Gallstones and incident colorectal cancer in a large pan-European cohort study

Gallstones, a common gastrointestinal condition, can lead to several digestive complications and can result in inflammation. Risk factors for gallstones include obesity, diabetes, smoking and physical inactivity, all of which are known risk factors for colorectal cancer (CRC), as is inflammation. However, it is unclear whether gallstones are a risk factor for CRC. We examined the association between history of gallstones and CRC in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, a prospective cohort of over half a million participants from ten European countries. History of gallstones was assessed at baseline using a self-reported questionnaire. The analytic cohort included 334,986 participants; a history of gallstones was reported by 3,917 men and 19,836 women, and incident CRC was diagnosed among 1,832 men and 2,178 women (mean follow-up: 13.6 years). Hazard ratios (HR) and 95% confidence intervals (CI) for the association between gallstones and CRC were estimated using Cox proportional hazards regression models, stratified by sex, study centre and age at recruitment. The models were adjusted for body mass index, diabetes, alcohol intake and physical activity. A positive, marginally significant association was detected between gallstones and CRC among women in multivariable analyses (HR = 1.14, 95%CI 0.99-1.31, p = 0.077). The relationship between gallstones and CRC among men was inverse but not significant (HR = 0.81, 95%CI 0.63-1.04, p = 0.10). Additional adjustment for details of reproductive history or waist circumference yielded minimal changes to the observed associations. Further research is required to confirm the nature of the association between gallstones and CRC by sex.

DNA methylation, colon cancer and Mediterranean diet: results from the EPIC-Italy cohort

The biological mechanisms through which adherence to Mediterranean Diet (MD) protects against colon cancer (CC) are poorly understood. Evidence suggests that chronic inflammation may be implicated in the pathway. Both diet and CC are related to epigenetic regulation. We performed a nested case-control study on 161 pairs from the Italian component of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, in which we looked for the methylation signals in DNA extracted from leucocytes associated with both CC and MD in 995 CpGs located in 48 inflammation genes. The DNA methylation signals detected in this analysis were validated in a subgroup of 47 case-control pairs and further replicated (where validated) in 95 new pairs by means of pyrosequencing. Among the CpG sites selected a-priori in inflammation-related genes, seven CpG sites were found to be associated with CC status and with MD, in line with its protective effect. Only two CpG sites (cg17968347-SERPINE1 and cg20674490-RUNX3) were validated using bisulphite pyrosequencing and, after replication, we found that DNA methylation of cg20674490-RUNX3 may be a potential molecular mediator explaining the protective effect of MD on CC onset. The use of a 'meet-in-the-middle' approach to identify the overlap between exposure and predictive markers of disease is innovative in studies on the relationship between diet and cancer, in which exposure assessment is difficult and the mechanisms through which the nutrients exert their protective effect is largely unknown.

Socioeconomic Effect of Education on Pancreatic Cancer Risk in Western Europe: An Update on the EPIC Cohorts Study

BACKGROUND

To analyze the potential effect of social inequality on pancreatic cancer risk in Western Europe, by reassessing the association within the European Prospective Investigation into Cancer and Nutrition (EPIC) Study, including a larger number of cases and an extended follow-up.

METHODS

Data on highest education attained were gathered for 459,170 participants (70% women) from 10 European countries. A relative index of inequality (RII) based on adult education was calculated for comparability across countries and generations. Cox regression models were applied to estimate relative inequality in pancreatic cancer risk, stratifying by age, gender, and center, and adjusting for known pancreatic cancer risk factors.

RESULTS

A total of 1,223 incident pancreatic cancer cases were included after a mean follow-up of 13.9 (±4.0) years. An inverse social trend was found in models adjusted for age, sex, and center for both sexes [HR of RII, 1.27; 95% confidence interval (CI), 1.02-1.59], which was also significant among women (HR, 1.42; 95% CI, 1.05-1.92). Further adjusting by smoking intensity, alcohol consumption, body mass index, prevalent diabetes, and physical activity led to an attenuation of the RII risk and loss of statistical significance.

CONCLUSIONS

The present reanalysis does not sustain the existence of an independent social inequality influence on pancreatic cancer risk in Western European women and men, using an index based on adult education, the most relevant social indicator linked to individual lifestyles, in a context of very low pancreatic cancer survival from (quasi) universal public health systems.

IMPACT

The results do not support an association between education and risk of pancreatic cancer.

Heterogeneity of Colorectal Cancer Risk Factors by Anatomical Subsite in 10 European Countries: A Multinational Cohort Study

BACKGROUND & AIMS

Colorectal cancer located at different anatomical subsites may have distinct etiologies and risk factors. Previous studies that have examined this hypothesis have yielded inconsistent results, possibly because most studies have been of insufficient size to identify heterogeneous associations with precision.

METHODS

In the European Prospective Investigation into Cancer and Nutrition study, we used multivariable joint Cox proportional hazards models, which accounted for tumors at different anatomical sites (proximal colon, distal colon, and rectum) as competing risks, to examine the relationships between 14 established/suspected lifestyle, anthropometric, and reproductive/menstrual risk factors with colorectal cancer risk. Heterogeneity across sites was tested using Wald tests.

RESULTS

After a median of 14.9 years of follow-up of 521,330 men and women, 6291 colorectal cancer cases occurred. Physical activity was related inversely to proximal colon and distal colon cancer, but not to rectal cancer (P heterogeneity = .03). Height was associated positively with proximal and distal colon cancer only, but not rectal cancer (P heterogeneity = .0001). For men, but not women, heterogeneous relationships were observed for body mass index (P heterogeneity = .008) and waist circumference (P heterogeneity = .03), with weaker positive associations found for rectal cancer, compared with proximal and distal colon cancer. Current smoking was associated with a greater risk of rectal and proximal colon cancer, but not distal colon cancer (P heterogeneity = .05). No heterogeneity by anatomical site was found for alcohol consumption, diabetes, nonsteroidal anti-inflammatory drug use, and reproductive/menstrual factors.

