Metabolically defined body size and body shape phenotypes and risk of postmenopausal breast cancer in the European Prospective Investigation into Cancer and Nutrition.

BACKGROUND: Excess body fatness and hyperinsulinemia are both associated with an increased risk of postmenopausal breast cancer. However, whether women with high body fatness but normal insulin levels or those with normal body fatness and high levels of insulin are at elevated risk of breast cancer is not known. We investigated the associations of metabolically defined body size and shape phenotypes with the risk of postmenopausal breast cancer in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition. METHODS: Concentrations of C-peptide-a marker for insulin secretion-were measured at inclusion prior to cancer diagnosis in serum from 610 incident postmenopausal breast cancer cases and 1130 matched controls. C-peptide concentrations among the control participants were used to define metabolically healthy (MH; in first tertile) and metabolically unhealthy (MU; >1st tertile) status. We created four metabolic health/body size phenotype categories by combining the metabolic health definitions with normal weight (NW; BMI < 25 kg/m2 , or WC < 80 cm, or WHR < 0.8) and overweight or obese (OW/OB; BMI ≥ 25 kg/m2 , or WC ≥ 80 cm, or WHR ≥ 0.8) status for each of the three anthropometric measures separately: (1) MHNW, (2) MHOW/OB, (3) MUNW, and (4) MUOW/OB. Conditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Women classified as MUOW/OB were at higher risk of postmenopausal breast cancer compared to MHNW women considering BMI (OR = 1.58, 95% CI = 1.14-2.19) and WC (OR = 1.51, 95% CI = 1.09-2.08) cut points and there was also a suggestive increased risk for the WHR (OR = 1.29, 95% CI = 0.94-1.77) definition. Conversely, women with the MHOW/OB and MUNW were not at statistically significant elevated risk of postmenopausal breast cancer risk compared to MHNW women. CONCLUSION: These findings suggest that being overweight or obese and metabolically unhealthy raises risk of postmenopausal breast cancer while overweight or obese women with normal insulin levels are not at higher risk. Additional research should consider the combined utility of anthropometric measures with metabolic parameters in predicting breast cancer risk.

Timing of HPV16-E6 antibody seroconversion before OPSCC: findings from the HPVC3 consortium.

BACKGROUND: Human papillomavirus type 16 (HPV16)-E6 antibodies are detectable in peripheral blood before diagnosis in the majority of HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), but the timing of seroconversion is unknown. PATIENTS AND METHODS: We formed the HPV Cancer Cohort Consortium which comprises nine population cohorts from Europe, North America and Australia. In total, 743 incident OPSCC cases and 5814 controls provided at least one pre-diagnostic blood sample, including 111 cases with multiple samples. Median time between first blood collection and OPSCC diagnosis was 11.4 years (IQR = 6-11 years, range = 0-40 years). Antibodies against HPV16-E6 were measured by multiplex serology (GST fusion protein based Luminex assay). RESULTS: HPV16-E6 seropositivity was present in 0.4% of controls (22/5814; 95% CI 0.2% to 0.6%) and 26.2% (195/743; 95% CI 23.1% to 29.6%) of OPSCC cases. HPV16-E6 seropositivity increased the odds of OPSCC 98.2-fold (95% CI 62.1-155.4) in whites and 17.2-fold (95% CI 1.7-170.5) in blacks. Seropositivity in cases was more frequent in recent calendar periods, ranging from 21.9% pre-1996 to 68.4% in 2005 onwards, in those with blood collection near diagnosis (lead time <5 years). HPV16-E6 seropositivity increased with lead time: 0.0%, 13.5%, 23.7%, and 38.9% with lead times of >30 years (N = 24), 20-30 years (N = 148), 10-20 years (N = 228), and <10 years (N = 301 cases) (p-trend < 0.001). Of the 47 HPV16-E6 seropositive cases with serially-collected blood samples, 17 cases seroconverted during follow-up, with timing ranging from 6 to 28 years before diagnosis. For the remaining 30 cases, robust seropositivity was observed up to 25 years before diagnosis. CONCLUSIONS: The immune response to HPV16-driven tumorigenesis is most often detectable several decades before OPSCC diagnosis. HPV16-E6 seropositive individuals face increased risk of OPSCC over several decades.

The role of plasma microseminoprotein-beta in prostate cancer: an observational nested case-control and Mendelian randomization study in the European prospective investigation into cancer and nutrition.

