BACKGROUND:Gastric cancer (GC) is clinically heterogenous according to location (cardia/non-cardia) and histopathology (diffuse/intestinal). We aimed to characterize the genetic risk architecture of GC according to its subtypes. Another aim was to examine whether cardia GC and oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett's oesophagus (BO), which are all located at the gastro-oesophageal junction (GOJ), share polygenic risk architecture.METHODS:We did a meta-analysis of ten European genome-wide association studies (GWAS) of GC and its subtypes. All patients had a histopathologically confirmed diagnosis of gastric adenocarcinoma. For the identification of risk genes among GWAS loci we did a transcriptome-wide association study (TWAS) and expression quantitative trait locus (eQTL) study from gastric corpus and antrum mucosa. To test whether cardia GC and OAC/BO share genetic aetiology we also used a European GWAS sample with OAC/BO.FINDINGS:Our GWAS consisting of 5816 patients and 10,999 controls highlights the genetic heterogeneity of GC according to its subtypes. We newly identified two and replicated five GC risk loci, all of them with subtype-specific association. The gastric transcriptome data consisting of 361 corpus and 342 antrum mucosa samples revealed that an upregulated expression of MUC1, ANKRD50, PTGER4, and PSCA are plausible GC-pathomechanisms at four GWAS loci. At another risk locus, we found that the blood-group 0 exerts protective effects for non-cardia and diffuse GC, while blood-group A increases risk for both GC subtypes. Furthermore, our GWAS on cardia GC and OAC/BO (10,279 patients, 16,527 controls) showed that both cancer entities share genetic aetiology at the polygenic level and identified two new risk loci on the single-marker level.INTERPRETATION:Our findings show that the pathophysiology of GC is genetically heterogenous according to location and histopathology. Moreover, our findings point to common molecular mechanisms underlying cardia GC and OAC/BO.FUNDING:German Research Foundation (DFG).

The authors would like to acknowledge that the name of one co-author was misspelled. In addition, the Acknowledgement in the Supplement omitted information about one third-party funding source. The corrected name of the co-author is presented above and the corrected Acknowledgement in the Supplement is presented below. This study was indirectly supported by the Heinz Nixdorf Recall Study (HNR); German Cancer Aid (Mildred-Scheel-Doktorandenprogramm (70113577)); Baden-Württemberg State Ministry of Research, Science and Arts; Institute of Clinical Cancer Research at Northwest Hospital Frankfurt; Sanofi-Aventis; Chugai; Stiftung Leben mit Krebs Foundation; CIMED; Riga East University Hospital and Digestive Diseases Centre GASTRO; Institute of Clinical and Preventive Medicine and Riga East University Hospital; Lithuanian Research Council (VP1-3.1-ŠMM-07-156 and 09.3.3-LMT-K-712-01-0130); Polish National Science Centre (2012/07/B/NZ2/00115); Instituto de Salud Carlos III (PI22/00537); European Union (ERDF/ESF) (2014-2020.4.01.15-0012 and HEALTH-2007-201550); Gobierno de Aragón, Grupos de investigación DGA; CIBERehd; Fundação para a Ciência e Tecnologia (FCT) (SFRH/BPD/114803/2016); MCTES; MEDeA Onlus; Italian Ministry of Health; Ministero della Salute Ricerca Corrente Italy; National Institutes of Health (NIH), National Cancer Institute (U01CA155309); Lille University Hospital (FREGAT study); French National Cancer Institute (INCa) (FREGAT study), la Région Hauts-de-France. The authors thank the Biological Resources Centers of the Centre Hospitalier Universitaire de Lille (BB 0033-00030), the Hospices Civiles de Lyon (BB-0033-00046), the Centre Hospitalier Universitaire de Rennes (BB-0033-00056) and the Centre Hospitalier Universitaire de Bordeaux for providing the biological samples of the FREGAT database. Dissecting the genetic heterogeneity of gastric cancerOur findings show that the pathophysiology of GC is genetically heterogenous according to location and histopathology. Moreover, our findings point to common molecular mechanisms underlying cardia GC and OAC/BO. Full-Text PDF Open Access

