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Ghrelin is a hormone produced in the oxyntic glands of the stomach. Previous work by our group has suggested that serum ghrelin concentrations are inversely associated with gastric and esophageal cancer risk. We measured ghrelin concentrations in the Linxian General Population Nutrition Intervention Trial (NIT), and the Shanghai Women's Health Study (SWHS). In NIT, we analyzed serum samples from 298 esophageal squamous cell carcinoma (ESCC) cases, 518 gastric cardia adenocarcinoma (GCA) cases, 258 gastric noncardia adenocarcinoma (GNCA) cases and 770 subcohort controls (case–cohort). In SWHS, we measured ghrelin in plasma samples from 249 GNCA cases and 498 matched controls (nested case–control). Ghrelin was measured using radioimmunoassay. In NIT and SWHS, low ghrelin concentrations were associated with an increased risk of developing GNCA and GCA. The hazard ratio (HR Q1:Q4) for GNCA in NIT was 1.35 (95% CI: 0.89–2.05; p‐trend = 0.02); the odds ratio in SWHS was 1.66 (95% CI: 1.02–2.70; p‐trend = 0.06). Low ghrelin was associated with a twofold increase of GCA (HR Q1:Q4 = 2.00, 95% CI: 1.45–2.77; p‐trend<0.001). In contrast, a lower risk of ESCC (NIT ESCC HR Q1:Q4 = 0.65, 95% CI: 0.45–0.92; p‐trend = 0.02) was found in NIT. Low baseline ghrelin concentrations were associated with an increased risk for GNCA and GCA in the NIT and the SWHS. In contrast, low ghrelin concentrations at baseline were associated with a reduced risk of developing ESCC in the NIT. Ghrelin may be an early marker of future cancer risk for developing upper gastrointestinal cancer in regions of high incidence. What's new? Ghrelin, a stomach‐produced hormone, has numerous metabolic functions and possibly anti‐inflammatory properties. This is the first prospective epidemiologic study of circulating ghrelin conducted in China, a region with a very high burden of esophageal and gastric cancer. Low circulating ghrelin concentrations were associated with increased risk of both gastric noncardia adenocarcinoma and gastric cardia adenocarcinoma, which was consistent with previous findings in a Finnish population. Alterations in serum ghrelin levels occurred over 10 years before the development of clinically‐evident gastric and esophageal cancers. The findings highlight Ghrelin as a potential early marker for upper gastrointestinal cancer risk in regions of high incidence. [ABSTRACT FROM AUTHOR]

Background: Populations in north central China are at high risk for oesophageal squamous cell carcinoma (ESCC) and gastric cancer (GC), and genetic variation in epigenetic machinery genes and pathways may contribute to this risk.Methods: We used the adaptive multilocus joint test to analyse 192 epigenetic genes involved in chromatin remodelling, DNA methylation and microRNA biosynthesis in 1942 ESCC and 1758 GC cases [1126 cardia (GCA) and 632 non-cardia adenocarcinoma (GNCA)] and 2111 controls with Chinese ancestry. We examined potential function of risk alleles using in silico and expression quantitative trait loci (eQTLs) analyses.Results: Suggestive pathway-based associations were observed for the overall epigenetic (P-value(PATH) = 0.034) and chromatin remodelling (P-value(PATH) = 0.039) pathways with risk of GCA, but not GC, GNCA or ESCC. Overall, 37 different epigenetic machinery genes were associated with risk of one or more upper gastrointestinal (UGI) cancer sites (P-value(GENE )< 0.05), including 14 chromatin remodelling genes whose products are involved in the regulation of HOX genes. We identified a gastric eQTL (rs12724079; rho = 0.37; P = 0.0006) which regulates mRNA expression of ASH1L. Several suggestive eQTLs were also found in oesophageal (rs10898459 in EED), gastric cardia (rs7157322 in DICER1; rs8179271 in ASH1L), and gastric non-cardia (rs1790733 in PPP1CA) tissues.Conclusions: Results of our analyses provide limited but suggestive evidence for a role of epigenetic gene variation in the aetiology of UGI cancer. [ABSTRACT FROM AUTHOR]

