Association of Helicobacter pylori infection with reduced risk for esophageal cancer is independent of environmental and genetic modifiers

The current infection with Helicobacter pylori and association with upper gastrointestinal lesions and risk of upper gastrointestinal cancer: Insights from multicenter population-based cohort study

The relationship between Helicobacter pylori (H. pylori) infection and upper gastrointestinal (UGI) cancers is complex. This multicenter, population-based cohort study conducted in seven areas in China aimed to assess the correlation between current H. pylori infection and the severity of UGI lesions, as well as its association with the risk of gastric cancer (GC) and esophageal cancer (EC). From 2015 to 2017, 27,085 participants (aged 40-69) completed a standardized questionnaire, and underwent a 13C-urea breath test. Then a subset underwent UGI endoscopy to assess the UGI lesion detection rates. All individuals were followed up until December 2021 to calculate the hazard ratios (HRs) for UGI cancers. H. pylori infection prevalence was 45.9%, and among endoscopy participants, 22.2% had gastric lesions, 19.2% had esophageal lesions. Higher detection rates of gastric lesions were noted in the H. pylori-positive population across all lesion severity levels. Over a median follow-up of 6.3 years, 104 EC and 179 GC cases were observed, including 103 non-cardia gastric cancer (NCGC) cases and 76 cardia gastric cancer (CGC) cases. H. pylori-infected individuals exhibited a 1.78-fold increased risk of GC (HR 1.78, 95% confidence interval [CI] 1.32-2.40) but no significant increase in EC risk (HR 1.07, 95% CI 0.73-1.57). Notably, there was a higher risk for both NCGC and CGC in H. pylori-infected individuals. This population-based cohort study provides valuable evidence supporting the association between current H. pylori infection and the risk of both NCGC and CGC. These findings contribute to the empirical basis for risk stratification and recommendations for UGI cancer screening.

Familial Esophageal Cancer in Taihang Mountain, China: An Era of Personalized Medicine Based on Family and Population Perspective

In the Taihang Mountain areas, known as the “esophageal cancer zone” in China, the incidence of esophageal cancer (ESCA) ranks the first in the country and shows a familial and regional clustering trend. Taihang Mountain areas are located in a mountainous area, with inconvenient transportation, limited living conditions, unbalanced diet, and poor nutrition. Ninety percent of the pathological types of ESCA in Taihang Mountain areas are squamous cell carcinoma, among which the risk factors have not been well understood. These areas are usually remote villages and mountains with low population mobility, large family members, similar environmental factors, and a clear and stable genetic background. Therefore, according to the current situation, second-generation sequencing and multigroup analysis technology are used to analyze the familial ESCA patients; disease-related genetic variation are located; and then disease-related susceptibility genes associated with ESCA are screened and analyzed. Health education, tobacco control, endoscopic screening, and other health management projects for suspected and high-risk patients in areas with a high incidence of ESCA can be carried out for screening and early diagnosis, and the incidence of ESCA in Taihang Mountain areas can be reduced. A comprehensive continuous care pattern based on traditional medical nursing to track, monitor, evaluate, and intervene with patients diagnosed with ESCA to facilitate them with medications guidance, dietary guidance, and timely health problem-solving is established. Furthermore, statistical analysis of epidemiology, gene sequencing, and family genetics information can be performed on patients with ESCA in the Taihang Mountains areas to clarify the relationship between genetic phenotype and genotype during the occurrence of ESCA.

Non-Acid Fluid Exposure and Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) accounts for the large majority of esophageal cancer cases worldwide. In this review, we examine the potential role of non-acidic fluid (NAF) exposure in ESCC carcinogenesis. Esophageal NAF consists of a mixture of salivary, esophageal, gastric, and duodenal fluids, containing inflammatory constituents such as digestive enzymes and bile acids that induce DNA damage, as well as known carcinogens such as acetaldehyde and N-nitrosamines. Exposure to NAF can occur in the setting of increased non-acid reflux, decreased gastric acidity, and decreased esophageal fluid clearance. Non-acid reflux has been associated with ESCC in small observational studies, and in animal models bile reflux can promote the development of ESCC. Associations have been found between increased ESCC risk and atrophic gastritis, a history of partial gastrectomy, and proton pump inhibitor use, all of which raise the pH of refluxate. Additionally, a minimally or non-acidic gastric environment contains an altered microbiome that can increase the production of acetaldehyde and N-nitrosamines. Esophageal motility disorders such as achalasia and opioid-induced esophageal dysfunction result in increased stasis and exposure to these potentially proinflammatory constituents of NAF. NAF may promote the development of ESCC via multiple mechanisms and is an understudied area of research.

Epidemiology of Helicobacter pylori in Australia: a scoping review

Background

Helicobacter pylori (H. pylori), a bacterium implicated in the development of peptic ulcer and gastric cancer, is estimated to infect around half the world's population. Its prevalence in Australia is unclear. This scoping review aimed to evaluate all Australian literature providing estimates of the prevalence of H. pylori.

Methods

Australian studies examining H. pylori prevalence from 1982 onwards were eligible for inclusion. Medline, Embase and Scopus databases, and grey literature sources, were searched. Two independent reviewers undertook a two-stage screening process. Data were extracted by two independent reviewers using a pre-specified template.

Results

Of 444 identified studies, 75 were included in the review. H. pylori prevalence in Australian population-based studies (n = 8) ranged from 38.0% in 1991 to 15.1% in 2002; however, estimated prevalence across all non-clinical population studies in diverse sub-groups (n = 29) has varied dramatically. Decreased prevalence has been more marked in populations with gastrointestinal symptoms and conditions compared to non-clinical populations. Data on H. pyloriprevalence in vulnerable populations are lacking.

Conclusions

This is the first scoping review of Australian studies reporting H. pylori prevalence. A wide range of study designs, population groups, geographic regions, and diagnostic methods was included, involving data collected over a 50-year period (1969 to 2018). The summary of H. pylori prevalence estimates over time in this review points to a decrease in prevalence in Australia, particularly among populations with gastrointestinal symptoms and illnesses; however, it is unknown whether there is inequity in prevalence trends across vulnerable sub-groups of the Australian population. Future research and interventions supporting the health and wellbeing of vulnerable populations is required to ensure equitable health gains are made for all.

The Role of Tumor Necrosis Factor-α (TNF-α) Polymorphisms in Gastric Cancer: a Meta-Analysis

PURPOSE

Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine which may play a role in the development of gastric cancer (GC). This study aimed to investigate the association of five TNF-α polymorphisms including TNF-α-857, TNF-α-1031, TNF-α-863, TNF-α-308, and TNF-α-238 polymorphisms with GC risk.

METHODS

All eligible case-control studies were collected by searching PubMed, Scopus, and Web of Science. The association of the risk of GC with TNF-α polymorphisms was estimated using odds ratio (OR) and 95% confidence interval (CI). Heterogeneity was assessed via Cochrane's Q and I² analyses.

RESULTS

A total of 46 publications involving 16, 715 cases with GC and 27, 998 controls were recruited. The study revealed a significant association for TNF-α 308 (recessive model: OR = 0.646, P = 0.035), TNF-α-1031 (homozygote model: OR = 1.584, P = 0.027), and TNF-α-857 (homozygote model: OR = 1.760, P = 0.001) polymorphisms with the GC risk. The results of subgroup analysis based ethnicity found a significant association between GC risk and TNF-α-857 polymorphism in Caucasian subgroup (P = 0.005) and TNF-α-1031 polymorphism and GC risk in Asians (P = 0.018).

