Relation between hysterectomy, oophorectomy and the risk of incident differentiated thyroid cancer: The E3N cohort.

BACKGROUND: Thyroid cancers are threefold more frequent in women than in men. A role of reproductive or hormonal factors has been suggested but with contradictory results. We investigated potential associations between history of hysterectomy, with or without oophorectomy, and history of benign gynaecological disease (uterine fibroids, endometriosis) and the incidence of differentiated thyroid cancer, in a large French prospective cohort. METHODS: A total of 89 340 women from the E3N cohort were followed up between 1990 and 2012. Gynaecological diseases treated by surgery were self-reported. Thyroid cancers were validated by histological reports. Time-dependent covariates included smoking status, BMI and history of benign thyroid disease. Cox proportional hazard models with age as timescale were used to estimate Hazard Ratios (HR) and 95% confidence intervals (CI). RESULTS: A total of 412 cases of thyroid cancer were diagnosed during follow-up. A history of hysterectomy was associated with an increased risk of differentiated thyroid cancer (adjusted HR=2.05; 95%CI: 1.65-2.55). The association was not altered after further adjustment for reproductive factors. Endometriosis, uterine polyps, ovarian cysts and oophorectomy without hysterectomy were not associated with the risk of thyroid cancer. A history of fibroids was also significantly related to the risk of thyroid cancer over the follow-up period (adjusted HR=1.91; 95%CI: 1.50-2.44) and the increased risk persisted after adjustment for history of hysterectomy. CONCLUSIONS: Women who had either a history of fibroids or hysterectomy had an increased risk of differentiated thyroid cancer. These findings suggest shared biological mechanisms between fibroids and thyroid cancer, which deserve to be further dissected.

Life course evolution of body size and breast cancer survival in the E3N cohort.

Although adult obesity has been associated with poor breast cancer survival, data on adiposity at different periods in life and its lifelong evolution are scarce. Our aims were to assess the associations between breast cancer survival and body size during childhood, puberty and early adulthood and body size trajectories from childhood to adulthood. Self-assessed body size at age 8, at puberty, at age 20-25 and at age 35-40 and trajectories of body size of 4,662 breast cancer survivors from the prospective E3N cohort were studied in relation to risk of death from any cause, death from breast cancer and second invasive cancer event using multivariate Cox regression models. Four trajectories of body size were identified (T1 "moderate increase," T2 "stable/low increase," T3 "increase at puberty" and T4 "constantly high"). Compared with stable body size, an increase in body size during adult life was associated with an increased risk of death from any cause (HR T1 vs. T2 = 1.27; 95% CI = 1.01-1.60) and an increased risk of second invasive cancer event (HR T1 vs. T2 = 1.25; 95% CI = 1.06-1.47). Silhouettes at various ages were not associated with survival. Our results suggest that the evolution of body size from childhood to adulthood has a long-term influence on breast cancer survival. Although these results need to be confirmed, this work sheds light on the need to combine lifelong approaches to current BMI to better identify breast cancer survivors who are at higher risk of recurrence or second primary cancer, or of death.

Influence of a cancer diagnosis on changes in fruit and vegetable consumption according to cancer site, stage at diagnosis and socioeconomic factors: Results from the large E3N-EPIC study.

Many studies have demonstrated that lifestyle factors, including diet, may influence cancer survival. The number of cancer survivors is increasing worldwide and little is known about long-term diet changes in people who had cancer. We studied 53,981 women from the prospective E3N-EPIC cohort study with available dietary data in 1993 and 2005, among whom 4,619 had a cancer diagnosis inbetween (including n = 2,699 breast cancers). We evaluated the potential impact of a cancer diagnosis (comparing women with cancer to women with no cancer) on changes in FV consumption using multivariable linear regression models considering cancer site, stage at diagnosis and socioeconomic factors. Compared to women with no cancer, a statistically significant increase in FV consumption (ß=+2.65%, [1.22-4.09]) was observed in women who had cancer, and this association appeared to be driven by breast cancer exclusively. The increase in FV consumption was larger in women who had an advanced stage of breast cancer (stages II-IV) (ß=+7.23%, [3.92-10.5]) than in women with stages 0-I (ß=+2.03%, [-0.20 to 4.26]). Women with no partner and no children were those having the highest increase in FV consumption (ß=+18.71%, [6.51-30.91]). These changes were only observed in specific SE groups. When considering adherence to guidelines, the proportion of women who consumed less than 7.5 portions a day in 1993 and more in 2005 was greater in women with advanced breast cancer. More research is now needed to understand how the inequities we observed impact the long-term health after cancer.

