Helicobacter pylori infection and the risk of Barrett's oesophagus: a community-based study

Helicobacter pylori Diagnosis and Treatment in Africa: The First Lagos Consensus Statement of the African Helicobacter and Microbiota Study Group

BACKGROUND

Helicobacter pylori (H. pylori) infection is the most prevalent type of bacterial infection. Current guidelines from different regions of the world neglect specific African conditions and requirements. The African Helicobacter and Microbiota Study Group (AHMSG), founded in 2022, aimed to create an Africa-specific consensus report reflecting Africa-specific issues.

SUMMARY

Eighteen experts from nine African countries and two European delegates supported by nine African collaborators from eight other countries prepared statements on the most important African issues in four working groups: (1) epidemiology, (2) diagnosis, (3) indications and prevention, and (4) treatment. Limited resources, restricted access to medical systems, and underdeveloped diagnostic facilities differ from those of other regions. The results of the individual working groups were presented for the final consensus voting, which included all board members.

KEY MESSAGES

There is a need for further studies on H. pylori prevalence in Africa, with diagnosis hinged on specific African situation. Treatment of H. pylori in the African setting should be based on accessibility and reimbursement, while indication and prevention should be defined in specific African countries.

Cancer Risk in Barrett's Esophagus: A Clinical Review

Esophageal adenocarcinoma (EAC) is rapidly increasing in incidence and is associated with a poor prognosis. Barrett's esophagus (BE) is a known precursor of esophageal adenocarcinoma. This review aims to explore Barrett's esophagus, esophageal adenocarcinoma, and the progression from the former to the latter. An overview of the definition, diagnosis, epidemiology, and risk factors for both entities are presented, with special attention being given to the areas of debate in the literature. The progression from Barrett's esophagus to esophageal adenocarcinoma is reviewed and the relevant molecular pathways are discussed. The definition of Barrett's esophagus remains debated and without international consensus. This, alongside other factors, has made establishing the true prevalence of Barrett's esophagus challenging. The degree of dysplasia can be a histological challenge, but is necessary to guide clinical management. The progression of BE to EAC is likely driven by inflammatory pathways, pepsin exposure, upregulation of growth factor pathways, and mitochondrial changes. Surveillance is maintained through serial endoscopic evaluation, with shorter intervals recommended for high-risk features.

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.

Association of Barrett's esophagus with Helicobacter pylori infection: a meta-analysis

Background and Aims:

Barrett’s esophagus (BE) is the only recognized precursor for esophageal adenocarcinoma. Helicobacter pylori (H. pylori) infection is a major contributing factor towards upper gastrointestinal diseases, but its relationship with BE remains controversial. Some previous studies suggested that H. pylori infection negatively correlated with BE, while others did not. This may be attributed to the difference in the selection of control groups among studies. The present meta-analysis aims to clarify their association by combining all available data from well-designed studies.

Methods:

The PubMed, EMBASE, and Cochrane Library databases were searched. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled by a random-effects model. Heterogeneity was evaluated using the Cochran’s Q test and I² statistics. Meta-regression, subgroup, and leave-one-out sensitivity analyses were employed to explore the sources of heterogeneity.

Results:

Twenty-four studies with 1,354,369 participants were included. Meta-analysis found that patients with BE had a significantly lower prevalence of H. pylori infection than those without (OR = 0.53, 95% CI = 0.45–0.64; p < 0.001). The heterogeneity was statistically significant (I² = 79%; p < 0.001). Meta-regression, subgroup, and leave-one-out sensitivity analyses did not find any source of heterogeneity. Meta-analysis of 7 studies demonstrated that CagA-positive H. pylori infection inversely correlated with BE (OR = 0.25, 95% CI = 0.15–0.44; p = 0.000), but not CagA-negative H. pylori infection (OR = 1.22, 95% CI = 0.90–1.67; p = 0.206). Meta-analysis of 4 studies also demonstrated that H. pylori infection inversely correlated with LSBE (OR = 0.39, 95% CI = 0.18–0.86; p = 0.019), but not SSBE (OR = 0.73, 95% CI = 0.30–1.77; p = 0.484).

Conclusion:

H. pylori infection negatively correlates with BE. More experimental studies should be necessary to elucidate the potential mechanisms in future.

Helicobacter pylori infection is associated with reduced risk of Barrett's esophagus: a meta-analysis and systematic review

BACKGROUND

Helicobacter pylori (Hp) is a class I carcinogen in gastric carcinogenesis, but its role in Barrett's esophagus (BE) is unknown. Therefore, we aimed to explore the possible relationship.

METHODS

We reviewed observational studies published in English until October 2019. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for included studies.

RESULTS

46 studies from 1505 potential citations were eligible for inclusion. A significant inverse relationship with considerable heterogeneity was found between Hp (OR = 0.70; 95% CI, 0.51-0.96; P = 0.03) and BE, especially the CagA-positive Hp strain (OR = 0.28; 95% CI, 0.15-0.54; P = 0.0002). However, Hp infection prevalence was not significantly different between patients with BE and the gastroesophageal reflux disease (GERD) control (OR = 0.99; 95% CI, 0.82-1.19; P = 0.92). Hp was negatively correlated with long-segment BE (OR = 0.47; 95% CI, 0.25-0.90; P = 0.02) and associated with a reduced risk of dysplasia. However, Hp had no correlated with short-segment BE (OR = 1.11; 95% CI, 0.78-1.56; P = 0.57). In the present infected subgroup, Hp infection prevalence in BE was significantly lower than that in controls (OR = 0.69; 95% CI, 0.54-0.89; P = 0.005); however, this disappeared in the infection history subgroup (OR = 0.88; 95% CI, 0.43-1.78; P = 0.73).

CONCLUSIONS

Hp, especially the CagA-positive Hp strain, and BE are inversely related with considerable heterogeneity, which is likely mediated by a decrease in GERD prevalence, although this is not observed in the absence of current Hp infection.

Management of Helicobacter pylori infection: The Bhubaneswar Consensus Report of the Indian Society of Gastroenterology

The Indian Society of Gastroenterology (ISG) felt the need to organize a consensus on Helicobacter pylori (H. pylori) infection and to update the current management of H. pylori infection; hence, ISG constituted the ISG's Task Force on Helicobacter pylori. The Task Force on H. pylori undertook an exercise to produce consensus statements on H. pylori infection. Twenty-five experts from different parts of India, including gastroenterologists, pathologists, surgeons, epidemiologists, pediatricians, and microbiologists participated in the meeting. The participants were allocated to one of following sections for the meeting: Epidemiology of H. pylori infection in India and H. pylori associated conditions; diagnosis; treatment and retreatment; H. pylori and gastric cancer, and H. pylori prevention/public health. Each group reviewed all published literature on H. pylori infection with special reference to the Indian scenario and prepared appropriate statements on different aspects for voting and consensus development. This consensus, which was produced through a modified Delphi process including two rounds of face-to-face meetings, reflects our current understanding and recommendations for the diagnosis and management of H. pylori infection. These consensus should serve as a reference for not only guiding treatment of H. pylori infection but also to guide future research on the subject.