CONCLUSIONS

This study suggested that TNF-α-857 and TNF-α-1031 polymorphisms may be associated with the increased gastric cancer risk.

Gastrointestinal cancers in China, the USA, and Europe

Gastrointestinal (GI) cancers, including colorectal cancer, gastric cancer, and esophageal cancer, are a major medical and economic burden worldwide and have the largest number of new cancer cases and cancer deaths each year. Esophageal and gastric cancers are most common in developing countries, while colorectal cancer forms the major GI malignancy in Western countries. However, a great shift in the predominant GI-cancer type is happening in countries under economically transitioning and, at the same time, esophageal and gastric cancers are reigniting in Western countries due to the higher exposure to certain risk factors. The development of all GI cancers is highly associated with lifestyle habits and all can be detected by identified precancerous diseases. Thus, they are all suitable for cancer screening. Here, we review the epidemiological status of GI cancers in China, the USA, and Europe; the major risk factors and their distribution in these regions; and the current screening strategies.

Esophageal Cancer: An Updated Review

The incidence of esophageal cancer (EC) is on the rise. With the distinct subtypes of adenocarcinoma and squamous cell carcinoma comes specific risk factors, and as a result, people of certain regions of the world can be more prone to a subtype. For example, squamous cell carcinoma of the esophagus has the highest incidence in eastern Africa and eastern Asia, with smoking being a major risk factor, whereas adenocarcinoma is more prevalent in North America and western Europe, with gastroesophageal reflux disease being a leading risk factor. With that being said, adenocarcinoma and squamous cell carcinoma have similar and unfortunately poor survival rates, partly because EC is prone to early metastasis given that the esophagus does not have a serosa, as well as the superficial nature of its lymphatics compared with the rest of the gastrointestinal tract. This makes early detection of the utmost importance, and certain patients have been shown to have the benefit of screening/surveillance endoscopies, including those with Barrett's esophagus, lye-induced/caustic strictures, tylosis, and Peutz-Jeghers syndrome. Until treatments significantly improve, identifying EC at the earliest stage will have the best success for patient outcomes, and further elucidation of its pathogenesis and risk factors may lead to identifying other high-risk groups that should be screened.

Shedding Light on the African Enigma: In Vitro Testing of Homo sapiens-Helicobacter pylori Coevolution

The continuous characterization of genome-wide diversity in population and case–cohort samples, allied to the development of new algorithms, are shedding light on host ancestry impact and selection events on various infectious diseases. Especially interesting are the long-standing associations between humans and certain bacteria, such as the case of Helicobacter pylori, which could have been strong drivers of adaptation leading to coevolution. Some evidence on admixed gastric cancer cohorts have been suggested as supporting Homo-Helicobacter coevolution, but reliable experimental data that control both the bacterium and the host ancestries are lacking. Here, we conducted the first in vitro coinfection assays with dual human- and bacterium-matched and -mismatched ancestries, in African and European backgrounds, to evaluate the genome wide gene expression host response to H. pylori. Our results showed that: (1) the host response to H. pylori infection was greatly shaped by the human ancestry, with variability on innate immune system and metabolism; (2) African human ancestry showed signs of coevolution with H. pylori while European ancestry appeared to be maladapted; and (3) mismatched ancestry did not seem to be an important differentiator of gene expression at the initial stages of infection as assayed here.

Opportunities and Challenges of the Human Microbiome in Ovarian Cancer

Ovarian cancer is the most lethal malignancy among gynecological cancers worldwide. Most ovarian cancer patients are diagnosed at an advanced stage because of non-specific clinical symptoms. The human microbiome plays a crucial role in maintaining the normal physiological and pathological state of the body. With the development of technologies such as DNA and 16S rRNA sequencing, an increasing number of findings on the role of microbiome in cancers are being reported. Microbiome abnormalities are increasingly associated with diseases, including cancer development, and response to therapies. Some studies have shown the relationship between microbiome changes and ovarian cancer. However, the mechanisms underlying this relationship are not yet fully understood. Here, we summarize the key findings in this regard by focusing on estrogen metabolism and host recognition receptors in microorganisms and changes in the gut or pelvic microbiome in patients with ovarian cancer. We further discuss the potential of using the microbiome as a novel biomarker for cancers. We also highlight the possibility to use microorganisms as a treatment modality to enhance the immune system, activate anti-tumor response, mediate chemotherapy resistance, and ameliorate the adverse effects of the treatment.

Community-Based Upper Gastrointestinal Cancer Screening in a Randomized Controlled Trial: Baseline Results in a Non-high-incidence Area

A cluster-randomized controlled trial (RCT) was conducted to evaluate to the effectiveness of reducing mortality of upper gastrointestinal cancer (UGC) and feasibility of screening through a questionnaire combined with endoscopy in non-high-incidence urban areas in China. The trial design, recruitment performance, and preliminary results from baseline endoscopy are reported. Seventy-five communities in two urban cities with a non-high-incidence of UGC were randomized to a screening endoscopy arm (n = 38) or a control arm (n = 37). In the screening arm, individuals at high risk of UGC underwent endoscopic screening. The primary outcome was the UGC mortality, and secondary outcomes included the UGC detection rate, incidence rate, survival rate, and clinical stage at the time of diagnosis. A total of 10,416 and 9,565 individuals were recruited into the screening and control arms, respectively. The participation rate was 74.3%. In the screening arm, 5,242 individuals (50.3%) were estimated to be high-risk. Among them, 2,388 (45.6%) underwent endoscopic screening. Age and household income were associated with undergoing endoscopy. Three early esophageal cancer (0.13%), one gastric cancer (0.04%), 29 precancerous esophageal lesions (1.21%), and 53 precancerous gastric lesions (2.22%) were detected. Age, sex, a family history of cancer, intake of meat-egg-milk frequently, superficial gastritis, and clinical symptoms of gastric cancer were associated with the presence of precancerous lesions. The detection rate was low using endoscopic screening in non-high-incidence area given the relatively low compliance rate. These findings provide a reference for designing effective community-based UGC screening strategies in non-high-incidence urban areas.

Systematic Review with Meta-analysis: Association of Helicobacter pylori Infection with Esophageal Cancer

Background

Helicobacter pylori is an important carcinogenic factor in gastric cancer. Studies have shown that Helicobacter pylori infection is inversely associated with certain diseases such as esophageal cancer and whose infection appears to have a “protective effect.” At present, the relationship between Helicobacter pylori infection and esophageal cancer remains controversial. This study was designed to investigate the relationship between Helicobacter pylori infection and the risk of esophageal cancer in different regions and ethnicities.

Methods

Systematic search of the articles on the relationship between Helicobacter pylori infection and esophageal cancer from the database with the duration time up to December 2018. This systematic review was performed under the MOOSE guidelines.