Socioeconomic status and the 25 × 25 risk factors as determinants of premature mortality: a multicohort study and meta-analysis of 1·7 million men and women.

BACKGROUND: In 2011, WHO member states signed up to the 25 × 25 initiative, a plan to cut mortality due to non-communicable diseases by 25% by 2025. However, socioeconomic factors influencing non-communicable diseases have not been included in the plan. In this study, we aimed to compare the contribution of socioeconomic status to mortality and years-of-life-lost with that of the 25 × 25 conventional risk factors. METHODS: We did a multicohort study and meta-analysis with individual-level data from 48 independent prospective cohort studies with information about socioeconomic status, indexed by occupational position, 25 × 25 risk factors (high alcohol intake, physical inactivity, current smoking, hypertension, diabetes, and obesity), and mortality, for a total population of 1 751 479 (54% women) from seven high-income WHO member countries. We estimated the association of socioeconomic status and the 25 × 25 risk factors with all-cause mortality and cause-specific mortality by calculating minimally adjusted and mutually adjusted hazard ratios [HR] and 95% CIs. We also estimated the population attributable fraction and the years of life lost due to suboptimal risk factors. FINDINGS: During 26·6 million person-years at risk (mean follow-up 13·3 years [SD 6·4 years]), 310 277 participants died. HR for the 25 × 25 risk factors and mortality varied between 1·04 (95% CI 0·98-1·11) for obesity in men and 2 ·17 (2·06-2·29) for current smoking in men. Participants with low socioeconomic status had greater mortality compared with those with high socioeconomic status (HR 1·42, 95% CI 1·38-1·45 for men; 1·34, 1·28-1·39 for women); this association remained significant in mutually adjusted models that included the 25 × 25 factors (HR 1·26, 1·21-1·32, men and women combined). The population attributable fraction was highest for smoking, followed by physical inactivity then socioeconomic status. Low socioeconomic status was associated with a 2·1-year reduction in life expectancy between ages 40 and 85 years, the corresponding years-of-life-lost were 0·5 years for high alcohol intake, 0·7 years for obesity, 3·9 years for diabetes, 1·6 years for hypertension, 2·4 years for physical inactivity, and 4·8 years for current smoking. INTERPRETATION: Socioeconomic circumstances, in addition to the 25 × 25 factors, should be targeted by local and global health strategies and health risk surveillance to reduce mortality. FUNDING: European Commission, Swiss State Secretariat for Education, Swiss National Science Foundation, the Medical Research Council, NordForsk, Portuguese Foundation for Science and Technology.

Determinants of folate and vitamin B12 plasma levels in the French E3N-EPIC cohort.

PURPOSE: Impaired B vitamin status has been identified as a risk factor for major chronic diseases. This study aims at examining the determinants of plasma folate and vitamin B12 concentrations, considering lifestyle factors and MTHFR polymorphisms. METHODS: A total of 988 women aged 40-65 years from the French E3N cohort were investigated. Intakes of folate and vitamin B12 were assessed using food frequency questionnaires, and plasma concentrations were measured by microbiological assay. Dietary scores were computed to summarize folate and vitamin B12 dietary sources. MTHFR-C677T and MTHFR-A1298C were determined by Kaspar assay. Pearson's partial correlation coefficients and multivariable linear regression models were used to assess correlations between main determinants and plasma folate and vitamin B12 levels. RESULTS: The partial correlation coefficient between dietary intakes and plasma folate was 0.19 (p value <0.001) and 0.08 (p value = 0.008) for vitamin B12. Dietary scores were the main determinant of B vitamin plasma concentrations with a percent change per unit increase of 12.64% (p value <0.001) for folate and 7.6% (p value <0.001) for vitamin B12. Homozygous (T/T) or heterozygous (C/T) women for MTHFR-C677T had lower plasma folate concentrations [C/T: -6.48% (p value = 0.038) and T/T: -15.89% (p value <0.001)] compared to women carrying the C/C genotype. Other determinants of B vitamin plasma concentration include: smoking status for folate, and age and hormone replacement therapy for vitamin B12. CONCLUSIONS: We confirmed previous findings on the role of diet as main determinant of folate and vitamin B12 plasma concentrations. However, the impact of genetic polymorphisms and lifestyle factors on plasma B vitamin concentrations should not be neglected.