Summary: Background: Gastric cancer (GC) is clinically heterogenous according to location (cardia/non-cardia) and histopathology (diffuse/intestinal). We aimed to characterize the genetic risk architecture of GC according to its subtypes. Another aim was to examine whether cardia GC and oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett’s oesophagus (BO), which are all located at the gastro-oesophageal junction (GOJ), share polygenic risk architecture. Methods: We did a meta-analysis of ten European genome-wide association studies (GWAS) of GC and its subtypes. All patients had a histopathologically confirmed diagnosis of gastric adenocarcinoma. For the identification of risk genes among GWAS loci we did a transcriptome-wide association study (TWAS) and expression quantitative trait locus (eQTL) study from gastric corpus and antrum mucosa. To test whether cardia GC and OAC/BO share genetic aetiology we also used a European GWAS sample with OAC/BO. Findings: Our GWAS consisting of 5816 patients and 10,999 controls highlights the genetic heterogeneity of GC according to its subtypes. We newly identified two and replicated five GC risk loci, all of them with subtype-specific association. The gastric transcriptome data consisting of 361 corpus and 342 antrum mucosa samples revealed that an upregulated expression of MUC1, ANKRD50, PTGER4, and PSCA are plausible GC-pathomechanisms at four GWAS loci. At another risk locus, we found that the blood-group 0 exerts protective effects for non-cardia and diffuse GC, while blood-group A increases risk for both GC subtypes. Furthermore, our GWAS on cardia GC and OAC/BO (10,279 patients, 16,527 controls) showed that both cancer entities share genetic aetiology at the polygenic level and identified two new risk loci on the single-marker level. Interpretation: Our findings show that the pathophysiology of GC is genetically heterogenous according to location and histopathology. Moreover, our findings point to common molecular mechanisms underlying cardia GC and OAC/BO. Funding: German Research Foundation (DFG).

Abstract Genetic associations between variants on chromosome 5p13 and 8q24 and gastric cancer (GC) have been previously reported in the Asian population. We aimed to replicate these findings and to characterize the associations at the genome and transcriptome level. We performed a fine‐mapping association study in 1926 GC patients and 2012 controls of European descent using high dense SNP marker sets on both chromosomal regions. Next, we performed expression quantitative trait locus (eQTL) analyses using gastric transcriptome data from 143 individuals focusing on the GC associated variants. On chromosome 5p13 the strongest association was observed at rs6872282 (P = 2.53 × 10−04) and on chromosome 8q24 at rs2585176 (P = 1.09 × 10−09). On chromosome 5p13 we found cis‐eQTL effects with an upregulation of PTGER4 expression in GC risk allele carrier (P = 9.27 × 10−11). On chromosome 8q24 we observed cis‐eQTL effects with an upregulation of PSCA expression in GC risk allele carrier (P = 2.17 × 10−47). In addition, we found trans‐eQTL effects for the same variants on 8q24 with a downregulation of MBOAT7 expression in GC risk allele carrier (P = 3.11 × 10−09). In summary, we confirmed and refined the previously reported GC associations at both chromosomal regions. Our data point to shared etiological factors between Asians and Europeans. Furthermore, our data imply an upregulated expression of PTGER4 and PSCA as well as a downregulated expression of MBOAT7 in gastric tissue as risk‐conferring GC pathomechanisms.

Variations in DNA repair genes have been reported as key factors in gastric cancer (GC) susceptibility but results among studies are inconsistent. We aimed to assess the relevance of DNA repair gene polymorphisms and environmental factors to GC risk and phenotype in a Caucasian population in Spain. Genomic DNA from 603 patients with primary GC and 603 healthy controls was typed for 123 single nucleotide polymorphisms in DNA repair genes using the Illumina platform. Helicobacter pylori infection with CagA strains (odds ratio (OR): 1.99; 95% confidence interval (CI): 1.55-2.54), tobacco smoking (OR: 1.77; 95% CI: 1.22-2.57), and family history of GC (OR: 2.87; 95% CI: 1.85-4.45) were identified as independent risk factors for GC. By contrast, the TP53 rs9894946A (OR: 0.73; 95% CI: 0.56-0.96), TP53 rs1042522C (OR: 0.76; 95% CI: 0.56-0.96), and BRIP1 rs4986764T (OR: 0.55; 95% CI: 0.38-0.78) variants were associated with lower GC risk. Significant associations with specific anatomopathological GC subtypes were also observed, most notably in the ERCC4 gene with the rs1799801C, rs2238463G, and rs3136038T variants being inversely associated with cardia GC risk. Moreover, the XRCC3 rs861528 allele A was significantly increased in the patient subgroup with diffuse GC (OR: 1.75; 95% CI: 1.30-2.37). Our data show that specific TP53, BRIP1, ERCC4, and XRCC3 polymorphisms are relevant in susceptibility to GC risk and specific subtypes in Caucasians.