Background: China has some of the highest incidence rates for gastric adenocarcinoma (GA) and esophageal squamous cell carcinoma (ESCC) in the world. Prospective studies suggested that vitamin C may reduce risks; however, associations are unclear because of limited sample size. Objective: The objective was to examine the relation between prediagnostic plasma vitamin C and the risk of GA and ESCC. Design: A case-cohort study was used to assess the association between prediagnostic plasma vitamin C and incidence of GA (n = 467) and ESCC (n = 618) in the General Population Nutrition Intervention Trial. With the use of multivariate Cox proportional hazards models, we estimated the HRs and 95% CIs. We also conducted a meta-analysis of the literature up to 1 October 2012 on the relation between circulating vitamin C and gastric cancer incidence. Two cohort studies and the current study were included to assess the body of evidence. Results: For GA, each 20-µmol/L increase in plasma vitamin C was associated with a 14% decrease in risk (HR: 0.86; 95% CI: 0.76, 0.96). Compared with individuals with low plasma vitamin C concentrations (≤28 µmol/L), those with normal concentrations (> 28 µmol/L) had a 27% reduced risk of GA (HR: 0.73; 95% CI: 0.56, 0.94). No association between vitamin C concentrations and ESCC was seen. Meta-analysis showed that the risk of incident GA among those with the highest concentration of plasma vitamin C was 31% lower (random-effects-pooled-odds ratio 0.69; 95% CI: 0.54, 0.89) than those in the lowest category. Conclusion: Our data provide evidence that higher circulating vitamin C was associated with a reduced risk of incident GA, but no association was seen for ESCC. [ABSTRACT FROM AUTHOR]

We conducted a genome-wide association study of gastric cancer and esophageal squamous cell carcinoma (ESCC) in ethnic Chinese subjects in which we genotyped 551,152 SNPs. We report a combined analysis of 2,240 gastric cancer cases, 2,115 ESCC cases and 3,302 controls drawn from five studies. In logistic regression models adjusted for age, sex and study, multiple variants at 10q23 had genome-wide significance for gastric cancer and ESCC independently. A notable signal was rs2274223, a nonsynonymous SNP located in PLCE1, for gastric cancer (P = 8.40 × 10−9; per-allele odds ratio (OR) = 1.31) and ESCC (P = 3.85 × 10−9; OR = 1.34). The association with gastric cancer differed by anatomic subsite. For tumors in the cardia the association was stronger (P = 4.19 × 10−15; OR = 1.57), and for those in the noncardia stomach it was absent (P = 0.44; OR = 1.05). Our findings at 10q23 could provide insight into the high incidence of both cancers in China. [ABSTRACT FROM AUTHOR]

Gastric cancer shows a strong male predominance, and sex steroid hormones have been hypothesized to explain this sex disparity. Previous studies examining the associations between sex hormones and sex hormone binding globulin (SHBG) and risk of gastric cancer come primarily from western populations and additional studies in diverse populations will help us better understand the association. We performed a nested case-control study in Linxian Nutrition Intervention Trials cohorts to evaluate the associations among Chinese men, where we had sufficient cases to perform a well-powered study. Using radioimmunoassays and immunoassays, we quantitated androgens, estrogens, and SHBG in baseline serum from 328 men that developed noncardia gastric cancer and matched controls. We used multivariable unconditional logistic regression to calculate ORs and 95% confidence intervals (CI) and explored interactions with body mass index (BMI), age, alcohol drinking, smoking, and follow-up time. Subjects with SHBG in the highest quartile, as compared with those in the lowest quartile, had a significantly increased risk of gastric cancer (OR = 1.87; 95% CI, 1.01-3.44). We found some evidence for associations of sex steroid hormones in men with lower BMI. Our study found a novel association suggesting that higher serum concentrations of SHBG may be associated with risk of gastric cancer in men. We found no overall associations with sex hormones themselves, but future studies should expand the scope of these studies to include women and further explore whether BMI modifies a potential association. PREVENTION RELEVANCE: It was the first study to investigate the association of gastric cancer with prediagnostic sex steroid hormones and SHBG in an Asian male population. Although there were no overall associations for sex steroid hormone concentrations, higher concentrations of SHBG was associated with increased risk of noncardia gastric cancer., (©2021 American Association for Cancer Research.)