Intestinal Metaplasia of the "Cardia": Accurate Differentiation of Gastric or Esophageal Origin With an Expanded Biopsy Protocol

Whether intestinal metaplasia (IM) distal to the endoscopic gastroesophageal junction (GEJ), that is, the cardia, is gastric or esophageal or both is controversial. Biopsies from this region are believed to be unreliable in resolving this issue and are not recommended. Our objective was to develop an accurate method of histologic diagnosis for IM of the cardia. An expanded biopsy protocol was employed in 986 patients irrespective of indication for endoscopy. This sampled columnar lined esophagus (CLE) when present, the endoscopic GEJ defined by the proximal limit of rugal folds, the area 1 cm distal to the GEJ, and distal stomach. The prevalence and associations of IM in these 4 locations were evaluated. IM was found in 79/91 patients with CLE above the GEJ. This was significantly associated with IM at the GEJ in 40/79 patients (P<0.001). The biopsy taken distal to the endoscopic GEJ had IM in 21/79 patients. No patient with CLE had IM in the distal stomach. In patients without CLE, IM was present at or distal to the endoscopic GEJ in 221 patients. In 32 patients, this was significantly associated with IM in the distal stomach (P<0.001). The remaining 189/986 (19.2%) patients had IM limited to the GEJ region. These data, in association with recent evidence, indicate that IM limited to the area distal to the GEJ in patients without distal gastric IM represents microscopic Barrett esophagus in a dilated distal esophagus. This is presently mistaken for IM of the proximal stomach because of a flawed endoscopic definition of the GEJ.

The interplay between Helicobacter pylori and gastrointestinal microbiota

The complex population of microbes in the human gastrointestinal (GI) tract interacts with itself and with the host, exerting a deep influence on health and disease development. The development of modern sequencing technology has enabled us to gain insight into GI microbes. Helicobacter pylori colonization significantly affects the gastric microenvironment, which in turn affects gastric microbiota and may be correlated with colonic microbiota changes. Crosstalk between H. pylori and GI commensal flora may play a role in H. pylori-related carcinogenicity and extragastric manifestations. We review current knowledge on how H. pylori shapes GI microbiota with a specific focus on its impact on the stomach and colon. We also review current evidence on colonic microbiota changes attributed to eradication therapy based on the clinical studies performed to date.

Narrative review of the role of gastroenterologist in the diagnosis, treatment and palliation in gastric and gastroesophageal cancer

Esophageal cancer (EC) and gastric cancer (GC) carry a high mortality rate. Unfortunately, a majority of patients are asymptomatic and at the time of diagnosis, the disease may invariably be in its advanced stages with limited curative options. Thus, it is imperative to recognize certain risk factors including gastroesophageal reflux disease (GERD), male gender, pre-existing Barrett’s esophagus, smoking history, obesity, Helicobacter pylori infection, atrophic gastritis among others for both EC and GC, intervene on time with screening and surveillance modalities if indicated and optimize treatment plans. With advances in endoscopic techniques, early neoplastic lesions are increasingly managed by gastroenterologists, offering an alternative to surgery. The gold standard for diagnosis of EC and GC is high definition endoscopy with adequate targeted biopsies. Endoscopic ultrasound (EUS) is a key in the staging of early cancers dictating the pathway for treatment options. We also play a key role in palliation cases with the aim to reduce the symptoms like nausea, vomiting and even when possible, restore oral intake and improve nutrition in both advanced GC and EC. This review article discusses the risk factors, diagnostic and endoscopic treatment modalities of early EC and GC and palliation of advanced cancer where gastroenterologists play a key role.

Association Between Helicobacter pylori Infection and Short-segment/Long-segment Barrett's Esophagus in a Japanese Population: A Large Cross-Sectional Study

GOAL

The goal of this study was to investigate the relationship between Helicobacter pylori (H. pylori) infection and short-segment and long-segment Barrett's esophagus (SSBE and LSBE).

BACKGROUND

H. pylori infection is reported to be inversely associated with Barrett's esophagus (BE) in western countries. However, the impact of BE segment length on the association between BE and H. pylori infection has scarcely been investigated.

MATERIALS AND METHODS

The study subjects were 41,065 asymptomatic Japanese individuals who took medical surveys between October 2010 and September 2017. Using this large database of healthy Japanese subjects, we investigated the association between H. pylori infection and SSBE/LSBE. We used multivariable logistic regression analysis to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among the study subjects, 36,615 were eligible for the analysis. H. pylori seropositivity was significantly associated with a lower rate of LSBE (OR: 0.42; 95% CI: 0.16-0.91) and a higher rate of SSBE (OR: 1.66; 95% CI: 1.56-1.78) after multivariate adjustment. In the subgroup analysis, H. pylori seropositivity was significantly associated with a high rate of SSBE in subjects without reflux esophagitis (RE) (OR: 1.73; 95% CI: 1.61-1.85). However, H. pylori seropositivity was not associated with SSBE in subjects with RE (OR: 1.07; 95% CI: 0.84-1.37).

CONCLUSION

In a Japanese population, H. pylori infection was inversely associated with LSBE but significantly associated with SSBE only in subjects without RE. H. pylori may be a risk factor for SSBE, especially in individuals without RE.

Proton Pump Inhibitors and Radiofrequency Ablation for Treatment of Barrett's Esophagus

Gastroesophageal Reflux Disease (GERD) is characterized by acid and bile reflux in the distal oesophagus, and this may cause the development of reflux esophagitis and Barrett's oesophagus (BE). The natural histological course of untreated BE is non-dysplastic or benign BE (ND), then lowgrade (LGD) and High-Grade Dysplastic (HGD) BE, with the expected increase in malignancy transfer to oesophagal adenocarcinoma (EAC). The gold standard for BE diagnostics involves high-resolution white-light endoscopy, followed by uniform endoscopy findings description (Prague classification) with biopsy performance according to Seattle protocol. The medical treatment of GERD and BE includes the use of proton pump inhibitors (PPIs) regarding symptoms control. It is noteworthy that long-term use of PPIs increases gastrin level, which can contribute to transfer from BE to EAC, as a result of its effects on the proliferation of BE epithelium. Endoscopy treatment includes a wide range of resection and ablative techniques, such as radio-frequency ablation (RFA), often concomitantly used in everyday endoscopy practice (multimodal therapy). RFA promotes mucosal necrosis of treated oesophagal region via high-frequency energy. Laparoscopic surgery, partial or total fundoplication, is reserved for PPIs and endoscopy indolent patients or in those with progressive disease. This review aims to explain distinct effects of PPIs and RFA modalities, illuminate certain aspects of molecular mechanisms involved, as well as the effects of their concomitant use regarding the treatment of BE and prevention of its transfer to EAC.

