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Although it appears biologically plausible for iron to be associated with gastric carcinogenesis, the evidence is insufficient to lead to any conclusions. To further investigate the relationship between body iron status and gastric cancer risk, we conducted a nested case-control study in the multicentric European Prospective Investigation into Cancer and Nutrition (EPIC) study. The study included 456 primary incident gastric adenocarcinoma cases and 900 matched controls that occurred during an average of 11 years of follow-up. We measured prediagnostic serum iron, ferritin, transferrin and C-reactive protein, and further estimated total iron-binding capacity (TIBC) and transferrin saturation (TS). Odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of gastric cancer by iron metrics were estimated from multivariable conditional logistic regression models. After adjusting for relevant confounders, we observed a statistically significant inverse association between gastric cancer and ferritin and TS indices (ORlog2  = 0.80, 95% CI = 0.72-0.88; OR10%increment  = 0.87, 95% CI = 0.78-0.97, respectively). These associations appear to be restricted to noncardia gastric cancer (ferritin showed a p for heterogeneity = 0.04 and TS had a p for heterogeneity = 0.02), and no differences were found by histological type. TIBC increased risk of overall gastric cancer (OR50 µg/dl  = 1.13, 95% CI = 1.02-1.2) and also with noncardia gastric cancer (p for heterogeneity = 0.04). Additional analysis suggests that time between blood draw and gastric cancer diagnosis could modify these findings. In conclusion, our results showed a decreased risk of gastric cancer related to higher body iron stores as measured by serum iron and ferritin. Further investigation is needed to clarify the role of iron in gastric carcinogenesis., (© 2015 UICC.)

Background: Experimental studies suggest protective effects of vitamin D on breast carcinogenesis, particularly on estrogen receptor-positive tumors. Epidemiologic data are less conclusive., Objective: Our objective was to investigate the association between postmenopausal breast cancer risk and current or past vitamin D supplementation overall and according to the use of menopausal hormone therapy (MHT)., Design: Between 1995 and 2008, 2482 invasive breast cancer cases were diagnosed among 57,403 postmenopausal women from the E3N prospective cohort during 581,085 person-years. Vitamin D supplementation was assessed from biennially self-administered questionnaires sent in 1995, 2000, 2002, and 2005 and from medico-administrative data on drug reimbursements since 2004. Multivariable HRs for primary invasive breast cancer and 95% CIs were estimated by using Cox models., Results: A decreased postmenopausal breast cancer risk was associated with current (HR: 0.82; 95% CI: 0.69, 0.97) but not past (HR: 1.10; 95% CI: 0.92, 1.31) vitamin D supplementation (P-homogeneity = 0.02). The association with current vitamin D supplementation differed according to MHT use: ever users (HR: 0.74; 95% CI: 0.60, 0.90) and never users (HR: 1.13; 95% CI: 0.89, 1.56); P-homogeneity = 0.02., Conclusions: In this observational study, current vitamin D supplementation, mostly taken daily and combined with calcium, was associated with a decreased postmenopausal breast cancer risk in MHT users. These findings should be confirmed before considering vitamin D supplementation to partly balance the MHT-associated increased breast cancer risk., (© 2015 American Society for Nutrition.)

Evidence of a protective effect of several antioxidants and other nutrients on pancreatic cancer risk is inconsistent. The aim of this study was to investigate the association for prediagnostic plasma levels of carotenoids, vitamin C, retinol and tocopherols with risk of pancreatic cancer in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC). 446 incident exocrine pancreatic cancer cases were matched to 446 controls by age at blood collection, study center, sex, date and time of blood collection, fasting status and hormone use. Plasma carotenoids (α- and β-carotene, lycopene, β-cryptoxanthin, canthaxanthin, zeaxanthin and lutein), α- and γ-tocopherol and retinol were measured by reverse phase high-performance liquid chromatography and plasma vitamin C by a colorimetric assay. Incidence rate ratios (IRRs) with 95% confidence intervals (95%CIs) for pancreatic cancer risk were estimated using a conditional logistic regression analysis, adjusted for smoking status, smoking duration and intensity, waist circumference, cotinine levels and diabetes status. Inverse associations with pancreatic cancer risk were found for plasma β-carotene (IRR highest vs. lowest quartile 0.52, 95%CI 0.31-0.88, p for trend = 0.02), zeaxanthin (IRR highest vs. lowest quartile 0.53, 95%CI 0.30-0.94, p for trend = 0.06) and α-tocopherol (IRR highest vs. lowest quartile 0.62, 95%CI 0.39-0.99, p for trend = 0.08. For α- and β-carotene, lutein, sum of carotenoids and γ-tocopherol, heterogeneity between geographical regions was observed. In conclusion, our results show that higher plasma concentrations of β-carotene, zeaxanthin and α-tocopherol may be inversely associated with risk of pancreatic cancer, but further studies are warranted., (© 2014 UICC.)