Use of benzodiazepines and cardiovascular mortality in a cohort of women aged over 50 years.

PURPOSE: To assess the association between use of benzodiazepines (including the Z-drugs zopiclone and zolpidem) and cardiovascular mortality in women aged over 50 years. METHODS: We used data from the E3N cohort. Data self-reported in biennial questionnaires was matched with drug reimbursement and vital status/causes of death data. In Cox models, exposure to benzodiazepines was fitted using time-varying variables, the reference category being women with no benzodiazepine delivery since January 2004. RESULTS: Among 85,353 women born 1925-1950 and followed between 2004 and 2011, 506 cardiovascular deaths occurred. Exposure to benzodiazepines was associated with increased cardiovascular mortality when hazard ratios (HRs) were adjusted only for age (HRever use 1.65; 95% CI 1.39, 1.97), but not when further adjusted for antidepressant use (HRever use 1.15; 95% CI 0.94, 1.40), nor in the multivariable model (HRever use 0.93; 95% CI 0.75, 1.16). Exposure to hypnotic benzodiazepines remained associated with increased cardiovascular mortality (HRever use 1.23; 95% CI 1.01, 1.51), but with no consistent trend across duration/dose or time since last use, while exposure to anxiolytic benzodiazepines was not (HRever use 0.83; 95% CI 0.67, 1.02). CONCLUSION: In our study, adjustment for antidepressant use strongly attenuated any benzodiazepine-cardiovascular mortality association. Whether the modest association observed with hypnotic benzodiazepines is due to residual confounding deserves further investigation.

Patterns of Ultraviolet Radiation Exposure and Skin Cancer Risk: the E3N-SunExp Study.

BACKGROUND: While ultraviolet (UV) radiation exposure is a recognized risk factor for skin cancer, associations are complex and few studies have allowed a direct comparison of exposure profiles associated with cutaneous melanoma, basal-cell carcinoma (BCC), and squamous-cell carcinoma (SCC) within a single population. METHODS: We examined associations between UV exposures and skin cancer risk in a nested case-control study within E3N, a prospective cohort of 98,995 French women born in 1925-1950. In 2008, a lifetime UV exposure questionnaire was sent to all reported skin cancer cases and three controls per case, which were matched on age, county of birth, and education. Analyses were performed using conditional logistic regression and included 366 melanoma cases, 1,027 BCC cases, 165 SCC cases, and 3,647 controls. RESULTS: A history of severe sunburns <25 years was associated with increased risks of all skin cancers (melanoma: OR 2.7; BCC: OR 1.7; SCC: OR 2.0 for ≥6 sunburns vs. none), while sunburns ≥25 years were associated with BCC and SCC only. While high-sun protection factor sunscreen use before age 25 was associated with lower BCC risk (Ptrend = 0.02), use since age 25 and reapplication of sunscreen were associated with higher risks of all three types of skin cancer. There were positive linear associations between total UV score and risks of BCC (Ptrend = 0.01) and SCC (Ptrend = 0.09), but not melanoma. While recreational UV score was strongly associated with BCC, total and residential UV scores were more strongly associated with SCC. CONCLUSIONS: Melanoma, BCC, and SCC are associated with different sun exposure profiles in women.

Socio-economic factors associated with an increase in fruit and vegetable consumption: a 12-year study in women from the E3N-EPIC study.

OBJECTIVE: To identify individual and contextual socio-economic factors associated with an increase in fruit and vegetable (F&V) consumption over a 12-year period and evaluate if some socio-economic factors were differentially associated with the change in consumption of some types of F&V. DESIGN: Associations between increased F&V consumption and socio-economic factors were studied with multivariate logistic regression. SETTING: E3N, a French prospective cohort study of 98 995 women. SUBJECTS: E3N participants (n 58 193) with information on diet in 1993 and 2005, and numerous individual and contextual socio-economic factors available. RESULTS: Associations between some individual socio-economic factors and changes in F&V consumption were observed. For instance, women who lived in a large household (>3 children v. no child) had higher probability of increasing their vegetable consumption (OR=1·33; 95 % CI 1·24, 1·42). This association was driven by higher consumption of courgette and raw cucumber. Living with a partner was associated with higher odds of increasing consumption of fruits (OR=1·07; 95 % CI 1·02, 1·13) such as pear, peach and grape. CONCLUSIONS: Certain individual socio-economic factors, but none of the contextual socio-economic factors examined, were associated with an increase in F&V consumption. Factors associated with an increase in total F&V consumption were not necessarily associated with an increase in fruit or vegetable consumption separately, or with an increase in each subtype of fruit or vegetable. Magnitudes of the different associations observed also differed when F&V were considered together, separately or by subtype. Increases in F&V consumption were mostly observed in women with high socio-economic position. To develop effective nutritional interventions and policies that take the socio-economic environment of individuals into account, we recommend future research to further focus on (i) pathways through which population characteristics might influence changes in F&V consumption and (ii) existing interactions between individual and contextual socio-economic factors.

