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- Aleksandrova, Krasimira, et al.
(author)
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Adiposity, mediating biomarkers and risk of colon cancer in the European prospective investigation into cancer and nutrition study
- 2014
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In: International Journal of Cancer. - : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 134:3, s. 612-621
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Journal article (peer-reviewed)abstract
- Adiposity is a risk factor for colon cancer, but underlying mechanisms are not well understood. We evaluated the extent to which 11 biomarkers with inflammatory and metabolic actions mediate the association of adiposity measures, waist circumference (WC) and body mass index (BMI), with colon cancer in men and women. We analyzed data from a prospective nested case-control study among 662 incident colon cancer cases matched within risk sets to 662 controls. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. The percent effect change and corresponding CIs were estimated after adjusting for biomarkers shown to be associated with colon cancer risk. After multivariable adjustment, WC was associated with colon cancer risk in men (top vs. bottom tertile RR 1.68, 95% CI 1.06-2.65; ptrend = 0.02) and in women (RR 1.67, 95% CI 1.09-2.56; ptrend = 0.03). BMI was associated with risk only in men. The association of WC with colon cancer was accounted mostly for by three biomarkers, high-density lipoprotein cholesterol, non-high-molecular-weight adiponectin and soluble leptin receptor, which in combination explained 46% (95% CI 37-57%) of the association in men and 50% (95% CI 40-65%) of the association in women. Similar results were observed for the associations with BMI in men. These data suggest that alterations in levels of these metabolic biomarkers may represent a primary mechanism of action in the relation of adiposity with colon cancer. Further studies are warranted to determine whether altering their concentrations may reduce colon cancer risk.
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- Kaaks, Rudolf, et al.
(author)
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Insulin-like growth factor I and risk of breast cancer by age and hormone receptor status : A prospective study within the EPIC cohort
- 2014
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In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 134:11, s. 2683-2690
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Journal article (peer-reviewed)abstract
- Experimental evidence shows cross-talk in mammary cells between estrogen, insulin-like growth factor I (IGF-I) and their respective receptors and possible synergistic effects of estrogen receptor (ER) activation and increased IGF-I signaling with regard to breast tumor development, and epidemiological evidence suggests that circulating IGF-I levels may be related more to the risk of ER-positive than ER-negative breast cancer. Using a case–control study nested within the prospective European EPIC cohort (938 breast cancer cases and 1,394 matched control subjects), we analyzed the relationships of prediagnostic serum IGF-I levels with the risk of estrogen and progesterone receptor-positive and -negative breast tumors. IGF-I levels were positively associated with the risk of ER+ breast tumors overall (pre- and postmenopausal women combined, odds ratio (OR)Q4-Q1 = 1.41 [95% confidence interval (CI) 1.01–1.98] for the highest vs. lowest quartile; OR = 1.17 [95% CI 1.04–1.33] per 1-standard deviation (SD) increase in IGF-I, ptrend = 0.01) and among women who were diagnosed with breast cancer at 50 years or older (ORQ3-Q1 = 1.38 [95% CI 1.01–1.89]; OR = 1.19 [95% CI 1.04–1.36] per 1-SD increase in IGF-I, ptrend = 0.01) but not with receptor-positive disease diagnosed at an earlier age. No statistically significant associations were observed for ER− breast tumors overall and by age at diagnosis. Tests for heterogeneity by receptor status of the tumor were not statistically significant, except for women diagnosed with breast cancer at 50 years or older (phet = 0.03 for ER+/PR+ vs. ER−/PR− disease). Our data add to a global body of evidence indicating that higher circulating IGF-I levels may increase risk specifically of receptor-positive, but not receptor-negative, breast cancer diagnosed at 50 years or older.
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- Tikk, Kaja, et al.