CONCLUSIONS

The relationships between physical activity, anthropometry, and smoking with colorectal cancer risk differed by subsite, supporting the hypothesis that tumors in different anatomical regions may have distinct etiologies.

Dietary cadmium and risk of breast cancer subtypes defined by hormone receptor status: A prospective cohort study

Diet is the primary source of cadmium-a proven Group 1 human carcinogen-for non-smokers. Observational studies investigating the effect of cadmium from food sources on breast cancer risk have produced inconsistent results. We examined the association between dietary cadmium and risk of breast cancer defined by estrogen receptor (ER), progesterone receptor (PR) and HER2 status, in 8924 women recruited to a prospective study between 1987 and 1992. Dietary cadmium intake was estimated using a semi-quantitative food frequency questionnaire at baseline. During a median of 22 years of follow-up, 451 incident cases of breast cancer were identified through the Varese Cancer Registry. Multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for breast cancer and receptor-defined breast cancer subtypes were estimated for quintiles of dietary cadmium intake, adjusting for confounding factors. Mean dietary cadmium intake was 7.8 (standard deviation 1.4) μg/day. Women with highest quintile of cadmium intake had a greater risk of breast cancer (HR 1.54; 95% CI, 1.06-2.22; p trend = 0.028) than those with lowest quintile of intake. Women premenopausal at recruitment had HR = 1.73 (95% CI, 1.10-2.71, highest vs. lowest quintile); postmenopausal women had HR = 1.32 (95% CI, 1.05-1.66 for each standard deviation increase in cadmium). Cadmium-related risk of breast cancer did not vary with ER, PR or HER2 status (p-heterogeneity not significant). These findings support the hypothesis that dietary cadmium is a risk factor for breast cancer.

Association between physical activity and risk of hepatobiliary cancers: A multinational cohort study

BACKGROUND & AIMS

To date, evidence on the association between physical activity and risk of hepatobiliary cancers has been inconclusive. We examined this association in the European Prospective Investigation into Cancer and Nutrition cohort (EPIC).

METHODS

We identified 275 hepatocellular carcinoma (HCC) cases, 93 intrahepatic bile duct cancers (IHBCs), and 164 non-gallbladder extrahepatic bile duct cancers (NGBCs) among 467,336 EPIC participants (median follow-up 14.9 years). We estimated cause-specific hazard ratios (HRs) for total physical activity and vigorous physical activity and performed mediation analysis and secondary analyses to assess robustness to confounding (e.g. due to hepatitis virus infection).

RESULTS

In the EPIC cohort, the multivariable-adjusted HR of HCC was 0.55 (95% CI 0.38-0.80) comparing active and inactive individuals. Regarding vigorous physical activity, for those reporting >2 hours/week compared to those with no vigorous activity, the HR for HCC was 0.50 (95% CI 0.33-0.76). Estimates were similar in sensitivity analyses for confounding. Total and vigorous physical activity were unrelated to IHBC and NGBC. In mediation analysis, waist circumference explained about 40% and body mass index 30% of the overall association of total physical activity and HCC.

CONCLUSIONS

These findings suggest an inverse association between physical activity and risk of HCC, which is potentially mediated by obesity.

LAY SUMMARY

In a pan-European study of 467,336 men and women, we found that physical activity is associated with a reduced risk of developing liver cancers over the next decade. This risk was independent of other liver cancer risk factors, and did not vary by age, gender, smoking status, body weight, and alcohol consumption.

Epigenome-wide association study for lifetime estrogen exposure identifies an epigenetic signature associated with breast cancer risk

BACKGROUND

It is well established that estrogens and other hormonal factors influence breast cancer susceptibility. We hypothesized that a woman's total lifetime estrogen exposure accumulates changes in DNA methylation, detectable in the blood, which could be used in risk assessment for breast cancer.

METHODS

An estimated lifetime estrogen exposure (ELEE) model was defined using epidemiological data from EPIC-Italy (n = 31,864). An epigenome-wide association study (EWAS) of ELEE was performed using existing Illumina HumanMethylation450K Beadchip (HM450K) methylation data obtained from EPIC-Italy blood DNA samples (n = 216). A methylation index (MI) of ELEE based on 31 CpG sites was developed using HM450K data from EPIC-Italy and the Generations Study and evaluated for association with breast cancer risk in an independent dataset from the Generations Study (n = 440 incident breast cancer cases matched to 440 healthy controls) using targeted bisulfite sequencing. Lastly, a meta-analysis was conducted including three additional cohorts, consisting of 1187 case-control pairs.

RESULTS

We observed an estimated 5% increase in breast cancer risk per 1-year longer ELEE (OR = 1.05, 95% CI 1.04-1.07, P = 3 × 10-12) in EPIC-Italy. The EWAS identified 694 CpG sites associated with ELEE (FDR Q < 0.05). We report a DNA methylation index (MI) associated with breast cancer risk that is validated in the Generations Study targeted bisulfite sequencing data (ORQ4_vs_Q1 = 1.77, 95% CI 1.07-2.93, P = 0.027) and in the meta-analysis (ORQ4_vs_Q1 = 1.43, 95% CI 1.05-2.00, P = 0.024); however, the correlation between the MI and ELEE was not validated across study cohorts.

