Public Health Center-based Prospective Study Research Articles

Increased risk of death from pneumonia among cancer survivors: A propensity score-matched cohort analysis.

The repeated global pandemic of the new virus has led to interest in the possibility of severe pneumonia among cancer patients and survivors. Here, we aimed to assess the association between incident cancer and risk of death from pneumonia in Japanese in a large population-based cohort study. We used the data from The Japan Public Health Center-based Prospective Study (JPHC Study), which enrolled subjects aged 40 to 69 between 1990 and 1994 and followed their cancer incidence and mortality until 2013. After identifying 103,757 eligible subjects for analysis and imputing missing data on covariates by the chained equations approach, we conducted propensity score-matched analysis for 1:4 matching, leaving 14,520 cases diagnosed with cancer and 48,947 controls without cancer during the study period for final analysis. A Cox proportional hazards regression model was used to estimate the hazard ratio (HR) and corresponding confidence interval (CI) for the risk of death from pneumonia with comparison of cancer cases and cancer-free controls. Compared to cancer-free individuals, risk of death from pneumonia was significantly higher among those who had any diagnosed cancer (HR, 1.41; 95%CI, 1.08-1.84); those within 1year of diagnosis (HR, 23.0; 95% CI, 2.98-177.3); within 1 to <2 years (HR, 3.66; 95% CI, 1.04-12.9); and those with regional spread or distant metastatic cancer at initial diagnosis (HR, 2.01; 95% CI, 1.26-3.21). A history of lung, oesophageal, and head and neck cancer conferred the higher risk among site-specific cancers. We found a positive association between incident cancer and risk of death from pneumonia in this study. These results imply the possibility that the immunocompromised status and respiratory failure due to antitumor treatment may have resulted in a more severe outcome from pneumonia among cancer survivors than the general population.

Association of chronic kidney disease with total and site-specific cancer incidence in participants of the Japan Public Health Center-based Prospective Study.

Although studies have found an association between chronic kidney disease (CKD) and cancer incidence, the results are inconsistent. This study included participants in the Japan Public Health Center-based Prospective Study who had data on serum creatinine measurements. We assessed the association between estimated glomerular filtration rate (eGFR) and the risk of total and site-specific cancer incidence using a systematic survey in Japan. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) with adjustment for participant demographics and lifestyle factors. A total of 21978 participants who met the inclusion criteria were followed up for a mean period of 12.9 years, during which a total of 2997 incident cancer cases were reported. In the multivariable adjusted models, an eGFR of <45mL/min/1.73 m2 was not significantly associated with total cancer incidence (adjusted HR 1.22, 95% CI 0.94-1.60), compared with an eGFR of 60-89mL/min/1.73 m2 (reference). The HR among those with eGFRs of ≥90mL/min/1.73 m2 was 1.10 (95% CI 1.00-1.22). In this large prospective study, a low eGFR was not significantly associated with an increased risk of total cancer incidence in patients with CKD, which may be partly due to an underpowered sample size. This finding may be due to the many shared risk factors between CKD and cancer.

Inverse Association between Fruit and Vegetable Intake and All-Cause Mortality: Japan Public Health Center-Based Prospective Study