Time-Dependent Associations Between Body Composition, Physical Activity, and Current Asthma in Women: A Marginal Structural Modeling Analysis.

The role of obesity in adult asthma is well-known and has been partly attributed to a confounding role of physical inactivity. However, the interrelationships between obesity, physical activity, and asthma have been incompletely addressed, probably because their time-dependent and bidirectional nature represents a methodologically challenging research question. We aimed to estimate the independent causal effects of body mass index (BMI; weight (kg)/height (m)2) and physical activity on current asthma using marginal structural models (MSMs). MSMs were applied to 15,353 adult women from a 2011 case-control study of asthma (Asthma-E3N) nested within the French E3N study (Etude Epidémiologique auprès de Femmes de la Mutuelle Générale de l'Education Nationale). Three time periods (1997-2000-2002, 2000-2002-2005, and 2002-2005-2011) were defined, where exposures (BMI and physical activity) were measured at time t, outcome (current asthma) was measured at time t + 1, and covariates were measured at time t - 1 or at baseline. A strong significant and positive dose-response relationship between BMI and current asthma was observed (odds ratios were 0.90 (95% confidence interval (CI): 0.79, 1.03), 1.29 (95% CI: 1.17, 1.42), and 1.87 (95% CI: 1.60, 2.18) for the BMI groups <20.0, 25.0-29.9, and ≥30.0, respectively, versus the normal-weight group (BMI 20.0-24.9)). We found no association between physical activity and current asthma. Our results suggest an independent causal deleterious effect of overweight and obesity on current asthma, whereas no independent causal effect of physical activity was found.

Associations between serum lipids and breast cancer incidence and survival in the E3N prospective cohort study.

PURPOSE: Several mechanistic studies support a role of cholesterol or its metabolites in breast cancer etiology, but associations have been inconsistent in epidemiological studies. In observational studies, possible reverse causation must be accounted for using a prospective design. We investigated prospective associations between pre-diagnostic serum lipid concentrations [total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides], and both breast cancer risk and survival in the E3N cohort study. METHODS: Analyses were performed on 583 cases from the E3N prospective cohort diagnosed between 1994 and 2005, and 1,043 controls matched on date, age, recruitment center and menopausal status at blood collection. Odds ratios (OR) and 95% confidence intervals were estimated using conditional logistic regression. Risks of recurrence were estimated among cases using Cox proportional hazards model. Models were adjusted for lifestyle risk factors and mutually adjusted for lipid concentrations. Survival analyses were additionally adjusted for tumor characteristics. RESULTS: Overall, there was no association between any serum lipid and breast cancer risk or survival. In stratified analyses, statistically significant interaction was observed between TC and menopausal status (P interaction = 0.05) and between TC and waist circumference (P interaction = 0.03), although the ORs did not reach statistical significance in any of the strata. There was no statistically significant effect modification by BMI, time between blood donation and diagnosis or ER status. CONCLUSIONS: Our results suggest that serum lipids are not associated with breast cancer risk overall, but that menopausal status and waist circumference should be considered in further studies.

Nevi, Ambient Ultraviolet Radiation, and Thyroid Cancer Risk: A French Prospective Study.