Background: Blood type has been associated with the risk of gastric cancer, but few studies have examined the association with esophageal squamous cell carcinoma (ESCC)., Methods: We conducted a case-control study using genotyping data of Chinese individuals, including cases of 2022 ESCC, 1189 gastric cardia adenocarcinoma, 1161 gastric noncardia adenocarcinoma, and 2696 controls. Genetic blood type was imputed using three single nucleotide polymorphisms. We used logistic regression to examine the association between blood type and the risk of each cancer., Results: Compared to blood type O, the risk of ESCC was significantly elevated for blood type B and AB, with the highest risk for type AB (OR, 95%CI: 1.34, 1.07-1.67). Analysis of genotype suggested that the association of ESCC was from carrying the B allele. Similarly, blood type was significantly associated with gastric noncardia adenocarcinoma (P < 0.001) with risk significantly elevated in type A (1.37, 1.14-1.65) and AB (1.44, 1.10-1.89) compared to type O. Blood type was not associated with gastric cardia adenocarcinoma (P = 0.13)., Conclusions: This study provides novel insights into the association between blood type and the risk of ESCC and restricted previously observed association to only gastric noncardia cancer, providing important evidence to clarify the pattern of association and suggesting mechanisms of action.

Based on our initial genome-wide association study (GWAS) on esophageal squamous cell carcinoma (ESCC) in Han Chinese, we conducted a follow-up study to examine the single nucleotide polymorphisms (SNPs) associated with family history (FH) of upper gastrointestinal cancer (UGI) cancer in cases with ESCC. We evaluated the association between SNPs and FH of UGI cancer among ESCC cases in a stage-1 case-only analysis of the National Cancer Institute (NCI, 541 cases with FH and 1399 without FH) and Henan GWAS (493 cases with FH and 869 without FH) data (discovery phase). The top SNPs (or their surrogates) from discovery were advanced to a stage-2 evaluation in additional Henan subjects (2801 cases with FH and 3136 without FH, replication phase). A total of 19 SNPs were associated with FH of UGI cancer in ESCC cases with P < 10 -5 in the stage-1 meta-analysis of NCI and Henan GWAS data. In stage-2, the association for rs79747906 (located at 18p11.31, P = 5.79 × 10 -6 in discovery) was replicated (P = 0.006), with a pooled-OR of 1.59 (95%CI: 1.11-2.28). We identified potential genetic variants associated with FH of UGI cancer. Our findings may provide important insights into new low-penetrance susceptibility regions involved in the susceptibility of families with multiple UGI cancer cases.

