Changes in Smoking Status and Mortality From All Causes and Lung Cancer: A Longitudinal Analysis of a Population-based Study in Japan.

BACKGROUND: To update the findings of relative risk associated with smoking for all-cause mortality and that for lung cancer by considering longitudinal changes in smoking status during follow-up. METHODS: Data from the JPHC study of 98,747 middle-aged Japanese adults, which started in 1990-1993, were analyzed. The information on smoking status was obtained from three questionnaire surveys (baseline, the 5th year, and the 10th year after the start of follow-up). A Poisson regression model was used to investigate the impact of smoking on mortality from all causes and lung cancer using two approaches. Model 1 used information only from baseline, while model 2 used the updated smoking status from all three surveys. RESULTS: During the 15-year follow-up, 10,702 all-cause deaths (including 870 lung cancer cases) were identified. We compared the results obtained from two models. The relative risks associated with former smokers versus never smokers were 1.42 (95% confidence interval [CI], 1.31-1.54) among men and 1.46 (95% CI, 1.23-1.73) among women for all-cause mortality and 2.98 (95% CI, 2.09-4.24) among men and 1.83 (95% CI, 0.92-3.64) among women for lung cancer mortality, as determined using model 2. All of these were higher than the relative risks obtained from model 1. In addition, former smokers who had quit smoking due to disease during follow-up had a higher mortality risk than continuous smokers did in this study. CONCLUSIONS: The relative risks of all-cause mortality and mortality due to lung cancer among former smokers be higher than previously documented based on updated smoking status data from repeated surveys.

Consumption of red and processed meat and breast cancer incidence: A systematic review and meta-analysis of prospective studies.

Prior studies on red and processed meat consumption with breast cancer risk have generated inconsistent results. We performed a systematic review and meta-analysis of prospective studies to summarize the evidence regarding the relation of red meat and processed meat consumption with breast cancer incidence. We searched in MEDLINE and EMBASE databases through January 2018 for prospective studies that reported the association between red meat and processed meat consumption with incident breast cancer. The multivariable-adjusted relative risk (RR) was combined comparing the highest with the lowest category of red meat (unprocessed) and processed meat consumption using a random-effect meta-analysis. We identified 13 cohort, 3 nested case-control and two clinical trial studies. Comparing the highest to the lowest category, red meat (unprocessed) consumption was associated with a 6% higher breast cancer risk (pooled RR,1.06; 95% confidence intervals (95%CI):0.99-1.14; I2 = 56.3%), and processed meat consumption was associated with a 9% higher breast cancer risk (pooled RR, 1.09; 95%CI, 1.03-1.16; I2 = 44.4%). In addition, we identified two nested case-control studies evaluating the association between red meat and breast cancer stratified by N-acetyltransferase 2 acetylator genotype. We did not observe any association among those with either fast (per 25 g/day pooled odds ratio (OR), 1.18; 95%CI, 0.93-1.50) or slow N-acetyltransferase 2 acetylators (per 25 g/day pooled OR, 0.99; 95%CI, 0.91-1.08). In the prospective observational studies, high processed meat consumption was associated with increased breast cancer risk.

Circulating inflammatory markers and colorectal cancer risk: A prospective case-cohort study in Japan.

Blood levels of inflammation-related markers may reveal molecular pathways contributing to carcinogenesis. To date, prospective associations with colorectal cancer (CRC) risk have been based on few studies with limited sets of analytes. We conducted a case-cohort study within the Japan Public Health Center-based Prospective Study Cohort II, comparing 457 incident CRC cases during median 18 years follow-up with a random subcohort of 774 individuals. Baseline plasma levels of 62 cytokines, soluble receptors, acute-phase proteins, and growth factor markers were measured using Luminex bead-based assays. We estimated hazard ratios (HRs) associating each marker with CRC risk by Cox proportional hazards models adjusted for potential confounders. Subanalyses compared cases by years after blood draw (<5 vs. ≥5) and anatomical subsite (colon vs. rectum). Linear trends in quantiles of four C-C motif ligand (CCL) chemokines, one C-X-C motif ligand (CXCL) chemokine, and a soluble receptor were nominally associated with CRC risk based on ptrend < 0.05, but none met false discovery rate corrected statistical significance. HRs for the 4th vs. 1st quartile were: 1.69 for CCL2/MCP1, 1.61 for soluble tumor necrosis factor receptor 2, 1.39 for CCL15/MIP1D, 1.35 for CCL27/CTACK, 0.70 for CXCL6/GCP2 and 0.61 for CCL3/MIP1A. Among cases diagnosed 5+ years after enrollment, CCL2/MCP1, CCL3/MIP1A and CXCL6/GCP2 retained nominal statistical significance. There were no significant differences in associations between colon and rectum. Our findings implicate chemokine alterations in colorectal carcinogenesis, but require replication for confirmation. Noninvasive chemokine assays may have potential application in colorectal cancer screening and etiologic research.