A dose-response and nonlinear association between fruit and vegetable intake and mortality has been reported in Europe and the United States, but little is known about this association in Asia. This study aimed to evaluate the association of fruit and vegetable intake with all-cause, cancer, cardiovascular, and respiratory disease mortality in a Japanese cohort. In the Japan Public Health Center-based prospective study, we included 94,658 participants (mean age: 56.4; 46.0% male) without cancer and cardiovascular disease at baseline. Information on fruit and vegetable intake was collected using a validated FFQ. The Cox proportional hazard model was used to estimate HRs and 95% CIs of each quintile of fruit and vegetable intake, separately, in relation to all-cause and cause-specific mortality using the first quintile as a reference. Nonlinear associations were evaluated using a likelihood ratio test, comparing a linear model with a restricted cubic spline model. During a median of 20.9 follow-up years (IQR: 19.6-23.8 y), 23,687 all-cause deaths were documented. After adjusting for age, sex, and potential confounding factors, fruit and vegetable intake was nonlinearly and significantly associated with lower all-cause mortality, with the fourth and fifth quintiles having comparable HRs (fruit: fourth quintile HR: 0.91; 95% CI: 0.87, 0.95 and fifth quintile HR: 0.92; 95% CI: 0.88, 0.96; P-nonlinearity <0.001; vegetable: fourth quintile HR: 0.92; 95% CI: 0.88, 0.97 and fifth quintile HR: 0.93; 95% CI: 0.89, 0.98; P-nonlinearity=0.002). Fruit intake was significantly associated with lower cardiovascular mortality (HR in the fifth quintile: 0.91; 95% CI: 0.83, 0.99; P-nonlinearity=0.01). In the Japanese population, higher intake of fruits and vegetables was nonlinearly associated with decreased all-cause mortality. These findings may contribute to the establishment of dietary recommendations for enhancing life expectancy in Asia.

Current status of awareness, knowledge, beliefs, and behavioral intentions regarding the Japanese physical activity guidelines and their relationship with physical activity and sedentary behavior

Objective This study clarified the current status of awareness, knowledge, beliefs, and behavioral intentions regarding the Japanese physical activity guidelines (Active Guide) and their relationship with physical activity, sedentary behavior, and the participants' characteristics.Methods A cross-sectional study was conducted with 7,000 participants aged 20-69 years registered with an online survey company. Awareness, knowledge, beliefs, and behavioral intentions regarding the Active Guide were examined. Awareness was assessed by unprompted and prompted recall. Knowledge was assessed by numerical responses to "the recommended daily activity time (18-64 years/65 years and older)" and "physical activity time to be increased (plus-ten)," respectively. To survey the beliefs and behavioral intentions, we created a 5-point scale for the Active Guide. For physical activity, the amount of moderate-to-vigorous intensity physical activity was calculated from the Japan Public Health Center-based prospective Study (JPHC study) questionnaire. Physical activity level was calculated from the standard specific medical checkup and health guidance questionnaire. For sedentary behavior, the Japanese version of the International Physical Activity Questionnaire (IPAQ) was used. The dependent variables were awareness, knowledge, beliefs, and behavioral intentions. The independent variables were physical activity, sedentary behavior, and the participants' characteristics (gender, age, body mass index, marital status, educational background, work status, and household income). After descriptive statistics were measured, a logistic regression analysis was performed to examine the associations.Results Unprompted and prompted recall of the Active Guide were 1.7% and 5.3-13.4%, respectively. Those with knowledge of it scored 37.2%, 7.0%, 24.8%, and 2.6% for recommended daily activity time (18-64 years), daily physical activity time (65 years and older), plus-ten, and all three items answered correctly, respectively. The median (interquartile range) score of the beliefs was 21 (16-25) points (32-point scale). Those with behavioral intentions scored 51.4% for "recommended daily activity" and 66.9% for "plus-ten." Logistic regression analysis showed that awareness, knowledge, beliefs, and behavioral intentions were positively associated with moderate-to-vigorous intensity physical activity and level. The results were inconsistent for sedentary behavior. Although personal characteristics differed based on assessment item, they were mainly associated with age, education level, employment, and household income.Conclusions This study revealed that the number of people who had awareness and knowledge of the Active Guide remained low. Those with awareness, knowledge, beliefs, and behavioral intentions were more physically active. However, the results for sedentary behavior were not consistent. Hence, further research is required to understand this tendency. A future longitudinal study is also required.

Vegetable and fruit intake and colorectal cancer risk by smoking status in adults: The Japan Public Health Center-based Prospective Study.