Two recent genome‐wide association studies in Asians have reported the association between the PSCA (prostate stem cell antigen) rs2294008C>T gene polymorphism and two Helicobacter pylori infection‐related diseases such as gastric cancer (GC) and duodenal ulcer (DU). Since rs2294008 allele frequencies differ notably among ethnicities, we aimed to assess the role of rs2294008 on the susceptibility to GC and DU in a Caucasian population in Spain. Moreover, the relevance of rs2294008 on GC prognosis was evaluated. Genomic DNA from 603 Spanish patients with primary GC, 139 with DU and 675 healthy controls was typed for the PSCA rs2294008C>T polymorphism by PCR‐TaqMan assays. H. pylori infection [odds ratio (OR): 8.27; 95% confidence interval (CI): 3.45–15.33] and nonsteroidal anti‐inflammatory drugs (OR: 6.54; 95% CI: 3.19–12.43) were identified as independent risk factors for DU whereas the rs2294008T allele was associated with reduced risk of developing the disease (OR: 0.52; 95% CI: 0.33–0.82). Infection with CagA strains (OR: 2.10; 95% CI: 1.63–2.34), smoking (OR: 1.93; 95% CI: 1.54–2.61), family history of GC (OR: 2.83; 95% CI: 2.01–3.83), and the rs2294008T allele (OR: 1.46; 95% CI: 1.07–1.99) were associated with increased risk of GC. Interestingly, the association with the rs2294008T allele was restricted to noncardia GC (OR: 1.43; 95% CI: 1.12–1.82), particularly of the diffuse histotype (OR: 1.59; 95% CI: 1.16–1.92). Finally, Cox regression analysis identified the rs2294008T variant as a prognosis factor associated with worse overall survival in patients with diffuse‐type GC (hazard ratio: 1.85; 95% CI: 1.12–3.06). From these results we conclude that the PSCA rs2294008 polymorphism is involved in the susceptibility to GC and DU, as well as in the prognosis of the diffuse‐type of GC in Caucasians.

Colorectal cancer (CRC) screening has been shown to reduce CRC incidence and mortality through the endoscopic detection and removal of colorectal adenomas.Still, these patients are at increased risk for developing metachronous adenomas or even cancer, with the recurrence rate reaching the 50%.The pleiotropic effects of higher levels of PGE 2 contribute to key steps of cancer development, including cell proliferation, angiogenesis, invasiveness and migration, inhibition of apoptosis and immunosurveillance as a refletion of deregulation of ATP-binding cassete sub-family c member 4 (ABCC4) and solute carrier organic anion transporter family, member 2A1 (SLCO2A1) genes responsable for carrying PGE 2 accross the membrane.To evaluate the influence of genetic polymorphisms in ABCC4 and SLCO2A1 on the risk and time for colorectal adenoma recurrence a retrospective case-cohort study was designed gathering 195 patients diagnosed with colorectal adenomas.Adenoma reccurence was defined has the diagnosis of an adenoma after a total normal colonoscopy at least one year after the initial diagnosis.Thirty-three tagSNPs were characterized using the MassARRAY iPLEX Gold technology based on multiplex amplification followed by mass-spectrometric product separation.Three tagSNPs were identified as susceptibility biomarkers for colorectal adenoma recurrence after a bootstrap analysis.The rs1131598GG homozygous genotype of SLCO2A1 gene was associated with an enhanced risk of 6.3 (95%CI:1.31-30.0,P=0.021).In contrast and under a dominant model of inheritance, the rs1751031 and rs9524821 polymorphisms in ABCC4 gene displayed a protective behaviour (OR=0.29,95%CI:0.12-0.72,P=0.007 and OR=0.42, 95%CI:0.19-0.93,P=0.033, respectively).Furthermore, when stratifying patients considering the endoscopic findings at baseline colonoscopy, low-risk individuals carriers of rs2274403AA genotype in ABCC4 gene had a lower interval until recurrence (85 (29-140) vs 122 (109-135), P=0.011) with 44% of metachronous tumors developing by 36 months (vs 23% for AG/GG).This study demonstrates for the first time the involvement of genetic variants in PGE 2 transporters in colorectal adenoma recurrence.The incorporation of genetically-based approaches might allow an optimization of current risk models for the development of metachronous colorectal adenomas or even more advanced lesions possible laeding to a decrease in CRC burden and mortality.