Development of a risk prediction model for lung cancer: The Japan Public Health Center-based Prospective Study.

Although the impact of tobacco consumption on the occurrence of lung cancer is well-established, risk estimation could be improved by risk prediction models that consider various smoking habits, such as quantity, duration, and time since quitting. We constructed a risk prediction model using a population of 59 161 individuals from the Japan Public Health Center (JPHC) Study Cohort II. A parametric survival model was used to assess the impact of age, gender, and smoking-related factors (cumulative smoking intensity measured in pack-years, age at initiation, and time since cessation). Ten-year cumulative probability of lung cancer occurrence estimates were calculated with consideration of the competing risk of death from other causes. Finally, the model was externally validated using 47 501 individuals from JPHC Study Cohort I. A total of 1210 cases of lung cancer occurred during 986 408 person-years of follow-up. We found a dose-dependent effect of tobacco consumption with hazard ratios for current smokers ranging from 3.78 (2.00-7.16) for cumulative consumption ≤15 pack-years to 15.80 (9.67-25.79) for >75 pack-years. Risk decreased with time since cessation. Ten-year cumulative probability of lung cancer occurrence estimates ranged from 0.04% to 11.14% in men and 0.07% to 6.55% in women. The model showed good predictive performance regarding discrimination (cross-validated c-index = 0.793) and calibration (cross-validated χ2 = 6.60; P-value = .58). The model still showed good discrimination in the external validation population (c-index = 0.772). In conclusion, we developed a prediction model to estimate the probability of developing lung cancer based on age, gender, and tobacco consumption. This model appears useful in encouraging high-risk individuals to quit smoking and undergo increased surveillance.

Dietary patterns and prostate cancer risk in Japanese: the Japan Public Health Center-based Prospective Study (JPHC Study).

PURPOSE: The development of prostate cancer may be impacted by environmental factors, including diet. The aim of this study was to evaluate the association between dietary patterns and risk of prostate cancer in a large prospective cohort study among Japanese men. METHODS: A total of 43,469 men who participated in the Japan Public Health Center-based Prospective Study were followed from 1995 to 1998 to the end of 2012, during which 1,156 cases of prostate cancer were newly identified. Dietary intake was assessed using a validated food frequency questionnaire in the 5-year follow-up survey. RESULTS: Three major dietary patterns were derived using exploratory factors analysis: prudent, westernized, and traditional dietary patterns. The westernized dietary pattern was associated with a higher risk of total prostate cancer (HR: 1.22; 95% CI 1.00-1.49; p trend = 0.021), localized cancer (HR: 1.24; 95% CI 0.97-1.57; p trend = 0.045), and advanced cancer (HR: 1.23; 95% CI 0.82-1.84; p trend = 0.233). The prudent dietary pattern was associated with a lower risk of total and localized prostate cancer, with respective multivariable HRs for the highest and lowest quintiles of 0.71 (95% CI 0.50-1.02; p trend = 0.037) and 0.63 (95% CI 0.38-1.03; p trend = 0.048) among subjects detected by subjective symptoms. No association was found between the traditional dietary pattern and prostate cancer risk among our subjects. CONCLUSION: Our results suggest that a western-style diet may lead to a higher risk of prostate cancer in the total population, whereas the prudent diet contributes to a lower risk among subjects detected by subjective symptoms.

Coffee Consumption and Lung Cancer Risk: The Japan Public Health Center-Based Prospective Study.