BACKGROUND: Incidence rates have increased considerably worldwide for both differentiated thyroid cancer and cutaneous melanoma, and two-way associations between these neoplasms have been described. Whether melanoma risk factors are associated with thyroid cancer risk remains unknown. METHODS: Using Cox regression modeling, we prospectively analyzed the relationship between self-reported pigmentary traits, baseline residential ultraviolet (UV) exposure, and thyroid cancer risk in 86,960 women from the E3N cohort, followed-up over 1990-2008 through biennial questionnaires. We assessed associations of pigmentary traits and UV exposure with personal history of benign thyroid diseases using logistic regression modeling. All statistical tests were two sided. RESULTS: In models adjusted for age and thyroid cancer risk factors, number of nevi was positively associated with thyroid cancer risk ("very many" vs. "none": hazards ratio [HR] = 1.7, 95% confidence interval [CI] = 1.0, 2.8; Ptrend = 0.01), independently of residential UV exposure or iodine intake. Risk was inversely associated with latitude and positively associated with mean daily UV level at baseline (HRs for the fourth vs. first quartile of latitude and spring/summer UVB level = 0.7, 95% CI = 0.5, 0.9; Ptrend = 0.03, and HR = 1.9, 95% CI = 1.4, 2.7; Ptrend = 0.02, respectively); associations were restricted to women with dietary iodine below the median intake. Number of nevi and UV level were also associated with personal histories of dysthyroidism and of goiter/nodules, although more weakly so. CONCLUSIONS: Our results suggest that number of nevi and residential UV exposure are associated with the risks of thyroid cancer and benign conditions. They point to novel pathways in thyroid cancer or melanoma etiologies and warrant replication.

Accuracy of two geocoding methods for geographic information system-based exposure assessment in epidemiological studies.

BACKGROUND: Environmental exposure assessment based on Geographic Information Systems (GIS) and study participants' residential proximity to environmental exposure sources relies on the positional accuracy of subjects' residences to avoid misclassification bias. Our study compared the positional accuracy of two automatic geocoding methods to a manual reference method. METHODS: We geocoded 4,247 address records representing the residential history (1990-2008) of 1,685 women from the French national E3N cohort living in the Rhône-Alpes region. We compared two automatic geocoding methods, a free-online geocoding service (method A) and an in-house geocoder (method B), to a reference layer created by manually relocating addresses from method A (method R). For each automatic geocoding method, positional accuracy levels were compared according to the urban/rural status of addresses and time-periods (1990-2000, 2001-2008), using Chi Square tests. Kappa statistics were performed to assess agreement of positional accuracy of both methods A and B with the reference method, overall, by time-periods and by urban/rural status of addresses. RESULTS: Respectively 81.4% and 84.4% of addresses were geocoded to the exact address (65.1% and 61.4%) or to the street segment (16.3% and 23.0%) with methods A and B. In the reference layer, geocoding accuracy was higher in urban areas compared to rural areas (74.4% vs. 10.5% addresses geocoded to the address or interpolated address level, p < 0.0001); no difference was observed according to the period of residence. Compared to the reference method, median positional errors were 0.0 m (IQR = 0.0-37.2 m) and 26.5 m (8.0-134.8 m), with positional errors <100 m for 82.5% and 71.3% of addresses, for method A and method B respectively. Positional agreement of method A and method B with method R was 'substantial' for both methods, with kappa coefficients of 0.60 and 0.61 for methods A and B, respectively. CONCLUSION: Our study demonstrates the feasibility of geocoding residential addresses in epidemiological studies not initially recorded for environmental exposure assessment, for both recent addresses and residence locations more than 20 years ago. Accuracy of the two automatic geocoding methods was comparable. The in-house method (B) allowed a better control of the geocoding process and was less time consuming.

Socio-economic factors associated with a healthy diet: results from the E3N study.

OBJECTIVE: To identify individual and contextual socio-economic factors associated with a healthy diet. DESIGN: Dietary data from a large cohort study were used to derive two mutually exclusive dietary patterns through a latent class analysis. Associations between dietary patterns and socio-economic factors were studied with logistic regression. SETTING: E3N, a French prospective cohort study composed of women recruited from a national health insurance plan covering people working in the national education system. SUBJECTS: E3N participants (n 73 031) with dietary and socio-economic data available. RESULTS: The 'Healthy' pattern was characterized by a large consumption of fruits and vegetables and the 'Less Healthy' pattern by a large consumption of pizza and processed meat. When all socio-economic factors were analysed together, all of the individual factors considered were associated with a healthy diet (e.g. women with three or more children were less likely to follow a healthy diet v. women with no children, OR (95 % CI): 0·70 (0·66, 0·75)) while the contextual factors associated with a healthy diet included the size of the agglomeration of residence and the area of birth and residence (e.g. women living in the West of France were less likely to follow a healthy diet v. those living in the South of France: 0·78 (0·72, 0·83)). CONCLUSIONS: We demonstrated that individual and contextual factors are both associated with diet. Rather than focusing only on individual factors, we recommend future studies or public health and nutritional strategies on diet to consider both types of factors.