(author)
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Circulating prolactin and breast cancer risk among pre- and postmenopausal women in the EPIC cohort
- 2014
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In: Annals of Oncology. - : Oxford University Press. - 0923-7534 .- 1569-8041. ; 25:7, s. 1422-1428
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Journal article (peer-reviewed)abstract
- BACKGROUND: Experimental and epidemiological evidence suggests that prolactin might play a role in the etiology of breast cancer. We analyzed the relationship of pre-diagnostic circulating prolactin levels with the risk of breast cancer by menopausal status, use of postmenopausal hormone replacement therapy (HRT) at blood donation, and by estrogen and progesterone receptor-status of the breast tumors. METHODS: Conditional logistic regression was used to analyze the data from a case-control study nested within the prospective European EPIC cohort, including 2250 invasive breast cancer and their matched control subjects. RESULTS: Statistically significant heterogeneity in the association of prolactin levels with breast cancer risk between women who were either pre- or postmenopausal at the time of blood donation was observed (Phet=0.04). Higher serum levels of prolactin were associated with significant increase in risk of breast cancer among postmenopausal women (ORQ4-Q1=1.29 [95%CI 1.05-1.58], Ptrend=0.09); however this increase in risk seemed to be confined to women who used postmenopausal HRT at blood donation (ORQ4-Q1=1.45 [95%CI 1.08-1.95], Ptrend=0.01), whereas no statistically significant association was found for the non-users of HRT (ORQ4-Q1 =1.11 [95%CI 0.83-1.49], Ptrend=0.80) (Phet=0.08). Among premenopausal women, a statistically non-significant inverse association was observed (ORQ4-Q1 =0.70 [95%CI 0.48-1.03], Ptrend=0.16). There was no heterogeneity in the prolactin-breast cancer association by hormone receptor status of the tumor. CONCLUSION: Our study indicates that higher circulating levels of prolactin among the postmenopausal HRT users at baseline may be associated with increased breast cancer risk.
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- Aleksandrova, Krasimira, et al.
(author)
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Circulating C-reactive protein concentrations and risks of colon and rectal cancer : a nested case-control study within the European Prospective Investigation into Cancer and Nutrition
- 2010
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In: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 172:4, s. 407-418
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Journal article (peer-reviewed)abstract
- The authors investigated associations between serum C-reactive protein (CRP) concentrations and colon and rectal cancer risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (1992-2003) among 1,096 incident cases and 1,096 controls selected using risk-set sampling and matched on study center, age, sex, time of blood collection, fasting status, menopausal status, menstrual cycle phase, and hormone replacement therapy. In conditional logistic regression with adjustment for education, smoking, nutritional factors, body mass index, and waist circumference, CRP showed a significant nonlinear association with colon cancer risk but not rectal cancer risk. Multivariable-adjusted relative risks for CRP concentrations of > or = 3.0 mg/L versus <1.0 mg/L were 1.36 (95% confidence interval (CI): 1.00, 1.85; P-trend = 0.01) for colon cancer and 1.02 (95% CI: 0.67, 1.57; P-trend = 0.65) for rectal cancer. Colon cancer risk was significantly increased in men (relative risk = 1.74, 95% CI: 1.11, 2.73; P-trend = 0.01) but not in women (relative risk = 1.06, 95% CI: 0.67, 1.68; P-trend = 0.13). Additional adjustment for C-peptide, glycated hemoglobin, and high density lipoprotein cholesterol did not attenuate these results. These data provide evidence that elevated CRP concentrations are related to a higher risk of colon cancer but not rectal cancer, predominantly among men and independently of obesity, insulin resistance, and dyslipidemia.
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- Aleksandrova, Krasimira, et al.
(author)
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Combined impact of healthy lifestyle factors on colorectal cancer : a large European cohort study
- 2014
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In: BMC Medicine. - : BioMed Central. - 1741-7015. ; 12:1, s. 168-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Excess body weight, physical activity, smoking, alcohol consumption and certain dietary factors are individually related to colorectal cancer (CRC) risk; however, little is known about their joint effects. The aim of this study was to develop a healthy lifestyle index (HLI) composed of five potentially modifiable lifestyle factors - healthy weight, physical activity, non-smoking, limited alcohol consumption and a healthy diet, and to explore the association of this index with CRC incidence using data collected within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. METHODS: In the EPIC cohort, a total of 347,237 men and women, 25- to 70-years old, provided dietary and lifestyle information at study baseline (1992 to 2000). Over a median follow-up time of 12 years, 3,759 incident CRC cases were identified. The association between a HLI and CRC risk was evaluated using Cox proportional hazards regression models and population attributable risks (PARs) have been calculated. RESULTS: After accounting for study centre, age, sex and education, compared with 0 or 1 healthy lifestyle factors, the hazard ratio (HR) for CRC was 0.87 (95% confidence interval (CI): 0.44 to 0.77) for two factors, 0.79 (95% CI: 0.70 to 0.89) for three factors, 0.66 (95% CI: 0.58 to 0.75) for four factors and 0.63 (95% CI: 0.54 to 0.74) for five factors; P-trend <0.0001. The associations were present for both colon and rectal cancers, HRs, 0.61 (95% CI: 0.50 to 0.74; P for trend <0.0001) for colon cancer and 0.68 (95% CI: 0.53 to 0.88; P-trend <0.0001) for rectal cancer, respectively (P-difference by cancer sub-site = 0.10). Overall, 16% of the new CRC cases (22% in men and 11% in women) were attributable to not adhering to a combination of all five healthy lifestyle behaviours included in the index. CONCLUSIONS: Combined lifestyle factors are associated with a lower incidence of CRC in European populations characterized by western lifestyles. Prevention strategies considering complex targeting of multiple lifestyle factors may provide practical means for improved CRC prevention.