Results

This meta-analysis included 35 studies with 345,886 patients enrolled. There was no significant correlation between Helicobacter pylori infection and esophageal squamous cell carcinoma in the general population (OR: 0.84; 95% CI: 0.64-1.09/OR: 0.74; 95% CI: 0.54-0.97). However, a significant correlation was found in the Middle East (OR: 0.34; 95% CI: 0.22-0.52/95% CI: 0.26-0.44). There was no significant difference in the prevalence of Helicobacter pylori between the case group and the control group in esophageal adenocarcinoma (8.87% vs. 9.67%). The pooled OR was 0.55 (95% CI: 0.43-0.70) or 0.23 (95% CI: 0.15-0.36). When grouped by match or not, the pooled OR of the nonmatching group and the matching group was 0.48/0.21 (95% CI: 0.36-0.65/95% CI: 0.13-0.36) and 0.73/0.71 (95% CI: 0.57-0.92/95% CI: 0.60-0.84), respectively.

Conclusion

In the general populations, no significant association was found between Helicobacter pylori infection and the risk of esophageal squamous cell carcinoma. However, lower risk was found in the Middle East. Helicobacter pylori infection may reduce the risk of esophageal adenocarcinoma, but such “protection effect” may be overestimated.

Association between TNF-ɑ-308G/A polymorphism and esophageal cancer risk: An updated meta-analysis and trial sequential analysis

Background: TNF-α-308G/A (rs1800629) polymorphism has been previously implicated in the susceptibility to esophageal cancer, but results of these studies remained controversial or ambiguous. A meta-analysis was conducted to provide a more reliable conclusion about the association between TNF-ɑ-308G/A polymorphism and risk of esophageal cancer.

Methods: Databases such as PubMed, EMBASE, Web of Science and CNKI were searched for relevant articles published till June 1, 2018. We used the pooled odds ratios (ORs) with 95% confidence intervals (CIs) to evaluate the strength of such associations. Subgroup analysis was carried out according to ethnicity, source of controls and genotyping method. A trial sequential analysis (TSA) was performed to reduce the risk of type I error and evaluate whether the results of our meta-analysis were credible.

Results: A total of 9 published case-control studies with 1,435 esophageal cancer patients and 3,762 healthy controls were identified. Overall, our results indicated no significant correlation between TNF-α-308G/A polymorphism and increased risk of esophageal cancer in the fixed-effects model (allele model: pooled OR=1.11, 95% CI: 0.96-1.27, homozygote model: pooled OR=1.23, 95% CI: 0.77-1.95, heterozygote model: pooled OR=1.14, 95% CI: 0.97-1.35, dominant model: pooled OR=1.14, 95% CI: 0.97-1.34 and recessive model: pooled OR=1.00, 95% CI: 0.64-1.56). Subgroup analysis by ethnicity, source of controls and genotyping method showed no significant increase in the risk of esophageal cancer. TSA results need further investigation with a large sample size to certify such association.

Conclusions: This meta-analysis study suggested no significant association between TNF-ɑ-308G/A polymorphism and the risk of esophageal cancer.

An updated association between TNF-α -238G/A polymorphism and gastric cancer susceptibility in East Asians

Polymorphisms in the tumor necrosis factor α (TNF-α) gene are emerging as key determinants of gastric diseases. The TNF-α-238G/A single-nucleotide polymorphism (SNP) is the most extensively studied. However, this association is inconsistent amongst different populations. We therefore conducted an updated meta-analysis to obtain a more precise estimate of the association of TNF-α-238G/A polymorphism with gastric cancer (GC) risk. A comprehensive search of PubMed, Embase, Chinese (CNKI and WanFang) databases was performed to identify relevant studies through 5 May 2018. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of the association. Fourteen studies were included in our meta-analysis involving 2999 cases and 4685 controls. There was no significant association between TNF-α-238G/A polymorphism and GC risk in the overall populations. In the subgroup analysis, we found that TNF-α-238G/A polymorphism was associated with the increased risk of GC amongst Asians, especially in Chinese, but not in Caucasians. Subgroup analysis by genotyping methods revealed increased risk for other methods. In conclusion, our present meta-analysis shows that TNF-α-238G/A polymorphism is associated with the risk of GC in East Asian individuals.

Epidemiology of Gastroesophageal Junction Adenocarcinoma in Korea

The incidence of gastroesophageal junction adenocarcinoma (GEJAC) in Western countries has increased in recent decades, in addition to a rise in the incidence of esophageal adenocarcinoma (EAC). Gastroesophageal reflux disease (GERD), obesity, smoking, alcohol consumption, and low Helicobacter pylori (HP) infection rate have been nominated as risk factors for such cancers. Among these risk factors, the increased prevalence of GERD and obesity and the decreased prevalence of HP infection are of special interest owing to the currently increasing prevalence of GEJAC in Western countries. Although similar trends in the prevalence of GERD, obesity, and HP infection are observed in Asian countries after a time lag from Western countries, it is still uncertain if the prevalence of GEJAC in Asian countries is increasing, especially in Korea. The incidence of GERD in Korea is currently increasing; it was below 3% in the 1990s. The incidence of obesity in the Korean population is increasing owing to the adoption of westernized lifestyles, including food preferences, and the HP infection rate in Korea is known to be decreasing. Therefore, based on logical extrapolation of observations of Western countries, the incidence of GEJAC will increase in Korea. However, the proportion of GEJAC among other upper gastrointestinal malignancies in Korea appears to be currently unchanged compared with that in the 1990s. Presently, there is a lack of epidemiologic studies on this issue in this region; therefore, more studies are needed to clarify the characteristics of these tumors and to improve clinical outcomes for patients with these tumors.

Protective Propensity of Race or Environmental Features in the Development of Barrett's Esophagus in African Americans - A Single Center Pilot Study

BACKGROUND AND STUDY AIMS

Barrett's Esophagus (BE) is a well-recognized pre-malignant condition. Previous data indicate histologically confirmed BE frequency varies by ethnicity in the United States. However, clinical factor assessment to explain this has only occurred in a veteran population to date. The study aim was to determine which clinical factors may be associated with the ethnic variation seen in histologically confirmed BE among a general population.

PATIENTS AND METHODS

The University of Florida-Jacksonville endoscopy database was searched for all cases of endoscopic BE from September 2002 to October 2012. Histologic BE was diagnosed only if salmon colored, columnar-appearing esophageal mucosa was seen at endoscopy and biopsy revealed intestinal metaplasia with Alcian blue-stained goblet cells. Data collected included: age/BMI at diagnosis, ethnicity, sex, GERD history, atypical manifestations, endoscopic BE length, presence of esophageal stricture/ulcer/hiatal hernia, presence/absence of dysplasia and medication use (aspirin/NSAIDs/statin/PPI).

RESULTS

Salmon colored esophageal mucosa was observed in 1105 of 15,564 patients (7.1%) with BE histologically confirmed in 249 of 1105 patients (23%). Ethnic distribution of histologic BE patients: 83% non-Hispanic white (nHw), 13% African American (AA) and 4% other. No difference was seen between groups with regard to BMI, GERD symptom/complications, BE length, and cigarette, alcohol or medication use.

CONCLUSION

BE occurs primarily in nHw in north Florida. This occurs despite similarities in GERD history, cigarette/alcohol use, medications prescribed and BMI. Molecular level investigation is necessary to explain this observed disparity between nHw and AA.