CONCLUSION

We have identified a blood DNA methylation signature associated with breast cancer risk in this study. Further investigation is required to confirm the interaction between estrogen exposure and DNA methylation in the blood.

Circulating insulin-like growth factor I in relation to melanoma risk in the European prospective investigation into cancer and nutrition

Insulin-like growth factor-I (IGF-I) regulates cell proliferation and apoptosis, and is thought to play a role in tumour development. Previous prospective studies have shown that higher circulating concentrations of IGF-I are associated with a higher risk of cancers at specific sites, including breast and prostate. No prospective study has examined the association between circulating IGF-I concentrations and melanoma risk. A nested case-control study of 1,221 melanoma cases and 1,221 controls was performed in the European Prospective Investigation into Cancer and Nutrition cohort, a prospective cohort of 520,000 participants recruited from 10 European countries. Conditional logistic regression was used to estimate odds ratios (ORs) for incident melanoma in relation to circulating IGF-I concentrations, measured by immunoassay. Analyses were conditioned on the matching factors and further adjusted for age at blood collection, education, height, BMI, smoking status, alcohol intake, marital status, physical activity and in women only, use of menopausal hormone therapy. There was no significant association between circulating IGF-I concentration and melanoma risk (OR for highest vs lowest fifth = 0.93 [95% confidence interval [CI]: 0.71 to 1.22]). There was no significant heterogeneity in the association between IGF-I concentrations and melanoma risk when subdivided by gender, age at blood collection, BMI, height, age at diagnosis, time between blood collection and diagnosis, or by anatomical site or histological subtype of the tumour (Pheterogeneity≥0.078). We found no evidence for an association between circulating concentrations of IGF-I measured in adulthood and the risk of melanoma.

Long-term exposure to ambient air pollution and incidence of brain tumor: the European Study of Cohorts for Air Pollution Effects (ESCAPE)

Background

Epidemiological evidence on the association between ambient air pollution and brain tumor risk is sparse and inconsistent.

Methods

In 12 cohorts from 6 European countries, individual estimates of annual mean air pollution levels at the baseline residence were estimated by standardized land-use regression models developed within the ESCAPE and TRANSPHORM projects: particulate matter (PM) ≤2.5, ≤10, and 2.5–10 μm in diameter (PM_2.5, PM₁₀, and PM_coarse), PM_2.5 absorbance, nitrogen oxides (NO₂ and NO_x) and elemental composition of PM. We estimated cohort-specific associations of air pollutant concentrations and traffic intensity with total, malignant, and nonmalignant brain tumor, in separate Cox regression models, adjusting for risk factors, and pooled cohort-specific estimates using random-effects meta-analyses.

Results

Of 282194 subjects from 12 cohorts, 466 developed malignant brain tumors during 12 years of follow-up. Six of the cohorts also had data on nonmalignant brain tumor, where among 106786 subjects, 366 developed brain tumor: 176 nonmalignant and 190 malignant. We found a positive, statistically nonsignificant association between malignant brain tumor and PM_2.5 absorbance (hazard ratio and 95% CI: 1.67; 0.89–3.14 per 10^–5/m³), and weak positive or null associations with the other pollutants. Hazard ratio for PM_2.5 absorbance (1.01; 0.38–2.71 per 10^–5/m³) and all other pollutants were lower for nonmalignant than for malignant brain tumors.

Conclusion

We found suggestive evidence of an association between long-term exposure to PM_2.5 absorbance indicating traffic-related air pollution and malignant brain tumors, and no association with overall or nonmalignant brain tumors.

Coffee and tea consumption and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition

The epidemiological evidence regarding the association of coffee and tea consumption with prostate cancer risk is inconclusive, and few cohort studies have assessed these associations by disease stage and grade. We examined the associations of coffee (total, caffeinated and decaffeinated) and tea intake with prostate cancer risk in the European Prospective Investigation into Cancer and Nutrition. Among 142,196 men, 7,036 incident prostate cancer cases were diagnosed over 14 years of follow-up. Data on coffee and tea consumption were collected through validated country-specific food questionnaires at baseline. We used Cox proportional hazards regression models to compute hazard ratios (HRs) and 95% confidence intervals (CI). Models were stratified by center and age, and adjusted for anthropometric, lifestyle and dietary factors. Median coffee and tea intake were 375 and 106 mL/day, respectively, but large variations existed by country. Comparing the highest (median of 855 mL/day) versus lowest (median of 103 mL/day) consumers of coffee and tea (450 vs. 12 mL/day) the HRs were 1.02 (95% CI, 0.94-1.09) and 0.98 (95% CI, 0.90-1.07) for risk of total prostate cancer and 0.97 (95% CI, 0.79-1.21) and 0.89 (95% CI, 0.70-1.13) for risk of fatal disease, respectively. No evidence of association was seen for consumption of total, caffeinated or decaffeinated coffee or tea and risk of total prostate cancer or cancer by stage, grade or fatality in this large cohort. Further investigations are needed to clarify whether an association exists by different preparations or by concentrations and constituents of these beverages.