IS THERE A RELATION BETWEEN HELYBACTER PYLORI AND INTESTINAL METAPLASIA IN SHORT COLUMN EPITELIZATION UP TO 10 MM IN THE DISTAL ESOPHAGUS?

Background:

The presence of intestinal metaplasia in the distal esophagus (Barrett’s esophagus) is an important precursor of adenocarcinoma. Knowledge of the risk factors and the process by which the Barrett develops is very important and Helicobacter pylori (HP) can contribute to this development.

Aim:

To analyze the impact of HP in the gastric mucosa with intestinal metaplasia in the distal esophagus in areas of columnar epithelialization smaller than 10 mm in length and epidemiological data on prevalence

Method:

A retrospective study in which were included 373 consecutive patients diagnosed with columnar epithelium in the distal esophagus was done. In all, HP was investigated by urease and histology, exclusion and inclusion factors were applied and patients were divided into two groups: the first grouping the ones without histological diagnosis of Barrett’s esophagus (235-63%) and the second with it (138-37%).

Results:

There was no significant difference between HP and non-HP patients in relation to the probability of having intestinal metaplasia (p=0.587). When related to the general group, there was an inverse association between the bacterium and the columnar epithelia in the distal esophagus. Age (p=0.031), gender (p=0.013) and HP (p=0.613) when related together to intestinal metaplasia showed no significant relation. In isolation, when related to age and gender, regardless of HP, results confirmed that patients in more advanced age and women present a higher incidence of intestinal metaplasia.

Conclusion:

There is an inverse relation between HP and the areas of columnar epithelization in the distal esophagus, regardless of the presence or absence of intestinal metaplasia. Age and gender, regardless of HP, showed higher prevalence in women and in older the number of cases with intestinal metaplasia in the distal esophagus.

Impact of the Gastrointestinal Microbiome in Health and Disease: Co-evolution with the Host Immune System

Microbes within the gastrointestinal tract communicate with each other and with the host, which has profound effects on health and disease development. Only now, it is becoming apparent that how and when we acquire our own unique collection of "gut microbes" and also how we choose to maintain them is fundamental to our health. Helicobacter pylori is the most common bacterial infection worldwide, colonizing around half of the world's population, and is the major risk factor for gastric adenocarcinoma. More recently, it has also been shown to have some beneficial effects in terms of protecting against the development of other diseases. Here, we review the current knowledge on how H. pylori has shaped gastrointestinal microbiota colonization and the host immune system with specific focus on the impact of H. pylori on the various microbiome niches of the gastrointestinal tract. We discuss how the presence of H. pylori influences the physiology of three major regions within the gastrointestinal tract-specifically the oesophagus, stomach and colon. We pay particular attention to the role of H. pylori under chronic inflammatory conditions including the development of cancer. With increased incidence of diseases such as eosinophilic oesophagitis, oesophageal adenocarcinoma and squamous cell carcinoma being attributed to the decline in H. pylori, their disease pathogenesis in light of changing H. pylori colonization is also discussed.

Prevalence and risk factors for Barrett’s esophagus in Taiwan

BACKGROUND

Barrett’s esophagus (BE) is a pre-malignant condition associated with the development of esophageal adenocarcinoma. The prevalence of BE in the general populations of Asian countries ranges from 0.06% to 1%. However, with lifestyle changes in Asian countries and adoption of western customs, the prevalence of BE might have increased.

AIM

To determine the current prevalence of BE in Taiwan, and to investigate risk factors predicting the presence of BE.

METHODS

This retrospective study was conducted at the Health Evaluation Center of Kaohsiung Veterans General Hospital in Taiwan. Between January 2015 and December 2015, 3385 subjects undergoing routine esophagogastroduodenoscopy examinations as part of a health check-up at the Health Evaluation Center were included. Patient characteristics and endoscopic findings were carefully reviewed. Lesions with endoscopic findings consistent with BE awaiting histological evaluation were judged as endoscopically suspected esophageal metaplasia (ESEM). BE was defined based on extension of the columnar epithelium ≥ 1 cm above the gastroesophageal junction and was confirmed based on the presence of specialized intestinal metaplasia (IM) in the metaplastic esophageal epithelium. Clinical factors of subjects with BE and subjects without BE were compared, and the risk factors predicting BE were analyzed.

RESULTS

A total of 3385 subjects (mean age, 51.29 ± 11.42 years; 57.1% male) were included in the study, and 89 among them were confirmed to have IM and presence of goblet cells via biopsy examination. The majority of these individuals were classified as short segment BE (n = 85). The overall prevalence of BE was 2.6%. Multivariate analysis disclosed that old age [odds ratio (OR) = 1.033; 95% confidence interval (CI): 1.012-1.055; P = 0.002], male gender (OR = 2.106; 95%CI: 1.145-3.872; P = 0.017), ingestion of tea (OR = 1.695; 95%CI: 1.043-2.754; P = 0.033), and presence of hiatal hernia (OR = 3.037; 95%CI: 1.765-5.225; P < 0.001) were significant risk factors predicting BE. The independent risk factor for the presence of IM in ESEM lesions was old age alone (OR = 1.029; 95%CI: 1.006-1.053; P = 0.014).

CONCLUSION

Current prevalence of BE among the general population in Taiwan is 2.6%. Old age, male gender, ingestion of tea and hiatal hernia are significant risk factors for BE.