Comparison of Esophageal Function Tests to Investigate the Effect of Helicobacter Pylori Infection on Gastroesophageal Reflux Disease (GERD)

Background

The effects of Helicobacter pylori (H. pylori) infection on gastroesophageal reflux disease (GERD) remain unclear. The aim of this study was to compare the results of clinical esophageal function tests and the effect of H. pylori infection on GERD.

Material/Methods

A prospective clinical study included 124 patients diagnosed with GERD (four grades). H. pylori infection was determined by gastroscopy and a rapid urease test (RUT) to divide patients into an HP-positive and an HP-negative group. Esophageal function tests included high-resolution manometry (HRM), peristalsis break (PB), and 24-hour pH monitoring (composite pH DeMeester score). Different grades of GERD, with and without H. pylori infection, esophageal function test results were analyzed.

Results

The HP-positive group, compared with the HP-negative group with GERD, showed a significantly reduced median PB value (3.41±3.65 vs. 6.18±5.27), reduced PBs >5 cm per ten swallows (2.23±3.05 vs. 4.04±3.70) indicating that that H. pylori infection improved esophageal peristalsis. During 24-hour esophageal pH monitoring, the HP-positive group showed a significantly reduced percentage of time for esophageal pH <4.0, number of reflux events >5 min, and number of reflux episodes in 24 hours, compared with the HP-negative group. The DeMeester score was significantly increased in the HP-negative group, indicating a higher esophageal acid exposure (9.11±8.15 vs. 24.30±30.27).

Conclusions

H. pylori infection improved esophageal peristalsis, enhanced lower esophageal sphincter (LES) pressure, and reduced esophageal acid exposure, which might be protective factors for GERD.

Relationship Between Tumor Necrosis Factor-α rs361525 Polymorphism and Gastric Cancer Risk: A Meta-Analysis

Tumor necrosis factor (TNF)-α, a major part in inflammatory, infectious and tumor processes, and is pivotal at the early stages of gastric cancer. Relationship between its risk and TNF-α rs361525 polymorphism has been demonstrated, but remains conflicting and controversial. Therefore, a meta-analysis was conducted to more precisely estimate this relationship. PubMed, Web of Science, EMBASE and CNKI were comprehensively searched to find out relevant articles through October 5, 2017. The strength of the relationship was assessed using pooled odds ratios and 95% confidence intervals. Totally 20 articles were included involving 4,084 cases and 7,010 controls. No significant relationship between TNF-α rs361525 polymorphism and increased GC risk was found in the whole populations. Subgroup analyses uncovered TNF-α rs361525 polymorphism intensified the risk of GC among Asians under five models, but decreased the risk of GC among Caucasiansin the allelic and dominant models. Subgroup analysis by genotyping methods revealed increased risk for other methods. In conclusion, this meta-analysis suggests TNF-α rs361525 polymorphism is related to the risk of GC, especially for Asians.

Maintenance proton pump inhibition therapy and risk of oesophageal cancer

BACKGROUND

The association of long-term use of proton pump inhibitors (PPIs) with oesophageal adenocarcinoma has been poorly defined. Our aim was to assess the risk of oesophageal cancer assessing confounding by indication.

METHODS

This population-based cohort study included all 796,492 adults exposed to maintenance therapy with PPIs in Sweden in 2005-2012. Standardised incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated to assess the risk of oesophageal adenocarcinoma (and squamous cell carcinoma as a comparison) among long-term PPI users relative to the corresponding background population. The different indications for maintenance PPI therapy were analysed separately.

RESULTS

Among all individuals using maintenance PPI therapy, the overall SIR of oesophageal adenocarcinoma was 3.93 (95% CI 3.63-4.24). The SIRs of adenocarcinoma were increased also among individuals without gastro-oesophageal reflux disease who used PPIs for indications not associated with any increased risk of oesophageal adenocarcinoma. For example, the SIRs among participants using maintenance PPI therapy because of maintenance treatment with non-steroidal anti-inflammatory drugs and aspirin were 2.74 (95% CI 1.96-3.71) and 2.06 (95% CI 1.60-2.60), respectively. The SIRs of oesophageal squamous cell carcinoma were increased for most investigated indications, but to a lesser degree than for oesophageal adenocarcinoma.

CONCLUSION

In conclusion, the long term use of PPIs is associated with increased risk of oesophageal adenocarcinoma in the absence of other risk factors. Long term use of PPIs should be addressed with caution.

Early diagnostic potential of APC hypermethylation in esophageal cancer

Background

The hypermethylation of APC gene is observed in various cancers, including esophageal cancer (EC). However, the association between APC methylation and the initiation and progression of EC is poorly understood.

Purpose and methods

The current study systematically reviewed studies on abnormal methylation of APC in EC and quantitatively synthesized 18 studies by meta-analysis involving 1008 ECs, 570 Barrett's esophagus (BE), and 782 controls.

Results

Our results showed higher methylation of APC in EC (OR = 23.33, P < 0.001) and BE (OR = 9.34, P < 0.001) than in normal controls. Whereas APC methylation in EC was similar to that in BE (P = 0.052), it was not associated with tumor stage (P = 0.204). Additionally, APC methylation was not significantly associated with overall survival (OS) and relapse-free survival (RFS) in patients with EC. The performance of APC methylation for the detection of EC and BE achieved areas under the receiver operating characteristic curves of 0.94 and 0.88, respectively.

Conclusion

Our results imply that APC methylation detection is a potential diagnostic biomarker for EC and BE.

Changing Pattern of Adenocarcinoma of the Esophagogastric Junction in Recent 10 Years: Experience at a Large Tertiary Medical Center in China

Aims and background

To investigate the changing pattern of adenocarcinoma of the esophagogastric junction subtypes and its time trend relationship with that of reflux esophagitis over 10 years at a tertiary medical center in China.

Methods and study design

The medical records of all patients who underwent gastroscopy from 2000 to 2009 were reviewed. Subtypes of adenocarcinoma of the esophagogastric junction according to Siewert's classification, gastric non-cardiac adenocarcinoma, esophageal squamous cell carcinoma, reflux esophagitis and Helicobacter pylori infection were diagnosed according to the results of gastroscopy and mucosal histopathology. All the patients were divided into three cohorts (cohort A [2000–2003], cohort B [2004–2006]), cohort C [2007–2009]), and the proportion of adenocarcinoma of the esophagogastric junction and its subtypes in all upper gastrointestinal tumors (adenocarcinoma of the esophagogastric junction, gastric non-cardiac adenocarcinoma and esophageal squamous cell carcinoma) in each cohort were compared. The annual percentages of adenocarcinoma of the esophagogastric junction, reflux esophagitis and H pylori in all patients were also compared.