Chronic Consumption of Artificial Sweetener in Packets or Tablets and Type 2 Diabetes Risk: Evidence from the E3N-European Prospective Investigation into Cancer and Nutrition Study.

BACKGROUND: The influence of artificial sweeteners on metabolic diseases is controversial. Artificially sweetened beverages have been associated with an increased risk of type 2 diabetes (T2D) but biases and reverse causation have been suspected to have influenced the observed association. In addition, it has been suggested that investigation into the relationship between the frequency and duration of the consumption of packet or tablet artificial sweeteners and T2D risk is necessary. METHODS: We used data from 61,440 women in the prospective E3N-European Prospective Investigation into Cancer and Nutrition study, conducted between 1993 and 2011. We estimated hazards ratios (HRs) and 95% CIs of T2D risk associated with both the frequency and the duration of use of artificial sweeteners consumed in packets or tablets. RESULTS: Compared to "never or rare" consumers of artificial sweeteners, those using them "always or almost always" had an increased risk of T2D (HR = 1.83 [95% CI 1.66-2.02] in the multivariate model [MM], HR = 1.33 [95% CI 1.20-1.47] when further adjusted for body mass index, BMI). Women consuming artificial sweeteners in packets or tablets for more than 10 years also had an increased risk of T2D compared to never or rare users (HR = 2.10 [95% CI 1.83-2.40] in the MM and HR = 1.15 [95% CI 1.00-1.33] when adjusted for BMI, respectively). CONCLUSIONS: Our data suggest that both a higher frequency and a longer consumption of artificial sweeteners in packets or tablets was associated with T2D risk, independently of major T2D risk factors, but partially mediated by adiposity. A precautionary principle should be applied to the promotion of these products that are still largely recommended as healthy sugar substitutes.

Validity and reproducibility of a short food frequency questionnaire among patients with chronic kidney disease.

BACKGROUND: A balanced diet is essential to slowing the progression of chronic kidney disease (CKD) and managing the symptoms. Currently, no tool is available to easily and quickly assess energy and macronutrient intake in patients with non end-stage CKD. We aimed to develop and evaluate the validity and reproducibility of a new short 49-item food frequency questionnaire (SFFQ) adapted to patients with CKD. METHODS: The CKD-REIN study is a prospective cohort that enrolled 3033 patients with moderate or advanced CKD from a national sample of nephrology clinics. A sub-sample of 201 patients completed the SFFQ twice, at a one-year interval and were included in the reproducibility study. During this interval, 127 patients also completed six 24-h recalls and were included in the validity study. Main nutrient and dietary intakes were computed. Validity was evaluated by calculating crude, energy-adjusted and de-attenuated correlation coefficients (CC) between FFQ and the mean of the 24-h recall results. Bland-Altman plots were performed and cross-classification into quintiles of consumption of each nutrient and food group was computed. Reproducibility between the two SFFQs was evaluated by intraclass CC (ICC). RESULTS: Regarding validity, CC ranged from 0.05 to 0.79 (unadjusted CC, median: 0.40) and 0.10 to 0.59 (de-attenuated CC, median: 0.35) for food group and nutrient intakes, respectively. Five of the most important nutrients of interest in CKD, i.e. protein, calcium, phosphorus, potassium, and sodium had de-attenuated CC of 0.46, 0.43, 0.39, 0.32, and 0.12, respectively. The median of classification into the same or adjacent quintiles was 68% and 65% for food and nutrient intakes, respectively, and ranged from 63% to 69% for the five nutrients mentioned before. Bland-Altman plots showed good agreement across the range of intakes. ICC ranged from 0.18 to 0.66 (median: 0.46). CONCLUSIONS: The CKD-REIN SFFQ showed acceptable validity and reproducibility in a sample of patients with CKD, notably for CKD nutrients of importance. It can now be used in large-scale epidemiological studies to easily assess the relations between diet and CKD outcomes as well as in clinical routine. It may also serve as a basis for the development of FFQs in international CKD cohort networks.

Ability of ecological deprivation indices to measure social inequalities in a French cohort.