Human glutathione S-transferases (GSTs) are phase II metabolizing enzymes that play a key role in protecting against cancer by detoxifying numerous potentially cytotoxic/genotoxic compounds. The genes encoding the human GST isoenzymes GSTM(mu)1, GSTT(theta)1 and GSTP(pi)1 harbour polymorphisms, which have been considered important modifiers of the individual risk for environmentally induced cancers such as gastric cancer (GC). However, results are inconsistent among studies from different geographic areas and ethnic groups. Our goal was to perform a nationwide, case-control study in Spain to evaluate the relevance of several functional GST gene polymorphisms and environmental factors to GC risk and phenotype. DNA from 557 GC patients and 557 sex- and age-matched healthy controls (HC) was typed for two deletions in the GSTM1 and GSTT1 genes and two SNPs in the GSTP1 gene (rs1695 and rs1138272) using polymerase chain reaction-restriction fragment length polymorphism methods. Logistic regression analysis identified Helicobacter pylori infection with CagA strains [odds ratio (OR): 2.36; 95% confidence interval (CI): 1.78-3.15], smoking habit (OR: 2.10; 95% CI: 1.48-2.97) and family history of GC (OR: 3.2; 95% CI: 2.02-5.16) as independent risk factors for GC. No differences in the frequencies of GSTM1 or GSTT1 null genotypes were observed between cases and controls (GSTM1: 50.8% vs. 48%; GSTT1: 21.5% vs. 21%). Moreover, simultaneous carriage of both, the GSTM1 and the GSTT1 null genotypes, was almost identical in both groups (10.7% in GC vs. 10.6% in HC). In addition, no significant differences in GSTP1 Ile105Val (rs1695) and GSTP1 Val114Ala (rs1138272) genotype distribution were observed between GC patients and controls. Subgroup analysis for age, gender, Helicobacter pylori status, smoking habits, family history of GC, anatomic location and histological subtype revealed no significant association between GST variants and GC risk. Our results show that the GST polymorphisms evaluated in this study are not relevant when determining the individual susceptibility to GC or phenotype in a South-European population.

Ma Asunción García-González1,2,*, Enrique Quintero3, Luis Bujanda4,2, David Nicolás3, Rafael Benito5,2, Mark Strunk1,2, Santos Santolaria6, Federico Sopeña7,2, María Badía7, Elizabeth Hijona4, Ma Angeles Pérez-Aísa8, Isabel Ma Méndez-Sánchez8, Concha Thomson9, Patricia Carrera2, Elena Piazuelo1,2, Pilar Jiménez2, Jesús Espinel10, Rafael Campo11, Marisa Manzano12, Fernando Geijo13, Maria Pellisé14,2, Ferrán González-Huix15, Jorge Espinós16, LLusia Titó17, Manuel Zaballa18, Roberto Pazo19 and Angel Lanas1,2,7

data of cases were collected, characteristics of the carcinomas were described, and available FFPE tissue slides were immunostained for β-catenin, P53 and phospho-S6 (a downstream target of mTOR).Furthermore, we performed DNA mutation analyses for BRAF, KRAS, and P53, and LOH analyses for LKB1 and P53.Results: Twenty-eight of the 144 patients (19%, 64% males) from 20 families developed 30 GI malignancies at a median age of 44 years (IQR 35-57) at diagnosis of first cancer (Table ).Two patients were diagnosed with two primary GI carcinomas.Three (10%) malignancies were discovered during surveillance; all carcinomas in situ (one colorectal and two gastric lesions).Twenty-three patients (82%) deceased at a median age of 54 years (IQR 36-61); 19 (68%) of whom had died as a direct cause of GI cancer.Of these 23 patients, median survival after GI cancer diagnosis was 6 months (IQR 1-18).Of 16 carcinomas FFPE tissue was available for molecular analysis.Nuclear β-catenin was detected in 3/5 (60%) primary intestinal carcinomas.Overexpression of P53 was observed in 7/16 (44%) carcinomas, and a total absence of P53 was observed in one (6%) sample.All available samples showed heterogeneous expression of pS6, in which epithelial expression was more pronounced compared to the stromal component in 9/14 (64%) cases.Mutation and LOH analyses are currently being performed.Conclusion: Gastrointestinal cancer often affects PJS patients already at a young age.Alterations in Wnt/ β-catenin signaling and in P53 are observed in a subset of PJS carcinomas, while activation of mTOR signaling seems to be altered in the majority of these carcinomas, predominantly in the epithelial compartment.These results suggest that treatment with mTOR inhibitors may be beneficial in the anti-cancer treatment of PJS patients.