Results

70,073 patients (cohort A, n = 20298, cohort B, n = 20443, cohort C, n = 29332) who underwent gastroscopy were reviewed. Totally there were 279 patients with adenocarcinoma of the esophagogastric junction (0.398%, M:F = 5.6:1), 794 gastric non-cardiac adenocarcinoma patients (1.133%, M:F = 2:1), 366 esophageal squamous cell carcinoma patients (0.522%, M:F = 3.4:1) and 4681 reflux esophagitis patients. Among the three subtypes of adenocarcinoma of the esophagogastric junction, only type I adenocarcinoma of the esophagogastric junction in upper GI tumors exhibited increasing trend over time (1.86%, 3.39% and 4.94% for cohort A, B and C, respectively, P = 0.009). According to the WHO classification of histological types, the tubular types of adenocarcinoma of the esophagogastric junction have decreased (P = 0.008), whereas papillary type (P = 0.001) increased. The annual detection rate of type I adenocarcinoma of the esophagogastric junction appeared to be positively correlated with reflux esophagitis (r = 0.846, P = 0.002) and negatively with H pylori infection (r = -0.785, P = 0.007) in time trend.

Conclusions

Over a recent 10-year period, the three subtypes of adenocarcinoma of the esophagogastric junction showed different changing trends, suggesting heterogeneous characteristics of the three Siewert types of adenocarcinoma of the esophagogastric junction.

Helicobacter pylori infection and esophageal adenocarcinoma: a review and a personal view

Esophageal adenocarcinoma (EAC) is etiologically associated with gastroesophageal reflux disease (GERD). There is evidence to support the sequence GERD, Barrett's esophagus (BE), dysplasia, and finally EAC, with Helicobacter pylori (H. pylori) being implicated in each step to EAC. On the other side of this relation stands the hypothesis of the protective role of H. pylori against EAC. Based on this controversy, our aim was to review the literature, specifically original clinical studies and meta-analyses linking H. pylori infection with EAC, but also to provide our personal and others' relative views on this topic. From a total of 827 articles retrieved, 10 original clinical studies and 6 meta-analyses met the inclusion criteria. Original studies provided inconclusive data on an inverse or a neutral association between H. pylori infection and EAC, whereas meta-analyses of observational studies favor an inverse association. Despite these data, we consider that the positive association between H. pylori infection and GERD or BE, but not EAC, is seemingly a paradox. Likewise, the oncogenic effect of H. pylori infection on gastric and colon cancer, but not on EAC, also seems to be a paradox. In this regard, well-designed prospective cohort studies with a powered sample size are required, in which potential confounders should be taken into consideration since their design.

Non-acid gastro-oesophageal reflux is associated with squamous cell carcinoma of the oesophagus

INTRODUCTION

Squamous cell carcinoma of the oesophagus is a common cancer among South Africans. Due to the absence of effective screening and surveillance programme for early detection and late presentation, squamous cell carcinoma of the oesophagus is usually diagnosed at an advanced stage or when metastasis has already occurred. The 5-year survival is often quoted at 5%-10%, which is poor.

OBJECTIVES

To determine the association between oesophageal squamous cell carcinoma (OSCC) and non-acid gastro-oesophageal reflux disease.

METHODS

Study design: A cross-sectional case-control analytical study of patients referred to the Gastroenterology Division of Steve Biko Academic Hospital in Pretoria, South Africa. All patients had combined multichannel impedance and pH studies done and interpreted after upper gastroscopy using the American College of Gastroenterology guidelines by two clinicians.

RESULTS

Thirty-two patients with OSCC were recruited: non-acid reflux was found in 23 patients (73%), acid reflux in 2 patients (6%) and 7 patients (22%) had normal multichannel impedance and pH studies.Forty-nine patients matched by age, gender and race were recruited as a control group. Non-acid reflux was found in 11 patients (22%), acid reflux in 31 patients (63%) and 7 patients (14%) had normal multichannel impedance and pH monitoring study.

CONCLUSION

The significance of the association between non-acid reflux and OSCC was tested using χ2, and simple logistic regression was used to adjust for the effects of potential confounders.The OR of developing OSCC in patients with non-acid gastro-oesophageal reflux was 8.8 (95% CI 3.2 to 24.5, P<0.0001) in this South African group.Alcohol and smoking had no effect on these results.

Gastric microbiota: tracing the culprit

The gastric environment has been long time considered bacteria-free, but the discovery of Helicobacter pylori (H. pylori) in 1982 superseded this conception. Over the last decades new diagnostic methods have been developed, starting with culture-dependent and advancing to culture-independent ones. These modern techniques provide new insight into the composition and influence of this ecosystem on the entire gastrointestinal tract. H. pylori is no longer considered the only microorganism in the stomach, other non-H. pylori microbial species may populate the same environment and exercise their role. Current knowledge suggests possible links of these bacteria with gastroduodenal diseases, such as peptic ulcer and gastric cancer but most of them need further scientific evidence. This review summarizes current information on these complex interrelations between gastric microbial communities and host in health and disease.

Is There a Link Between H. Pylori and the Epidemiology of Crohn's Disease?

INTRODUCTION

Case control studies suggest an inverse association between Helicobacter pylori (H. pylori) and Crohn's disease (CD). It is possible this could be accounted for by confounders such as antibiotic therapy. Analyzing the geographic distribution of H. pylori and the links with the incidence and prevalence of CD would be an alternative approach to circumvent these confounders.

METHODS

The literature was searched for studies published between 1990 and 2016 that reported incidence or prevalence data for CD in random population samples in developed countries (GDP per capita >20,000 USD/year). Corresponding prevalence studies for H. pylori in these same regions were then sought matched to the same time period (±6 years). The association between the incidence and prevalence of CD and H. pylori prevalence rates were assessed before and after adjusting for GDP and life expectancy.

RESULTS

A total of 19 CD prevalence and 22 CD incidence studies from 10 European countries, Japan, USA, and Australia with date-matched H. pylori prevalence data were identified. The mean H. pylori prevalence rate was 43.4% (range 15.5-85%), and the mean rates for incidence and prevalence for CD were 6.9 and 91.0/100,000 respectively. The incidence (r = -0.469, p < 0.03) and prevalence (r = -0.527, p = 0.02) of CD was inversely and significantly associated with prevalence of H. pylori infection.

CONCLUSIONS

Our data demonstrate a significant inverse association between geographic distribution of H. pylori and CD. Thus, it is highly unlikely that the findings of previous case control studies were simply due to confounding factors such as concomitant antibiotic use in CD patients.

Risk of histologic Barrett's esophagus between African Americans and non-Hispanic whites: A meta-analysis

Background

Barrett's esophagus (BE) is rare in African Americans (AA). However, the risk difference magnitude in histologic BE prevalence between AA and non-Hispanic whites (nHw) has not been quantified to date.

Objective

The objective of this article is to determine the degree of histologic BE risk difference between AA and nHw.

Methods

PubMed, Web of Science and EMBASE were searched for studies reporting histologic BE in AA/nHw for inclusion. Pooled odds ratios (ORs) with risk estimates of histologic BE occurrence between AA/nHw were calculated along with 95% confidence intervals (CIs). Forest plots were used to quantify heterogeneity. Funnel plots and the Cochrane Collaboration Risk of Bias tool were used to assess bias risk.

Results

Eight studies reported BE histologic confirmation in AA/nHw. Analysis demonstrated a nearly 400% increased histologic BE risk in nHw patients compared to AA (OR 3.949, 95% CI 3.069-5.082). In the model without the case-control study, histologic BE risk remained elevated at approximately 360% in nHw compared to AA (OR 3.618, 95% CI 2.769-4.726). Heterogeneity was not present in either model. Risk of bias was significant.