BACKGROUND: Microseminoprotein-beta (MSP), a protein secreted by the prostate epithelium, may have a protective role in the development of prostate cancer. The only previous prospective study found a 2% reduced prostate cancer risk per unit increase in MSP. This work investigates the association of MSP with prostate cancer risk using observational and Mendelian randomization (MR) methods. PATIENTS AND METHODS: A nested case-control study was conducted with the European Prospective Investigation into Cancer and Nutrition (EPIC) with 1871 cases and 1871 matched controls. Conditional logistic regression analysis was used to investigate the association of pre-diagnostic circulating MSP with risk of incident prostate cancer overall and by tumour subtype. EPIC-derived estimates were combined with published data to calculate an MR estimate using two-sample inverse-variance method. RESULTS: Plasma MSP concentrations were inversely associated with prostate cancer risk after adjusting for total prostate-specific antigen concentration [odds ratio (OR) highest versus lowest fourth of MSP = 0.65, 95% confidence interval (CI) 0.51-0.84, Ptrend = 0.001]. No heterogeneity in this association was observed by tumour stage or histological grade. Plasma MSP concentrations were 66% lower in rs10993994 TT compared with CC homozygotes (per allele difference in MSP: 6.09 ng/ml, 95% CI 5.56-6.61, r2=0.42). MR analyses supported a potentially causal protective association of MSP with prostate cancer risk (OR per 1 ng/ml increase in MSP for MR: 0.96, 95% CI 0.95-0.97 versus EPIC observational: 0.98, 95% CI 0.97-0.99). Limitations include lack of complete tumour subtype information and more complete information on the biological function of MSP. CONCLUSIONS: In this large prospective European study and using MR analyses, men with high circulating MSP concentration have a lower risk of prostate cancer. MSP may play a causally protective role in prostate cancer.

Germline BRCA2 K3326X and CHEK2 I157T mutations increase risk for sporadic pancreatic ductal adenocarcinoma.

Rare truncating BRCA2 K3326X (rs11571833) and pathogenic CHEK2 I157T (rs17879961) variants have previously been implicated in familial pancreatic ductal adenocarcinoma (PDAC), but not in sporadic cases. The effect of both mutations in important DNA repair genes on sporadic PDAC risk may shed light on the genetic architecture of this disease. Both mutations were genotyped in germline DNA from 2,935 sporadic PDAC cases and 5,626 control subjects within the PANcreatic Disease ReseArch (PANDoRA) consortium. Risk estimates were evaluated using multivariate unconditional logistic regression with adjustment for possible confounders such as sex, age and country of origin. Statistical analyses were two-sided with p values <0.05 considered significant. K3326X and I157T were associated with increased risk of developing sporadic PDAC (odds ratio (ORdom ) = 1.78, 95% confidence interval (CI) = 1.26-2.52, p = 1.19 × 10-3 and ORdom = 1.74, 95% CI = 1.15-2.63, p = 8.57 × 10-3 , respectively). Neither mutation was significantly associated with risk of developing early-onset PDAC. This retrospective study demonstrates novel risk estimates of K3326X and I157T in sporadic PDAC which suggest that upon validation and in combination with other established genetic and non-genetic risk factors, these mutations may be used to improve pancreatic cancer risk assessment in European populations. Identification of carriers of these risk alleles as high-risk groups may also facilitate screening or prevention strategies for such individuals, regardless of family history.

Circulating plasma phospholipid fatty acids and risk of pancreatic cancer in a large European cohort.

