pattern was seen for all-cause and cancer mortality (elevated risk only for high BMI in women) and a U- or J-shaped association was seen for heart disease and cerebrovascular disease mortality. For total mortality, as compared with a BMI of 23 to 25, the HR was 1.78 for 14 to 19, 1.27 for 19 to 21, 1.11 for 21 to 23, and 1.36 for 30 to 40 in men, and 1.61 for 14 to 19, 1.17 for 19 to 21, 1.08 for 27 to 30, and 1.37 for 30 to 40 in women. High BMI (≥27) accounted for 0.9% and 1.5% of total mortality in men and women, respectively., Conclusions: The lowest risk of total mortality and mortality from major causes of disease was observed for a BMI of 21 to 27 kg/m(2) in middle-aged and elderly Japanese.

The impact of metabolic factors, which are major risk factors for cardiovascular disease, on total cancer risk has not been clarified. We prospectively examined whether metabolic factors and their aggregates predict the subsequent occurrence of total and major sites of cancer in the Japan Public Health Center-based Prospective Study. A total of 27 724 participants (9548 men and 18 176 women) aged 40-69 years participating in a questionnaire and health checkup survey in 1993-1995 were followed for total cancer incidence through 2004. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated for metabolic factors and for two criteria of their aggregates (three or more than three factors and two or more than two additional factors in addition to being overweight) with a Cox proportional hazards model to control for potential confounding factors. In both sexes, the presence of metabolic factors in the aggregate did not predict subsequent occurrence of cancer as a whole. By site, a significant increase in risk was observed for male liver cancer [HR = 1.73, CI = 1.03-2.91 (three or more than three factors); HR = 1.99, CI = 1.11-3.58 (two or more than two additional factors in addition to being overweight)], and female pancreatic cancer [HR = 1.99, CI = 1.00-3.96 (two or more than two additional factors in addition to being overweight)]. For other sites, positive associations were observed only for specific metabolic factors, that is, high triglycerides and male colon cancer (HR = 1.71, CI = 1.11-2.62), and obesity and female breast cancer (HR = 1.75, CI = 1.21-2.55). Metabolic factors in the aggregate may have little impact on total cancer risk in the Japanese population, although the association between specific components and specific cancers suggests an etiologic link between them.

Objectives: To promote prevention strategies aimed at reducing the incidence of cancer or cardiovascular disease (CVD), we present a method to project the probability that a subject with given lifestyle risk factors will survive free from either of cancer or CVD., Methods: Projection models were developed from data from a cohort study conducted in Japan. During 1990-2003, 96,592 subjects were followed and 5797 cancer and 2591 CVD cases and 2395 deaths were identified. Smoking, alcohol intake and body mass index (BMI) were used as common risk factors in projection models., Results: According to the projection of individualized probability, avoidance of smoking, excess alcohol intake and high BMI increased 10-year disease-free survival probability from 81.4% to 92.9% and from 88.0% to 94.3% in 50- to 54-year-old men and women, respectively. In terms of population average risk, smoking cessation and avoidance of excess alcohol exerted a large impact, while decreasing BMI had a small impact due to the small at-risk population., Conclusions: Current smoking, excess alcohol intake and obesity were suggested as common risk factors for cancer and CVD. Considering the distribution of risk factors in the Japanese population, smoking prevention/cessation and reduction of excess alcohol intake would prevent a large number of incident cases.

Background: Although lower education has been associated with poorer health, few studies have examined whether lower education affects mortality, incidence, both or neither of cancer and cardiovascular disease., Methods: The authors conducted a population-based prospective cohort study among 39,228 men and women who were aged 40-59 years and lived in four areas in Japan. Information on education and lifestyle variables were obtained by a self-administered questionnaire in 1990. Follow-up until the end of 2002 (for incidence) or 2003 (for mortality) ascertained 2573 and 1251 incident cases of cancer and cardiovascular disease, respectively, and 2430 deaths (1064 from cancer, 548 from cardiovascular disease and 818 from other causes)., Results: After adjustment for demographic and lifestyle variables, <10 years of education, as compared with >12 years of education, was associated with significantly higher mortality from all causes [hazard ratio (HR) = 1.22, 95% confidence interval (CI): 1.05-1.42] and cardiovascular disease (HR = 1.44, 95% CI: 1.01-2.06), but was not associated with higher incidence of cardiovascular disease (HR = 0.96, 95% CI: 0.78-1.18) or higher mortality or incidence of cancer., Conclusion: The findings suggest that lower education is associated with higher mortality from all causes and cardiovascular disease among the Japanese population that is not totally attributable to lifestyle differences or higher cardiovascular disease incidence.