Conclusions

Histologic BE risk is elevated in nHw by 3.6-4 times compared to AA. Investigation into understanding any clinical, molecular or genetic mechanisms underlying this risk disparity is warranted.

Genetic association between TNF-α promoter polymorphism and susceptibility to squamous cell carcinoma, basal cell carcinoma, and melanoma: A meta-analysis

Tumor necrosis factor-alpha (TNF-α) is a multifunctional pro-inflammatory cytokine that plays an important role in cancer development. We performed a meta-analysis to assess the relationship between single nucleotide polymorphisms in the TNF-α promoter region (rs1800629 and rs361525) and susceptibility to squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and melanoma. After database retrieval, article selection, data extraction, and quality assessment, 20 articles comprising 4865 cases and 6329 controls were included in this study. rs1800629 was associated with an increased overall risk of SCC, lung SCC, and oral SCC in the AA vs G and AA vs GG+GA genetic models (all OR>1, P_association<0.05). No increased risk of skin SCC, skin BCC or melanoma was observed (all P_association>0.05). Rs361525 was not associated with overall SCC risk in the allele, heterozygote, dominant, recessive, or carrier model (all P_association>0.05). Begg's and Egger's tests (P_Begg>0.05; P_Egger>0.05) demonstrated there was no significant publication bias. These data indicate that the AA genotype of TNF-α rs1800629, but not rs361525, is associated with an increased risk of SCC, suggesting it could potentially serve as a prognostic marker for predicting SCC risk.

The frequency of histologically confirmed Barrett's esophagus varies by the combination of ethnicity and gender

BACKGROUND

Barrett's esophagus (BE) is the primary risk factor for esophageal adenocarcinoma (EAC). Limited data exists regarding the frequency of histologically confirmed BE by both gender and ethnicity in the United States. The study aim was to determine whether the frequency of histologically confirmed BE varies by ethnicity and gender.

METHODS

The University of Florida-Jacksonville endoscopy database was reviewed for all cases of salmon colored esophageal mucosa from September 2002 to August 2007. Histologic BE was diagnosed only if salmon colored esophageal mucosa was seen endoscopically and biopsy confirmed intestinal metaplasia with goblet cells. Data collected included: age at diagnosis, self-reported ethnicity [non-Hispanic white (nHw) or African American (AA)], gender, procedure indication, gastroesophageal reflux disease (GERD) history, atypical manifestations, cigarette smoking, alcohol use, proton pump inhibitor (PPI) use, BE endoscopic length, absence/presence of hiatal hernia, stricture or ulcer, and absence/presence/grade of dysplasia.

RESULTS

Salmon colored esophageal mucosa was identified in 391/7,308 patients, distributed ethnically as 306 nHw and 85 AA. Histologic BE was confirmed in 111/391 patients with ethnic distribution of: 95 nHw and 16 AA. Histologically confirmed BE frequency varied both by gender and ethnicity with nHw males having the highest (42.3%) and AA females the lowest (12.3%). Histologically confirmed BE frequency differed significantly between nHw males and nHw/AA females only (P<0.005).

CONCLUSIONS

Histologically confirmed BE frequency varies by ethnicity and gender with nHw males having the highest frequency/risk and AA females the lowest. Investigation to improve understanding of the impact of race and gender in BE formation should be performed.

Adenocarcinoma risk in patients registered with Polish Barrett's Oesophagus Registry

Barrett's Oesophagus (BO) is a complication of chronic gastro-oesophageal reflux disease (GORD) and is a major risk factor for oesophageal adenocarcinoma. Current guidelines are based on data showing a 0.5% annual malignancy progression rate. The Polish Barrett's Oesophagus Registry (POBOR) was established to characterize Polish patients with BO and estimate the risk of malignant progression. POBOR was established in 1999 after a dedicated training of endoscopists and histopathologists. Physicians registered patients using a dedicated registry form. After excluding patients known to have endoscopic treatment for BO, follow-up <1 year and adenocarcinoma found at index endoscopy we have linked patients personal identification numbers (PESEL) with the National Cancer Registry to identify those with a diagnosis of oesophageal or gastric cardia adenocarcinoma. In total, 843 patients were registered [609 men (72.2%), male to female ratio 2.6:1] with median age at diagnosis of 56 years (IQR:47-67). Long segment BE was found at index endoscopy in 294 patients (39.4%) whereas low grade dysplasia in 147 (17.4%). 112 patients (13.3%) fulfilled the exclusion criteria and the remaining 731 were followed for a median of 9.8 years (IQR: 9.3-10.0). After 6779 patient-years, 6 adenocarcinomas were diagnosed yielding an incidence rate of 0.89 per 1000 patients-years (95% confidence interval [CI 0.40-1.97]) which corresponds to annual malignancy progression rate of less than 0.1%. The malignancy rate in patients with low grade dysplasia was 3.70 per 1000 patient-years (95% CI 1.39-9.85). In Polish BO patients the risk of malignant progression was lower than previously reported. It was notably higher in patients with low grade dysplasia than in those with no dysplasia at index endoscopy, which may warrant strict surveillance in these patients.

Tumor necrosis factor-alpha promoter polymorphism 308 G/A is not significantly associated with esophageal cancer risk: a meta-analysis

Many studies have investigated the association between Tumor necrosis factor-α-308 G>A (rs1800629) and the risk of esophageal cancer. However, their results are inconsistent. Therefore, we performed a meta-analysis of available data to investigate any possible association between this polymorphism and esophageal cancer risk. We searched PubMed, EMBASE, Web of Science, and the CNKI database for articles published up to 2016. Crude and adjusted odds ratio with 95% confidence intervals were calculated using fixed or random effects models. We used a dominant model (GA+AA vs GG), a recessive model (AA vs GG+GA), an over-dominant model (GG+AA vs GA), and allele frequency (G vs A) to identify any association. Eleven studies with 5617 participants were included in the meta-analysis. Our results suggest that TNF-α-308 G>A (rs1800629) is not significantly associated with a risk of esophageal squamous cell carcinoma and esophageal adenocarcinoma. For genetic association studies, negative results of meta-analysis have a high level of evidence, and these results are important in this era of high-throughput sequencing-based precision medicine.

The Role of Induction Therapy for Esophageal Cancer

Survival of esophageal cancer generally is poor but has been improving. Induction chemoradiation is recommended before esophagectomy for locally advanced squamous cell carcinoma. Both induction chemotherapy and induction chemoradiation are found to be beneficial for locally advanced adenocarcinoma. Although a clear advantage of either strategy has not yet been demonstrated, consensus-based guidelines recommend induction chemoradiation for locally advanced adenocarcinoma.