There are both limited and conflicting data on the role of dietary fat and specific fatty acids in the development of pancreatic cancer. In this study, we investigated the association between plasma phospholipid fatty acids and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The fatty acid composition was measured by gas chromatography in plasma samples collected at recruitment from375 incident pancreatic cancer cases and375 matched controls. Associations of specific fatty acids with pancreatic cancer risk were evaluated using multivariable conditional logistic regression models with adjustment for established pancreatic cancer risk factors. Statistically significant inverse associations were found between pancreatic cancer incidence and levels of heptadecanoic acid (ORT3-T1 [odds ratio for highest versus lowest tertile] =0.63; 95%CI[confidence interval] = 0.41-0.98; ptrend = 0.036), n-3 polyunsaturated α-linolenic acid (ORT3-T1 = 0.60; 95%CI = 0.39-0.92; ptrend = 0.02) and docosapentaenoic acid (ORT3-T1 = 0.52; 95%CI = 0.32-0.85; ptrend = 0.008). Industrial trans-fatty acids were positively associated with pancreatic cancer risk among men (ORT3-T1 = 3.00; 95%CI = 1.13-7.99; ptrend = 0.029), while conjugated linoleic acids were inversely related to pancreatic cancer among women only (ORT3-T1 = 0.37; 95%CI = 0.17-0.81; ptrend = 0.008). Among current smokers, the long-chain n-6/n-3 polyunsaturated fatty acids ratio was positively associated with pancreatic cancer risk (ORT3-T1 = 3.40; 95%CI = 1.39-8.34; ptrend = 0.007). Results were robust to a range of sensitivity analyses. Our findings suggest that higher circulating levels of saturated fatty acids with an odd number of carbon atoms and n-3 polyunsaturated fatty acids may be related to lower risk of pancreatic cancer. The influence of some fatty acids on the development of pancreatic cancer may be sex-specific and modulated by smoking.

Fibre intake and the development of inflammatory bowel disease: A European prospective multi-centre cohort study (EPIC-IBD).

BACKGROUND AND AIMS: Population-based prospective cohort studies investigating fibre intake and development of inflammatory bowel disease are lacking. Our aim was to investigate the association between fibre intake and the development of Crohn's disease [CD] and ulcerative colitis [UC] in a large European population. METHODS: In total, 401326 participants, aged 20-80 years, were recruited in eight countries in Europe between 1991 and 1998. At baseline, fibre intake [total fibres, fibres from fruit, vegetables and cereals] was recorded using food frequency questionnaires. The cohort was monitored for the development of inflammatory bowel disease. Each case was matched with four controls and odds ratios [ORs] for the exposures were calculated using conditional logistic regression. Sensitivity analyses according to smoking status were computed. RESULTS: In total, 104 and 221 participants developed incident CD and UC, respectively. For both CD and UC, there were no statistically significant associations with either quartiles, or trends across quartiles, for total fibre or any of the individual sources. The associations were not affected by adjusting for smoking and energy intake. Stratification according to smoking status showed null findings apart from an inverse association with cereal fibre and CD in non-smokers [Quartile 4 vs 1 OR = 0.12, 95% confidence interval = 0.02-0.75, p = 0.023, OR trend across quartiles = 0.50, 95% confidence interval = 0.29-0.86, p = 0.017]. CONCLUSION: The results do not support the hypothesis that dietary fibre is involved in the aetiology of UC, although future work should investigate whether there may be a protective effect of specific types of fibre according to smoking status in CD.

A prospective evaluation of plasma phospholipid fatty acids and breast cancer risk in the EPIC study.

BACKGROUND: Intakes of specific fatty acids have been postulated to impact breast cancer risk but epidemiological data based on dietary questionnaires remain conflicting. MATERIALS AND METHODS: We assessed the association between plasma phospholipid fatty acids and breast cancer risk in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition study. Sixty fatty acids were measured by gas chromatography in pre-diagnostic plasma phospholipids from 2982 incident breast cancer cases matched to 2982 controls. Conditional logistic regression models were used to estimate relative risk of breast cancer by fatty acid level. The false discovery rate (q values) was computed to control for multiple comparisons. Subgroup analyses were carried out by estrogen receptor (ER) and progesterone receptor expression in the tumours. RESULTS: A high level of palmitoleic acid [odds ratio (OR) for the highest quartile compared with the lowest OR (Q4-Q1) 1.37; 95% confidence interval (CI), 1.14-1.64; P for trend = 0.0001, q value = 0.004] as well as a high desaturation index (DI16) (16:1n-7/16:0) [OR (Q4-Q1), 1.28; 95% C, 1.07-1.54; P for trend = 0.002, q value = 0.037], as biomarkers of de novo lipogenesis, were significantly associated with increased risk of breast cancer. Levels of industrial trans-fatty acids were positively associated with ER-negative tumours [OR for the highest tertile compared with the lowest (T3-T1)=2.01; 95% CI, 1.03-3.90; P for trend = 0.047], whereas no association was found for ER-positive tumours (P-heterogeneity =0.01). No significant association was found between n-3 polyunsaturated fatty acids and breast cancer risk, overall or by hormonal receptor. CONCLUSION: These findings suggest that increased de novo lipogenesis, acting through increased synthesis of palmitoleic acid, could be a relevant metabolic pathway for breast tumourigenesis. Dietary trans-fatty acids derived from industrial processes may specifically increase ER-negative breast cancer risk.