Interactions between Helicobacter pylori and gastroesophageal reflux disease

Interactions between Helicobacter Pylori (HP) and gastroesophageal reflux disease (GERD) are a complex issue. Several pathophysiological factors influence the development and the course of GERD, HP infection might be only one of these. Many studies emphasize the co-existence of these diseases. HP infection could contribute to GERD through both a protective and an aggressive role. Gastric acid secretion is a key factor in the pathophysiology of reflux esophagitis. Depending on the type of gastritis related to HP, acid secretion may either increase or decrease. Gastritis in corpus leads to hypoacidity, while antrum gastritis leads to hyperacidity. In cases of antral gastritis and duodenal ulcers which have hyperacidity, the expectation is an improvement in pre-existing reflux esophagitis after eradication of HP. In adults, HP infection is often associated with atrophic gastritis in the corpus. Atrophic gastritis may protect against GERD. Pangastritis which leads to gastric atrophy is commonly associated with CagA strains of HP and it causes more severe gastric inflammation. In case of HP-positive corpus gastritis in the stomach, pangastritis, and atrophic gastritis, reflux esophagitis occurs frequently after eradication of HP. Nonetheless, as a predisposing disease of gastric cancer, HP should be treated. In conclusion, as the determinative factors affecting GERD involving in HP, detailed data on the location of gastric inflammation and CagA positivity should be obtained by the studies at future.

Helicobacter pylori Infection Is Associated With Reduced Risk of Barrett's Esophagus: An Analysis of the Barrett's and Esophageal Adenocarcinoma Consortium

OBJECTIVES

Epidemiological studies of Helicobacter pylori infection and risk of Barrett's esophagus (BE) have reported conflicting results. We examined the association between H. pylori infection and BE and sought to determine whether the association is mediated by gastroesophageal reflux disease (GERD) and to identify potential effect modifiers.

METHODS

We used individual level data from 1308 patients with BE (cases), 1388 population-based controls, and 1775 GERD controls in the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON). We estimated study-specific odds ratios (ORs) and 95% CIs using multivariable logistic regression models and obtained summary risk estimates using a random-effects meta-analytic approach. We examined potential effect modification by waist-to-hip ratio (WHR), body mass index (BMI), and smoking status by conducting stratified analyses.

RESULTS

For comparisons with population-based controls, H. pylori infection was inversely associated with the risk of BE (adjusted OR = 0.44, 95% CI = 0.36-0.55), with no evidence of between-study heterogeneity (I² = 0%). A stronger inverse association between H. pylori and BE was observed among individuals with the CagA-positive strain (P for interaction = 0.017). We found no evidence of interaction between WHR, BMI, smoking status, and H. pylori infection on the risk of BE. There was no association between H. pylori infection and BE for comparisons with GERD controls (OR = 0.96, 95% CI = 0.67-1.37; I² = 48%).

CONCLUSIONS

This study provides the strongest evidence yet that H. pylori infection is strongly inversely associated with BE. This effect is probably mediated by a decrease in GERD in infected patients, since the protective effect disappears in patients with GERD symptoms.

Helicobacter pylori infection reduces the risk of Barrett's esophagus: A meta-analysis and systematic review

INTRODUCTION

The prevalence of Helicobacter pylori infection (HPI) has been decreasing in developed countries, with an increasing prevalence of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) at the same time. The aim of our meta-analysis was to quantify the risk of BE in the context of HPI.

METHODS

A systematic search was conducted in 3 databases for studies on BE with data on prevalence of HPI from inception until December 2016. Odds ratios for BE in HPI were calculated by the random effects model with subgroup analyses for geographical location, presence of dysplasia in BE, and length of the BE segment.

RESULTS

Seventy-two studies were included in the meta-analysis, including 84 717 BE cases and 390 749 controls. The overall analysis showed that HPI reduces the risk of BE; OR = 0.68 (95% CI: 0.58-0.79, P < .001). Subgroup analyses revealed risk reduction in Asia OR = 0.53 (95% CI: 0.33-0.84, P = .007), Australia OR = 0.56 (95% CI: 0.39-0.80, P = .002), Europe OR = 0.77 (95% CI: 0.60-0.98, P = .035), and North-America OR = 0.59 (95% CI: 0.47-0.74, P < .001). The risk was significantly reduced for dysplastic BE, OR = 0.37 (95% CI: 0.26-0.51, P < .001) for non-dysplastic BE, OR = 0.51 (95% CI: 0.35-0.75, P = .001), and for long segment BE, OR = 0.25 (95% CI: 0.11-0.59, P = .001) in case of HPI.

CONCLUSIONS

This extensive meta-analysis provides additional evidence that HPI is associated with reduced risk of BE. Subgroup analyses confirmed that this risk reduction is independent of geographical location. HPI is associated with significantly lower risk of dysplastic, non-dysplastic, and long segment BE.

Gastroesophageal Reflux Frequency, Severity, Age of Onset, Family History and Acid Suppressive Therapy Predict Barrett Esophagus in a Large Population

GOALS

To identify risk factors associated with Barrett esophagus (BE) for potential improved surveillance and risk reduction.

BACKGROUND

Gastroesophageal reflux disease (GERD) is a known risk factor for esophageal adenocarcinoma, but the ability of GERD symptom frequency and severity to predict presence of its putative precursor lesion, BE, is less well-defined in large, community-based populations.

STUDY

We conducted a case-control study within the Kaiser Permanente Northern California population. Cases had new diagnoses of BE. To identify risk factors in the general population, we contrasted cases with population controls; to identify risk factors only among patients with GERD, we contrasted cases with GERD patients who lacked BE.

RESULTS

We interviewed 953 patients; 320 patients with BE, 316 patients with GERD who lacked BE and 317 population controls. Compared with population controls, BE risk was highest among patients with the most frequent and severe GERD symptoms [odds ratio (OR), 27.00; 95% confidence interval (CI), 14.52-50.21], nocturnal symptoms (OR, 5.40; 95% CI, 3.81-7.72), and family history of GERD (OR, 2.55; 95% CI, 1.80-3.62) or BE (OR, 10.08; 95% CI, 2.83-35.84). Although at least weekly proton pump inhibitor (PPI) use was a risk factor for BE (OR, 9.85; 95% CI, 6.54-14.84), among PPI users in the general population, GERD symptoms were not strongly associated with the risk of BE. Compared with GERD controls, cases were more likely to have onset of GERD symptoms before 30 years of age (OR, 1.93; 95% CI, 1.15-3.22) and a family history of BE (OR, 3.64; 95% CI, 1.50-8.83).

CONCLUSIONS

Severe and frequent GERD symptoms are strongly associated with increased risk of BE in the general population, especially in the absence of frequent PPI use. Among people with GERD, family history of BE and early age of symptom onset were stronger predictors of BE. These findings may improve identification of patients at highest risk for BE.

Barrett Esophagus and Intramucosal Esophageal Adenocarcinoma

Barrett esophagus (BE) is a precursor lesion for esophageal adenocarcinoma (EAC). Developments in imaging and molecular markers, and endoscopic eradication therapy, are available to curb the increase of EAC. Endoscopic surveillance is recommended, despite lack of data. The cancer risk gets progressively downgraded, raising questions about the understanding of risk factors and molecular biology involved. Recent data point to at least 2 carcinogenic pathways operating in EAC. The use of p53 overexpression and high-risk human papillomavirus may represent the best chance to detect progressors. Genome-wide technology may provide molecular signatures to aid diagnosis and risk stratification in BE.