Background: Genetic factors influencing the prognosis of gastric adenocarcinoma (GAC) are not well known. Given the relevance of cytokines and other pro-inflammatory mediators in cancer progression and invasiveness, we aimed to assess the prognostic role of several functional cytokine and cyclooxygenase gene polymorphisms in patients with GAC.Methodology: Genomic DNA from 380 Spanish Caucasian patients with primary GAC was genotyped for 23 polymorphisms in pro-inflammatory (IL1B, TNFA, LTA, IL6, IL12p40), anti-inflammatory (IL4, IL1RN, IL10, TGFB1) cytokine, and cyclooxygenase (PTGS1 and PTGS2) genes by PCR, RFLP and TaqMan assays. Clinical and histological information was collected prospectively. Survival curves were estimated by the Kaplan-Meier method and compared using the log rank test. Outcome was determined by analysis of Cox proportional hazards, adjusting for confounding factors.Results: The median follow-up period and median overall survival (OS) time were 9.9 months (range 0.4-120.3) and 10.9 months (95% CI: 8.9-14.1), respectively. Multivariate analysis identified tumor stages III (HR, 3.23; 95% CI: 2-5.22) and IV (HR, 5.5; 95% CI: 3.51-8.63) as independent factors associated with a significantly reduced OS, whereas surgical treatment (HR: 0.44; 95% CI: 0.3-0.6) was related to a better prognosis of the disease. Concerning genetic factors, none of the 23 polymorphisms evaluated in the current study did influence survival. Moreover, no gene-environment interactions on GAC prognosis were observed.Conclusions: Our results show that, in our population, the panel of selected pro-and anti-inflammatory cytokine, and cyclooxygenase gene polymorphisms are not relevant in determining the prognosis of gastric adenocarcinoma.

of the C allele is associated with increased risk for various cancers including colorectal cancer.Using reporter constructs bearing the COX-2 3'UTR, the presence of the C allele altered the ability of miR-542-3p to effectively target the 3'UTR.In addition, individuals that are carriers of the T8473C SNP display elevated COX-2 mRNA expression that correlates with the presence of the C allele.These findings demonstrate miRNA-specific targeting of COX-2 and implicates that alterations in the miRNA/COX-2 3'UTR interaction through disease-associated polymorphisms can contribute to pathogenic COX-2 overexpression observed in many cancers and chronic inflammatory states.

Relevance of GSTM1, GSTT1, and GSTP1 Gene Polymorphisms On Gastric Cancer Susceptibility Maria Asuncion Garcia-Gonzalez, Enrique Quintero, Rafael Benito, Mark Strunk, David Nicolas-Perez, Adolfo Parra-Blanco, Santos Santolaria, Federico Sopena, Elena Piazuelo, Pilar Jimenez, Maria Badia, Jesus Espinel, Rafael Campo, Marisa Manzano, Fernando Geijo, Maria Pellise, Ferran Gonzalez-Huix, Miguel Nieto, Jorge C. Espinos, LLucia Tito, Luis Bujanda, Manuel Zaballa, Maria Angeles Perez-Aisa, Isabel Maria Mendez-Sanchez, Angel Lanas

BACKGROUND AND AIMS: Recent studies have reported an association between cytokine gene polymorphisms and GC risk. However, results are inconsistent among studies from different geographic regions and ethnic groups. Our goal was to evaluate the influence of Helicobacter pylori (H. pylori) infection and host genetic factors on GC susceptibility in a population of Spanish white GC patients.METHODS: DNA from 404 unrelated patients with GC and 404 sex- and age-matched healthy controls was typed for several functional polymorphisms in pro- (IL-1B, TNFA, LTA, IL-12p40) and anti-inflammatory (IL-4, IL-1RN, IL-10, TGFB1) genes by PCR, RFLP, and TaqMan assays. H. pylori infection and CagA/VacA antibody status were also determined by western blot serology.RESULTS: Logistic regression analysis identified H. pylori infection with cagA strains (OR 2.54, 95% CI 1.77-3.66), smoking habit (OR 1.91, 95% CI 1.25-2.93), and positive family history of GC (OR 3.67, 95% CI 2.01-6.71) as independent risk factors for GC. None of the cytokine gene polymorphisms analyzed in this study were associated with susceptibility to GC development, whether GC patients were analyzed as a group or categorized according to anatomic location or histological subtype. Some simultaneous combinations of proinflammatory genotypes reportedly associated with greater GC risk yielded no significant differences between patients and controls.CONCLUSIONS: Our results show that, at least in some white populations, the contribution of the cytokine gene polymorphisms evaluated in this study (IL-1B, IL-1RN, IL-12p40, LTA, IL-10, IL-4, and TGF-B1) to GC susceptibility may be less relevant than previously reported.