No association of alcohol use and the risk of ulcerative colitis or Crohn's disease: data from a European Prospective cohort study (EPIC).

BACKGROUND/OBJECTIVES: The role of long-term alcohol consumption for the risk of developing ulcerative colitis (UC) and Crohn's disease (CD) is unclear. For the first time, to prospectively assess the role of pre-disease alcohol consumption on the risk of developing UC or CD. SUBJECTS/METHODS: Nested within the European Prospective Investigation into Cancer and Nutrition (EPIC-IBD), incident UC and CD cases and matched controls where included. At recruitment, participants completed validated food frequency and lifestyle questionnaires. Alcohol consumption was classified as either: non-use, former, light (⩽0.5 and 1 drink per week), below the recommended limits (BRL) (⩽1 and 2 drinks per day), moderate (⩽2.5 and 5 drinks per day), or heavy use (>2.5 and >5 drinks per day) for women and men, respectively; and was expressed as consumption at enrolment and during lifetime. Conditional logistic regression was applied adjusting for smoking and education, taking light users as the reference. RESULTS: Out of 262 451 participants in six countries, 198 UC incident cases/792 controls and 84 CD cases/336 controls were included. At enrolment, 8%/27%/32%/23%/11% UC cases and 7%/29%/40%/19%/5% CD cases were: non-users, light, BRL, moderate and heavy users, respectively. The corresponding figures for lifetime non-use, former, light, BRL, moderate and heavy use were: 3%/5%/23%/44%/19%/6% and 5%/2%/25%/44%/23%/1% for UC and CD cases, respectively. There were no associations between any categories of alcohol consumption and risk of UC or CD in the unadjusted and adjusted odds ratios. CONCLUSION: There was no evidence of associations between alcohol use and the odds of developing either UC or CD.

Biomarkers of folate and vitamin B12 and breast cancer risk: report from the EPIC cohort.

Epidemiological studies have reported inconsistent findings for the association between B vitamins and breast cancer (BC) risk. We investigated the relationship between biomarkers of folate and vitamin B12 and the risk of BC in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Plasma concentrations of folate and vitamin B12 were determined in 2,491 BC cases individually matched to 2,521 controls among women who provided baseline blood samples. Multivariable logistic regression models were used to estimate odds ratios by quartiles of either plasma B vitamin. Subgroup analyses by menopausal status, hormone receptor status of breast tumors (estrogen receptor [ER], progesterone receptor [PR] and human epidermal growth factor receptor 2 [HER2]), alcohol intake and MTHFR polymorphisms (677C > T and 1298A > C) were also performed. Plasma levels of folate and vitamin B12 were not significantly associated with the overall risk of BC or by hormone receptor status. A marginally positive association was found between vitamin B12 status and BC risk in women consuming above the median level of alcohol (ORQ4-Q1 = 1.26; 95% CI 1.00-1.58; Ptrend = 0.05). Vitamin B12 status was also positively associated with BC risk in women with plasma folate levels below the median value (ORQ4-Q1 = 1.29; 95% CI 1.02-1.62; Ptrend = 0.03). Overall, folate and vitamin B12 status was not clearly associated with BC risk in this prospective cohort study. However, potential interactions between vitamin B12 and alcohol or folate on the risk of BC deserve further investigation.

Changes in body weight and obesity status in German adults: results of seven population-based prospective studies.