Mechanistic and Technical Challenges in Studying the Human Microbiome and Cancer Epidemiology

This article reviews the significance of the microbiome in cancer epidemiology, mechanistic and technical challenges in the field, and characterization of the microbiome in different tumor types to identify biomarkers of risk, progression, and prognosis. Publications on the microbiome and cancer epidemiology were reviewed to analyze sample collection and processing, microbiome taxa characterization by 16S ribosomal RNA sequencing, and microbiome metabolite characterization (metabotyping) by nuclear magnetic resonance and mass spectrometry. The analysis identified methodology types, research design, sample types, and issues in integrating data from different platforms. Aerodigestive cancer epidemiology studies conducted by different groups demonstrated the significance of microbiome information in developing approaches to improve health. Challenges exist in sample preparation and processing (eg, standardization of methods for collection and analysis). These challenges relate to technology, data integration from "omics" studies, inherent bias in primer selection during 16S ribosomal RNA sequencing, the need for large consortia with well-characterized biospecimens, cause and effect issues, resilience of microbiota to exposure events (requires longitudinal studies), and expanding studies for fungal and viral diversity (most studies used bacterial 16S ribosomal RNA sequencing for microbiota characterization). Despite these challenges, microbiome and cancer epidemiology studies are significant and may facilitate cancer risk assessment, diagnosis, and prognosis. In the future, clinical trials likely will use microbiota modifications to improve the efficacy of existing treatments.

The Male Predominance in Esophageal Adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased rapidly during the past 4 decades in many Western populations, including North America and Europe. The established etiological factors for EAC include gastroesophageal reflux and obesity, Helicobacter pylori infection, tobacco smoking, and consumption of fruit and vegetables. There is a marked male predominance of EAC with a male-to-female ratio in incidence of up to 9:1. This review evaluates the available literature on the reasons for the male predominance, particularly an update on epidemiologic evidence from human studies during the past decade. The striking sex difference does not seem to be explained by established risk factors, given that the prevalence of the etiological factors and the strengths of associations between these factors and EAC risk are similar between the sexes. Sex hormonal factors may play a role in the development of EAC; estrogenic exposures may prevent such development, whereas androgens might increase the risk of EAC. However, continuing research efforts are still needed to fully understand the reasons for the male predominance of EAC.

Primary esophageal adenocarcinoma with distant metastasis to the skeletal muscle

Hematogenous metastasis of esophageal adenocarcinoma to the skeletal muscle is uncommon. We report a rare case of esophageal adenocarcinoma with metastasis to the skeletal muscle. During pretherapeutic examination, a painful mass was detected in the left thigh of a 49-year-old man. Endoscopic biopsy identified poorly differentiated, advanced esophageal adenocarcinoma. Computed tomography (CT) revealed wall thickening in the distal esophagus. Two enlarged lymph nodes were detected--the middle thoracic paraesophageal lymph node in the mediastinum and the right cardiac lymph node. (18)F-fluorodeoxyglucose (FDG) positron emission tomography demonstrated left thigh metastasis, which had not been detected by CT 3 weeks previously, with increased accumulation of FDG. Therefore, ultrasound-guided core-needle biopsy was performed. Histologic and immunohistochemical findings supported a diagnosis of poorly differentiated adenocarcinoma. The final diagnosis was primary esophageal adenocarcinoma with distant metastasis to the skeletal (left thigh) muscle. The rate of disease progression in this case emphasizes the malignant potential of esophageal adenocarcinoma. A few cases of skeletal metastasis from advanced esophageal adenocarcinoma have been previously reported. However, rapid metastasis to a distant skeletal muscle with no other hematogenous metastasis is quite rare. Early detection and rapid treatment are especially important in cases of esophageal adenocarcinoma.

African American ethnicity is not associated with development of Barrett's oesophagus after erosive oesophagitis

BACKGROUND

Barrett's oesophagus is the primary risk factor for oesophageal adenocarcinoma; erosive oesophagitis is considered an intermediate step with Barrett's oesophagus development potential upon healing. Barrett's oesophagus occurs in 9-19% following erosive oesophagitis but minimal data exists in African Americans. The study aim was to determine if ethnicity is associated with Barrett's oesophagus formation following erosive oesophagitis.

METHODS

Retrospective review of endoscopies from September 2007 to December 2012 was performed. Inclusion criteria were erosive oesophagitis on index endoscopy, repeat endoscopy ≥6 weeks later and non-Hispanic white or African American ethnicity. Barrett's oesophagus frequency following erosive oesophagitis by ethnicity was compared.

RESULTS

A total of 14,303 patients underwent endoscopy during the study period; 1636 had erosive oesophagitis. Repeat endoscopy was performed on 125 non-Hispanic white or African American patients ≥6 weeks from the index procedure. Barrett's oesophagus occurred in 8% of non-Hispanic whites while no African American developed it on repeat endoscopy following erosive oesophagitis (p=0.029). No significant difference was seen between ethnic groups in any clinical parameter assessed.

CONCLUSIONS

African American ethnicity appears to result in decreased Barrett's oesophagus formation following erosive oesophagitis. Further investigation to demonstrate factors resulting in decreased Barrett's oesophagus formation among African Americans should be performed.

Endoscopic therapy in early adenocarcinomas (Barrett's cancer) of the esophagus

The incidence of early esophageal adenocarcinoma has been increasing significantly in recent decades. Prognosis depends greatly on the choice of treatment. Early cancers can be treated by endoscopic resection, whereas advanced carcinomas have to be sent for surgery. Esophageal resection is associated with high perioperative mortality (1-5%) even in specialized centers. Early diagnosis enables curative endoscopic treatment option. Patients with gastrointestinal symptoms and a familial risk for esophageal cancer should undergo upper gastrointestinal endoscopy. High-definition endoscopes have been developed with technical add-on that helps endoscopists to find fine irregularities in the esophageal mucosa, but interpreting the findings remains challenging. In this review we discussed novel and old diagnostic procedures and their values, as well as our own recommendations and those of the authors discussed for the diagnosis and treatment of early Barrett's carcinoma. Endoscopic resection is the therapy of choice in early esophageal adenocarcinoma. It is mandatory to perform a subsequent ablation of all residual Barrett's mucosa to avoid metachronous lesions.

The tumor necrosis factor-α-238 polymorphism and digestive system cancer risk: a meta-analysis

Many studies have reported the association between tumor necrosis factor-α (TNF-α)-238 polymorphism and digestive system cancer susceptibility, but the results were inconclusive. We performed a meta-analysis to derive a more precise estimation of the relationship between TNF-α-238 G/A polymorphism and digestive system cancer risk. Pooled analysis for the TNF-α-238 G/A polymorphism contained 26 studies with a total of 4849 cases and 8567 controls. The meta-analysis observed a significant association between TNF-α-238 G/A polymorphism and digestive system cancer risk in the overall population (GA vs GG: OR 1.19, 95 % CI 1.00-1.40, P heterpgeneity = 0.016; A vs G: OR 1.19, 95 % CI 1.03-1.39, P heterpgeneity = 0.015; dominant model: OR 1.20, 95 % CI 1.02-1.41, P heterpgeneity = 0.012). In the analysis of the ethnic subgroups, however, similar results were observed only in the Asian population, but not in the Caucasian population. Therefore, this meta-analysis suggests that TNF-α-238 G/A polymorphism is associated with a significantly increased risk of digestive system cancer. Further large and well-designed studies are needed to confirm these findings.

Risk factors of early proximal gastric carcinoma in Chinese diagnosed using WHO criteria

OBJECTIVE

The incidence of proximal gastric carcinoma (PGC) is rising worldwide for unknown reasons. Herein we compare the risk factors of early PGC with distal gastric carcinoma (DGC) in patients treated at a single tertiary hospital in China.