A prospective evaluation of plasma polyphenol levels and colon cancer risk

Polyphenols have been shown to exert biological activity in experimental models of colon cancer; however, human data linking specific polyphenols to colon cancer is limited. We assessed the relationship between pre-diagnostic plasma polyphenols and colon cancer risk in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition study. Using high pressure liquid chromatography coupled to tandem mass spectrometry, we measured concentrations of 35 polyphenols in plasma from 809 incident colon cancer cases and 809 matched controls. We used multivariable adjusted conditional logistic regression models that included established colon cancer risk factors. The false discovery rate (qvalues ) was computed to control for multiple comparisons. All statistical tests were two-sided. After false discovery rate correction and in continuous log2 -transformed multivariable models, equol (odds ratio [OR] per log2 -value, 0.86, 95% confidence interval [95% CI] = 0.79-0.93; qvalue  = 0.01) and homovanillic acid (OR per log2 -value, 1.46, 95% CI = 1.16-1.84; qvalue  = 0.02) were associated with colon cancer risk. Comparing extreme fifths, equol concentrations were inversely associated with colon cancer risk (OR = 0.61, 95% CI = 0.41-0.91, ptrend  = 0.003), while homovanillic acid concentrations were positively associated with colon cancer development (OR = 1.72, 95% CI = 1.17-2.53, ptrend  < 0.0001). No heterogeneity for these associations was observed by sex and across other colon cancer risk factors. The remaining polyphenols were not associated with colon cancer risk. Higher equol concentrations were associated with lower risk, and higher homovanillic acid concentrations were associated with greater risk of colon cancer. These findings support a potential role for specific polyphenols in colon tumorigenesis.

Air pollution and incidence of cancers of the stomach and the upper aerodigestive tract in the European Study of Cohorts for Air Pollution Effects (ESCAPE)

Air pollution has been classified as carcinogenic to humans. However, to date little is known about the relevance for cancers of the stomach and upper aerodigestive tract (UADT). We investigated the association of long-term exposure to ambient air pollution with incidence of gastric and UADT cancer in 11 European cohorts. Air pollution exposure was assigned by land-use regression models for particulate matter (PM) below 10 µm (PM10 ), below 2.5 µm (PM2.5 ), between 2.5 and 10 µm (PMcoarse ), PM2.5 absorbance and nitrogen oxides (NO2 and NOX ) as well as approximated by traffic indicators. Cox regression models with adjustment for potential confounders were used for cohort-specific analyses. Combined estimates were determined with random effects meta-analyses. During average follow-up of 14.1 years of 305,551 individuals, 744 incident cases of gastric cancer and 933 of UADT cancer occurred. The hazard ratio for an increase of 5 µg/m3 of PM2.5 was 1.38 (95% CI 0.99; 1.92) for gastric and 1.05 (95% CI 0.62; 1.77) for UADT cancers. No associations were found for any of the other exposures considered. Adjustment for additional confounders and restriction to study participants with stable addresses did not influence markedly the effect estimate for PM2.5 and gastric cancer. Higher estimated risks of gastric cancer associated with PM2.5 was found in men (HR 1.98 [1.30; 3.01]) as compared to women (HR 0.85 [0.5; 1.45]). This large multicentre cohort study shows an association between long-term exposure to PM2.5 and gastric cancer, but not UADT cancers, suggesting that air pollution may contribute to gastric cancer risk.

Perturbation of metabolic pathways mediates the association of air pollutants with asthma and cardiovascular diseases

BACKGROUND

Epidemiologic evidence indicates common risk factors, including air pollution exposure, for respiratory and cardiovascular diseases, suggesting the involvement of common altered molecular pathways.

OBJECTIVES

The goal was to find intermediate metabolites or metabolic pathways that could be associated with both air pollutants and health outcomes ("meeting-in-the-middle"), thus shedding light on mechanisms and reinforcing causality.

METHODS

We applied a statistical approach named 'meet-in-the-middle' to untargeted metabolomics in two independent case-control studies nested in cohorts on adult-onset asthma (AOA) and cardio-cerebrovascular diseases (CCVD). We compared the results to identify both common and disease-specific altered metabolic pathways.

RESULTS

A novel finding was a strong association of AOA with ultrafine particles (UFP; odds ratio 1.80 [1.26, 2.55] per increase by 5000 particles/cm3). Further, we have identified several metabolic pathways that potentially mediate the effect of air pollution on health outcomes. Among those, perturbation of Linoleate metabolism pathway was associated with air pollution exposure, AOA and CCVD.

CONCLUSIONS

Our results suggest common pathway perturbations may occur as a consequence of chronic exposure to air pollution leading to increased risk for both AOA and CCVD.

Impact of a Mediterranean Dietary Pattern and Its Components on Cardiovascular Risk Factors, Glucose Control, and Body Weight in People with Type 2 Diabetes: A Real-Life Study

This study evaluates the relation of a Mediterranean dietary pattern and its individual components with the cardiovascular risk factors profile, plasma glucose and body mass index (BMI) in people with type 2 diabetes. We studied 2568 participants at 57 diabetes clinics. Diet was assessed with the EPIC (European Prospective Investigation into Cancer and Nutrition) questionnaire, adherence to the Mediterranean diet was evaluated with the relative Mediterranean diet score (rMED). A high compared to a low score was associated with a better quality of diet and a greater adherence to the nutritional recommendations for diabetes. However, even in the group achieving a high score, only a small proportion of participants met the recommendations for fiber and saturated fat (respectively 17% and 30%). Nonetheless, a high score was associated with lower values of plasma lipids, blood pressure, glycated hemoglobin, and BMI. The relationship of the single food items components of the rMED score with the achievement of treatment targets for plasma lipids, blood pressure, glucose, and BMI were also explored. The study findings support the Mediterranean dietary model as a suitable model for type 2 diabetes and the concept that the beneficial health effects of the Mediterranean diet lie primarily in its synergy among various nutrients and foods rather than on any individual component.