Cigarette smoke contains many oxidants and free radicals which may affect the association between vegetable and fruit intake and colorectal cancer (CRC) risk. However, this relationship remains unclear. This study aimed to investigate the associations between vegetable and fruit intake and CRC risk by smoking status. The Japan Public Health Center-based Prospective Study is a population-based prospective cohort study. Participants completed a self-administered questionnaire in 1995-1999 (baseline survey) and were followed through to 2013. At the baseline survey, 89,283 residents (41,797 men and 47,486 women) aged 45-74 years were included. Participants were asked about their lifestyle and dietary habits. To investigate the association of vegetable and fruit intake with risk of CRC, Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). We analyzed the relationship between vegetable and fruit intake and CRC risk stratified by sex and smoking status. During follow-up, 2261 participants were diagnosed with CRC. Overall, vegetable and fruit intake were not associated with CRC risk in either sex. When stratified by sex and smoking status, CRC risk among male never smokers was inversely associated with intake of vegetables and fruit combined (HR: 0.72; 95% CI: 0.53, 0.98; highest vs lowest quartile p trend = 0.01) and fruit alone (HR: 0.62; 95% CI: 0.45, 0.86; p trend < 0.01). Cigarette smoking may affect the association between vegetable and fruit intake and CRC risk among men.

Sugary drink consumption and the subsequent risk of gastric cancer: The Japan Public Health Center-based Prospective Study.

Evidence on the association between sugary drink consumption and gastric cancer (GC) risk is limited, especially in Asian populations. This study aimed to investigate the association between consumption of sugary drinks (sugar-sweetened beverages and 100% fruit juices) and GC risk in a Japanese population. This study included 74,455 Japanese individuals aged 45-74 years (35,102 males and 39,353 females) who participated in a population-based cohort study (Japan Public Health Center-based Prospective Study). Sugary drinks were assessed using a food frequency questionnaire. Cox proportional hazard regression was used to obtain hazard ratios (HRs) and 95% confidence intervals (CIs) of GC incidence according to the quintile of sugary drink consumption. We identified 2141 patients with GC cases during 16.7 years of follow-up. Sugary drink consumption was not associated with GC risk. The multivariate HR of total, cardia, and non-cardia GC in the highest vs. lowest quintile of sugary drinks consumption in males was 0.98 (95% CI: 0.82-1.17; p-trend 0.48), 0.48 (95% CI: 0.23-0.99; p-trend 0.03), and 1.03 (95% CI: 0.86-1.24; p-trend 0.88), respectively. In females, the respective multivariate HRs were 1.03 (95% CI: 0.79-1.33; p-trend 0.47), 1.28 (95% CI: 0.32-5.12; p-trend 0.53), and 1.01 (95% CI: 0.78-1.32; p-trend 0.56). The results did not change significantly after adjusting for Helicobacter pylori infection and atrophic gastritis status in the subgroup analysis. In this Japanese prospective cohort study, sugary drink consumption was not associated with GC risk.

Association Between Alcohol Consumption and Risk of Pancreatic Cancer: The Japan Public Health Center-Based Prospective Study.

Several studies have investigated the association between alcohol consumption and pancreatic cancer risk. However, these studies reported inconsistent results. This study included 95,812 participants from the Japan Public Health Center-Based Prospective Study, whose alcohol drinking habit was collected through the questionnaire of the baseline survey in 1990 to 1994 for Cohort I and in 1993 to 1995 for Cohort II, and followed-up until December 2013. The hazard ratios (HR) and 95% confidence intervals (CI) were calculated using multivariable-adjusted Cox proportional hazard regression models. During 1,969,101 person-years of follow-up, 598 patients (315 men and 283 women) were newly diagnosed with pancreatic cancer. No association was observed between alcohol consumption at baseline and pancreatic cancer risk in either men or women, even in the analyses conducted among men stratified by facial flushing responses or smoking status. When the population was limited to men whose alcohol drinking habit remained unchanged from the baseline survey to the 5-year follow-up survey, a significant association was observed in drinkers with alcohol consumption of 1 to 299 g/week compared with non/occasional drinkers (multivariable-adjusted HR, 1.73; 95% CI, 1.15-2.60). A significant association between alcohol consumption and pancreatic cancer risk was observed when the population was limited to men with a 5-year unchanged alcohol drinking habit and was particularly strong in never smokers. This study suggested an association between continuous alcohol consumption and pancreatic cancer risk in the Japanese population. However, further investigations using other cohort studies are required.