BACKGROUND/OBJECTIVES: The objective of this study was to quantify body weight changes in German adult populations during the past decades. SUBJECTS/METHODS: Longitudinal analysis of seven cohort studies covering different age ranges between 18 and 83 years. Baseline examinations were between 1994 and 2007 and follow-up durations between 4.0 and 11.9 years. For each study, mean change in body weight per year and 10-year change in body mass index (BMI) classification were analyzed. For the middle age group of 45-64 years, meta-analysis was conducted to obtain an overall estimate for Germany. RESULTS: Among men weight gain was highest in the youngest participants and decreased with advancing age. Among women weight gain was on a stable high level among those younger than 45 years and decreased at older age. Within 10 years, 30-40% of middle-aged participants with normal baseline weight became pre-obese or obese and 20-25% of those with pre-obesity at baseline became obese, whereas >80% of persons who were obese at baseline remained obese over time. The estimated average weight change in adults aged 45-64 years was 0.25 (95% confidence interval (CI): 0.18-0.33) kg/year among men and 0.24 (0.17-0.30) kg/year among women. CONCLUSIONS: We could observe a moderate weight gain over the past years in German middle-aged populations of 0.25 kg/year. Obesity prevention needs to be targeted to specific subgroups in the population, especially to younger adults, who seem to be most vulnerable for gaining weight. Obesity intervention needs to be improved, as the majority of obese adults remained obese over time.

An epidemiologic risk prediction model for ovarian cancer in Europe: the EPIC study.

BACKGROUND: Ovarian cancer has a high case-fatality ratio, largely due to late diagnosis. Epidemiologic risk prediction models could help identify women at increased risk who may benefit from targeted prevention measures, such as screening or chemopreventive agents. METHODS: We built an ovarian cancer risk prediction model with epidemiologic risk factors from 202,206 women in the European Prospective Investigation into Cancer and Nutrition study. RESULTS: Older age at menopause, longer duration of hormone replacement therapy, and higher body mass index were included as increasing ovarian cancer risk, whereas unilateral ovariectomy, longer duration of oral contraceptive use, and higher number of full-term pregnancies were decreasing risk. The discriminatory power (overall concordance index) of this model, as examined with five-fold cross-validation, was 0.64 (95% confidence interval (CI): 0.57, 0.70). The ratio of the expected to observed number of ovarian cancer cases occurring in the first 5 years of follow-up was 0.90 (293 out of 324, 95% CI: 0.81-1.01), in general there was no evidence for miscalibration. CONCLUSION: Our ovarian cancer risk model containing only epidemiological data showed modest discriminatory power for a Western European population. Future studies should consider adding informative biomarkers to possibly improve the predictive ability of the model.

Healthy lifestyle index and risk of gastric adenocarcinoma in the EPIC cohort study.

Several modifiable lifestyle factors, including smoking, alcohol, certain dietary factors and weight are independently associated with gastric cancer (GC); however, their combined impact on GC risk is unknown. We constructed a healthy lifestyle index to investigate the joint influence of these behaviors on GC risk within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The analysis included 461,550 participants (662 first incident GC cases) with a mean follow-up of 11.4 years. A healthy lifestyle index was constructed, assigning 1 point for each healthy behavior related to smoking status, alcohol consumption and diet quality (represented by the Mediterranean diet) for assessing overall GC and also body mass index for cardia GC and 0 points otherwise. Risk of GC was calculated using Cox proportional hazards regression models while adjusting for relevant confounders. The highest versus lowest score in the healthy lifestyle index was associated with a significant lower risk of GC, by 51% overall (HR 0.49 95% CI 0.35, 0.70), by 77% for cardia GC (HR 0.23 95% CI 0.08, 0.68) and by 47% for noncardia GC (HR 0.53 (95% CI 0.32, 0.87), p-trends<0.001. Population attributable risk calculations showed that 18.8% of all GC and 62.4% of cardia GC cases could have been prevented if participants in this population had followed the healthy lifestyle behaviors of this index. Adopting several healthy lifestyle behaviors including not smoking, limiting alcohol consumption, eating a healthy diet and maintaining a normal weight is associated with a large decreased risk of GC.

[Individual linkage of primary data with secondary and registry data within large cohort studies - capabilities and procedural proposals]. / Individuelle Datenverknüpfung von Primärdaten mit Sekundär- und Registerdaten in Kohortenstudien: Potenziale und Verfahrensvorschläge.

Some German cohort studies have already linked secondary and registry data with primary data from interviews and medical examinations. This offers the opportunity to obtain more valid information by taking advantage of the strengths of these data synergistically and overcome their individual weaknesses at the same time. The potential and the requirements for linking secondary and registry data with primary data from cohort studies is described generally and illustrated by the example of the "German National Cohort" (GNC). The transfer and usage of secondary and registry data require that administrative and logistic efforts be made over the whole study period. In addition, rigid data protection regulations for using social data have to be observed. The particular strengths of secondary and registry data, namely their objectivity and independence from recall bias, add to the strengths of newly collected primary data and improve the assessment of morbidity endpoints, exposure history and need of patient care. Moreover, new insights on quality and on the added value of linking different data sources may be obtained.