Abstract 5316: DNA methylation index of lifetime estrogen exposure in breast cancer

Breast cancer is the most common female cancer worldwide and makes up 25% of all cancers diagnosed in women. There is a need for improved risk assessment methods to identify women at high risk before the disease develops. It is well established that estrogens are involved in estrogen receptor positive (ER+) breast cancer carcinogenesis, however the mechanisms are not fully understood. We hypothesize that lifetime estrogen exposure accumulates changes in DNA methylation detectable in blood as a surrogate for other tissues. Here, we have identified a methylation signature of estrogen exposure measured in blood DNA that could improve risk assessment for breast cancer.

Our Estimated Lifetime Estrogen Exposure (ELEE) model, taking into account reproductive time (age at menopause minus age at menarche), number of pregnancies and breastfeeding duration, shows a 5% increased risk of developing breast cancer per unit increase in ELEE (range 18 – 44) in the European Prospective into Cancer and Nutrition (EPIC)-Italy study cohort (30671 healthy controls, 1193 cases, age at diagnosis ≥ 50). An Epigenome-Wide Association Study (EWAS) of ELEE was conducted on 450K methylation data in EPIC-Italy (199 controls, 97 cases) and the Generations Study (GS) cohort (n=65 controls). For validation targeted bisulfite sequencing using the Fluidigm 48.48 Access Array was performed on independent DNA samples from the GS cohort (440 matched ER+ case-control pairs). The Methylation Index (MI) of ELEE was developed on 450K data using ridge regression and includes DNA methylation levels at selected CpG sites.

DNA methylation levels at 694 CpG sites show significant (false discovery rate q &lt; 0.05) association with ELEE in the EWAS and of these 42 CpG sites from the top-probes were selected for validation. The MI was developed on 28 CpG sites passing quality control and shows high correlation with ELEE in 450K training data (r=0.69) and significant association with breast cancer risk in EPIC-Italy with an OR of 1.38 per unit MI (range 24 – 43, 95% CI: 1.23 – 1.57, P=2.0E-07). Validation step is yet to be finalized; initial analysis on the first 318 case-control pairs suggests a modest but significant association with ER+ breast cancer risk (unadjusted OR=1.04 per unit MI, 95% CI: 1.00 – 1.07, P=0.030, MI range 20 – 53).

In summary, we show that changes in DNA methylation following estrogen exposure are detectable in blood and we have developed a Methylation Index of ELEE that is significantly increased in breast cancer cases compared to controls in EPIC-Italy, and modestly increased in the GS validation cohort. This molecular measure of estrogen exposure could potentially improve risk assessment methods and be used to identify women at high risk of developing breast cancer.

Citation Format: Annelie Johansson, Domenico Palli, Giovanna Masala, Sara Grioni, Claudia Agnoli, Rosario Tumino, Maria Concetta Giurdanella, Francesca Fasanelli, Carlotta Sacerdote, Salvatore Panico, Amalia Mattiello, Anthony Swerdlow, Minouk Schoemaker, Michael Jones, Nick Orr, Olivia Fletcher, Nichola Johnson, Katarzyna Tomczyk, Paolo Vineis, James M. Flanagan. DNA methylation index of lifetime estrogen exposure in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5316.

Interplay between genetic predisposition, macronutrient intake and type 2 diabetes incidence: analysis within EPIC-InterAct across eight European countries

AIMS/HYPOTHESIS

Gene-macronutrient interactions may contribute to the development of type 2 diabetes but research evidence to date is inconclusive. We aimed to increase our understanding of the aetiology of type 2 diabetes by investigating potential interactions between genes and macronutrient intake and their association with the incidence of type 2 diabetes.

METHODS

We investigated the influence of interactions between genetic risk scores (GRSs) for type 2 diabetes, insulin resistance and BMI and macronutrient intake on the development of type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct, a prospective case-cohort study across eight European countries (N = 21,900 with 9742 incident type 2 diabetes cases). Macronutrient intake was estimated from diets reported in questionnaires, including proportion of energy derived from total carbohydrate, protein, fat, plant and animal protein, saturated, monounsaturated and polyunsaturated fat and dietary fibre. Using multivariable-adjusted Cox regression, we estimated country-specific interaction results on the multiplicative scale, using random-effects meta-analysis. Secondary analysis used isocaloric macronutrient substitution.

RESULTS

No interactions were identified between any of the three GRSs and any macronutrient intake, with low-to-moderate heterogeneity between countries (I2 range 0-51.6%). Results were similar using isocaloric macronutrient substitution analyses and when weighted and unweighted GRSs and individual SNPs were examined.

CONCLUSIONS/INTERPRETATION

Genetic susceptibility to type 2 diabetes, insulin resistance and BMI did not modify the association between macronutrient intake and incident type 2 diabetes. This suggests that macronutrient intake recommendations to prevent type 2 diabetes do not need to account for differences in genetic predisposition to these three metabolic conditions.

Risk thresholds for alcohol consumption: combined analysis of individual-participant data for 599 912 current drinkers in 83 prospective studies

BACKGROUND

Low-risk limits recommended for alcohol consumption vary substantially across different national guidelines. To define thresholds associated with lowest risk for all-cause mortality and cardiovascular disease, we studied individual-participant data from 599 912 current drinkers without previous cardiovascular disease.

