Helicobacter pylori infection: a protective factor for esophageal squamous cell carcinoma in a Taiwanese population

Infectious Agents and Esophageal Cancer: A Comprehensive Review

Esophageal cancer, primarily comprising the squamous cell carcinoma (ESCC) and adenocarcinoma (EAC) subtypes, is the sixth leading cause of cancer deaths globally. In addition to many well-established endogenous and exogenous risk factors, there is emerging evidence for the etiologic role of infectious agents in esophageal cancer, although these associations are incompletely understood. Here, we review the currently available literature on the relationship between infectious agents and esophageal cancer. By far, human papilloma virus (HPV), particularly HPV 16 and 18, have the strongest etiologic association with ESCC. Less robust is the association of high-risk HPV (hr-HPV) with EAC. Although H. pylori has been implicated in the development of EAC via increased acid reflux, decreased lower esophageal sphincter tone, and the resultant Barrett's metaplasia-dysplasia-adenocarcinoma pathway, some hypothesize based on epidemiological trends that H. pylori may in fact be a protective factor. In rare cases, EBV can cause esophageal lymphoepithelial carcinoma. Several other agents including HSV, polyomaviruses, and Candida are associated with esophageal cancer to varying degrees. In summary, while several studies, including those conflicting with each other, implicate several infectious agents, the evidence is weak, at best. Clearly, further work is needed to help solidify clear etiologies that will help facilitate prevention and treatment.

Should we pay more attention to the potential link between Helicobacter pylori and esophageal cancer in Asian countries

The presence of Helicobacter pylori (H. pylori) infection has been indicated to have a protective influence on esophageal cancer (EC) in some studies, but its specific impact on the risk of esophageal squamous cell carcinoma and esophageal adenocarcinoma remains inconclusive. This manuscript comment addresses the recent study by López-Gómez et al. Despite it was a retrospective observational study without a control group, this study revealed a notably low prevalence of H. pylori infection among EC patients, indicating a potential association between H. pylori and EC in Spain. It is important to note that the relationship between H. pylori and the risk of EC varies geographically. We also conducted a meta-analysis focusing on this association in Asian populations to offer precise clinical insights. However, no significant correlation between H. pylori infection and EC was identified, suggesting that the perceived protective effect of H. pylori against EC may have been overestimated in the Asian population.

Role of Helicobacter pylori in esophageal carcinogenesis: Friend or foe?

In this letter, we comment on the article by López-Gómez et al, which explores the prevalence of Helicobacter pylori (H. pylori) infection among patients with esophageal carcinoma (EC) in a cohort of Spain population. The relationship between H. pylori infection and EC is very complex. Previous research results are often contradictory due to the influence of dietary habits, age, region, and other factors. López-Gómez et al reported a very low prevalence of previous H. pylori infection in their cohort of patients with EC, and most of them had previously received or concomitantly received proton pump inhibitors treatment. These results are similar to previous results, which suggest that H. pylori infection is related to the low incidence of EC. Therefore, this study may provide a direction for preventing EC and eradicating H. pylori in Spain.

The protective effects of Helicobacter pylori: A comprehensive review

Previous reports have estimated that approximately half of the world’s population is infected with Helicobacter pylori, the most prevalent infectious agent responsible for gastrointestinal illnesses. Due to the life-threatening effects of H. pylori infections, numerous studies have focused on developing medical therapies for H. pylori infections, while the commensal relationship and positive impacts of this bacterium on overall human health have been largely overlooked. The inhibitory efficacy of H. pylori on the progression of several chronic inflammatory disorders and gastrointestinal diseases has recently raised concerns about whether this bacterium should be eradicated in affected individuals or maintained in an appropriate balance depending on the patient’s condition. This review investigates the beneficial effects of H. pylori in preventing various diseases and discusses the potential association of conditions such as inflammatory disorders with the absence of H. pylori.

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.

Inverse relations between Helicobacter pylori infection and risk of esophageal precancerous lesions in drinkers and peanut consumption

BACKGROUND

Helicobacter pylori (H. pylori) is a Gram-negative bacterium found in the upper digestive tract. Although H. pylori infection is an identified risk factor for gastric cancer, its role in esophageal squamous cell carcinoma (ESCC) remains a topic of much debate.