BACKGROUND: Despite the increasing interest in place effect to explain health inequalities, there is currently no consensus on which kind of area-based socioeconomic measures researchers should use to assess neighborhood socioeconomic position (SEP). The study aimed to evaluate the reliability of different area-based deprivation indices (DIs) in capturing socioeconomic residential conditions of French elderly women cohort. METHODS: We assessed area-based SEP using 3 DIs: Townsend Index, French European Deprivation Index (FEDI) and French Deprivation index (FDep), among women from E3N (Etude épidémiologique auprès des femmes de la Mutuelle Générale de l'Education Nationale). DIs were derived from the 2009 French census at IRIS level (smallest geographical units in France). Educational level was used to evaluate individual-SEP. To evaluate external validity of the 3 DIs, associations between two well-established socially patterned outcomes among French elderly women (smoking and overweight) and SEP, were compared. Odd ratios were computed with generalized estimating equations to control for clustering effects from participants within the same IRIS. RESULTS: The analysis was performed among 63,888 women (aged 64, 47% ever smokers and 30% overweight). Substantial agreement was observed between the two French DIs (Kappa coefficient = 0.61) and between Townsend and FEDI (0.74) and fair agreement between Townsend and FDep (0.21). As expected among French elderly women, those with lower educational level were significantly less prone to be ever smoker (Low vs. High; OR [95% CI] = 0.43 [0.40-0.46]) and more prone to being overweight (1.89 [1.77-2.01]) than women higher educated. FDep showed expected associations at area-level for both smoking (most deprived vs. least deprived quintile; 0.77 [0.73-0.81]) and overweight (1.52 [1.44-1.62]). For FEDI opposite associations with smoking (1.13 [1.07-1.19]) and expected association with overweight (1.20 [1.13-1.28]) were observed. Townsend showed opposite associations to those expected for both smoking and overweight (1.51 [1.43-1.59]; 0.93 [0.88-0.99], respectively). CONCLUSION: FDep seemed reliable to capture socioeconomic residential conditions of the E3N women, more educated in average than general French population. Results varied strongly according to the DI with unexpected results for some of them, which suggested the importance to test external validity before studying social disparities in health in specific populations.

Postmenopausal breast cancer risk and interactions between body mass index, menopausal hormone therapy use, and vitamin D supplementation: Evidence from the E3N cohort.

Experimental studies suggest protective effects of vitamin D on breast carcinogenesis, but epidemiological evidence is not conclusive. Body mass index (BMI) has been shown to modulate the effect of supplementation on the vitamin D status, but its potential influence on the relationship with breast cancer risk has been little studied. We investigated a potential interaction between BMI and vitamin D supplementation on breast cancer risk while considering an already reported interaction between vitamin D supplementation and menopausal hormone therapy (MHT) use. Vitamin D supplementation was prospectively investigated in 57,403 postmenopausal women from the French E3N cohort including 2,482 incident breast cancer cases diagnosed between 1995 and 2008. Multivariable hazard ratios (HR) for primary invasive breast cancer and 95% confidence intervals (CI) were estimated using Cox models. Among MHT ever users, vitamin D supplementation was associated with decreased breast cancer risk, similarly across BMI strata (Phomogeneity = 0.83). Among MHT never users, ever vitamin D supplementation was associated with increased postmenopausal breast cancer risk in women with baseline BMI <25 kg/m(2) (HR = 1.51, 95% CI: 1.13, 2.02), but not in women with higher BMI (0.98, 95% CI: 0.62, 1.56), Phomogeneity = 0.12. In conclusion, our findings suggest that vitamin D supplementation may reduce the excess breast cancer risk in MHT users, but draw attention on a potential risk in postmenopausal women not exposed to high exogenous or endogenous hormones, i.e. non-overweight MHT-non users, especially in the present context of increasing vitamin D supplement use and decreasing MHT use.

Prediagnostic body size and breast cancer survival in the E3N cohort study.