Objective: Although several genome-wide association studies (GWAS) of non-cardia gastric cancer have been published, more novel association signals could be exploited by combining individual studies together, which will further elucidate the genetic susceptibility of non-cardia gastric cancer., Design: We conducted a meta-analysis of two published Chinese GWAS studies (2031 non-cardia gastric cancer cases and 4970 cancer-free controls) and followed by genotyping of additional 3564 cases and 4637 controls in two stages., Results: The overall meta-analysis revealed two new association signals. The first was a novel locus at 5q14.3 and marked by rs7712641 (per-allele OR=0.84, 95% CI 0.80 to 0.88; p=1.21×10 -11 ). This single-nucleotide polymorphism (SNP) marker maps to the intron of the long non-coding RNA, lnc-POLR3G-4 ( XLOC&#95;004464 ), which we observed has lower expression in non-cardia gastric tumour compared with matched normal tissue (P wilcoxon signed-rank =7.20×10 -4 ). We also identified a new signal at the 1q22 locus, rs80142782 (per-allele OR=0.62; 95% CI 0.56 to 0.69; p=1.71×10 -19 ), which was independent of the previously reported SNP at the same locus, rs4072037 (per-allele OR=0.74; 95% CI 0.69 to 0.79; p=6.28×10 -17 ). Analysis of the new SNP conditioned on the known SNP showed that the new SNP remained genome-wide significant (P conditional =3.47×10 -8 ). Interestingly, rs80142782 has a minor allele frequency of 0.05 in East Asians but is monomorphic in both European and African populations., Conclusion: These findings add new evidence for inherited genetic susceptibility to non-cardia gastric cancer and provide further clues to its aetiology in the Han Chinese population., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Objective: Genome-wide association studies (GWAS) of gastric cancer have reported differences in single-nucleotide polymorphism (SNP) associations for tumour subtypes, particularly when divided by location into the gastric cardia versus the non-cardia., Design: Here we present results for a GWAS using 2350 East Asian gastric cancer cases divided as 1189 gastric cardia and 1027 gastric non-cardia cases and 2708 controls. We also included up to 3042 cardia cases, 4359 non-cardia cases and 7548 controls for replication from two Chinese studies and one Korean study. From the GWAS, we selected 12 top SNPs for each gastric cancer subtype, 4 top SNPs for total gastric cancer and 1 SNP in MUC1 for replication testing., Results: We observed genome-wide significant associations for rs10074991 in PRKAA1 at 5p13.1 for cardia (p=7.36×10(-12)) and non-cardia cancers (p=2.42×10(-23)) with per allele OR (95% CI) for the combined endpoint of 0.80 (0.77 to 0.83). At 6p21.1, rs2294693 near UNC5CL was significantly associated with gastric non-cardia cancer risk (p=2.50×10(-8)), with OR (95% CI) of 1.18 (1.12 to 1.26), but there was only a nominal association for cardia cancer (p=1.47×10(-2)). We also confirmed a previously reported association for rs4072037 in MUC1 with p=6.59×10(-8) for total gastric cancer and similar estimates for cardia and non-cardia cancers. Three SNPs in PSCA previously reported to be associated with gastric non-cardia cancer showed no apparent association for cardia cancer., Conclusions: Our results suggest that associations for SNPs with gastric cancer show some different results by tumour location in the stomach., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: Oesophageal cancer is the fourth leading cause of cancer death in China where essentially all cases are histologically oesophageal squamous cell carcinoma (ESCC). Agnostic pathway-based analyses of genome-wide association study (GWAS) data combined with tissue-specific expression quantitative trait loci (eQTL) analysis and publicly available functional data can identify biological pathways and/or genes enriched with functionally-relevant disease-associated variants., Method: We used the adaptive multilocus joint test to analyse 1827 pathways containing 6060 genes using GWAS data from 1942 ESCC cases and 2111 controls with Chinese ancestry. We examined the function of risk alleles using in silico and eQTL analyses in oesophageal tissues., Results: Associations with ESCC risk were observed for 36 pathways predominantly involved in apoptosis, cell cycle regulation and DNA repair and containing known GWAS-associated genes. After excluding genes with previous GWAS signals, candidate pathways (and genes) for ESCC risk included taste transduction (KEGG&#95;hsa04742; TAS2R13, TAS2R42, TAS2R14, TAS2R46,TAS2R50), long-patch base excision repair (Reactome&#95;pid; POLD2) and the metabolics pathway (KEGG&#95;hsa01100; MTAP, GAPDH, DCTD, POLD2, AMDHD1). We identified and validated CASP8 rs13016963 and IDH2 rs11630814 as eQTLs, and CASP8 rs3769823 and IDH2 rs4561444 as the potential functional variants in high-linkage disequilibrium with these single nucleotide polymorphisms (SNPs), respectively. Further, IDH2 mRNA levels were down-regulated in ESCC (tumour:normal-fold change = 0.69, P =  .75E-14)., Conclusion: Agnostic pathway-based analyses and integration of multiple types of functional data provide new evidence for the contribution of genes in taste transduction and metabolism to ESCC susceptibility, and for the functionality of both established and new ESCC risk-related SNPs., (Published by Oxford University Press on behalf of the International Epidemiological Association 2015. This work is written by US Government employees and is in the public domain in the US.)