METHODS

We did a combined analysis of individual-participant data from three large-scale data sources in 19 high-income countries (the Emerging Risk Factors Collaboration, EPIC-CVD, and the UK Biobank). We characterised dose-response associations and calculated hazard ratios (HRs) per 100 g per week of alcohol (12·5 units per week) across 83 prospective studies, adjusting at least for study or centre, age, sex, smoking, and diabetes. To be eligible for the analysis, participants had to have information recorded about their alcohol consumption amount and status (ie, non-drinker vs current drinker), plus age, sex, history of diabetes and smoking status, at least 1 year of follow-up after baseline, and no baseline history of cardiovascular disease. The main analyses focused on current drinkers, whose baseline alcohol consumption was categorised into eight predefined groups according to the amount in grams consumed per week. We assessed alcohol consumption in relation to all-cause mortality, total cardiovascular disease, and several cardiovascular disease subtypes. We corrected HRs for estimated long-term variability in alcohol consumption using 152 640 serial alcohol assessments obtained some years apart (median interval 5·6 years [5th-95th percentile 1·04-13·5]) from 71 011 participants from 37 studies.

FINDINGS

In the 599 912 current drinkers included in the analysis, we recorded 40 310 deaths and 39 018 incident cardiovascular disease events during 5·4 million person-years of follow-up. For all-cause mortality, we recorded a positive and curvilinear association with the level of alcohol consumption, with the minimum mortality risk around or below 100 g per week. Alcohol consumption was roughly linearly associated with a higher risk of stroke (HR per 100 g per week higher consumption 1·14, 95% CI, 1·10-1·17), coronary disease excluding myocardial infarction (1·06, 1·00-1·11), heart failure (1·09, 1·03-1·15), fatal hypertensive disease (1·24, 1·15-1·33); and fatal aortic aneurysm (1·15, 1·03-1·28). By contrast, increased alcohol consumption was log-linearly associated with a lower risk of myocardial infarction (HR 0·94, 0·91-0·97). In comparison to those who reported drinking >0-≤100 g per week, those who reported drinking >100-≤200 g per week, >200-≤350 g per week, or >350 g per week had lower life expectancy at age 40 years of approximately 6 months, 1-2 years, or 4-5 years, respectively.

INTERPRETATION

In current drinkers of alcohol in high-income countries, the threshold for lowest risk of all-cause mortality was about 100 g/week. For cardiovascular disease subtypes other than myocardial infarction, there were no clear risk thresholds below which lower alcohol consumption stopped being associated with lower disease risk. These data support limits for alcohol consumption that are lower than those recommended in most current guidelines.

FUNDING

UK Medical Research Council, British Heart Foundation, National Institute for Health Research, European Union Framework 7, and European Research Council.

Inflammatory potential of the diet and risk of gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Background

Chronic inflammation plays a critical role in the pathogenesis of the 2 major types of gastric cancer. Several foods, nutrients, and nonnutrient food components seem to be involved in the regulation of chronic inflammation.

Objective

We assessed the association between the inflammatory potential of the diet and the risk of gastric carcinoma, overall and for the 2 major subsites: cardia cancers and noncardia cancers.

Design

A total of 476,160 subjects (30% men, 70% women) from the European Investigation into Cancer and Nutrition (EPIC) study were followed for 14 y, during which 913 incident cases of gastric carcinoma were identified, including 236 located in the cardia, 341 in the distal part of the stomach (noncardia), and 336 with overlapping or unknown tumor site. The dietary inflammatory potential was assessed by means of an inflammatory score of the diet (ISD), calculated with the use of 28 dietary components and their corresponding inflammatory scores. The association between the ISD and gastric cancer risk was estimated by HRs and 95% CIs calculated by multivariate Cox regression models adjusted for confounders.

Results

The inflammatory potential of the diet was associated with an increased risk of gastric cancer. The HR (95% CI) for each increase in 1 SD of the ISD were 1.25 (1.12, 1.39) for all gastric cancers, 1.30 (1.06, 1.59) for cardia cancers, and 1.07 (0.89, 1.28) for noncardia cancers. The corresponding values for the highest compared with the lowest quartiles of the ISD were 1.66 (1.26, 2.20), 1.94 (1.14, 3.30), and 1.07 (0.70, 1.70), respectively.

Conclusions

Our results suggest that low-grade chronic inflammation induced by the diet may be associated with gastric cancer risk. This pattern seems to be more consistent for gastric carcinomas located in the cardia than for those located in the distal stomach. This study is listed on the ISRCTN registry as ISRCTN12136108.

Oxidative stress and inflammation mediate the effect of air pollution on cardio- and cerebrovascular disease: A prospective study in nonsmokers

Air pollution is associated with a broad range of adverse health effects, including mortality and morbidity due to cardio- and cerebrovascular diseases (CCVD), but the molecular mechanisms involved are not entirely understood. This study aims to investigate the involvement of oxidative stress and inflammation in the causal chain, and to identify intermediate biomarkers that are associated retrospectively with the exposure and prospectively with the disease. We designed a case-control study on CCVD nested in a cohort of 18,982 individuals from the EPIC-Italy study. We measured air pollution, inflammatory biomarkers, and whole-genome DNA methylation in blood collected up to 17 years before the diagnosis. The study sample includes all the incident CCVD cases among former- and never-smokers, with available stored blood sample, that arose in the cohort during the follow-up. We identified enrichment of altered DNA methylation in "ROS/Glutathione/Cytotoxic granules" and "Cytokine signaling" pathways related genes, associated with both air pollution (multiple comparisons adjusted p for enrichment ranging from 0.01 to 0.03 depending on pollutant) and with CCVD risk (P = 0.04 and P = 0.03, respectively). Also, Interleukin-17 was associated with higher exposure to NO2 (P = 0.0004), NOx (P = 0.0005), and CCVD risk (OR = 1.79; CI 1.04-3.11; P = 0.04 comparing extreme tertiles). Our findings indicate that chronic exposure to air pollution can lead to oxidative stress, which in turn activates a cascade of inflammatory responses mainly involving the "Cytokine signaling" pathway, leading to increased risk of CCVD. Inflammatory proteins and DNA methylation alterations can be detected several years before CCVD diagnosis in blood samples, being promising preclinical biomarkers. Environ. Mol. Mutagen. 59:234-246, 2018. © 2017 Wiley Periodicals, Inc.

