GWAS meta-analysis of 16 790 patients with Barrett's oesophagus and oesophageal adenocarcinoma identifies 16 novel genetic risk loci and provides insights into disease aetiology beyond the single marker level.

OBJECTIVE: Oesophageal cancer (EC) is the sixth leading cause of cancer-related deaths. Oesophageal adenocarcinoma (EA), with Barrett's oesophagus (BE) as a precursor lesion, is the most prevalent EC subtype in the Western world. This study aims to contribute to better understand the genetic causes of BE/EA by leveraging genome wide association studies (GWAS), genetic correlation analyses and polygenic risk modelling. DESIGN: We combined data from previous GWAS with new cohorts, increasing the sample size to 16 790 BE/EA cases and 32 476 controls. We also carried out a transcriptome wide association study (TWAS) using expression data from disease-relevant tissues to identify BE/EA candidate genes. To investigate the relationship with reported BE/EA risk factors, a linkage disequilibrium score regression (LDSR) analysis was performed. BE/EA risk models were developed combining clinical/lifestyle risk factors with polygenic risk scores (PRS) derived from the GWAS meta-analysis. RESULTS: The GWAS meta-analysis identified 27 BE and/or EA risk loci, 11 of which were novel. The TWAS identified promising BE/EA candidate genes at seven GWAS loci and at five additional risk loci. The LDSR analysis led to the identification of novel genetic correlations and pointed to differences in BE and EA aetiology. Gastro-oesophageal reflux disease appeared to contribute stronger to the metaplastic BE transformation than to EA development. Finally, combining PRS with BE/EA risk factors improved the performance of the risk models. CONCLUSION: Our findings provide further insights into BE/EA aetiology and its relationship to risk factors. The results lay the foundation for future follow-up studies to identify underlying disease mechanisms and improving risk prediction.

[Therapy of esophageal motility disorders]. / Therapieoptionen von primären Motilitätsstörungen des Ösophagus.

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2020 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

[Diagnosis of esophageal motility disorders - Significance of the new Chicago classification v4.0]. / Diagnostik von Motilitätsstörungen des Ösophagus ­ Bedeutung der neuen Chicago-Klassifikation v4.0.

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2021 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

[Diagnosis of esophageal motility disorders - Significance of the new Chicago classification v4.0]. / Diagnostik von Motilitätsstörungen des Ösophagus ­ Bedeutung der neuen Chicago-Klassifikation v4.0.

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2021 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

[Therapy of esophageal motility disorders]. / Therapieoptionen von primären Motilitätsstörungen des Ösophagus.

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2020 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

No Association Between Vitamin D Status and Risk of Barrett's Esophagus or Esophageal Adenocarcinoma: A Mendelian Randomization Study.

BACKGROUND & AIMS: Epidemiology studies of circulating concentrations of 25 hydroxy vitamin D (25(OH)D) and risk of esophageal adenocarcinoma (EAC) have produced conflicting results. We conducted a Mendelian randomization study to determine the associations between circulating concentrations of 25(OH)D and risks of EAC and its precursor, Barrett's esophagus (BE). METHODS: We conducted a Mendelian randomization study using a 2-sample (summary data) approach. Six single-nucleotide polymorphisms (SNPs; rs3755967, rs10741657, rs12785878, rs10745742, rs8018720, and rs17216707) associated with circulating concentrations of 25(OH)D were used as instrumental variables. We collected data from 6167 patients with BE, 4112 patients with EAC, and 17,159 individuals without BE or EAC (controls) participating in the Barrett's and Esophageal Adenocarcinoma Consortium, as well as studies from Bonn, Germany, and Cambridge and Oxford, United Kingdom. Analyses were performed separately for BE and EAC. RESULTS: Overall, we found no evidence for an association between genetically estimated 25(OH)D concentration and risk of BE or EAC. The odds ratio per 20 nmol/L increase in genetically estimated 25(OH)D concentration for BE risk estimated by combining the individual SNP association using inverse variance weighting was 1.21 (95% CI, 0.77-1.92; P = .41). The odds ratio for EAC risk, estimated by combining the individual SNP association using inverse variance weighting, was 0.68 (95% CI, 0.39-1.19; P = .18). CONCLUSIONS: In a Mendelian randomization study, we found that low genetically estimated 25(OH)D concentrations were not associated with risk of BE or EAC.