Isoflavone and soy food intake and risk of lung cancer in never smokers: report from prospective studies in Japan and China.

Evidence from several cohorts has suggested that a higher intake of isoflavone is associated with lower risk of lung cancer in never smokers, but the association has not been investigated by histologic type of lung cancer. Adenocarcinoma is a common histologic type found in never smokers. We hypothesized that a higher intake of isoflavone is associated with a lower risk of lung adenocarcinoma among never smokers. Here, we examined the associations of isoflavone and soy food intake with lung cancer and its histologic types in never smokers. We performed a pooled analysis using data from the Japan Public Health Center-based Prospective Study, Shanghai Women's Health Study and Shanghai Men's Study with 147,296 never smokers aged 40-74years with no history of cancer. During 1,990,040 person-years of follow-up, 1247 lung cancer cases were documented. Dietary isoflavone and soy food intake were assessed using a food-frequency questionnaire. Multivariable Cox proportional hazards models assessed the associations between isoflavone and soy intake with incidence of lung cancer by histologic type. A higher intake of dietary isoflavone and soy food were associated with reduced risk of lung adenocarcinoma. The multivariable hazard ratios (HRs) (95% CI) of risk of lung adenocarcinoma for the highest versus lowest intakes of isoflavone and soy food were 0.74 (0.60-0.92) and 0.78 (0.63-0.96), respectively. The multivariable HRs of risk of lung adenocarcinoma associated with each 10mg/day increase in isoflavone and each 50g/day increase in soy food intake were 0.81 (0.70-0.94) and 0.84 (0.73-0.96), respectively. Higher intake of isoflavone and soy food was associated with lower risk of lung adenocarcinoma in never smokers.

Prediagnostic plasma polyphenol concentrations and colon cancer risk: The JPHC nested case–control study

Epidemiological studies that assessed the associations between dietary polyphenol intakes and colon cancer risk have reported largely null results, possibly due to measurement error associated with dietary assessment. We adopted an objective approach by measuring prediagnostic plasma concentrations of 35 polyphenols and assessing associations with colon cancer risk. We conducted a nested-case control study within the Japan Public Health Center-based prospective study (JPHC Study) utilizing plasma samples collected at the time of a five-year follow-up survey between 1995 and 1999. We identified colon cancer cases who developed cancer during the follow-up from the time of blood collection. Controls were matched by age, sex, area code, population size of the area, season of blood collection, year of blood collection, and duration of fasting time before the blood collection. Prediagnostic concentrations of 35 polyphenols from 375 incident colon cancer cases (followed until 2012) and 710 matched controls were measured by tandem mass spectrometry coupled with ultra-high-pressure liquid chromatography. We used multivariable conditional logistic regression models adjusted for established colon cancer risk factors to estimate odds ratios (ORs) and 95% confidence intervals (CIs). In sexes combined log2-transformed multivariable models, circulating levels of 3,4-dihydroxyphenylpropionic acid (P=0.02), ferulic acid (P=0.02), and caffeic acid (P=0.03) were inversely, and 3-hydroxybenzoic acid (P=0.03) was positively, associated with colon cancer risk. For men only, circulating levels of 3,4-dihydroxyphenylpropionic acid was inversely, and 3,5-dihydroxyphenylpropionic acid, gallic acid, (+)-epigallocatechin, 3-hydroxybenzoic acid, and epicatechin were positively, associated with colon cancer risk. In women, plasma caffeic acid and ferulic acid concentration were inversely associated with colon cancer risk. However, all these associations were nonsignificant after adjustment for multiple comparisons. The remaining polyphenols were not associated with colon cancer risk. Coffee-derived 3,4-dihydroxyphenylpropionic acid, ferulic acid, and caffeic acid concentrations were inversely associated with colon cancer risk although the association were nonsignificant after adjustment for multiple comparisons. These results support a possible role of coffee polyphenols in preventing colorectal cancer.