Consumption of fatty foods and incident type 2 diabetes in populations from eight European countries.

BACKGROUND/OBJECTIVES: Diets high in saturated and trans fat and low in unsaturated fat may increase type 2 diabetes (T2D) risk, but studies on foods high in fat per unit weight are sparse. We assessed whether the intake of vegetable oil, butter, margarine, nuts and seeds and cakes and cookies is related to incident T2D. SUBJECTS/METHODS: A case-cohort study was conducted, nested within eight countries of the European Prospective Investigation into Cancer (EPIC), with 12,403 incident T2D cases and a subcohort of 16,835 people, identified from a cohort of 340,234 people. Diet was assessed at baseline (1991-1999) by country-specific questionnaires. Country-specific hazard ratios (HRs) across four categories of fatty foods (nonconsumers and tertiles among consumers) were combined with random-effects meta-analysis. RESULTS: After adjustment not including body mass index (BMI), nonconsumers of butter, nuts and seeds and cakes and cookies were at higher T2D risk compared with the middle tertile of consumption. Among consumers, cakes and cookies were inversely related to T2D (HRs across increasing tertiles 1.14, 1.00 and 0.92, respectively; P-trend <0.0001). All these associations attenuated upon adjustment for BMI, except the higher risk of nonconsumers of cakes and cookies (HR 1.57). Higher consumption of margarine became positively associated after BMI adjustment (HRs across increasing consumption tertiles: 0.93, 1.00 and 1.12; P-trend 0.03). Within consumers, vegetable oil, butter and nuts and seeds were unrelated to T2D. CONCLUSIONS: Fatty foods were generally not associated with T2D, apart from weak positive association for margarine. The higher risk among nonconsumers of cakes and cookies needs further explanation.

Steroid hormone measurements from different types of assays in relation to body mass index and breast cancer risk in postmenopausal women: Reanalysis of eighteen prospective studies.

Epidemiological studies have examined breast cancer risk in relation to sex hormone concentrations measured by different methods: "extraction" immunoassays (with prior purification by organic solvent extraction, with or without column chromatography), "direct" immunoassays (no prior extraction or column chromatography), and more recently with mass spectrometry-based assays. We describe the associations of estradiol, estrone and testosterone with both body mass index and breast cancer risk in postmenopausal women according to assay method, using data from a collaborative pooled analysis of 18 prospective studies. In general, hormone concentrations were highest in studies that used direct assays and lowest in studies that used mass spectrometry-based assays. Estradiol and estrone were strongly positively associated with body mass index, regardless of the assay method; testosterone was positively associated with body mass index for direct assays, but less clearly for extraction assays, and there were few data for mass spectrometry assays. The correlations of estradiol with body mass index, estrone and testosterone were lower for direct assays than for extraction and mass spectrometry assays, suggesting that the estimates from the direct assays were less precise. For breast cancer risk, all three hormones were strongly positively associated with risk regardless of assay method (except for testosterone by mass spectrometry where there were few data), with no statistically significant differences in the trends, but differences may emerge as new data accumulate. Future epidemiological and clinical research studies should continue to use the most accurate assays that are feasible within the design characteristics of each study.

Insulin-like growth factor I and risk of epithelial invasive ovarian cancer by tumour characteristics: results from the EPIC cohort.

BACKGROUND: Prospective studies on insulin-like growth factor I (IGF-I) and epithelial ovarian cancer (EOC) risk are inconclusive. Data suggest risk associations vary by tumour characteristics. METHODS: We conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC) to evaluate IGF-I concentrations and EOC risk by tumour characteristics (n=565 cases). Multivariable conditional logistic regression models were used to estimate associations. RESULTS: We observed no association between IGF-I and EOC overall or by tumour characteristics. CONCLUSIONS: In the largest prospective study to date was no association between IGF-I and EOC risk. Pre-diagnostic serum IGF-I concentrations may not influence EOC risk.

Dietary folate intake and breast cancer risk: European prospective investigation into cancer and nutrition.