Stress biomarkers in minimally invasive and conventional colorectal resections.

INTRODUCTION: Any surgical procedure develops a stress situation for the patient, which can modulate the individual outcome. At present, there is only limited information about stress response in colorectal resections by laparoscopic compared to conventional surgery. Therefore, our objectives were the feasibility and the investigation of stress biomarkers including copeptin and steroid hormones before, during and after colorectal surgery. METHODS: Eleven patients underwent minimally invasive and ten patients conventionally open colorectal surgery. Blood samples were collected before, during and 24 h after surgery and copeptin, NT-proBNP, cortisol, cortisone, interleukin-6 and glucose were analyzed. RESULTS: Both, minimally invasive and conventional-open colorectal surgery caused a fast but heterogeneous response of stress biomarkers. However, the postoperative decrease of cortisol, cortisone and glucose differed between both groups. The stress biomarkers decreased faster down to baseline after minimally invasive surgery, while in open surgery cortisol, cortisone and glucose did not return to baseline within 24 h after operation. CONCLUSIONS: We show in this feasibility study for the first time an increase of copeptin in combination with glucocorticoids as stress biomarkers by open surgery compared to minimally invasive procedures in patients undergoing colorectal surgery. Exceeding an individual threshold of 'stress burden' may have unfavorable effects on the long-time clinical outcome.

Genome-wide association studies in oesophageal adenocarcinoma and Barrett's oesophagus: a large-scale meta-analysis.

BACKGROUND: Oesophageal adenocarcinoma represents one of the fastest rising cancers in high-income countries. Barrett's oesophagus is the premalignant precursor of oesophageal adenocarcinoma. However, only a few patients with Barrett's oesophagus develop adenocarcinoma, which complicates clinical management in the absence of valid predictors. Within an international consortium investigating the genetics of Barrett's oesophagus and oesophageal adenocarcinoma, we aimed to identify novel genetic risk variants for the development of Barrett's oesophagus and oesophageal adenocarcinoma. METHODS: We did a meta-analysis of all genome-wide association studies of Barrett's oesophagus and oesophageal adenocarcinoma available in PubMed up to Feb 29, 2016; all patients were of European ancestry and disease was confirmed histopathologically. All participants were from four separate studies within Europe, North America, and Australia and were genotyped on high-density single nucleotide polymorphism (SNP) arrays. Meta-analysis was done with a fixed-effects inverse variance-weighting approach and with a standard genome-wide significance threshold (p<5 × 10-8). We also did an association analysis after reweighting of loci with an approach that investigates annotation enrichment among genome-wide significant loci. Furthermore, the entire dataset was analysed with bioinformatics approaches-including functional annotation databases and gene-based and pathway-based methods-to identify pathophysiologically relevant cellular mechanisms. FINDINGS: Our sample comprised 6167 patients with Barrett's oesophagus and 4112 individuals with oesophageal adenocarcinoma, in addition to 17 159 representative controls from four genome-wide association studies in Europe, North America, and Australia. We identified eight new risk loci associated with either Barrett's oesophagus or oesophageal adenocarcinoma, within or near the genes CFTR (rs17451754; p=4·8 × 10-10), MSRA (rs17749155; p=5·2 × 10-10), LINC00208 and BLK (rs10108511; p=2·1 × 10-9), KHDRBS2 (rs62423175; p=3·0 × 10-9), TPPP and CEP72 (rs9918259; p=3·2 × 10-9), TMOD1 (rs7852462; p=1·5 × 10-8), SATB2 (rs139606545; p=2·0 × 10-8), and HTR3C and ABCC5 (rs9823696; p=1·6 × 10-8). The locus identified near HTR3C and ABCC5 (rs9823696) was associated specifically with oesophageal adenocarcinoma (p=1·6 × 10-8) and was independent of Barrett's oesophagus development (p=0·45). A ninth novel risk locus was identified within the gene LPA (rs12207195; posterior probability 0·925) after reweighting with significantly enriched annotations. The strongest disease pathways identified (p<10-6) belonged to muscle cell differentiation and to mesenchyme development and differentiation. INTERPRETATION: Our meta-analysis of genome-wide association studies doubled the number of known risk loci for Barrett's oesophagus and oesophageal adenocarcinoma and revealed new insights into causes of these diseases. Furthermore, the specific association between oesophageal adenocarcinoma and the locus near HTR3C and ABCC5 might constitute a novel genetic marker for prediction of the transition from Barrett's oesophagus to oesophageal adenocarcinoma. Fine-mapping and functional studies of new risk loci could lead to identification of key molecules in the development of Barrett's oesophagus and oesophageal adenocarcinoma, which might encourage development of advanced prevention and intervention strategies. FUNDING: US National Cancer Institute, US National Institutes of Health, National Health and Medical Research Council of Australia, Swedish Cancer Society, Medical Research Council UK, Cambridge NIHR Biomedical Research Centre, Cambridge Experimental Cancer Medicine Centre, Else Kröner Fresenius Stiftung, Wellcome Trust, Cancer Research UK, AstraZeneca UK, University Hospitals of Leicester, University of Oxford, Australian Research Council.