BACKGROUND: Many epidemiological studies have indicated a positive association between coffee intake and lung cancer risk, but such findings were suggested to be confounded by smoking. Furthermore, only a few of these studies have been conducted in Asia. Here, we investigated the association between coffee intake and lung cancer risk in one of the largest prospective cohort studies in Japan. METHODS: We investigated the association of coffee drinking and subsequent incidence of lung cancer among 41,727 men and 45,352 women in the Japan Public Health Center-based Prospective Study using Cox proportional hazards regression, with adjustment for potential confounders and by strata of smoking status. Coffee and other dietary intakes were assessed once at baseline with a food frequency questionnaire (FFQ). RESULTS: During 1,481,887 person-years of follow-up between 1990 and 2011, a total of 1,668 lung cancer cases were identified. In a multivariate regression model, coffee consumption was not associated with risk of lung cancer (HR 1.16; 95% CI, 0.82-1.63; Ptrend = 0.285 for men and HR 1.49; 95% CI, 0.79-2.83; Ptrend = 0.942 for women). However, there was a significant increase in the risk for small cell carcinoma (HR 3.52; 95% CI, 1.49-8.28; Ptrend < 0.001). CONCLUSION: Our prospective study suggests that habitual consumption of coffee is not associated with an increased risk of lung cancer incidence, despite observing a significant increase in the risk for small cell carcinoma.

Impact of Alcohol Intake and Drinking Patterns on Mortality From All Causes and Major Causes of Death in a Japanese Population.

BACKGROUND: We examined the associations of alcohol consumption and liver holidays with all-cause mortality and with mortality due to cancer, heart disease, cerebrovascular disease, respiratory disease, and injury using a large-scale prospective study in Japan. METHODS: We followed 102,849 Japanese who were aged between 40 and 69 years at baseline for 18.2 years on average, during which 15,203 deaths were reported. Associations between alcohol intake and mortality risk were assessed using a Cox proportional hazards model, with analysis by the number of liver holidays (in which a person abstains from drinking for several days a week). RESULTS: A J-shaped association was observed between alcohol intake and total mortality in men (nondrinkers: reference; occasional drinkers: hazard ratio [HR] 0.74; 95% confidence interval [CI], 0.68-0.80; 1-149 g/week: HR 0.76; 95% CI, 0.71-0.81; 150-299 g/week: HR 0.75; 95% CI, 0.70-0.80; 300-449 g/week: HR 0.84; 95% CI, 0.78-0.91; 450-599 g/week: HR 0.92; 95% CI, 0.83-1.01; and ≥600 g/week: HR 1.19; 95% CI, 1.07-1.32) and in women (nondrinkers: reference; occasional: HR 0.75; 95% CI, 0.70-0.82; 1-149 g/week: HR 0.80; 95% CI, 0.73-0.88; 150-299 g/week: HR 0.91; 95% CI, 0.74-1.13; 300-449 g/week: HR 1.04; 95% CI, 0.73-1.48; and ≥450 g/week: HR 1.59; 95% CI, 1.07-2.38). In current drinkers, alcohol consumption was associated with a linear, positive increase in mortality risk from all causes, cancer, and cerebrovascular disease in both men and women, but not heart disease in men. Taking of liver holidays was associated with a lower risk of cancer and cerebrovascular disease mortality in men. CONCLUSIONS: Alcohol intake showed J-shaped associations with the risk of total mortality and three leading causes of death. However, heavy drinking increases the risk of mortality, which highlights the necessity of drinking in moderation coupled with liver holidays.

Body-Mass Index and Pancreatic Cancer Incidence: A Pooled Analysis of Nine Population-Based Cohort Studies With More Than 340,000 Japanese Subjects.

BACKGROUND: A high body mass index (BMI) has been proposed as an important risk factor for pancreatic cancer. However, this association of BMI with pancreatic cancer risk has not been confirmed in Asian populations. METHODS: We evaluated the association between BMI (either at baseline or during early adulthood) and pancreatic cancer risk by conducting a pooled analysis of nine population-based prospective cohort studies in Japan with more than 340,000 subjects. Summary hazard ratios (HRs) were estimated by pooling study-specific HRs for unified BMI categories with a random-effects model. RESULTS: Among Japanese men, being obese at baseline was associated with a higher risk of pancreatic cancer incidence (≥30 kg/m2 compared with 23 to <25 kg/m2, adjusted HR 1.71; 95% confidence interval [CI], 1.03-2.86). A J-shaped association between BMI during early adulthood and pancreatic cancer incidence was seen in men. In contrast, we observed no clear association among women, although there may be a positive linear association between BMI at baseline and the risk of pancreatic cancer (per 1 kg/m2, adjusted HR 1.02; 95% CI, 1.00-1.05). CONCLUSIONS: Pooling of data from cohort studies with a considerable number of Japanese subjects revealed a significant positive association between obesity and pancreatic cancer risk among men. This information indicates that strategies that effectively prevent obesity among men might lead to a reduced burden of pancreatic cancer, especially in Asian populations.