Consumption of fruits, vegetables and fruit juices and differentiated thyroid carcinoma risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Fruit and vegetable (F&V) intake is considered as probably protective against overall cancer risk, but results in previous studies are not consistent for thyroid cancer (TC). The purpose of this study is to examine the association between the consumption of fruits, vegetables, fruit juices and differentiated thyroid cancer risk within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The EPIC study is a cohort including over half a million participants, recruited between 1991 and 2000. During a mean follow-up of 14 years, 748 incident first primary differentiated TC cases were identified. F&V and fruit juice intakes were assessed through validated country-specific dietary questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression models adjusted for potential confounding factors. Comparing the highest versus lowest quartile of intake, differentiated TC risk was not associated with intakes of total F&V (HR: 0.89; 95% CI: 0.68-1.15; p-trend = 0.44), vegetables (HR: 0.89; 95% CI: 0.69-1.14; p-trend = 0.56), or fruit (HR: 1.00; 95% CI: 0.79-1.26; p-trend = 0.64). No significant association was observed with any individual type of vegetable or fruit. However, there was a positive borderline trend with fruit juice intake (HR: 1.23; 95% CI: 0.98-1.53; p-trend = 0.06). This study did not find any significant association between F&V intakes and differentiated TC risk; however a positive trend with fruit juice intake was observed, possibly related to its high sugar content.

Separate and combined associations of obesity and metabolic health with coronary heart disease: a pan-European case-cohort analysis

Aims

The hypothesis of 'metabolically healthy obesity' implies that, in the absence of metabolic dysfunction, individuals with excess adiposity are not at greater cardiovascular risk. We tested this hypothesis in a large pan-European prospective study.

Methods and results

We conducted a case-cohort analysis in the 520 000-person European Prospective Investigation into Cancer and Nutrition study ('EPIC-CVD'). During a median follow-up of 12.2 years, we recorded 7637 incident coronary heart disease (CHD) cases. Using cut-offs recommended by guidelines, we defined obesity and overweight using body mass index (BMI), and metabolic dysfunction ('unhealthy') as ≥ 3 of elevated blood pressure, hypertriglyceridaemia, low HDL-cholesterol, hyperglycaemia, and elevated waist circumference. We calculated hazard ratios (HRs) and 95% confidence intervals (95% CI) within each country using Prentice-weighted Cox proportional hazard regressions, accounting for age, sex, centre, education, smoking, diet, and physical activity. Compared with metabolically healthy normal weight people (reference), HRs were 2.15 (95% CI: 1.79; 2.57) for unhealthy normal weight, 2.33 (1.97; 2.76) for unhealthy overweight, and 2.54 (2.21; 2.92) for unhealthy obese people. Compared with the reference group, HRs were 1.26 (1.14; 1.40) and 1.28 (1.03; 1.58) for metabolically healthy overweight and obese people, respectively. These results were robust to various sensitivity analyses.

Conclusion

Irrespective of BMI, metabolically unhealthy individuals had higher CHD risk than their healthy counterparts. Conversely, irrespective of metabolic health, overweight and obese people had higher CHD risk than lean people. These findings challenge the concept of 'metabolically healthy obesity', encouraging population-wide strategies to tackle obesity.

Is There an Association Between Ambient Air Pollution and Bladder Cancer Incidence? Analysis of 15 European Cohorts

BACKGROUND

Ambient air pollution contains low concentrations of carcinogens implicated in the etiology of urinary bladder cancer (BC). Little is known about whether exposure to air pollution influences BC in the general population.

OBJECTIVE

To evaluate the association between long-term exposure to ambient air pollution and BC incidence.

DESIGN, SETTING, AND PARTICIPANTS

We obtained data from 15 population-based cohorts enrolled between 1985 and 2005 in eight European countries (N=303431; mean follow-up 14.1 yr). We estimated exposure to nitrogen oxides (NO2 and NOx), particulate matter (PM) with diameter <10μm (PM10), <2.5μm (PM2.5), between 2.5 and 10μm (PM2.5-10), PM2.5absorbance (soot), elemental constituents of PM, organic carbon, and traffic density at baseline home addresses using standardized land-use regression models from the European Study of Cohorts for Air Pollution Effects project.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used Cox proportional-hazards models with adjustment for potential confounders for cohort-specific analyses and meta-analyses to estimate summary hazard ratios (HRs) for BC incidence.

RESULTS AND LIMITATIONS

During follow-up, 943 incident BC cases were diagnosed. In the meta-analysis, none of the exposures were associated with BC risk. The summary HRs associated with a 10-μg/m3 increase in NO2 and 5-μg/m3 increase in PM2.5 were 0.98 (95% confidence interval [CI] 0.89-1.08) and 0.86 (95% CI 0.63-1.18), respectively. Limitations include the lack of information about lifetime exposure.

CONCLUSIONS

There was no evidence of an association between exposure to outdoor air pollution levels at place of residence and risk of BC.

PATIENT SUMMARY

We assessed the link between outdoor air pollution at place of residence and bladder cancer using the largest study population to date and extensive assessment of exposure and comprehensive data on personal risk factors such as smoking. We found no association between the levels of outdoor air pollution at place of residence and bladder cancer risk.

Long-Term Exposure to Ambient Air Pollution and Incidence of Postmenopausal Breast Cancer in 15 European Cohorts within the ESCAPE Project

BACKGROUND

Epidemiological evidence on the association between ambient air pollution and breast cancer risk is inconsistent.