The influence of Helicobacter pylori on the ethnic distribution of Barrett's metaplasia

BACKGROUND

Environmental risk factors associated with ethnicity may contribute to the occurrence of Barrett's metaplasia.

AIM

To investigate the interaction between ethnicity and Helicobacter pylori infection in the occurrence of Barrett's metaplasia among patients undergoing oesophago-gastro-duodenoscopy.

METHODS

The Miraca Life Sciences Database is an electronic repository of histopathological patient records. A case-control study evaluated the influence of age, gender, ethnicity and histological diagnosis of H. pylori on the occurrence of Barrett's metaplasia.

RESULTS

The total study population comprised 596 479 subjects, of whom 76 475 harboured a diagnosis of Barrett's metaplasia. Male sex, age and H. pylori infection in declining order exerted the strongest influence on the occurrence of BM. In comparison with the population comprising Caucasians and African Americans, Barrett's metaplasia was less common among subjects of African (OR = 0.09, 95% CI = 0.01-0.43), Middle Eastern (0.26, 0.20-0.34), East Asian (0.35, 0.31-0.40), Indian (0.39, 0.32-0.47), Hispanic (0.62, 0.59-0.64) or Jewish descent (0.50, 0.45-0.54), but more common among subjects of Northern European descent (1.14, 1.03-1.26). With the exception of Jews and Northern Europeans, all other ethnic subgroups were characterised by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of Barrett's metaplasia (R² = 0.82, P < 0.001), as well as dysplasia or oesophageal adenocarcinoma (R² = 0.81, P < 0.001).

CONCLUSION

Our analysis reveals an inverse relationship between the prevalence of Barrett's metaplasia and H. pylori gastritis among different ethnic groups within the United States.

Central Obesity and H. pylori Infection Influence Risk of Barrett's Esophagus in an Asian Population

Background and Aim

The prevalence rates of Barrett’s esophagus (BE) in western countries are higher than Asian ones, but little is known about their difference among risk factors of BE. The aim of this study is to investigate the associations of various risk factors including central obesity, body mass index (BMI), metabolic syndrome and H. pylori infection, with BE.

Methods

A total of 161 subjects with BE were enrolled and compared to age- and gender-matched controls randomly sampled (1:4) from check-up center in same hospital. Central obesity was defined by waist circumference (female>80cm; male>90cm), metabolic syndrome by the modified National Cholesterol Education Program Adult Treatment Panel III criteria in Taiwan. Independent risk factors for BE were identified by multiple logistic regression analyses.

Results

The mean age for BE was 53.8±13.7 years and 75.8% was male. H. pylori infection status was detected by the rapid urease test with the prevalence of 28.4% and 44.4% in the BE patients and controls, respectively. The univariate logistic regression analyses showed the risk was associated with higher waist circumference (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.78–3.60), metabolic syndrome (OR, 2.02; 95% CI, 1.38–2.96) and negative H. pylori infection (OR, 0.50; 95% CI, 0.34–0.74). However, multivariate logistic regression analyses revealed that BE associated with higher waist circumference (adjusted OR, 2.79; 95% CI, 1.89–4.12) and negative H. pylori infection (adjusted OR, 0.46; 95% CI, 0.30–0.70).

Conclusions

Central obesity is associated with a higher risk of BE whereas H. pylori infection with a lower risk in an ethnic Chinese population.

Methylation of DAPK and THBS1 genes in esophageal gastric-type columnar metaplasia

AIM: To explore methylation of DAPK, THBS1, CDH-1, and p14 genes, and Helicobacter pylori (H. pylori) status in individuals harboring esophageal columnar metaplasia.

METHODS: Distal esophageal mucosal samples obtained by endoscopy and histologically diagnosed as gastric-type (non-specialized) columnar metaplasia, were studied thoroughly. DNA was extracted from paraffin blocks, and methylation status of death-associated protein kinase (DAPK), thrombospondin-1 (THBS1), cadherin-1 (CDH1), and p14 genes, was examined using a methyl-sensitive polymerase chain reaction (MS-PCR) and sodium bisulfite modification protocol. H. pylori cagA status was determined by PCR.

RESULTS: In total, 68 subjects (33 females and 35 males), with a mean age of 52 years, were included. H. pylori cagA positive was present in the esophageal gastric-type metaplastic mucosa of 18 individuals. DAPK, THSB1, CDH1, and p14 gene promoters were methylated by MS-PCR in 40 (58.8%), 33 (48.5%), 46 (67.6%), and 23 (33.8%) cases of the 68 esophageal samples. H. pylori status was associated with methylation of DAPK (P = 0.003) and THBS1 (P = 0.019).

CONCLUSION: DNA methylation occurs in cases of gastric-type (non-specialized) columnar metaplasia of the esophagus, and this modification is associated with H. pylori cagA positive infection.

Gastric Helicobacter pylori Infection Affects Local and Distant Microbial Populations and Host Responses

Helicobacter pylori is a late-in-life human pathogen with potential early-life benefits. Although H. pylori is disappearing from the human population, little is known about the influence of H. pylori on the host's microbiota and immunity. Studying the interactions of H. pylori with murine hosts over 6 months, we found stable colonization accompanied by gastric histologic and antibody responses. Analysis of gastric and pulmonary tissues revealed increased expression of multiple immune response genes, conserved across mice and over time in the stomach and more transiently in the lungs. Moreover, H. pylori infection led to significantly different population structures in both the gastric and intestinal microbiota. These studies indicate that H. pylori influences the microbiota and host immune responses not only locally in the stomach, but distantly as well, affecting important target organs.

Ghrelin and Leptin Have a Complex Relationship with Risk of Barrett's Esophagus

BACKGROUND

Abdominal obesity is a risk factor for Barrett's esophagus independent of GERD symptoms, but little is understood about the biological mechanisms between obesity and the carcinogenic pathway of esophageal adenocarcinoma.

AIMS

To evaluate whether ghrelin and leptin may partially explain the association between obesity and Barrett's esophagus.

METHODS

We conducted a case-control study using patients with a new diagnosis of Barrett's esophagus (cases) and two control groups frequency matched to cases for age, gender, and geographic region: (1) patients with gastroesophageal reflux disease (GERD) and (2) a sample of the general population. We generated odds ratios using logistic regressions to evaluate quartiles of serum ghrelin or serum leptin, adjusting for known risk factors for Barrett's esophagus. We evaluated potential interaction variables using cross products and ran stratified analyses to generate stratum-specific odds ratios.