Psychological burden of achalasia: Patients' screening rates of depression and anxiety and sex differences.

OBJECTIVE: Achalasia is associated with reduced quality of life in affected patients but research regarding the psychological burden of achalasia in terms of depression and anxiety is scarce. The current study therefore aims to investigate rates of depression and anxiety in patients with achalasia in relation to prevalence rates in the general population and to examine the extent to which achalasia-related characteristics (time since diagnosis, symptom load, achalasia-related quality of life, treatment history) predict symptoms of depression and anxiety. METHODS: Using validated screening instruments, rates of depression and anxiety were assessed in a cross-sectional survey of a sample of 993 patients with achalasia and compared to population controls stratified by age and sex. Associations between depression and anxiety and achalasia-related factors were explored using linear regression. RESULTS: Compared to population controls, screening rates of female patients with achalasia were between 3.04 (p = .004) and 7.87 (p < .001) times higher for depression and 3.10 (p < .001) times higher for anxiety, respectively. No significant differences were found for male patients with achalasia. Both achalasia-related quality of life and symptom load were independently related to impaired mental health. CONCLUSION: Women appear to be specifically affected by the psychological burden of achalasia, pointing to sex-specific or gendered experiences of the disease. In addition to symptom reduction, psychological support may prove beneficial for improving the well-being of patients with achalasia.

Dissecting the genetic heterogeneity of gastric cancer.

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).

Anxiety and depression in patients with Barrett's esophagus: estimates of disorder rates and associations with symptom load and treatment-seeking.

BACKGROUND: Patients with Barrett's esophagus (BE) may experience psychological burden from living with a chronic medical condition, which has been identified as the most important risk factor for esophageal adenocarcinoma. The aim of this study was to estimate rates of depression and anxiety in a large sample of patients with BE. METHODS: A total of 794 patients with endoscopically and histologically confirmed diagnosis of BE completed validated screening instruments for depression (Patient Health Questionnaire-9) and anxiety (Generalized Anxiety Disorder-7). Screening rates in the study sample were compared to general population estimates. Multivariable regression analyses were used to model associations between outcome variables and respondents' sociodemographic characteristics, BE-related symptom load and incidence of inpatient treatment due to BE in the last 12 months. RESULTS: Rates of positive screens were 14.2% for depression and 9.9% for anxiety. For several age by sex subgroups, rates of depression and anxiety were about three to five times higher in the study sample than in the general population. BE-related reflux and pain symptoms showed strong associations with higher levels of depressive and anxiety symptoms, while the effect of treatment was small. CONCLUSION: Study results indicate that a relevant proportion of patients with BE is at an increased risk for depression and anxiety, compared to general population controls. Lacking information on patients' disease characteristics limited generalizability of results.