Validity of claims data for identifying cancer incidence in the Japan public health center-based prospective study for the next generation.

This study determined the validity of claims-based definitions for identifying the incidence of total and site-specific cancers in a population-based cohort study. Claims data were obtained for 21 946 participants aged 40-74 years enrolled in the Japan Public Health Center-based Prospective Study for the Next Generation. We defined total and site-specific cancer incidence using combinations of codes from claims data, including diagnosis and procedure codes for cancer therapy. Data from the cancer registry were used as the gold standard to evaluate validity. Among 21 946 participants, 454 total, 89 stomach, 67 colorectal, 51 lung, 39 breast and 99 prostate invasive cancer cases were newly diagnosed in the cancer registry. For invasive cancer, the sensitivity and specificity of the definition that combined codes for diagnosis and procedures for cancer therapy were 87.0% and 99.4% for total, 88.8% and 99.9% for stomach, 80.6% and 99.9% for colorectal, 86.3% and 99.9% for lung, 100% and 99.9% for breast and 91.9% and 99.9% for prostate cancer, respectively. Furthermore, for invasive and/or in situ cancer, the sensitivity and specificity of the definition were 84.5% and 99.5% for total, 66.7% and 99.9% for colorectal and 100% and 99.9% for breast cancer. Our findings suggest that claims-based definitions using diagnosis and procedure codes generally have high validity for total, stomach, lung, breast and prostate cancer incidence, but may underestimate colorectal cancer incidence.

Cross-sectional associations between the types/amounts of beverages consumed and the glycemia status: The Japan Public Health Center-based Prospective Diabetes study

BackgroundThe associations between the types/amounts of beverages consumed in daily life and measures of the glycemia status were investigated in a Japanese population-based cohort. MethodsData from the baseline survey of the Japan Public Health Center-based Prospective Diabetes cohort were used. A cross-sectional analysis was performed in 3852 men and 6003 women who were evaluated under the fasting condition. The daily consumptions of coffee, green tea, oolong tea, black tea, soft drinks, fruit juices, or plain water were assessed using a self-reported questionnaire. Multivariable-adjusted linear regression analyses were performed using measures of the glycemia status (fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) ) as dependent variables and the types/amounts of beverages consumed as the independent variables, to calculate the differences according to the types/amounts of beverages consumed. ResultsIn the multivariable-adjusted models, coffee consumption of ≥240 mL/day was significantly associated with a change of the FPG level by −1.9 mg/dL in men (p = 0.013) and −1.4 mg/dL in women (p = 0.015), as compared to coffee consumption of 0 mL/day. No significant association of the FPG level was observed with any of the other types/amounts of beverages consumed. On the other hand, significant associations were found between the HbA1c levels and consumption of several types of beverages. ConclusionsHigh coffee consumption was associated with lower FPG levels in this Japanese population. Some unexpected associations of the HbA1c levels with the consumption of some types of beverages were observed, which need to be further investigated.

The association between midlife living arrangement and psychiatrist-diagnosed depression in later life: who among your family members reduces the risk of depression?

This study investigates the longitudinal association between living arrangements and psychiatrists’ diagnosis of depression in the general population. In 1990, 1254 Japanese men and women aged 40–59 years were enroled and completed questionnaires on the living arrangement in the Japan Public Health Center-based Prospective Study (JPHC Study) and participated in a mental health screening (2014–2015). The study diagnosed a major depressive disorder (MDD) assessed by well-trained certified psychiatrists through medical examinations. During the follow-up, a total of 105 participants (36 men and 69 women) aged 64–84 years were diagnosed with MDD by psychiatrists. Living with a child (ren) was associated with a reduced risk of MDD for men but not for women; the respective multivariable ORs (95% CIs) were 0.42 (0.19–0.96) and 0.59 (0.32–1.09). These associations remained unchanged after adjusting for living with spouse and parent(s). In conclusion, living with a child (ren) was associated with a reduced risk of MDD in men, suggesting the role of a child (ren) in the prevention of MDD.