RESULTS

A total of 886 participants were included in the analysis. Higher ghrelin concentrations were associated with an increased risk of Barrett's esophagus, when compared to the population controls, but not the GERD controls. Ghrelin concentrations were not associated with the frequency of GERD symptoms, but ghrelin's relationship with Barrett's esophagus varied significantly with the frequency of GERD symptoms. Leptin concentrations were positively associated with at least weekly GERD symptoms among the population controls and were inversely associated with Barrett's esophagus only among the GERD controls. Adjusting for waist circumference did not change the main associations.

CONCLUSION

Higher levels of ghrelin were associated with an increased risk of Barrett's esophagus among the general population. In contrast, leptin was positively associated with frequent GERD symptoms, but inversely associated with the risk of Barrett's esophagus among the GERD controls.

Current Status and Prospects for a Helicobacter pylori Vaccine

Helicobacter pylori infection contributes to a variety of gastric diseases. H pylori-associated gastric cancer is diagnosed in advanced stages, and a vaccine against H pylori is desirable in parts of the world where gastric cancer remains a common form of cancer. Some of the strategies of vaccine development used in animals have been tested in several phase 3 clinical trials; these trials have been largely unsuccessful, although H pylori-specific immune responses have been induced. New insights into promoting immunity and overcoming the immunosuppressive nature of H pylori infection are required to improve the efficacy of an H pylori vaccine.

Bacterial Composition of the Human Upper Gastrointestinal Tract Microbiome Is Dynamic and Associated with Genomic Instability in a Barrett's Esophagus Cohort

Background

The incidence of esophageal adenocarcinoma (EAC) has increased nearly five-fold over the last four decades in the United States. Barrett’s esophagus, the replacement of the normal squamous epithelial lining with a mucus-secreting columnar epithelium, is the only known precursor to EAC. Like other parts of the gastrointestinal (GI) tract, the esophagus hosts a variety of bacteria and comparisons among published studies suggest bacterial communities in the stomach and esophagus differ. Chronic infection with Helicobacter pylori in the stomach has been inversely associated with development of EAC, but the mechanisms underlying this association remain unclear.

Methodology

The bacterial composition in the upper GI tract was characterized in a subset of participants (n=12) of the Seattle Barrett’s Esophagus Research cohort using broad-range 16S PCR and pyrosequencing of biopsy and brush samples collected from squamous esophagus, Barrett’s esophagus, stomach corpus and stomach antrum. Three of the individuals were sampled at two separate time points. Prevalence of H. pylori infection and subsequent development of aneuploidy (n=339) and EAC (n=433) was examined in a larger subset of this cohort.

Results/Significance

Within individuals, bacterial communities of the stomach and esophagus showed overlapping community membership. Despite closer proximity, the stomach antrum and corpus communities were less similar than the antrum and esophageal samples. Re-sampling of study participants revealed similar upper GI community membership in two of three cases. In this Barrett’s esophagus cohort, Streptococcus and Prevotella species dominate the upper GI and the ratio of these two species is associated with waist-to-hip ratio and hiatal hernia length, two known EAC risk factors in Barrett’s esophagus. H. pylori-positive individuals had a significantly decreased incidence of aneuploidy and a non-significant trend toward lower incidence of EAC.

Epidemiology of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC), a disease with increasing burden in the Western world, especially in white men. Risk factors for BE include obesity, tobacco smoking, and gastroesophageal reflux disease (GERD). EAC is the most common form of esophageal cancer in the United States. Risk factors include GERD, tobacco smoking, and obesity, whereas nonsteroidal antiinflammatory drugs and statins may be protective. Factors predicting progression from nondysplastic BE to EAC include dysplastic changes on esophageal histology and length of the involved BE segment. Biomarkers have shown promise, but none are approved for clinical use.

Predictors of Progression to High-Grade Dysplasia or Adenocarcinoma in Barrett's Esophagus

The prevalence of esophageal adenocarcinoma is increasing dramatically. Barrett's esophagus remains the most well-established risk factor for the development of esophageal adenocarcinoma. There are multiple clinical, endoscopic, and pathologic factors that increase the risk of neoplastic progression to high-grade dysplasia or esophageal adenocarcinoma in Barrett's esophagus. This article reviews both risk and protective factors for neoplastic progression in patients with Barrett's esophagus.

Australian clinical practice guidelines for the diagnosis and management of Barrett's esophagus and early esophageal adenocarcinoma

Barrett's esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE as most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histological definitions of BE and early EAC; prevalence, incidence, natural history, and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic, and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability.

Helicobacter pylori-Mediated Protection against Extra-Gastric Immune and Inflammatory Disorders: The Evidence and Controversies

A large number of studies link H. pylori infection with a reduced risk of developing extra-gastric conditions such as allergy, asthma, inflammatory bowel disease, coeliac disease and multiple sclerosis. The strength of the evidence for these protective associations is quite variable, and published studies often do not agree. This review article discusses some of the reasons for these discrepancies, and the difficulties faced when designing studies. Examples of some protective disease associations are described in detail, where the evidence is most abundant and thought to be more reliable. The most convincing of these are supported by published mechanistic data, for example with animal models, or incidence of disease exacerbation in humans following H. pylori eradication. Although controversial, this field is very important as the prevalence of H. pylori is decreasing throughout the world whilst many chronic diseases are becoming more common. These trends are likely to continue in the future, therefore it is important that we fully understand if and how H. pylori confers protection.

Smoking as an independent determinant of Barrett's esophagus and, to a lesser degree, of reflux esophagitis

PURPOSE

To evaluate the role of smoking in Barrett's esophagus (BE) and erosive esophagitis (E) compared to endoscopic controls with no BE or E. Smoking is considered a cause of both BE and E, but results on this topic are quite controversial.

METHODS

Patients with BE (339), E (462) and controls (619: 280 with GERD (gastroesophageal reflux disease)-negative and 339 with GERD-positive anamnesis) were recruited in 12 Italian endoscopy units. Data were obtained from structured questionnaires.

RESULTS

Among former smokers, a remarkable upward linear trend was found in BE for all smoking-related predictors. In particular, having smoked for more than 32 years increased the risk more than two times (OR 2.44, 95 % CL 1.33-4.45). When the analysis was performed in the subgroup of subjects with GERD-negative anamnesis, the risk of late quitters (<9 years) passed from OR 2.11 (95 % CL 1.19-3.72) to OR 4.42 (95 % CL 1.52-12.8). A noticeably positive dose-response relationship with duration was seen also among current smokers. As regards E, no straightforward evidence of association was detected, but for an increased risk of late quitters (OR 1.84, 95 % CL 1.14-2.98) in former smokers and for early age at starting (OR 3.63, 95 % CL 1.19-11.1) in GERD-negative current smokers.