AIM

To evaluate the association between H. pylori infection and the risk of precancerous lesions of ESCC, and further explore the association between dietary factors and the risk of H. pylori infection.

METHODS

Two hundred patients with esophageal precancerous lesions (EPL) aged 63.01 ± 6.08 years and 200 healthy controls aged 62.85 ± 6.03 years were included in this case-control study. Epidemiological data and qualitative food frequency data were investigated. Enzyme-linked immunosorbent assay measuring serum immunoglobulin G antibodies was used to determine H. pylori seropositivity. An unconditional logistic regression model was used to assess the association between H. pylori infection and EPL risk dichotomized by gender, age, and the use of tobacco and alcohol, as well as the association between dietary factors and the risk of H. pylori infection.

RESULTS

A total of 47 (23.5%) EPL cases and 58 (29.0%) healthy controls had positive H. pylori infection. An inverse relation between H. pylori infection and the risk of EPL was found in the group of drinkers after adjustment for covariates [odds ratio (OR) = 0.32, 95% confidence interval (95%CI): 0.11-0.95]. Additionally, peanut intake was significantly associated with a decreased risk of H. pylori infection (OR = 0.39, 95%CI: 0.20-0.74).

CONCLUSION

Our study suggested that H. pylori infection may decrease the risk of EPL for drinkers in a rural adult Chinese population, and the consumption of peanut may reduce the risk of H. pylori infection. These findings should be framed as preliminary evidence, and further studies are required to address whether the mechanisms are related to the localization of lesions and alcohol consumption.

Risk factors for esophageal cancer in a high-incidence area of Malawi

PURPOSE

To explore associations of nutritional, infectious, and lifestyle factors with esophageal cancer (EC) occurrence in a high-risk area of Malawi.

METHODS

This case-control study was performed with 227 patients undergoing endoscopy for dysphagia or other upper gastrointestinal complaints. Data on clinicopathological characteristics and risk factors were collected using a questionnaire developed for this study specifically. Ninety-eight blood samples were collected and the prevalence of antibodies against human immunodeficiency virus, herpes simplex virus, cytomegalovirus, Epstein-Barr virus, varicella-zoster virus, and Helicobacter pylori were determined serologically.

RESULTS

The tumor and control groups comprised 157 (69.2%) and 70 (31.8%) patients, respectively. Patients with tumors were significantly older than controls (55.5 vs. 43.5 years, p < 0.001). The male/female ratio did not differ between groups (59% and 54% male, respectively; p = 0.469). EC was associated with smoking (p < 0.001), and alcohol consumption (p = 0.020), but 43% of patients with tumors did not smoke or drink. EC was associated with the consumption of hot food and tea (p = 0.003) and smoked fish (p = 0.011). EC was not associated with any serologically investigated infectious agents. In an age adjusted binary logistic regression analysis of all nutritive factors, only locally made alcohol was significant [odds ratio (OR), 9.252; 95% confidence interval (CI), 1.455-58.822; p = 0.018].

CONCLUSIONS

Apart from alcohol consumption and smoking, the consumption of hot food or tea and smoked fish are associated with EC. Locally distilled alcohol consumption increases the EC risk in Malawi.

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.

Prevalence of human papillomavirus and Helicobacter pylori in esophageal and gastroesophageal junction cancer biopsies from a case-control study in Ethiopia

BACKGROUND

Ethiopia lies in the high-risk corridor of esophageal squamous cell carcinoma in East Africa, where individuals with this malignancy often do not report established risk factors, suggesting unidentified etiologies. Here, we report the prevalence of mucosal human papillomavirus (HPV) and of Helicobacter pylori (H. pylori) detection in endoscopy-obtained esophageal and gastroesophageal junction biopsies and in oral cell specimens taken at the time of esophageal cancer diagnosis in a case-control study in Addis Ababa, Ethiopia.

METHODS

DNA extraction was performed from fresh frozen tissue and oral cell pellets obtained with saline solution gargling subsequently fixed with ethanol. Mucosal HPV and H. pylori DNA was detected using highly sensitive assays that combine multiplex polymerase chain reaction and bead-based Luminex technology. The proportions of specimens testing positive were expressed as percentages, with binomial 95% confidence intervals. Agreement of results between tissue biopsy and oral cell specimens was estimated using the kappa statistic. Comparison of study participants' characteristics by test results was done using the Pearson chi-square test.