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- Aleksandrova, Krasimira, et al.
(author)
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Total and high-molecular-weight adiponectin and risk of colorectal cancer : the European prospective investigation into cancer and nutrition study
- 2012
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In: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 33:6, s. 1211-1218
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Journal article (peer-reviewed)abstract
- Adiponectin - an adipose-tissue-derived protein may provide a molecular link between obesity and colorectal cancer (CRC), but evidence from large prospective studies is limited. In particular, no epidemiological study explored high-molecular-weight (HMW) and non-HMW adiponectin fractions in relation to CRC risk, despite they were hypothesised to have differential biological activities, i.e. regulating insulin sensitivity (HMW-adiponectin) versus inflammatory response (non-HMW-adiponectin). In a prospective nested case-control study we investigated whether pre-diagnostic serum concentrations of total, HMW and non-HMW-adiponectin are associated with risk of CRC, independent of obesity and other known CRC risk factors. A total of 1206 incident cases (755 colon, 451 rectal) were matched to 1206 controls using incidence density sampling. In conditional logistic regression, adjusted for dietary and lifestyle factors, total adiponectin and non-HMW-adiponectin concentrations were inversely associated with risk of CRC [relative risk (RR) comparing highest versus lowest quintile = 0.71, 95% confidence interval (CI) = 0.53-0.95, P (trend)=0.03 for total adiponectin and 0.45, 95%CI=0.34-0.61, P (trend)<0.0001 for non-HMW-adiponectin]. HMW-adiponectin concentrations were not associated with CRC risk (RR=0.91, 95%CI=0.68-1.22, P (trend)=0.55). Non-HMW-adiponectin was associated with CRC risk even after adjustment for body mass index and waist circumference (RR=0.39, 95%CI=0.26-0.60, P (trend)<0.0001); whereas the association with total adiponectin was no longer significant (RR=0.81, 95%CI=0.60-1.09, P (trend)=0.23). When stratified by cancer site, non-HMW-adiponectin was inversely associated with both colon and rectal cancer. These findings suggest an important role of the relative proportion of non-HMW-adiponectin in CRC pathogenesis. Future studies are warranted to confirm these results and to elucidate the underlying mechanisms.
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- Bakker, Marije F., et al.
(author)
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Plasma carotenoids, vitamin C, tocopherols, and retinol and the risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition cohort
- 2016
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In: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 103:2, s. 454-464
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Journal article (peer-reviewed)abstract
- Background: Carotenoids and vitamin C are thought to be associated with reduced cancer risk because of their antioxidative capacity.Objective: This study evaluated the associations of plasma carotenoid, retinol, tocopherol, and vitamin C concentrations and risk of breast cancer.Design: In a nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort, 1502 female incident breast cancer cases were included, with an oversampling of premenopausal (n = 582) and estrogen receptor-negative (ER-) cases (n = 462). Controls (n = 1502) were individually matched to cases by using incidence density sampling. Prediagnostic samples were analyzed for alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin, retinol, alpha-tocopherol, gamma-tocopherol, and 454 vitamin C. Breast cancer risk was computed according to hormone receptor status and age at diagnosis (proxy for menopausal status) by using conditional logistic regression and was further stratified by smoking status, alcohol consumption, and body mass index (BMI). All statistical tests were 2-sided.Results: In quintile 5 compared with quintile 1, alpha-carotene (OR: 0.61; 95% CI: 0.39, 0.98) and beta-carotene (OR: 0.41; 95% CI: 0.26, 0.65) were inversely associated with risk of ER- breast tumors. The other analytes were not statistically associated with ER- breast cancer. For estrogen receptor-positive (ER+) tumors, no statistically significant associations were found. The test for heterogeneity between ER- and ER+ tumors was statistically significant only for beta-carotene (P-heterogeneity = 0.03). A higher risk of breast cancer was found for retinol in relation to ER-/progesterone receptor-negative tumors (OR: 2.37; 95% CI: 1.20, 4.67; P-heterogeneity with ER+/progesterone receptor positive = 0.06). We observed no statistically significant interaction between smoking, alcohol, or BMI and all investigated plasma analytes (based on tertile distribution).Conclusion: Our results indicate that higher concentrations of plasma beta-carotene and alpha-carotene are associated with lower breast cancer risk of ER tumors.
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