METHODS

Risk factors of 379 consecutive surgically resected early gastric carcinoma (EGC) diagnosed according to the 2010 World Health Organization criteria were studied by reviewing their medical records and esophagogastroduodenoscopy/biopsy findings and interviewing patients and family members for the patients' history of environmental toxin exposure (ETE), dietary habits, family (FCH) and personal cancer history (PCH) and survival. Differences between PGC (n = 115), DGC (n = 264) and age-matched and gender-matched controls (n = 225) were compared.

RESULTS

Proportion of early PGC in all EGC patients was increased significantly (P < 0.05). The independent risk factors for both PGC and DGC identified by multivariate analysis were intake of preserved food and little fruit, and gastric mucosal intestinal metaplasia and atrophy (all P < 0.05). Advanced age (odds ratio [OR] 9.83, P < 0.01), PCH (OR 5.09, P < 0.05), a high body mass index (>24 kg/m(2) ) (OR 2.79, P < 0.01) and ETE (OR 2.31, P < 0.05) were independent risk factors for PGC, but not male gender, tobacco or alcohol abuse, hiatus hernia, gastroesophageal reflux disease or columnar-lined esophagus. In contrast, FCH (OR 2.34, P < 0.01) and Helicobacter pylori infection (OR 2.81, P < 0.001) were independent risk factors for DGC.

CONCLUSION

Independent risk factors for PGC in Chinese patients differ from those of DGC or esophageal adenocarcinoma, supporting the classification of PGC as a separate gastric carcinoma entity in the Chinese populations.

Variations of gastric corpus microbiota are associated with early esophageal squamous cell carcinoma and squamous dysplasia

Observational studies revealed a relationship between changes in gastric mucosa and risk of esophageal squamous cell carcinoma (ESCC) which suggested a possible role for gastric microbiota in ESCC carcinogenesis. In this study we aimed to compare pattern of gastric corpus microbiota in ESCC with normal esophagus. Cases were included subjects with early ESCC (stage I-II) and esophageal squamous dysplasia (ESD) as the cancer precursor. Control groups included age and sex-matched subjects with mid-esophagus esophagitis (diseased-control), and histologically normal esophagus (healthy-control). DNA was extracted from snap-frozen gastric corpus tissues and 16S rRNA was sequenced on GS-FLX Titanium. After noise removal, an average of 3004 reads per sample was obtained from 93 subjects. We applied principal coordinate analysis to ordinate distances from beta diversity data. Pattern of gastric microbiota using Unifrac (p = 0.004) and weighted Unifrac distances (p = 0.018) statistically varied between cases and healthy controls. Sequences were aligned to SILVA database and Clostridiales and Erysipelotrichales orders were more abundant among cases after controling for multiple testing (p = 0.011). No such difference was observed between mid-esophagitis and healthy controls. This study is the first to show that composition of gastric corpus mucosal microbiota differs in early ESCC and ESD from healthy esophagus.

Smoking behaviour modifies IL23r-associated disease risk in patients with Crohn's disease

BACKGROUND AND AIM

The etiology of Crohn's disease (CD) implicates both genetic and environmental factors. Smoking behavior is one environmental risk factor to play a role in the development of CD. The study aimed to assess the contribution of the interleukin 23 receptor (IL23R) in determining disease susceptibility in two independent cohorts of CD, and to investigate the interactions between IL23R variants, smoking behavior, and CD-associated genes, NOD2 and ATG16L1.

METHODS

Ten IL23R single-nucleotide polymorphisms (SNPs) were genotyped in 675 CD cases, and 1255 controls from Brisbane, Australia (dataset 1). Six of these SNPs were genotyped in 318 CD cases and 533 controls from Canterbury, New Zealand (dataset 2). Case-control analysis of genotype and allele frequencies, and haplotype analysis for all SNPs was conducted.

RESULTS

We demonstrate a strong increased CD risk for smokers in both datasets (odds ratio 3.77, 95% confidence interval 2.88-4.94), and an additive interaction between IL23R SNPs and cigarette smoking. Ileal involvement was a consistent marker of strong SNP-CD association (P ≤ 0.001), while the lowest minor allele frequencies for location were found in those with colonic CD (L2). Three haplotype blocks were identified across the 10 IL23R SNPs conferring different risk of CD. Haplotypes conferred no further risk of CD when compared with single SNP analyses.

CONCLUSION

IL23R gene variants determine CD susceptibility in the Australian and New Zealand population, particularly ileal CD. A strong additive interaction exists between IL23R SNPs and smoking behavior resulting in a dramatic increase in disease risk depending upon specific genetic background.

Helicobacter pylori Infection in Gastroesophageal Reflux Disease in the Asian Countries

Helicobacter pylori infection, a common infection in many countries, is related to the clinical course of upper gastrointestinal diseases. Gastroesophageal reflux disease (GERD) is a common esophageal disease in Western countries and its prevalence is increasing in Asian countries. The pathophysiology of GERD is multifactorial. Although no single factor has been isolated as the cause of GERD, a negative association between the prevalence of H. pylori and the severity of GERD, including Barrett's esophagus, has been demonstrated in epidemiological studies. The high prevalence of H. pylori infection affects the incidence of GERD in Asian countries. In the subjects with East Asian CagA-positive strains, acid injury may be minimized by hypochlorhydria from pangastritis and gastric atrophy. Additionally, host genetic factors may affect the development of GERD. The interactions between genetic factors and the virulence of H. pylori infection may be the reason for the low prevalence of GERD in Asian countries. H. pylori eradication is not considered pivotal in GERD exacerbation based on evidence from Western studies. A recent meta-analysis demonstrated that eradication therapy of H. pylori was related to a higher risk of developing de novo GERD in Asian studies. H. pylori infection remains an inconclusive and important issue in GERD in Asian countries.

Risk of esophageal adenocarcinoma decreases with height, based on consortium analysis and confirmed by Mendelian randomization

BACKGROUND & AIMS

Risks for some cancers increase with height. We investigated the relationship between height and risk of esophageal adenocarcinoma (EAC) and its precursor, Barrett's esophagus (BE).

METHODS

We analyzed epidemiologic and genome-wide genomic data from individuals of European ancestry in the Barrett's and Esophageal Adenocarcinoma Consortium, from 999 cases of EAC, 2061 cases of BE, and 2168 population controls. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for associations between height and risks of EAC and BE. We performed a Mendelian randomization analysis to estimate an unconfounded effect of height on EAC and BE using a genetic risk score derived from 243 genetic variants associated with height as an instrumental variable.

RESULTS

Height was associated inversely with EAC (per 10-cm increase in height: OR, 0.70; 95% CI, 0.62-0.79 for men and OR, 0.57; 95% CI 0.40-0.80 for women) and BE (per 10-cm increase in height: OR, 0.69; 95% CI, 0.62-0.77 for men and OR, 0.61; 95% CI, 0.48-0.77 for women). The risk estimates were consistent across strata of age, education level, smoking, gastroesophageal reflux symptoms, body mass index, and weight. Mendelian randomization analysis yielded results quantitatively similar to those from the conventional epidemiologic analysis.

CONCLUSIONS

Height is associated inversely with risks of EAC and BE. Results from the Mendelian randomization study showed that the inverse association observed did not result from confounding factors. Mechanistic studies of the effect of height on EAC and BE are warranted; height could have utility in clinical risk stratification.