Background: Populations in north central China are at high risk for oesophageal squamous cell carcinoma (ESCC) and gastric cancer (GC), and genetic variation in epigenetic machinery genes and pathways may contribute to this risk., Methods: We used the adaptive multilocus joint test to analyse 192 epigenetic genes involved in chromatin remodelling, DNA methylation and microRNA biosynthesis in 1942 ESCC and 1758 GC cases [1126 cardia (GCA) and 632 non-cardia adenocarcinoma (GNCA)] and 2111 controls with Chinese ancestry. We examined potential function of risk alleles using in silico and expression quantitative trait loci (eQTLs) analyses., Results: Suggestive pathway-based associations were observed for the overall epigenetic (P-value(PATH) = 0.034) and chromatin remodelling (P-value(PATH) = 0.039) pathways with risk of GCA, but not GC, GNCA or ESCC. Overall, 37 different epigenetic machinery genes were associated with risk of one or more upper gastrointestinal (UGI) cancer sites (P-value(GENE )< 0.05), including 14 chromatin remodelling genes whose products are involved in the regulation of HOX genes. We identified a gastric eQTL (rs12724079; rho = 0.37; P = 0.0006) which regulates mRNA expression of ASH1L. Several suggestive eQTLs were also found in oesophageal (rs10898459 in EED), gastric cardia (rs7157322 in DICER1; rs8179271 in ASH1L), and gastric non-cardia (rs1790733 in PPP1CA) tissues., Conclusions: Results of our analyses provide limited but suggestive evidence for a role of epigenetic gene variation in the aetiology of UGI cancer., (Published by Oxford University Press on behalf of the International Epidemiological Association 2015. This work is written by US Government employees and is in the public domain in the US.)

Background: Few studies have examined the association of common genetic variants related to vitamin D metabolism and signaling to esophageal squamous cell carcinoma (ESCC)., Methods: We evaluated the association between 12 single nucleotide polymorphisms (SNPs) in four genes related to vitamin D levels and ESCC risk using data from a genome-wide association study. Participants were recruited from the Shanxi Upper Gastrointestinal Cancer Genetics Project and the Linxian Nutrition Intervention Trials, and included 1942 ESCC cases and 2111 controls. We used logistic models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the SNP associations, after controlling for age and gender., Results: None of the 12 evaluated SNPs in the four vitamin D-related genes were significantly associated with risk of ESCC. The strongest associations were for rs3794060 (P=0.07) and rs12800438 (P=0.08) in the DHCR7/NADSYN1 gene. No association between vitamin D-related SNPs and risk of ESCC was observed in a genotype score analysis that included all 12 SNPs. ORs for quartiles 2, 3 and 4 of the genotype scores were 0.83 (95% CI: 0.68, 1.01), 1.02 (0.85, 1.21), and 1.08 (0.89, 1.30), respectively, with no evidence for a significant monotonic trend (P=0.120)., Conclusions: Our results suggested that common genetic variants related to vitamin D levels are not associated with risk of ESCC in this Chinese population., (Published by Elsevier Ltd.)

Purpose: Tobacco causes many adverse health conditions and may alter the upper gastrointestinal (UGI) microbiome. However, the few studies that studied the association between tobacco use and the microbiome were small and underpowered. Therefore, we investigated the association between tobacco use and the UGI microbiome in Chinese men., Methods: We included 278 men who underwent esophageal cancer screening in Henan Province, China. Men were categorized as current, former, or never smokers from questionnaire data. UGI tract bacterial cells were characterized using the Human Oral Microbial Identification Microarray. Counts of unique bacterial species and genera estimated alpha diversity. For beta diversity, principal coordinate (PCoA) vectors were generated from an unweighted UniFrac distance matrix. Polytomous logistic regression models were used for most analyses., Results: Of the 278 men in this study, 46.8% were current smokers and 12.6% were former smokers. Current smokers tended to have increased alpha diversity (mean 42.3 species) compared to never smokers (mean 38.9 species). For a 10 species increase, the odds ratio (OR) for current smoking was 1.29 (95% CI 1.04-1.62). Beta diversity was also associated with current smoking. The first two PCoA vectors were strongly associated with current smoking (PCoA1 OR 0.66; 95% CI 0.51-0.87; PCoA2 OR 0.73; 95% CI 0.56-0.95). Furthermore, Dialister invisus and Megasphaera micronuciformis were more commonly detected in current smokers than in never smokers., Conclusions: Current smoking was associated with both alpha and beta diversity in the UGI tract. Future work should consider how the UGI microbiome is associated with smoking-related diseases.