Different Prevalence of Alarm, Dyspeptic and Reflux Symptoms in Patients with Cardia and Non-cardia Gastric Cancer.

BACKGROUND AND AIMS: Symptoms of patients with gastric cancer (GC) are often unspecific and differences in symptoms between patients with cardia and non-cardia GC have been poorly investigated. We aimed to characterize symptoms of patients with cardia and non-cardia GC. METHODS: Patients with cardia (Siewert type II and III) and non-cardia GC were recruited in the German multicenter cohort of the Gastric Cancer Research (staR) study between 2013 and 2017. Alarm, dyspeptic and reflux symptoms at the time of presentation were documented using a self-administered questionnaire. RESULTS: A completed self-administered questionnaire was available for 568/759 recruited patients (132 cardia GC, 436 non-cardia GC, male 61%, mean age 64 years). Dyspeptic symptoms were more common in patients with non-cardia GC (69.0 vs. 54.5%, p=0.0024). Cardia GC patients reported more frequently alarm symptoms (69.7 vs. 44.7%, p<0.0001), and were more likely to have Union for International Cancer Control (UICC) stage III-IV (54.1vs. 38.9%, p=0.0034). Especially, dysphagia and weight loss were more common in patients with cardia GC (49.2 vs. 6.4 %, p<0.0001 and 37.1 vs. 25.7%, p=0.02, respectively). No differences between the two groups were observed with respect to reflux symptoms. Patients with alarm symptoms were more likely to have UICC stage III-IV at presentation (69.4 vs. 42.9%, p<0.0001). CONCLUSIONS: In clinical practice the symptom pattern at presentation may serve as a hint for tumor localization. Despite the fact that they are common in the general population, dyspeptic symptoms offer a chance for earlier GC detection. Thus, in patients with dyspeptic symptoms who fail empiric approaches, endoscopy should not be delayed.

[Hybrid esophagectomy with intraoperative hyperspectral imaging : Video article]. / Hybridösophagektomie mit intraoperativem Hyperspektral-Imaging : Videobeitrag.

The technique of hybrid esophagectomy with systematic 2­field lymphadenectomy for esophageal cancer showed a significant reduction in postoperative morbidity in a recently published prospective randomized study. This video publication presents the abdominothoracic hybrid procedure with (i) laparoscopic gastrolysis and ischemic conditioning of the stomach and (ii) 2-stage transthoracic esophagectomy with gastric pull-up, intrathoracic gastric tube formation and anastomosis. Intraoperative hyperspectral imaging (HSI) during the thoracic part of the operation is used for identification of the ideally perfused anastomotic region.

[Ablative treatment options for locally advanced unresectable and borderline resectable pancreatic carcinoma]. / Ablative Therapieoptionen beim lokal fortgeschrittenen, irresektablen und grenzwertig resektablen Pankreaskarzinom.

BACKGROUND: Locally advanced unresectable (nonmetastatic) and borderline resectable pancreatic carcinomas represent a therapeutic challenge. Several minimally invasive local ablative techniques are available for local treatment in these situations. OBJECTIVE: Which interventional techniques and application options are currently available for pancreatic carcinoma and which oncological results could be achieved so far? MATERIAL AND METHODS: An analysis of reviews and studies was carried out. The selection of literature was based on searches in PubMed and the Cochrane library. The studies analyzed were reviews, meta-analyses and original articles mainly from the period between 2013 and 2018. Single case reports were not included in this review. RESULTS: Local ablative techniques are performed with various forms of energy and are associated with specific advantages and disadvantages. They have to be individually tailored to the specific patient and situation. Noninvasive thermal ablation with high-intensity focused ultrasound (HIFU) is primarily used for palliative pain relief. Solid tumors are the main indication for thermal necrosis with microwave ablation (MWA) and radiofrequency ablation (RFA). The use of irreversible electroporation (IRE) enables a selective destruction of tumor cells and can be performed in the vicinity of sensitive structures. This technique is applied for primary tumor control and also for accentuation of tumor margins during resection. CONCLUSION: With local ablative techniques an improvement in the quality of life and possibly the prognosis can be achieved in patients with unresectable pancreatic cancer; however, the latter aspect has to be viewed with caution due to a current lack of well-founded data.