CONCLUSIONS

Smoking seems to be an independent determinant of BE and, to a lesser degree, of E. The elevation in risk is independent from GERD and is already present in light cigarette smokers. Smoking cessation may reduce, but not remove this risk.

Risk factors for Barrett's esophagus compared between African Americans and non-Hispanic Whites

OBJECTIVES

Esophageal adenocarcinoma is more common among non-Hispanic Whites (NHWs) than African Americans (AAs). It is unclear whether its precursor, Barrett's esophagus (BE), is also less common among AAs, and whether differences in risk factor profiles explain the racial disparity.

METHODS

Data were from a case-control study among eligible Veterans Affairs patients scheduled for an upper endoscopy, and a sample identified from primary care clinics. Participants completed a questionnaire on sociodemographic and clinical factors and underwent a study esophagogastroduodenoscopy. We calculated race-specific BE prevalence rates and used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for BE.

RESULTS

There were 301 BE cases and 1,651 controls. BE prevalence was significantly higher among NHWs than AAs (21.3 vs. 5.0%; P<0.001). NHWs were more likely than AAs to be male, have a high waist-to-hip ratio (WHR), hiatal hernia, and use proton-pump inhibitors (PPIs), but less likely to have Helicobacter pylori (P<0.001). Among cases, NHWs were more likely to have long-segment BE and dysplasia than AAs. Independent BE risk factors for AAs included a hiatus hernia ≥3 cm (OR 4.12; 95% CI, 1.57-10.81) and a history of gastroesophageal reflux disease or PPI use (OR, 3.70; 95% CI, 1.40-9.78), whereas high WHR (OR, 2.82; 95% CI, 1.41-5.63), hiatus hernia ≥3 cm (OR, 4.95; 95% CI, 3.05-8.03), PPI use (OR, 1.88; 95% CI, 1.33-2.66), and H. pylori (OR, 0.64; 95% CI, 0.41-0.99) were statistically significantly associated with BE risk for NHWs. Among all cases and controls, race was a risk factor for BE, independent of other BE risk factors (OR for AAs, 0.26; 95% CI, 0.17-0.38).

CONCLUSIONS

Among veterans, the prevalence of BE was lower in AAs compared with NHWs. This disparity was not accounted for by differences in risk estimates or prevalence of risk factors between NHWs and AAs.

Risk factors associated with Barrett’s epithelial dysplasia

AIM: To elucidate risk factors associated with dysplasia of short-segment Barrett’s esophagus (BE).

METHODS: A total of 151 BE patients who underwent endoscopic examination from 2004 to 2008 in Aoyama Hospital, Tokyo Women’s Medical University, Japan and whose diagnosis was confirmed from biopsy specimens were enrolled in the study. BE was diagnosed based on endoscopic findings of gastric-appearing mucosa or apparent columnar-lined esophagus proximal to the esophagogastric junction. Dysplasia was classified into three grades - mild, moderate and severe - according to the guidelines of the Vienna Classification System for gastrointestinal epithelial neoplasia. Anthropometric and biochemical data were analyzed to identify risk factors for BE dysplasia. The prevalence of Helicobacter pylori (H. pylori) infection and the expression of p53 by immunohistological staining were also investigated.

RESULTS: Histological examination classified patients into three types: specialized columnar epithelium (SCE) (n = 65); junctional (n = 38); and gastric fundic (n = 48). The incidence of dysplasia or adenocarcinoma from BE of the SCE type was significantly higher than that of the other two types (P < 0.01). The univariate analysis revealed that sex, H. pylori infection, body weight, p53 overexpression, and low diastolic blood pressure (BP) were associated with BE dysplasia. In contrast, body mass index, waist circumference, metabolic syndrome complications, and variables related to glucose or lipid metabolism were not associated with dysplasia. Multivariate logistic analysis showed that overexpression of p53 [odds ratio (OR) = 13.1, P = 0.004], H. pylori infection (OR = 0.19, P = 0.066), and diastolic BP (OR = 0.87, P = 0.021) were independent risk factors for epithelial dysplasia in BE patients with the SCE type.

CONCLUSION: Overexpression of p53 is a risk factor for dysplasia of BE, however, H. pylori infection and diastolic BP inversely associated with BE dysplasia might be protective.

Barrett's oesophagus: epidemiology, cancer risk and implications for management

Although endoscopic surveillance of patients with Barrett's oesophagus has been widely implemented, its effectiveness is debateable. The recently reported low annual oesophageal adenocarcinoma risk in population studies, the failure to identify most Barrett's patients at risk of disease progression, the poor adherence to surveillance and biopsy protocols, and the significant risk of misclassification of dysplasia all tend to undermine the effectiveness of current management, in particular, endoscopic surveillance programmes, to prevent or improve the outcomes of patients with oesophageal adenocarcinoma. The ongoing increase in incidence of Barrett's oesophagus and consequent growth of the surveillance population, together with the associated discomfort and costs of endoscopic surveillance, demand improved techniques for accurately determining individual risk of oesophageal adenocarcinoma. More accurate techniques are needed to run efficient surveillance programmes in the coming decades. In this review, we will discuss the current knowledge on the epidemiology of Barrett's oesophagus, and the challenging epidemiological dilemmas that need to be addressed when assessing the current screening and surveillance strategies.

Genomics, the origins of agriculture, and our changing microbe-scape: time to revisit some old tales and tell some new ones

Though agriculture is often viewed as one of humanity's crowning achievements, skeletal evidence indicates that dependence on domesticated plants and animals was accompanied by an increase in infectious disease. Scientists have proposed that many important infections emerged in the period following the advent of agriculture, as a result of newly dense populations and novel proximity to domestic animals that served as reservoirs for novel pathogens. Here, we review genomic evidence regarding pathogen origins, analyzing these data using the epidemiological transition framework. Genetic information has forced us to reconsider how and when many important pathogens emerged; it appears that a number of infections thought to result from contact with domesticated animals arose much earlier than agriculture was adopted. We also consider the broader effect of agriculture upon the microbiome, exploring potential consequences for human health. We end by discussing the changes in the human microbe-scape we are likely to see in the future.