The relationship between vegetable/fruit consumption and gallbladder/bile duct cancer: A population-based cohort study in Japan.

Vegetable and fruit consumption may have a protective effect against several types of cancers. However, the effect on biliary cancers is unclear. We investigated the association of vegetable/fruit consumption with the risks of gallbladder cancer (GBC), intrahepatic bile duct cancer (IHBDC) and extrahepatic bile duct cancer (EHBDC) in a population-based prospective cohort study in Japan. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using the Cox proportional hazard model, and the exposure level was categorized into quartiles, with the lowest group used as the reference. A total of 80,371 people aged 45 to 74 years were enrolled between 1995 and 1999, and followed up for 1,158,632 person-years until 2012, during which 133 GBC, 99 IHBDC, and 161 EHBDC cases were identified. Increased consumption of total vegetable and fruit was significantly associated with a decreased risk of EHBDC (HR = 0.49; 95% CI: 0.29-0.81 for the highest group; p trend = 0.005). From the analysis of relevant nutrients, significantly decreased risk of EHBDC was associated with folate and insoluble fiber (HR = 0.48, 0.53; 95% CI: 0.28-0.85, 0.31-0.88 for the highest group; p trend = 0.010, 0.023; respectively), and a significant trend of decreased EHBDC risk associated with vitamin C was observed (p trend = 0.029). No decreased risk of GBC and IHBDC was found. Our findings suggest that increased vegetable/fruit consumption may decrease a risk of EHBDC, and folate, vitamin C, and insoluble fiber might be key contributors to the observed protective effect.

Fruit and vegetable consumption, Helicobacter pylori antibodies, and gastric cancer risk: A pooled analysis of prospective studies in China, Japan, and Korea.

Epidemiological findings on the association between fruit and vegetable consumption and gastric cancer risk remain inconsistent. The present analysis included 810 prospectively ascertained non-cardia gastric cancer cases and 1,160 matched controls from the Helicobacter pylori Biomarker Cohort Consortium, which collected blood samples, demographic, lifestyle, and dietary data at baseline. Conditional logistic regression adjusting for total energy intake, smoking, and H. pylori status, was applied to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for gastric cancer risk across cohort- and sex-specific quartiles of fruit and vegetable intake. Increasing fruit intake was associated with decreasing risk of non-cardia gastric cancer (OR = 0.71, 95% CI: 0.52-0.95, p trend = 0.02). Compared to low-fruit consumers infected with CagA-positive H. pylori, high-fruit consumers without evidence of H. pylori antibodies had the lowest odds for gastric cancer incidence (OR = 0.12, 95% CI: 0.06-0.25), whereby the inverse association with high-fruit consumption was attenuated among individuals infected with CagA-positive H. pylori (OR = 0.82, 95% CI: 0.66-1.03). To note, the small number of H. pylori negative individuals does influence this finding. We observed a weaker, nondose-response suggestion of an inverse association of vegetable intake with non-cardia gastric cancer risk. High fruit intake may play a role in decreasing risk of non-cardia gastric cancer in Asia.

Body mass index change during adulthood and risk of oesophageal squamous-cell carcinoma in a Japanese population: the Japan Public Health (JPHC)-based prospective study.

BACKGROUND: The influence of body mass index (BMI) change during adulthood on the development of oesophageal squamous-cell carcinoma (ESCC) is unknown. METHODS: Based on the Japan Public Health Center-based Prospective Study, we enrolled 103 238 participants from 1990 to 1994. Anthropometric data at age 20 years, baseline, and 5- and/or 10-year follow-up surveys were collected by questionnaire. The effect of BMI change between age 20 years and baseline on ESCC risk was estimated by Cox proportional hazards regression models. The updated BMI was taken into account by fitting a simple linear regression model for each individual, where the slope was incorporated into regressions as a time-varying variable. RESULTS: After excluding the first 5 years of observation, we identified 342 newly diagnosed ESCC cases. An increase in BMI during adulthood was linked with a decreased risk of ESCC development, with each 1% increase per 5 years corresponding to a 15% decrease in ESCC risk (95% confidence interval 9-21%). Identical estimates were obtained from time-dependent models. The importance of BMI change was not modified by gender, smoking, or alcohol drinking but confined to participants assessed as non-overweight at baseline. CONCLUSIONS: An increase in BMI during adulthood is associated with a lower risk of developing ESCC among non-overweight subjects.