Gastric cancer in autoimmune gastritis: A case-control study from the German centers of the staR project on gastric cancer research.

OBJECTIVES: Patients with autoimmune gastritis (AIG) are reported to have an increased risk of developing gastric cancer (GC). In this study, we assess the characteristics and outcomes of GC patients with AIG in a multicenter case-control study. METHODS: Between April 2013 and May 2017, patients with GC, including cancers of the esophagogastric junction (EGJ) Siewert type II and III, were recruited. Patients with histological characteristics of AIG were identified and matched in a 1:2 fashion for age and gender to GC patients with no AIG. Presenting symptoms were documented using a self-administered questionnaire. RESULTS: Histological assessment of gastric mucosa was available for 572/759 GC patients. Overall, 28 (4.9%) of GC patients had AIG (67 ± 9 years, female-to-male ratio 1.3:1). In patients with AIG, GC was more likely to be localized in the proximal (i.e. EGJ, fundus, corpus) stomach (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.0-7.1). In GC patients with AIG, pernicious anemia was the leading clinical sign (OR 22.0, 95% CI 2.6-187.2), and the most common indication for esophagogastroduodenoscopy (OR 29.0, 95% CI 7.2-116.4). GC patients with AIG were more likely to present without distant metastases (OR 6.2, 95% CI 1.3-28.8) and to be treated with curative intention (OR 3.0, 95% CI 1.0-9.0). The five-year survival rates with 95% CI in GC patients with and with no AIG were 84.7% (83.8-85.6) and 53.5% (50.9-56.1), respectively (OR 0.25, 95% CI 0.08-0.75, p = 0.001). CONCLUSIONS: Pernicious anemia leads to earlier diagnosis of GC in AIG patients and contributes significantly to a better clinical outcome.

Shared Genetic Etiology of Obesity-Related Traits and Barrett's Esophagus/Adenocarcinoma: Insights from Genome-Wide Association Studies.

BACKGROUND: Obesity is a major risk factor for esophageal adenocarcinoma (EA) and its precursor Barrett's esophagus (BE). Research suggests that individuals with high genetic risk to obesity have a higher BE/EA risk. To facilitate understanding of biological factors that lead to progression from BE to EA, the present study investigated the shared genetic background of BE/EA and obesity-related traits. METHODS: Cross-trait linkage disequilibrium score regression was applied to summary statistics from genome-wide association meta-analyses on BE/EA and on obesity traits. Body mass index (BMI) was used as a proxy for general obesity, and waist-to-hip ratio (WHR) for abdominal obesity. For single marker analyses, all genome-wide significant risk alleles for BMI and WHR were compared with summary statistics of the BE/EA meta-analyses. RESULTS: Sex-combined analyses revealed a significant genetic correlation between BMI and BE/EA (rg = 0.13, P = 2 × 10-04) and a rg of 0.12 between WHR and BE/EA (P = 1 × 10-02). Sex-specific analyses revealed a pronounced genetic correlation between BMI and EA in females (rg = 0.17, P = 1.2 × 10-03), and WHR and EA in males (rg = 0.18, P = 1.51 × 10-02). On the single marker level, significant enrichment of concordant effects was observed for BMI and BE/EA risk variants (P = 8.45 × 10-03) and WHR and BE/EA risk variants (P = 2 × 10-02). CONCLUSIONS: Our study provides evidence for sex-specific genetic correlations that might reflect specific biological mecha-nisms. The data demonstrate that shared genetic factors are particularly relevant in progression from BE to EA. IMPACT: Our study quantifies the genetic correlation between BE/EA and obesity. Further research is now warranted to elucidate these effects and to understand the shared pathophysiology.