Association Between Birth Weight and Risk of Pregnancy-Induced Hypertension and Gestational Diabetes in Japanese Women: JPHC-NEXT Study.

BackgroundAlthough prevalence of low birth weight has increased in the last 3 decades in Japan, no studies in Japanese women have investigated whether birth weight is associated with the risk of pregnancy complications, such as pregnancy-induced hypertension (PIH) and gestational diabetes mellitus (GDM).MethodsWe used data from the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT), a population-based cohort study in Japan that launched in 2011. In the main analysis, we included 46,365 women who had been pregnant at least once, for whom information on birth weight and events during their pregnancy was obtained using a self-administered questionnaire. Women were divided into five categories according to their birth weight, and the relationship between birth weight and risk of PIH and GDM was examined using multilevel logistic regression analyses with place of residence as a random effect.ResultsCompared to women born with birth weight of 3,000–3,999 grams, the risk of PIH was significantly higher among women born <1,500 grams (adjusted odd ratio [aOR] 1.60; 95% confidence interval [CI], 1.17–2.21), 1,500–2,499 grams (aOR 1.16; 95% CI, 1.03–1.30), and 2,500–2,999 grams (aOR 1.13; 95% CI, 1.04–1.22). The risk of GDM was significantly higher among women born 1,500–2,499 grams (aOR 1.20; 95% CI, 1.02–1.42), albeit non-significant association among women in other birthweight categories.ConclusionsWe observed an increased risk of PIH among women born with lower birth weight albeit non-significant increased risk of GDM among Japanese women.

Long-term exposure to fine particle matter and all-cause mortality and cause-specific mortality in Japan: the JPHC Study

BackgroundMany epidemiological studies have reported the association between exposure to particulate matter and mortality, but long-term prospective studies from Asian populations are sparse. Furthermore, associations at low levels of air pollution are not well clarified. Here, we evaluated associations between long-term exposure to particulate matter <2.5 µg/m3 (PM2.5) and mortality in a Japanese cohort with a relatively low exposure level.MethodsThe Japan Public Health Center-based Prospective Study (JPHC Study) is a prospective cohort study of men and women aged 40-69 years in 1990 who were followed up through 2013 for mortality. In this cohort of 87,385 subjects who did not move residence during follow-up, average PM2.5 levels from 1998 to 2013 by linkage with 1-km2 grids of PM2.5 concentration were assigned to the residential addresses of all participants. To avoid exposure misclassification, we additionally evaluated the association between 5-year (1998-2002) cumulative exposure level and mortality during the follow-up period from 2003 to 2013 in 79,078 subjects. Cox proportional hazards models were used to calculate the association of long-term exposure to PM2.5 on mortality, with adjustment for several individual confounding factors.ResultsAverage PM2.5 was 11.6 µg/m3. Average PM2.5 exposure was not associated with all-cause mortality or cancer and respiratory disease mortality. However, average PM2.5 was positively associated with mortality from cardiovascular disease (hazard ratio (HR) of 1.23 (95%CI=1.08-1.40) per 1-µg/m3 increase; in particular, HR in mortality from cerebrovascular disease was 1.34 (95%CI=1.11-1.61) per 1-µg/m3 increase. Additionally, these results using cumulative 5-year PM2.5 data were similar to those using average PM2.5 over 15 years.ConclusionsWe found evidence for a positive association between PM2.5 exposure and mortality from cardiovascular disease in a Japanese population, even in an area with relatively low-level air pollution.

Vegetable and fruit intake and the risk of bladder cancer: Japan Public Health Center-based prospective study.

