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Background: Genome-wide association studies (GWAS) identify associations of individual single-nucleotide polymorphisms (SNPs) with cancer risk but usually only explain a fraction of the inherited variability. Pathway analysis of genetic variants is a powerful tool to identify networks of susceptibility genes., Methods: We conducted a large agnostic pathway-based meta-analysis of GWAS data using the summary-based adaptive rank truncated product method to identify gene sets and pathways associated with pancreatic ductal adenocarcinoma (PDAC) in 9040 cases and 12 496 controls. We performed expression quantitative trait loci (eQTL) analysis and functional annotation of the top SNPs in genes contributing to the top associated pathways and gene sets. All statistical tests were two-sided., Results: We identified 14 pathways and gene sets associated with PDAC at a false discovery rate of less than 0.05. After Bonferroni correction (P ≤ 1.3 × 10-5), the strongest associations were detected in five pathways and gene sets, including maturity-onset diabetes of the young, regulation of beta-cell development, role of epidermal growth factor (EGF) receptor transactivation by G protein-coupled receptors in cardiac hypertrophy pathways, and the Nikolsky breast cancer chr17q11-q21 amplicon and Pujana ATM Pearson correlation coefficient (PCC) network gene sets. We identified and validated rs876493 and three correlating SNPs (PGAP3) and rs3124737 (CASP7) from the Pujana ATM PCC gene set as eQTLs in two normal derived pancreas tissue datasets., Conclusion: Our agnostic pathway and gene set analysis integrated with functional annotation and eQTL analysis provides insight into genes and pathways that may be biologically relevant for risk of PDAC, including those not previously identified., (Published by Oxford University Press 2018. This work is written by US Government employees and is in the public domain in the US.)

Rationale: Host antioxidant defense, consisting of enzymatic antioxidant activity and nonenzymatic antioxidant micronutrients, is implicated in asthma pathogenesis. Studies of antioxidant defense and adult incident asthma have either used measures of antioxidants estimated from questionnaires or not considered enzymatic aspects of host defense., Objectives: We conducted the first study designed and powered to investigate the association of antioxidant defenses on adult incident asthma., Methods: In a nested case-control study, we followed Shanghai women (aged 40-70 years) without prevalent asthma at baseline, over 8 years. Subjects with incident asthma were ascertained prospectively by gold standard testing of symptomatic women and matched to two asymptomatic control subjects., Measurements and Main Results: Baseline urinary F2-isoprostanes, plasma concentrations of antioxidant micronutrients (tocopherols, xanthines, carotenes, and lycopene), and antioxidant enzyme activity (platelet-activating factor acetylhydrolase [PAF-AH] and superoxide dismutase) were measured from samples collected before disease onset. Among 65,372 women, 150 (0.24%) developed asthma. F2-isoprostane levels before asthma onset were not different between cases and control subjects. Doubling of α-tocopherol concentrations and PAF-AH activity was associated with 50 and 37% decreased risk of incident asthma (α-tocopherol: adjusted odds ratio = 0.52; 95% confidence interval, 0.32-0.84; PAF-AH: adjusted odds ratio = 0.63; 95% confidence interval, 0.42-0.93)., Conclusions: In this prospective study, α-tocopherol, within normal reference ranges, and PAF-AH enzymatic activity were associated with decreased asthma development. These modifiable risk factors may be an effective strategy to test for primary asthma prevention.

Limited epidemiological evidence suggests that calcium intake may be related to breast cancer risk. Data from a large, population-based, case-control study (n = 1,459 cases, 1,556 controls) conducted in Shanghai, China, between 1996 and 1998 were used to investigate the association between calcium intake and risk for breast cancer. Diet was assessed using a quantitative food-frequency questionnaire. The multivariate-adjusted odds ratio (OR) comparing all women combined in the highest to lowest deciles of total calcium intake was 0.74 (95% confidence interval [CI] = 0.46-1.20). Whereas calcium primarily derived from poultry was inversely associated with risk for breast cancer (comparing the highest to lowest quintile OR = 0.71, 95% CI = 0.55-0.93) with a statistically significant test for trend, calcium derived from milk, seafood, fruit, and vegetables was not associated with risk of breast cancer. Given that breast cancer is one of the top contributors to cancer incidence worldwide, even a moderate inverse association between calcium and breast cancer risk, if confirmed, could have important public health implications in breast cancer prevention.