Smoking and alcohol and subsequent risk of myelodysplastic syndromes in Japan: the Japan Public Health Centre-based Prospective Study.

Smoking and alcohol are important modifiable risk factors for human cancers. However, few epidemiological studies have investigated their association with the risk of myelodysplastic syndromes (MDS). Here, we investigated the association of smoking and alcohol consumption and the risk of MDS in a large-scale population-based cohort study in Japan. We included 95 510 Japanese subjects (45 451 men and 50 059 women; age 40-69 years at baseline) and identified 70 MDS cases (50 men and 20 women) during 18·3 years of follow-up. Hazard ratios (HRs) and 95% confidence intervals (95% CI) were estimated using a Cox regression model adjusted for potential confounders. Smoking was marginally associated with an increased risk of MDS among men, with a HR for current smokers relative to never smokers of 2·11 (95% CI: 0·91-4·89). In contrast, alcohol consumption was associated with a dose-dependent decrease in the risk of MDS among men (nondrinkers: reference, occasional drinkers: HR = 0·48, 0·16-1·41; 0-299 g/week: HR = 0·37, 0·19-0·73; ≥300 g/week: HR = 0·49, 0·22-1·08, P for trend = 0·010). This study showed that alcohol has a significant protective effect on the risk of MDS. In addition, this study might indicate that smoking increases the risk of MDS among Japanese population, as it does in Western populations.

Dietary fiber intake and risk of breast cancer defined by estrogen and progesterone receptor status: the Japan Public Health Center-based Prospective Study.

PURPOSE: Epidemiological studies have suggested a protective effect of dietary fiber intake on breast cancer risk while the results have been inconsistent. Our study aimed to investigate the association between dietary fiber intake and breast cancer risk and to explore whether this association is modified by reproductive factors and hormone receptor status of the tumor. METHODS: A total of 44,444 women aged 45 to 74 years from the Japan Public Health Center-based Prospective Study were included in analyses. Dietary intake assessment was performed using a validated 138-item food frequency questionnaire (FFQ). Hazard ratios (HRs) and 95% confidence intervals (CIs) for breast cancer incidence were calculated by multivariate Cox proportional hazards regression models. RESULTS: During 624,423 person-years of follow-up period, 681 breast cancer cases were identified. After adjusting for major confounders for breast cancer risk, inverse trends were observed but statistically non-significant. Extremely high intake of fiber was associated with decreased risk of breast cancer but this should be interpreted with caution due to limited statistical power. In stratified analyses by menopausal and hormone receptor status, null associations were observed except for ER-PR- status. CONCLUSIONS: Our findings suggest that extreme high fiber intake may be associated with decreased risk of breast cancer but the level of dietary fiber intake among Japanese population might not be sufficient to examine the association between dietary fiber intake and breast cancer risk.

Receiver operating characteristic analysis of prediction for gastric cancer development using serum pepsinogen and Helicobacter pylori antibody tests.

BACKGROUND: Chronic Helicobacter pylori infection plays a central role in the development of gastric cancer as shown by biological and epidemiological studies. The H. pylori antibody and serum pepsinogen (PG) tests have been anticipated to predict gastric cancer development. METHODS: We determined the predictive sensitivity and specificity of gastric cancer development using these tests. Receiver operating characteristic analysis was performed, and areas under the curve were estimated. The predictive sensitivity and specificity of gastric cancer development were compared among single tests and combined methods using serum pepsinogen and H. pylori antibody tests. RESULTS: From a large-scale population-based cohort of over 100,000 subjects followed between 1990 and 2004, 497 gastric cancer subjects and 497 matched healthy controls were chosen. The predictive sensitivity and specificity were low in all single tests and combination methods. The highest predictive sensitivity and specificity were obtained for the serum PG I/II ratio. The optimal PG I/II cut-off values were 2.5 and 3.0. At a PG I/II cut-off value of 3.0, the sensitivity was 86.9% and the specificity was 39.8%. Even if three biomarkers were combined, the sensitivity was 97.2% and the specificity was 21.1% when the cut-off values were 3.0 for PG I/II, 70 ng/mL for PG I, and 10.0 U/mL for H. pylori antibody. CONCLUSIONS: The predictive accuracy of gastric cancer development was low with the serum pepsinogen and H. pylori antibody tests even if these tests were combined. To adopt these biomarkers for gastric cancer screening, a high specificity is required. When these tests are adopted for gastric cancer screening, they should be carefully interpreted with a clear understanding of their limitations.