Obesity has been associated with poor breast cancer prognosis, however most studies have focused on body mass index (BMI) and few have considered the distribution of adipose tissue. We investigated associations between prediagnostic adiposity and breast cancer survival, considering BMI, waist and hip circumferences (WC and HC), and waist-to-hip ratio (WHR). Analyses included 3,006 women from the French E3N prospective cohort study diagnosed with primary invasive breast cancer between 1995 and 2008. We investigated overall, breast cancer-specific, and disease-free survival, overall and according to stage, menopausal and hormonal status and year of diagnosis, using Cox proportional hazard models adjusted for tumor characteristics and lifestyle risk factors. Women with a prediagnostic HC > 100 cm were at increased risk of death from all causes (hazard ratio (HR)>100 vs < 95 cm = 1.38, 95% Confidence Interval (CI) = 1.02-1.86, Ptrend = 0.02) and from breast cancer (HR>100 vs < 95 cm = 1.50, CI = 1.03-2.17, Ptrend = 0.03), and of second invasive cancer event (HR>100 vs < 95 cm = 1.36, CI = 1.11-1.67, Ptrend = 0.002), compared to those with HC <95 cm. Associations were stronger after adjustment for BMI. BMI, WC and WHR were not associated with survival after breast cancer. Our study underlines the importance of going beyond BMI when studying the association between adiposity and breast cancer survival. Further studies should be conducted to confirm our results on hip circumference.

Proportion of premenopausal and postmenopausal breast cancers attributable to known risk factors: Estimates from the E3N-EPIC cohort.

Breast cancer is the most frequently diagnosed cancer among women worldwide. Breast cancer risk factors have been widely explored individually; however, little is known about their combined impact. We included 67,634 women from the French E3N prospective cohort, aged 42-72 at baseline. During a 15-year follow-up period, 497 premenopausal and 3,138 postmenopausal invasive breast cancer cases were diagnosed. Population-attributable fractions (PAFs) were used to estimate cases proportions attributable to risk factors under hypothetical scenarios of lowest exposure. We examined overall premenopausal and postmenopausal invasive breast cancers and tumour subtypes (ER status and HER2 expression). Premenopausal breast cancer was not significantly attributable to non-behavioral (61.2%, -15.5 to 91.88%) nor to behavioral (39.9%, -71.0 to 93.9%) factors, contrary to postmenopausal breast cancer (41.9%, 4.5 to 68.7% and 53.5%, 12.8 to 78.7%, respectively). Individually, the highest statistically significant PAFs were obtained in premenopause for birth weight (33.6%, 5.7 to 56.6%) and age at menarche (19.8%, 5.2 to 33.6%) for non-behavioral factors and in postmenopause for history of benign breast diseases (14.9%, 11.6 to 18.0%) and age at menarche (9.7%, 3.9 to 15.5%) for non-behavioral factors and for body shape at menarche (17.1%, 9.7 to 24.3%), use of hormone replacement therapy (14.5%, 9.2 to 19.6%), dietary pattern (10.1%, 2.6 to 17.4%) and alcohol consumption (5.6%, 1.9 to 9.3%) for behavioral factors. These proportions were higher for ER+, HER2- and ER+/HER2- postmenopausal breast cancers. Our data support the hypothesis that in postmenopause, never starting unhealthy behaviors can reduce the number of diagnosed breast cancers.

Flavonoid and lignan intake and pancreatic cancer risk in the European prospective investigation into cancer and nutrition cohort.

Despite the potential cancer preventive effects of flavonoids and lignans, their ability to reduce pancreatic cancer risk has not been demonstrated in epidemiological studies. Our aim was to examine the association between dietary intakes of flavonoids and lignans and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. A total of 865 exocrine pancreatic cancer cases occurred after 11.3 years of follow-up of 477,309 cohort members. Dietary flavonoid and lignan intake was estimated through validated dietary questionnaires and the US Department of Agriculture (USDA) and Phenol Explorer databases. Hazard ratios (HR) and 95% confidence intervals (CIs) were calculated using age, sex and center-stratified Cox proportional hazards models, adjusted for energy intake, body mass index (BMI), smoking, alcohol and diabetes status. Our results showed that neither overall dietary intake of flavonoids nor of lignans were associated with pancreatic cancer risk (multivariable-adjusted HR for a doubling of intake = 1.03, 95% CI: 0.95-1.11 and 1.02; 95% CI: 0.89-1.17, respectively). Statistically significant associations were also not observed by flavonoid subclasses. An inverse association between intake of flavanones and pancreatic cancer risk was apparent, without reaching statistical significance, in microscopically confirmed cases (HR for a doubling of intake = 0.96, 95% CI: 0.91-1.00). In conclusion, we did not observe an association between intake of flavonoids, flavonoid subclasses or lignans and pancreatic cancer risk in the EPIC cohort.