BACKGROUND: There is limited evidence on the association between dietary folate intake and the risk of breast cancer (BC) by hormone receptor expression in the tumors. We investigated the relationship between dietary folate and BC risk using data from the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: A total of 367993 women age 35 to 70 years were recruited in 10 European countries. During a median follow-up of 11.5 years, 11575 women with BC were identified. Dietary folate intake was estimated from country-specific dietary questionnaires. Cox proportional hazards regression models were used to quantify the association between dietary variables and BC risk. BC tumors were classified by receptor status. Subgroup analyses were performed by menopausal status and alcohol intake. Intake of other B vitamins was considered. All statistical tests were two-sided. RESULTS: A borderline inverse association was observed between dietary folate and BC risk (hazard ratio comparing top vs bottom quintile [HRQ5-Q1] = 0.92, 95% CI = 0.83 to 1.01, P trend = .037). In premenopausal women, we observed a statistically significant trend towards lower risk in estrogen receptor-negative BC (HRQ5-Q1 = 0.66, 95% CI = 0.45 to 0.96, P trend = .042) and progesterone receptor-negative BC (HRQ5-Q1 = 0.70, 95% CI = 0.51 to 0.97, P trend = .021). No associations were found in postmenopausal women. A 14% reduction in BC risk was observed when comparing the highest with the lowest dietary folate tertiles in women having a high (>12 alcoholic drinks/week) alcohol intake (HRT3-T1 = 0.86, 95% CI = 0.75 to 0.98, P interaction = .035). CONCLUSIONS: Higher dietary folate intake may be associated with a lower risk of sex hormone receptor-negative BC in premenopausal women.

Flavonoid and lignan intake in relation to bladder cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

BACKGROUND: There is growing evidence of the protective role of dietary intake of flavonoids and lignans on cancer, but the association with bladder cancer has not been thoroughly investigated in epidemiological studies. We evaluated the association between dietary intakes of total and subclasses of flavonoids and lignans and risk of bladder cancer and its main morphological type, urothelial cell carcinoma (UCC), within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. METHODS: A cohort of 477 312 men and women mostly aged 35-70 years, were recruited in 10 European countries. At baseline, dietary flavonoid and lignan intakes were estimated using centre-specific validated questionnaires and a food composition database based on the Phenol-Explorer, the UK Food Standards Agency and the US Department of Agriculture databases. RESULTS: During an average of 11 years of follow-up, 1575 new cases of primary bladder cancer were identified, of which 1425 were UCC (classified into aggressive (n=430) and non-aggressive (n=413) UCC). No association was found between total flavonoid intake and bladder cancer risk. Among flavonoid subclasses, significant inverse associations with bladder cancer risk were found for intakes of flavonol (hazard ratio comparing fifth with first quintile (HRQ5-Q1) 0.74, 95% confidence interval (CI): 0.61-0.91; P-trend=0.009) and lignans (HRQ5-Q1 0.78, 95% CI: 0.62-0.96; P-trend=0.046). Similar results were observed for overall UCC and aggressive UCC, but not for non-aggressive UCC. CONCLUSIONS: Our study suggests an inverse association between the dietary intakes of flavonols and lignans and risk of bladder cancer, particularly aggressive UCC.

Dietary intake of acrylamide and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort.

BACKGROUND: Three prospective studies have evaluated the association between dietary acrylamide intake and endometrial cancer (EC) risk with inconsistent results. The objective of this study was to evaluate the association between acrylamide intake and EC risk: for overall EC, for type-I EC, and in never smokers and never users of oral contraceptives (OCs). Smoking is a source of acrylamide, and OC use is a protective factor for EC risk. METHODS: Cox regression was used to estimate hazard ratios (HRs) for the association between acrylamide intake and EC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Acrylamide intake was estimated from the EU acrylamide monitoring database, which was matched with EPIC questionnaire-based food consumption data. Acrylamide intake was energy adjusted using the residual method. RESULTS: No associations were observed between acrylamide intake and overall EC (n=1382) or type-I EC risk (n=627). We observed increasing relative risks for type-I EC with increasing acrylamide intake among women who both never smoked and were non-users of OCs (HRQ5vsQ1: 1.97, 95% CI: 1.08-3.62; likelihood ratio test (LRT) P-value: 0.01, n=203). CONCLUSIONS: Dietary intake of acrylamide was not associated with overall or type-I EC risk; however, positive associations with type I were observed in women who were both non-users of OCs and never smokers.