Cruciferous Vegetable Intake Is Inversely Associated with Lung Cancer Risk among Current Nonsmoking Men in the Japan Public Health Center (JPHC) Study.

Background: Cruciferous vegetables, a rich source of isothiocyanates, have been reported to lower the risk of several types of cancer, including lung cancer. However, evidence from prospective observations of populations with a relatively high intake of cruciferous vegetables is sparse.Objective: We investigated the association between cruciferous vegetable intake and lung cancer risk in a large-scale population-based prospective study in Japan.Methods: We studied 82,330 participants (38,663 men; 43,667 women) aged 45-74 y without a past history of cancer. Participants were asked to respond to a validated questionnaire that included 138 food items. The association between cruciferous vegetable intake and lung cancer incidence was assessed with the use of Cox proportional hazard regression analysis to estimate HRs and 95% CIs (with adjustments for potential confounding factors).Results: After 14.9 y of follow-up, a total of 1499 participants (1087 men; 412 women) were diagnosed with lung cancer. After deleting early-diagnosed cancer and adjusting for confounding factors, we observed a nonsignificant inverse trend between cruciferous vegetable intake and lung cancer risk in men in the highest compared with the lowest quartiles (multivariate HR: 0.85; 95% CI: 0.69, 1.06; P-trend = 0.13). Stratified analysis by smoking status revealed a significant inverse association between cruciferous vegetable intake and lung cancer risk among those who were never smokers and those who were past smokers after deleting lung cancer cases in the first 3 y of follow-up [multivariate HR for never smokers: 0.49 (95% CI: 0.27, 0.87; P-trend = 0.04); multivariate HR for past smokers: 0.59 (95% CI: 0.35, 0.99; P-trend = 0.10)]. No association was noted in men who were current smokers and women who were never smokers.Conclusion: This study suggests that cruciferous vegetable intake may be associated with a reduction in lung cancer risk among men who are currently nonsmokers.

Fermented Soy Product Intake Is Inversely Associated with the Development of High Blood Pressure: The Japan Public Health Center-Based Prospective Study.

Background: Randomized controlled studies have investigated the short-term effect of soy product intake on blood pressure (BP) in normotensive people. To our knowledge, no prospective studies exist on the effect of habitual intake of fermented soy products, separate from total soy products, on BP in the general population.Objective: We examined the association between the habitual intake of soy products, including fermented soy products, and the development of high BP during a 5-y period among participants in a population-based prospective cohort study in Japan.Methods: The study included normotensive participants aged 40-69 y at baseline (926 men and 3239 women) who completed 2 questionnaires and whose BP was measured at the baseline survey between 1993 and 1994 and the 5-y follow-up in the Japan Public Health Center-Based Prospective Study Cohort II. The intake of soy products was assessed with a food-frequency questionnaire. High BP was defined as systolic blood pressure ≥130 mm Hg, diastolic blood pressure ≥85 mm Hg, or antihypertensive medication use. ORs and 95% CIs of high BP by frequency of soy products (miso, natto, and tofu) consumption, intake of total and fermented soy products, and intake of isoflavones from total and fermented soy products were estimated with the use of multiple logistic regression analysis.Results: Multivariable-adjusted ORs of high BP for the highest compared with the lowest tertile of total and fermented soy product intake were 1.03 (95% CI: 0.84, 1.25; P-trend = 0.786) and 0.72 (95% CI: 0.56, 0.92; P-trend = 0.009), respectively. The frequency of nonfermented soy product (tofu) intake was not associated with the development of high BP (P-trend = 0.597).Conclusions: The intake of fermented soy products, but not total or nonfermented soy products, was inversely associated with developing high BP in men and women with normal BP.

Estimation of lifetime cumulative incidence and mortality risk of gastric cancer.