First genotype-phenotype study reveals HLA-DQß1 insertion heterogeneity in high-resolution manometry achalasia subtypes.

Background: Achalasia is a primary oesophageal motility disorder. Although aetiology remains mainly unknown, a genetic risk variant, rs28688207 in HLA-DQB1, showed strong achalasia association suggesting involvement of immune-mediated processes in the pathogenesis. High-resolution manometry recognises three types of achalasia. The aim of our study was to perform the first genotype-phenotype analysis investigating the frequency of rs28688207 across the high-resolution manometry subtypes. Methods: This was a cross-sectional retrospective study. Achalasia patients from tertiary centres in the Czech Republic (n = 163), Germany (n = 114), Greece (n = 70) and controls were enrolled. All subjects were genotyped for the rs28688207 insertion. The Kruskal-Wallis test was used for the genotype-phenotype analysis. Results: A total of 347 achalasia patients (type I - 89, II - 210, III - 48) were included. The overall frequency of the rs28688207 was 10.3%. The distribution of the insertion was significantly different across the high-resolution manometry subtypes (p = 0.038), being most prevalent in type I (14.6%), followed by type II (9.5%) and III (6.3%). Conclusion: The frequency of the HLA-DQB1 insertion differs among high-resolution manometry achalasia subtypes. The insertion is most prevalent in type I, suggesting that immune-mediated mechanisms triggered by the insertion may play a more prominent role in the pathogenesis of this subtype.

Identification of loci of functional relevance to Barrett's esophagus and esophageal adenocarcinoma: Cross-referencing of expression quantitative trait loci data from disease-relevant tissues with genetic association data.

Esophageal adenocarcinoma (EA) and its precancerous condition Barrett's esophagus (BE) are multifactorial diseases with rising prevalence rates in Western populations. A recent meta-analysis of genome-wide association studies (GWAS) data identified 14 BE/EA risk loci located in non-coding genomic regions. Knowledge about the impact of non-coding variation on disease pathology is incomplete and needs further investigation. The aim of the present study was (i) to identify candidate genes of functional relevance to BE/EA at known risk loci and (ii) to find novel risk loci among the suggestively associated variants through the integration of expression quantitative trait loci (eQTL) and genetic association data. eQTL data from two BE/EA-relevant tissues (esophageal mucosa and gastroesophageal junction) generated within the context of the GTEx project were cross-referenced with the GWAS meta-analysis data. Variants representing an eQTL in at least one of the two tissues were categorized into genome-wide significant loci (P < 5×10-8) and novel candidate loci (5×10-8 ≤ P ≤ 5×10-5). To follow up these novel candidate loci, a genetic association study was performed in a replication cohort comprising 1,993 cases and 967 controls followed by a combined analysis with the GWAS meta-analysis data. The cross-referencing of eQTL and genetic data yielded 2,180 variants that represented 25 loci. Among the previously reported genome-wide significant loci, 22 eQTLs were identified in esophageal mucosa and/or gastroesophageal junction tissue. The regulated genes, most of which have not been linked to BE/EA etiology so far, included C2orf43/LDAH, ZFP57, and SLC9A3. Among the novel candidate loci, replication was achieved for two variants (rs7754014, Pcombined = 3.16×10-7 and rs1540, Pcombined = 4.16×10-6) which represent eQTLs for CFDP1 and SLC22A3, respectively. In summary, the present approach identified candidate genes whose expression was regulated by risk variants in disease-relevant tissues. These findings may facilitate the elucidation of BE/EA pathophysiology.

Evidence for PTGER4, PSCA, and MBOAT7 as risk genes for gastric cancer on the genome and transcriptome level.

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.