OBJECTIVE

We examined the association between long-term exposure to ambient air pollution and incidence of postmenopausal breast cancer in European women.

METHODS

In 15 cohorts from nine European countries, individual estimates of air pollution levels at the residence were estimated by standardized land-use regression models developed within the European Study of Cohorts for Air Pollution Effects (ESCAPE) and Transport related Air Pollution and Health impacts – Integrated Methodologies for Assessing Particulate Matter (TRANSPHORM) projects: particulate matter (PM) ≤2.5μm, ≤10μm, and 2.5–10μm in diameter (PM2.5, PM10, and PMcoarse, respectively); PM2.5 absorbance; nitrogen oxides (NO2 and NOx); traffic intensity; and elemental composition of PM. We estimated cohort-specific associations between breast cancer and air pollutants using Cox regression models, adjusting for major lifestyle risk factors, and pooled cohort-specific estimates using random-effects meta-analyses.

RESULTS

Of 74,750 postmenopausal women included in the study, 3,612 developed breast cancer during 991,353 person-years of follow-up. We found positive and statistically insignificant associations between breast cancer and PM2.5 {hazard ratio (HR)=1.08 [95% confidence interval (CI): 0.77, 1.51] per 5 μg/m3}, PM10 [1.07 (95% CI: 0.89, 1.30) per 10 μg/m3], PMcoarse[1.20 (95% CI: 0.96, 1.49 per 5 μg/m3], and NO2 [1.02 (95% CI: 0.98, 1.07 per 10 μg/m3], and a statistically significant association with NOx [1.04 (95% CI: 1.00, 1.08) per 20 μg/m3, p=0.04].

CONCLUSIONS

We found suggestive evidence of an association between ambient air pollution and incidence of postmenopausal breast cancer in European women. https://doi.org/10.1289/EHP1742.

Dietary glycemic index, glycemic load, and cancer risk: results from the EPIC-Italy study

Factors linked to glucose metabolism are involved in the etiology of several cancers. High glycemic index (GI) or high glycemic load (GL) diets, which chronically raise postprandial blood glucose, may increase cancer risk by affecting insulin-like growth factor. We prospectively investigated cancer risk and dietary GI/GL in the EPIC-Italy cohort. After a median 14.9 years, 5112 incident cancers and 2460 deaths were identified among 45,148 recruited adults. High GI was associated with increased risk of colon and bladder cancer. High GL was associated with: increased risk of colon cancer; increased risk of diabetes-related cancers; and decreased risk of rectal cancer. High intake of carbohydrate from high GI foods was significantly associated with increased risk of colon and diabetes-related cancers, but decreased risk of stomach cancer; whereas high intake of carbohydrates from low GI foods was associated with reduced colon cancer risk. In a Mediterranean population with high and varied carbohydrate intake, carbohydrates that strongly raise postprandial blood glucose may increase colon and bladder cancer risk, while the quantity of carbohydrate consumed may be involved in diabetes-related cancers. Further studies are needed to confirm the opposing effects of high dietary GL on risks of colon and rectal cancers.

Coffee Drinking and Mortality in 10 European Countries: A Multinational Cohort Study

BACKGROUND

The relationship between coffee consumption and mortality in diverse European populations with variable coffee preparation methods is unclear.

OBJECTIVE

To examine whether coffee consumption is associated with all-cause and cause-specific mortality.

DESIGN

Prospective cohort study.

SETTING

10 European countries.

PARTICIPANTS

521 330 persons enrolled in EPIC (European Prospective Investigation into Cancer and Nutrition).

MEASUREMENTS

Hazard ratios (HRs) and 95% CIs estimated using multivariable Cox proportional hazards models. The association of coffee consumption with serum biomarkers of liver function, inflammation, and metabolic health was evaluated in the EPIC Biomarkers subcohort (n = 14 800).

RESULTS

During a mean follow-up of 16.4 years, 41 693 deaths occurred. Compared with nonconsumers, participants in the highest quartile of coffee consumption had statistically significantly lower all-cause mortality (men: HR, 0.88 [95% CI, 0.82 to 0.95]; P for trend < 0.001; women: HR, 0.93 [CI, 0.87 to 0.98]; P for trend = 0.009). Inverse associations were also observed for digestive disease mortality for men (HR, 0.41 [CI, 0.32 to 0.54]; P for trend < 0.001) and women (HR, 0.60 [CI, 0.46 to 0.78]; P for trend < 0.001). Among women, there was a statistically significant inverse association of coffee drinking with circulatory disease mortality (HR, 0.78 [CI, 0.68 to 0.90]; P for trend < 0.001) and cerebrovascular disease mortality (HR, 0.70 [CI, 0.55 to 0.90]; P for trend = 0.002) and a positive association with ovarian cancer mortality (HR, 1.31 [CI, 1.07 to 1.61]; P for trend = 0.015). In the EPIC Biomarkers subcohort, higher coffee consumption was associated with lower serum alkaline phosphatase; alanine aminotransferase; aspartate aminotransferase; γ-glutamyltransferase; and, in women, C-reactive protein, lipoprotein(a), and glycated hemoglobin levels.

LIMITATIONS

Reverse causality may have biased the findings; however, results did not differ after exclusion of participants who died within 8 years of baseline. Coffee-drinking habits were assessed only once.

CONCLUSION

Coffee drinking was associated with reduced risk for death from various causes. This relationship did not vary by country.

PRIMARY FUNDING SOURCE

European Commission Directorate-General for Health and Consumers and International Agency for Research on Cancer.