Background: C-reactive protein (CRP) is a marker of systemic inflammation that has been associated with the incidence and prognosis for a number of different cancers. Recent data suggest that CRP may be a prognostic factor for liver cancer and cirrhosis. However, few long-term studies are available., Methods: We prospectively examined associations between serum CRP and subsequent risk of liver cancer incidence or chronic liver disease mortality in a nested case-control study performed in the Linxian Nutrition Intervention Trials cohort. Baseline serum CRP was measured for 220 incident liver cancer cases, 276 participants who died of chronic liver disease, and 1,018 age-, sex-, and trial-matched controls. Unconditional logistical regression models were used to estimate ORs and 95% confidence intervals (CI)., Results: Compared with the lowest quartile, subjects in the fourth quartile of serum CRP had a higher risk of liver cancer incidence (OR, 1.63; 95% CI, 1.06-2.51), with a significant Ptrend across quartiles (P = 0.01). The association with liver cancer was only significant among men (Q4 vs. Q1; OR, 2.00; 1.10-3.62), but not among women (Q4 vs. Q1; OR, 1.15; 0.60-2.22). For chronic liver disease deaths, the corresponding risk estimate in men and women was 2.95 (1.90-4.57), with a monotonic trend (P < 0.001)., Conclusions: Higher serum CRP concentrations at baseline were associated with subsequent incidence of liver cancer and death from chronic liver disease., Impact: Our findings suggest that levels of systemic inflammation may serve as a long-term marker of liver cancer and liver disease., (©2015 American Association for Cancer Research.)

Background: Mechanisms involved in wound healing play some role in carcinogenesis in multiple organs, likely by creating a chronic inflammatory milieu. This study sought to assess the role of genetic markers in selected inflammation-related genes involved in wound healing (interleukin (IL)-1a, IL-1b, IL-1 Receptor type I (IL-1Ra), IL-1 Receptor type II (IL-1Rb), tumour necrosis factor (TNF)-α, tumour necrosis factor receptor superfamily member (TNFRSF)1A, nuclear factor kappa beta (NF-kB)1, NF-kB2, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, hypoxia induced factor (HIF)-1α, vascular endothelial growth factor (VEGF)A and P-53) in risk to oesophageal squamous cell carcinoma (OSCC)., Methods: We genotyped 125 tag single nucleotide polymorphism (SNP)s in 410 cases and 377 age and sex matched disease-free individuals from Nutritional Intervention Trial (NIT) cohort, and 546 cases and 556 controls individually matched for age, sex and neighbourhood from Shanxi case-control study, both conducted in high-risk areas of north-central China (1985-2007). Cox proportional-hazard models and conditional logistic regression models were used for SNPs analyses for NIT and Shanxi, respectively. Fisher's inverse test statistics were used to obtain gene-level significance., Results: Multiple SNPs were significantly associated with OSCC in both studies, however, none retained their significance after a conservative Bonferroni adjustment. Empiric p-values for tag SNPs in VEGFA in NIT were highly concentrated in the lower tail of the distribution, suggesting this gene may be influencing risk. Permutation tests confirmed the significance of this pattern. At the gene level, VEGFA yielded an empiric significance (P=0.027) in NIT. We also observed some evidence for interaction between environmental factors and some VEGFA tag SNPs., Conclusion: Our finding adds further evidence for a potential role for markers in the VEGFA gene in the development and progression of early precancerous lesions of oesophagus., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Populations in north central China are at high risk for gastric cancers (GC), and altered FAS-mediated cell signaling and/or apoptosis may contribute to this risk. We examined the association of 554 single nucleotide polymorphisms (SNPs) in 53 Fas signaling-related genes using a pathway-based approach in 1758 GC cases (1126 gastric cardia adenocarcinomas (GCA) and 632 gastric noncardia adenocarcinomas (GNCA)), and 2111 controls from a genome-wide association study (GWAS) of GC in ethnic Chinese. SNP associations with risk of overall GC, GCA and GNCA were evaluated using unconditional logistic regressions controlling for age, sex and study. Gene- and pathway-based associations were tested using the adaptive rank-truncated product (ARTP) method. Statistical significance was evaluated empirically by permutation. Significant pathway-based associations were observed for Fas signaling with risk of overall GC (p = 5.5E-04) and GCA (p = 6.3E-03), but not GNCA (p= 8.1E-02). Among examined genes in the Fas signaling pathway, MAP2K4, FAF1, MAPK8, CASP10, CASP8, CFLAR, MAP2K1, CAP8AP2, PAK2 and IKBKB were associated with risk of GC (nominal p < 0.05), and FAF1 and MAPK8 were significantly associated with risk of both GCA and GNCA (nominal p< 0.05). Our examination of genetic variation in the Fas signaling pathway is consistent with an association of altered Fas signaling and/or apoptosis with risk of GC. As one of the first attempts to investigate a pathway-level association, our results suggest that these genes and the Fas signaling pathway warrant further evaluation in relation to GC risk in other populations., (© 2013 UICC.)