The impact of total physical activity level on cancer risk has not been fully clarified, particularly in non-Western, relatively lean populations. The authors prospectively examined the association between daily total physical activity (using a metabolic equivalents/day score) and subsequent cancer risk in the Japan Public Health Center-based Prospective Study. A total of 79,771 general-population Japanese men and women aged 45-74 years who responded to a questionnaire in 1995-1999 were followed for total cancer incidence (4,334 cases) through 2004. Compared with subjects in the lowest quartile, increased daily physical activity was associated with a significantly decreased risk of cancer in both sexes. In men, hazard ratios for the second, third, and highest quartiles were 1.00 (95% confidence interval (CI): 0.90, 1.11), 0.96 (95% CI: 0.86, 1.07), and 0.87 (95% CI: 0.78, 0.96), respectively (p for trend = 0.005); in women, hazard ratios were 0.93 (95% CI: 0.82, 1.05), 0.84 (95% CI: 0.73, 0.96), and 0.84 (95% CI: 0.73, 0.97), respectively (p for trend = 0.007). The decreased risk was more clearly observed in women than in men, especially among the elderly and those who regularly engaged in leisure-time sports or physical exercise. By site, decreased risks were observed for cancers of the colon, liver, and pancreas in men and for cancer of the stomach in women. Increased daily physical activity may be beneficial in preventing cancer in a relatively lean population.

Few studies have investigated the effects of fruit and vegetables on the risk of both cancer and cardiovascular disease (CVD). The authors examined associations between fruit and vegetable consumption and risk of total cancer and CVD in the same Japanese population. During 1995-1998, a validated food frequency questionnaire was administered in nine areas to 77,891 men and women aged 45-74 years. During as many as 459,320 person-years of follow-up until the end of 2002, 3,230 cancer cases and 1,386 CVD cases were identified. Higher consumption of fruit, but not vegetables, was associated with significantly lower risk of CVD: multivariate hazard ratios for the highest versus lowest quartiles of intake were 0.81 (95% confidence interval (CI): 0.67, 0.97; trend p = 0.01) for fruit and 0.97 (95% CI: 0.82, 1.15; trend p = 0.66) for vegetables. Consumption of fruit or vegetables was not associated with decreased risk of total cancer: corresponding hazard ratios were 1.02 (95% CI: 0.90, 1.14; trend p = 0.95) for fruit and 0.94 (95% CI: 0.84, 1.05; trend p = 0.16) for vegetables. This prospective cohort study demonstrated that, in the Japanese population, consumption of fruit is associated with lower risk of CVD, whereas fruit or vegetables may not be associated with lower risk of total cancer.

Background: The present study aimed to provide information on awareness of the attributable fraction of cancer causes among the Japanese general population., Methods: A nationwide representative sample of 2,000 Japanese aged 20 or older was asked about their perception and level of concern about various environmental and genetic risk factors in relation to cancer prevention, as a part of an Omnibus Survey. Interviews were conducted with 1,355 subjects (609 men and 746 women)., Results: Among 12 risk factor candidates, the attributable fraction of cancer-causing viral and bacterial infection was considered highest (51%), followed by that of tobacco smoking (43%), stress (39%), and endocrine-disrupting chemicals (37%). On the other hand, the attributable fractions of cancer by charred fish and meat (21%) and alcohol drinking (22%) were considered low compared with other risk factor candidates. For most risk factors, attributable fraction responses were higher in women than in men. As a whole, the subjects tended to respond with higher values than those estimated by epidemiologic evidence in the West. The attributable fraction of cancer speculated to be genetically determined was 32%, while 36% of cancer was considered preventable by improving lifestyle., Conclusion: Our results suggest that awareness of the attributable fraction of cancer causes in the Japanese general population tends to be dominated by cancer-causing infection, occupational exposure, air pollution and food additives rather than major lifestyle factors such as diet.

Background: The present study aimed to obtain a relevant epidemiological index of the impact of tobacco smoking on the subsequent risk of cancer in Japan., Methods: We conducted a cohort analysis on the possible association between tobacco smoking habits and total cancer risk among a middle-aged Japanese population, using a large-scale population-based cohort of 92,792 subjects (44,521 men and 48,271 women) with 10-year follow-up., Results: During 1990-2001, 4,922 cases of cancer (2,969 men and 1,953 women) were newly diagnosed. From the baseline questionnaire, 52.2% of men were current smokers and they presented a significantly increased hazard ratio (HR) of subsequent cancer occurrence compared with never-smokers [HR 1.64, 95% confidence interval (95% CI) 1.48-1.82]. Only 5.6% of women were current smokers and their HR also represented a significant increase (HR 1.46, 95% CI 1.21-1.75). The corresponding population attributable fraction (PAF) (%) of total cancer incidence in men was 22.4% (95% CI 15.7%-28.5%) and 7.0% (95% CI 3.7%-10.3%) in relation to current and past exposures to tobacco smoke. In women, the PAF was only 2.2% and 0.6% due to the low prevalence of current and former smokers., Conclusions: Our results suggest that 29% of male cancer and 3% of female cancer would be preventable in Japanese middle-aged population by avoidance of tobacco smoking.