Helicobacter pylori infection in Europe: current perspectives

There is a commonly held perception that Helicobacter pylori related diseases are declining, however these are still associated with a high risk of morbidity and mortality. In recent years worrying themes have emerged such as increasing levels of antibiotic resistance and falling cure rates which illustrate there is no room for complacency with respect to H. pylori. In addition there are many significant issues which have not been elucidated regarding the role played by H. pylori in very serious pathologies such as gastric and esophageal cancer and other more benign disorders common in the developed world such as gastroesophageal reflux disease, functional dyspepsia and perhaps obesity which carry a significant impact both economically and as regards to symptoms. Future guidelines aimed at European practitioners and patients will need to address the questions raised by these issues as well as the more familiar areas such as constituents and duration of therapy.

Polymorphism in the Helicobacter pylori CagA and VacA toxins and disease

Half of the world's population is infected with Helicobacter pylori and approximately 20% of infected individuals develop overt clinical disease such as ulcers and stomach cancer. Paradoxically, despite its classification as a class I carcinogen, H. pylori has been shown to be protective against development of asthma, allergy, and esophageal disease. Given these conflicting roles for H. pylori, researchers are attempting to define the environmental, host, and pathogen interactions that ultimately result in severe disease in some individuals. From the bacterial perspective, the toxins, CagA and VacA, have each been shown to be polymorphic and to contribute to disease in an allele-dependent manner. Based on the notable advances that have recently been made in the CagA field, herein we review recent studies that have begun to shed light on the role of CagA polymorphism in H. pylori disease. Moreover, we discuss the potential interaction of CagA and VacA as a mediator of gastric disease.

The association between Barrett's esophagus and Helicobacter pylori infection: a meta-analysis

OBJECTIVE

The effect of Helicobacter pylori on Barrett's esophagus is poorly understood. We conducted a meta-analysis to summarize the existing literature examining the effect that H. pylori has on Barrett's esophagus.

DESIGN

 We performed a comprehensive search to identify studies pertaining to the association between H. pylori and Barrett's esophagus. We conducted meta-regression analyses to identify sources of variation in the effect of H. pylori on Barrett's esophagus.

RESULTS

 Our analysis included a total of 49 studies that examined the effect of H. pylori on Barrett's esophagus and seven studies that examined the effect of cag A positivity on Barrett's esophagus. Overall, H. pylori, and even more so cag A, tended to be protective for Barrett's esophagus in most studies; however, there was obvious heterogeneity across studies. The effect of H. pylori on Barrett's esophagus varied by geographic location and in the presence of selection and information biases. Only four studies were found without obvious selection and information bias, and these showed a protective effect of H. pylori on Barrett's esophagus (Relative risk = 0.46 [95% CI: 0.35, 0.60]).

CONCLUSIONS

 Estimates for the effect of H. pylori on Barrett's esophagus were heterogeneous across studies. We identified selection and information bias as potential sources of this heterogeneity. Few studies without obvious selection and information bias have been conducted to examine the effect of H. pylori on Barrett's esophagus, but in these, H. pylori infection is associated with a reduced risk of Barrett's esophagus.

Influence of sex on the survival of patients with esophageal cancer

PURPOSE

The prognostic value of sex for esophageal cancer survival is currently unclear, and growing data suggest that hormonal influences may account for incidence disparities between men and women. Therefore, moving from the hypothesis that hormones could affect the prognosis of patients with esophageal cancer, we investigated the primary hypothesis that sex is associated with survival and the secondary hypotheses that the relationship between sex and survival depends, at least in part, on age, histology, and race/ethnicity.

PATIENTS AND METHODS

By using the SEER databases from 1973 to 2007, we identified 13,603 patients (34%) with metastatic esophageal cancer (MEC) and 26,848 patients (66%) with locoregional esophageal cancer (LEC). Cox proportional hazards model for competing risks were used for analyses.

RESULTS

In the multivariate analysis, women had longer esophageal cancer-specific survival (ECSS) than men in both MEC (hazard ratio [HR], 0.949; 95% CI, 0.905 to 0.995; P = .029) and LEC (HR, 0.920; 95% CI, 0.886 to 0.955; P < .001) cohorts. When age and histology were accounted for, there was no difference for ECSS between men and women with adenocarcinoma. In contrast, women younger than age 55 years (HR, 0.896; 95% CI, 0.792 to 1.014; P = .081) and those age 55 years or older (HR, 0.905; 95% CI, 0.862 to 0.950; P < .001) with squamous cell LEC had longer ECSS than men. In the squamous cell MEC cohort, only women younger than age 55 years had longer ECSS (HR, 0.823; 95% CI, 0.708 to 0.957; P = .011) than men.

CONCLUSION

Sex is an independent prognostic factor for patients with LEC or MEC. As secondary hypotheses, in comparison with men, women age 55 years or older with squamous cell LEC and women younger than age 55 years with squamous cell MEC have a significantly better outcome. These last two findings need further validation.

Helicobacter pylori: Eradication or Preservation

Helicobacter pylori infects about 50% of the world's population and inevitably results in the development of gastritis. Of those infected, about 10% develop peptic ulcer disease and roughly 1% develop gastric cancer. Conversely, some take the view that H. pylori infection provides some protection against gastro-esophageal reflux disease and possibly asthma. This review aims to explore the case for and against eradication of the bacterium using a "test and treat" approach amongst the general population.

Risk factors and chemoprevention in Barrett's esophagus--an update

OBJECTIVE

Barrett's esophagus (BO) is a precursor of esophageal adenocarcinoma (OAC), a cancer with a poor prognosis and an increasing incidence. Hence there is an interest in mapping causal factors underlying BO and finding strategies to reduce the risk of dysplasia progression in patients with BO. Here we review current knowledge on established as well as less risk factors for the development of BO. Additionally, we summarize today's status on the use of chemoprevention aiming to reduce the risk of cancer progression in BO patients.

METHODS

We searched Medline and the Cochrane Library using the MeSH terms "Barrett's esophagus" and "Barrett esophagus," both alone and combined with the terms "risk factor," "aetiology," "diet," or "prevention." Focus was on original contributions, systematic reviews, and meta-analyses.

RESULTS

Established risk factors for the development of BO include gastro-esophageal reflux, obesity, male gender, Caucasian ethnicity, and increasing age. Smoking might increase the risk of BO, while aspirin/NSAIDs, Helicobacter pylori infection, and specific "healthy" dietary factors may lower the risk. The potential value of using chemoprevention with proton pump inhibitors, aspirin/NSAIDs, or statins is still uncertain.

CONCLUSIONS

There is today a substantial knowledge of risk factors of BO. Certain diet may be protective of BO, albeit yet to be proven. The efficiency of chemoprevention in BO is currently addressed further in randomized clinical trials.