Background: China has some of the highest incidence rates for gastric adenocarcinoma (GA) and esophageal squamous cell carcinoma (ESCC) in the world. Prospective studies suggested that vitamin C may reduce risks; however, associations are unclear because of limited sample size., Objective: The objective was to examine the relation between prediagnostic plasma vitamin C and the risk of GA and ESCC., Design: A case-cohort study was used to assess the association between prediagnostic plasma vitamin C and incidence of GA (n = 467) and ESCC (n = 618) in the General Population Nutrition Intervention Trial. With the use of multivariate Cox proportional hazards models, we estimated the HRs and 95% CIs. We also conducted a meta-analysis of the literature up to 1 October 2012 on the relation between circulating vitamin C and gastric cancer incidence. Two cohort studies and the current study were included to assess the body of evidence., Results: For GA, each 20-μmol/L increase in plasma vitamin C was associated with a 14% decrease in risk (HR: 0.86; 95% CI: 0.76, 0.96). Compared with individuals with low plasma vitamin C concentrations (≤28 μmol/L), those with normal concentrations (>28 μmol/L) had a 27% reduced risk of GA (HR: 0.73; 95% CI: 0.56, 0.94). No association between vitamin C concentrations and ESCC was seen. Meta-analysis showed that the risk of incident GA among those with the highest concentration of plasma vitamin C was 31% lower (random-effects-pooled-odds ratio 0.69; 95% CI: 0.54, 0.89) than those in the lowest category., Conclusion: Our data provide evidence that higher circulating vitamin C was associated with a reduced risk of incident GA, but no association was seen for ESCC.

The epidermal growth factor receptor (EGFR) signaling pathway regulates cell proliferation, differentiation, and survival, and is frequently dysregulated in esophageal and gastric cancers. Few studies have comprehensively examined the association between germline genetic variants in the EGFR pathway and risk of esophageal and gastric cancers. Based on a genome-wide association study in a Han Chinese population, we examined 3443 SNPs in 127 genes in the EGFR pathway for 1942 esophageal squamous cell carcinomas (ESCCs), 1758 gastric cancers (GCs), and 2111 controls. SNP-level analyses were conducted using logistic regression models. We applied the resampling-based adaptive rank truncated product approach to determine the gene- and pathway-level associations. The EGFR pathway was significantly associated with GC risk (P = 2.16×10(-3)). Gene-level analyses found 10 genes to be associated with GC, including FYN, MAPK8, MAP2K4, GNAI3, MAP2K1, TLN1, PRLR, PLCG2, RPS6KB2, and PIK3R3 (P<0.05). For ESCC, we did not observe a significant pathway-level association (P = 0.72), but gene-level analyses suggested associations between GNAI3, CHRNE, PAK4, WASL, and ITCH, and ESCC (P<0.05). Our data suggest an association between specific genes in the EGFR signaling pathway and risk of GC and ESCC. Further studies are warranted to validate these associations and to investigate underlying mechanisms.