OBJECTIVE: To estimate cumulative incidence and mortality risk for gastric cancer by risk category. METHODS: Risk was classified into four types according to the presence/absence of Helicobacter pylori infection and chronic atrophic gastritis: in order of lowest to highest risk, Group A: H. pylori(-) and atrophic gastritis(-); Group B: H. pylori(+) and atrophic gastritis(-); Group C:H. pylori(+) and atrophic gastritis(+); and, Group D: H. pylori(-) and atrophic gastritis(+). We used vital statistics for the crude all-cause and crude gastric cancer mortality rates in 2011 and data from population-based cancer registries (the Monitoring of Cancer Incidence in Japan) for gastric cancer incidence in 2011. For relative risk and prevalence, we used the results of a meta-analysis integrating previous studies and data from the Japan Public Health Center-based Prospective Study for the Next Generation, respectively (baseline survey 2011-16). We calculated the crude incidence and mortality rates and estimated the cumulative risk using a life-table method. RESULTS: The estimated lifetime cumulative incidence risk was 11.4% for men and 5.7% for women. The estimated risk for Groups A, B, C and D was 2.4%, 10.8%, 26.7% and 35.5% for men, and 1.2%, 5.5%, 13.5% and 18.0% for women, respectively. Similarly, the estimated lifetime cumulative mortality risk was 3.9% for men and 1.8% for women. The estimated risk of mortality for Groups A, B, C and D was 0.8%, 3.6%, 9.0% and 12.0% for men, and 0.4%, 1.7%, 4.2% and 5.7% for women, respectively. CONCLUSIONS: Our results may be useful for designing individually tailored prevention programs.

Smoking and subsequent risk of leukemia in Japan: The Japan Public Health Center-based Prospective Study.

BACKGROUND: Cigarette smoking has been reported to be associated with an increased risk of leukemia. Most epidemiological evidence on the association between cigarette smoking and leukemia risk is from studies conducted in Western populations, however, and evidence from Asian populations is scarce. METHODS: We conducted a large-scale population-based cohort study of 96,992 Japanese subjects (46,493 men and 50,499 women; age 40-69 years at baseline) with an average 18.3 years of follow-up, during which we identified 90 cases of acute myeloid leukemia (AML), 19 of acute lymphoblastic leukemia (ALL), and 28 of chronic myeloid leukemia (CML). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a Cox regression model adjusted for potential confounders. RESULTS: When we adjusted for age, sex, and study area, our findings showed no significant association or increasing dose-response relationship between risk of AML and cigarette smoking overall. However, after further adjustment for body mass index and occupation, current smokers with more than 30 pack-years of cigarette smoking had a significantly increased risk of AML compared to never smokers among men (HR 2.21; 95% CI, 1.01-4.83). This increased risk was not clear among women. CONCLUSIONS: Our results suggest that cigarette smoking increases the risk of AML in Japanese men. The associations of smoking with AML among women, and with CML and ALL among men and women, should be assessed in future studies.

Online version of the self-administered food frequency questionnaire for the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT) protocol: Relative validity, usability, and comparison with a printed questionnaire.

BACKGROUND: Online dietary assessment tools offer advantages over printed questionnaires, such as the automatic and direct data storage of answers, and have the potential to become valuable research methods. We developed an online survey system (web-FFQ) for the existing printed FFQ used in the JPHC-NEXT protocol, the platform of a large-scale genetic cohort study. Here, we examined the validity of ranking individuals according to dietary intake using this web-FFQ and its usability compared with the printed questionnaire (print-FFQ) for combined usage. METHODS: We included 237 men and women aged 40-74 years from five areas specified in the JPHC-NEXT protocol. From 2012 to 2013, participants were asked to provide 12-day weighed food records (12d-WFR) as the reference intake and to respond to the print- and web-FFQs. Spearman's correlation coefficients (CCs) between estimates using the web-FFQ and 12d-WFR were calculated. Cross-classification of intakes was compared with those using the print-FFQ. RESULTS: Most participants (83%) answered that completing the web-FFQ was comparable to or easier than completing the printed questionnaire. The median value of CCs across energy and 53 nutrients for men and women was 0.47 (range, 0.10-0.86) and 0.46 (range, 0.16-0.69), respectively. CCs for individual nutrient intakes were closely similar to those based on the print-FFQ, irrespective of response location. Cross-classification by quintile of intake based on two FFQs was reasonably accurate for many nutrients and food groups. CONCLUSION: This online survey system is a reasonably valid measure for ranking individuals by intake for many nutrients, like the printed FFQ. Mixing of two FFQs for exposure assessments in epidemiological studies appears acceptable.

Fruit and vegetable intake and the risk of overall cancer in Japanese: A pooled analysis of population-based cohort studies.

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.