Vegetable and fruit consumption may have a protective effect against several types of cancer. However, evidence suggesting that increased intake of vegetables and fruits, their subtypes, or the antioxidant nutrients they contain in abundance decreases the risk of bladder cancer is limited. This study included 80,952 participants from the Japan Public Health Center-based Prospective Study, who responded to a food frequency questionnaire in a 5-year follow-up survey in 1995-1998 and were followed up until December 2015 to investigate the associations between intake of vegetables and fruits, their subtypes, or the antioxidant nutrients and bladder cancer risk using Cox proportional hazards regression models. Within 1,287,514 person-years of follow-up, 401 bladder cancer cases (307 men and 94 women) were diagnosed. No association was found between intake of total vegetable and fruit, total vegetable, total fruit, subtypes of vegetables and fruits, or antioxidant nutrients and bladder cancer risk in both men and women, even in the analyses conducted among men stratified by smoking status. In this population, the consumption of vegetables and fruits was not associated with the risk of bladder cancer.

Meat consumption and gastric cancer risk: the Japan Public Health Center–based Prospective Study

The association of meat consumption with gastric cancer is inconclusive. We examined the association of meat consumption with gastric cancer risk among Japanese men and women. This cohort study included 42,328 male and 48,176 female participants of the Japan Public Health Center-based Prospective Study, who were aged 45 to 74 y at recruitment. Dietary intake data were collected from 1 January 1995 to 31 December 1999 using a validated food-frequency questionnaire. HRs and 95% CIs for gastric cancer were estimated using Cox proportional hazards regression models. During a mean follow-up of 15 y, 1868 male and 833 female incident gastric cancer cases were identified. Intake of total and subtypes of meat was not associated with total gastric cancer. However, higher chicken consumption was associated with reduced distal gastric cancer risk in women (HR for quintile 5 vs. quintile 1: 0.75; 95% CI: 0.56, 0.99; P-trend = 0.027), with a similar but nonsignificant risk reduction among women with Helicobacter pylori (HR: 0.59; 95% CI: 0.29, 1.20; P-trend = 0.06) in subgroup analysis. Meat consumption was not associated with total gastric cancer risk.

Low-intensity cigarette smoking and mortality risks.

In ‘Low-intensity cigarette smoking and mortality risks: a pooled analysis of prospective cohort studies in Japan’, the authors pool multiple prospective cohort studies to assess the relationship between low-intensity smoking and mortality risk. This study refutes the common belief that low-intensity smoking is not harmful and found a higher risk of mortality among all causes in low-intensity smokers versus never smokers.1 However, the study could be improved in the following ways. Although the authors do acknowledge that the cohorts included in this study only included a smoking status assessment at baseline (with the exception of the Japan Public Health Center-based Prospective Study Cohorts I and II, which re-assessed smoking status at 5 years of follow-up), the study could be improved with more elaboration regarding the impact of this limitation on the study findings. The authors discuss the large decline in smoking prevalence over the recent decades and make the claim that it is likely that many participants reduced or quit smoking, which would improve the observed effect measures; however, all cohorts included individuals over 40 years of age at the time of enrollment, with no stratification by the authors to account for differences in smoking habits by age groups. Research is still unclear as to whether or not the elderly are just as likely as the general population to quit or reduce their smoking. A study conducted in South Korea found that advancing age was not associated with a decline in prevalence of smokers, regardless of gender.2 Given that the readers cannot ascertain the age distribution of the included cohorts from the article, it is difficult to tell whether or not the majority of included participants fall into the age range of elderly or if most are between 40 and 64 years of age. If many of the participants were elderly at baseline, it cannot be safely assumed that many of them quit or reduced their smoking during the follow-up period.