In China, esophageal cancer is the fourth leading cause of cancer death where essentially all cases are histologically esophageal squamous cell carcinoma (ESCC), in contrast to esophageal adenocarcinoma in the West. Globally, ESCC is 2.4 times more common among men than women and recently it has been suggested that sex hormones may be associated with the risk of ESCC. We examined the association between genetic variants in sex hormone metabolic genes and ESCC risk in a population from north central China with high-incidence rates. A total of 1026 ESCC cases and 1452 controls were genotyped for 797 unique tag single-nucleotide polymorphisms (SNPs) in 51 sex hormone metabolic genes. SNP-, gene- and pathway-based associations with ESCC risk were evaluated using unconditional logistic regression adjusted for age, sex and geographical location and the adaptive rank truncated product (ARTP) method. Statistical significance was determined through use of permutation for pathway- and gene-based associations. No associations were observed for the overall sex hormone metabolic pathway (P = 0.14) or subpathways (androgen synthesis: P = 0.30, estrogen synthesis: P = 0.15 and estrogen removal: P = 0.19) with risk of ESCC. However, six individual genes (including SULT2B1, CYP1B1, CYP3A7, CYP3A5, SHBG and CYP11A1) were significantly associated with ESCC risk (P < 0.05). Our examination of genetic variation in the sex hormone metabolic pathway is consistent with a potential association with risk of ESCC. These positive findings warrant further evaluation in relation to ESCC risk and replication in other populations.

Genome-wide association studies have identified susceptibility loci for esophageal squamous cell carcinoma (ESCC). We conducted a meta-analysis of all single-nucleotide polymorphisms (SNPs) that showed nominally significant P-values in two previously published genome-wide scans that included a total of 2961 ESCC cases and 3400 controls. The meta-analysis revealed five SNPs at 2q33 with P< 5 × 10(-8), and the strongest signal was rs13016963, with a combined odds ratio (95% confidence interval) of 1.29 (1.19-1.40) and P= 7.63 × 10(-10). An imputation analysis of 4304 SNPs at 2q33 suggested a single association signal, and the strongest imputed SNP associations were similar to those from the genotyped SNPs. We conducted an ancestral recombination graph analysis with 53 SNPs to identify one or more haplotypes that harbor the variants directly responsible for the detected association signal. This showed that the five SNPs exist in a single haplotype along with 45 imputed SNPs in strong linkage disequilibrium, and the strongest candidate was rs10201587, one of the genotyped SNPs. Our meta-analysis found genome-wide significant SNPs at 2q33 that map to the CASP8/ALS2CR12/TRAK2 gene region. Variants in CASP8 have been extensively studied across a spectrum of cancers with mixed results. The locus we identified appears to be distinct from the widely studied rs3834129 and rs1045485 SNPs in CASP8. Future studies of esophageal and other cancers should focus on comprehensive sequencing of this 2q33 locus and functional analysis of rs13016963 and rs10201587 and other strongly correlated variants.

Background: Gastric cancer incidence rates are consistently lower in women than men in both high and low-risk regions worldwide. Sex hormones, such as progesterone and estrogen, may protect women against gastric cancer., Objective: To investigate the association of menstrual and reproductive factors and gastric cancer risk., Methods: These associations were prospectively investigated in 73 442 Shanghai women. After 419 260 person-years of follow-up, 154 women were diagnosed with gastric cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models adjusted for age, body mass index, education, income, and cigarette use., Results: No associations were observed between gastric cancer risk and age of menarche, number of children, breast feeding, or oral contraceptive use. In contrast, associations were observed with age of menopause (HR 0.80 per five-year increase in menopausal age, 95% CI 0.66-0.97), years of fertility (participants with less than 30 years of fertility were at increased risk compared with those with 30-36 years of fertility, HR 1.90, 95% CI 1.25-2.90), years since menopause (HR 1.26 per five years, 95% CI 1.03-1.53), and intrauterine device use (HR for users 1.61, 95% CI 1.08-2.39)., Conclusions: These results support the hypothesis that female hormones play a protective role in gastric cancer risk.