Association between working hours and cancer risk in Japan: The Japan public health center-based prospective study

In this study, we evaluated the association between working hours and cancer risk in the Japanese population, which has not been evaluated. Using a cohort database from a Japan Public Health Center-based Prospective Study, we evaluated 26 738 participants (16 351 men and 10387 women), who responded to a questionnaire about working hours and followed these participants from 1993-1994 to 2013. Participants were divided into four groups according to working hours (≤6, 7-8, 9-10, ≥11 h/day). The hazard ratio (HR) and 95% confidence interval (CI) of each cancer incidence were calculated using a multivariable-adjusted Cox proportional hazard model. During 488 383 person-years of follow-up, 481 patients with newly diagnosed cancers were identified. There was no clear association between long working hours and overall cancer, lung cancer, and stomach cancer risks. Long working hours tended to increase prostate cancer risk in men and breast cancer risk in women, although the difference was not statistically significant. Increased liver cancer risk with short working hours (HR [95% CI]; 3.15 [1.44-6.88] in the ≤6h/day group vs. 7-8 h/day) was observed. Colorectal cancer also tended to increase risk in short working hours, however, there were not statistically significance. In this population, long working hours were not associated with cancer risk with statistically significance. The association between short working hours and liver cancer risk was observed, probably due to the reverse causation of liver cancer.

Circulating Inflammation Markers and Pancreatic Cancer Risk: A Prospective Case-Cohort Study in Japan.

Previous prospective studies of associations between circulating inflammation-related molecules and pancreatic cancer risk have included limited numbers of markers. We conducted a case-cohort study nested within the Japan Public Health Center-based Prospective Study Cohort II. We selected a random subcohort (n = 774) from a total of 23,335 participants aged 40 to 69 years who returned a questionnaire and provided blood samples at baseline. During the follow-up period from 1993 to 2010, we identified 111 newly diagnosed pancreatic cancer cases, including one case within the subcohort. Plasma concentrations of 62 inflammatory markers of chemokines, cytokines, and growth factors were measured by a Luminex fluorescent bead-based assay. Cox regression models were applied to estimate HR and 95% confidence intervals (CI) for pancreatic cancer risk for quartiles of marker levels adjusted for potential confounders. The HR (95% CI) for the highest versus the lowest category of C-C motif ligand chemokine 8/monocyte chemoattractant protein 2 (CCL8/MCP2) was 2.03 (1.05-3.93; P trend = 0.048). After we corrected for multiple comparisons, none of the examined biomarkers were associated with pancreatic cancer risk at P-value <0.05. We found no significant associations between 62 inflammatory markers and pancreatic cancer risk. The suggestive association with circulating levels of leukocyte recruiting cytokine CCL8/MCP2 may warrant further investigation.

COT-6 Body mass index and height in relation to brain tumor risk in a Japanese population

Purpose: Because the prognosis of the malignant brain tumor including glioblastoma is extremely worse than other cancer, it is important to clarify the preventive factors of the brain tumor in the prospective cohort study. In the Japanese epidemiologic study of the brain tumor, the report of the prospective cohort study has not been accomplished. Therefore, we have reported the study in recent years from a multipurpose cohort study (Japan Public Health Center-based Prospective Study: JPHC study) that the national cancer center was mainly conducted. This prospective study investigated the association between height and BMI (Body mass index) and brain tumor risk in an Asian population, whose distribution of anthropometric data differs from Westerners. Methods: A total of 106,324 subjects (50,438 men and 55,886 women) enrolled in JPHC Study, was followed from 1990. We divided participants into 5 categories based on the distribution of BMI as <18.5, 18.5- <23, 23- <25, 25- <27.5, and >-27.5 Kg/m2. We used the Cox proportional hazards regression model and estimated brain tumor incidence by gender and tumor subtype, with adjustment for potential confounding variables; age, sex, pack-years of cigarette smoking, alcohol intake, coffee intake, green tea intake, past history of allergy and past history of diabetes mellitus.Results: During an average follow-up of 18.1 years, 157 incident cases of brain tumor were newly identified, included glioma (n=60), meningioma (n =51), lymphoma(n=9), schwannoma(n=3), pituitary adenoma(n=2), and others(n=32). Higher BMI was significantly positively associated with the risk of brain tumor. This positive association of BMI was stronger in men and for meningioma in subgroup analyses. In contrast, height showed no clear association with brain tumor risk. Conclusion: Higher BMI was associated with an increased risk of brain tumor, in particular of meningioma, and among men.Full article has been published annals of epidemiology.