RESULTS

HPV DNA was detected in 1 of 62 tumor specimens (2, 95% confidence interval (CI): 0-9%), corresponding to HPV16 type. HPV DNA was detected in the oral cavity of 7 cases (11, 95% CI: 5-22%) and 4 of 56 matched healthy controls (7, 95% CI: 2-17%), with multiple HPV types detected. Detection of H. pylori DNA was 55% (95% CI: 42-68%), and 20 of 34 H. pylori-positive specimens (59, 95% CI: 41-75%) were positive for the cagA gene. Agreement of detection rates between tissue and oral cells in cases was poor for HPV and for H. pylori.

CONCLUSIONS

The prevalence of mucosal-type HPV was very low, whereas H. pylori was more commonly detected, with a high proportion testing positive for the pro-inflammatory gene cagA. These novel findings remain to be replicated in larger studies and with the addition of serological determinations to better understand their biological significance in the context of esophageal and gastroesophageal junction cancers.

Risks of substance uses, alcohol flush response, Helicobacter pylori infection and upper digestive tract diseases-An endoscopy cross-sectional study

This study examines the effects of environmental hazards, including tobacco, alcohol/alcohol flush response, areca nut, and Helicobacter pylori (H pylori) infection on upper digestive diseases. This is a multi-hospital-based endoscopy-survey cross-sectional study. Subjects were received upper endoscopies in outpatient clinics at four hospitals in Taiwan between 2008 and 2013. Biopsy-based methods or urea breath test were used confirm the status of H pylori infection. In total, 8135 subjects were analyzed. Higher cumulative amounts of alcohol consumption were at higher risk of Barrett's esophagus and esophageal squamous cell carcinoma (ESCC), higher cumulative amounts of tobacco consumption were at higher risk of peptic ulcer, and higher cumulative amounts of areca nut consumption were at higher risk of duodenitis. Alcohol flush response was significant risk for reflux esophagitis and Barrett's esophagus (adjusted odds ratio [aOR] = 1.18 and 1.32, 95% confidence interval [CI] = 1.07-1.31 and 1.06-1.65, respectively). H pylori infection was inversely associated with ESCC risk (aOR = 0.20, 95% CI = 0.10-0.40). In addition, H pylori infection was consistently and significantly risk factors for gastrointestinal diseases, including peptic ulcer, gastric adenocarcinoma, and duodenitis (aOR = 5.51, 1.84, and 2.10, 95% CI = 4.85-6.26, 1.03-3.26, and 1.71-2.56, respectively). Besides the cumulative risk of alcohol, tobacco, and areca nut for Barrett's esophagus, ESCC, and peptic ulcer, respectively, presence of facial flushing was the significant risk for reflux esophagitis and Barrett's esophagus. H pylori infection was positively associated with peptic ulcer, gastric adenocarcinoma, and duodenitis, but inversely associated with ESCC.

Helicobacter Pylory infection in patients with esophageal squamous cell carcinoma

OBJECTIVE:

Esophageal squamous cell carcinoma is one of the most common esophageal diseases in the developing world, but the relationship between esophageal squamous cell carcinoma and Helicobacter pylori infection remains a neglected topic. The primary objective of this study was to determine the association between Helicobacter pylori infection and esophageal squamous cell carcinoma. A second purpose was to determine the incidence and factors associated with Helicobacter pylori infection following esophagectomy.

METHOD:

The microorganism was identified by testing the gastric biopsy materials from 95 esophageal squamous cell carcinoma patients (66 females; 39 were esophagectomized) for urease activity in a medium containing urea and a power of hydrogen detection reagent and comparing the results with those from a healthy population. Differences in patient characteristics were assessed with chi-square tests and t-tests for categorical and continuous factors, respectively.

RESULTS:

The patients with esophageal squamous cell carcinoma had a significantly lower prevalence of Helicobacter pylori compared with the healthy population (p<0.001). The naive and esophagectomized patients, in contrast, showed no significant differences in Helicobacter pylori infection (p>0.005). Patients with esophageal squamous cell carcinoma showed a significant association between leukocytosis and hypoglobulinemia and the presence of Helicobacter pylori infection (p=0.023 and p=0.045, respectively).

CONCLUSION:

These results suggest that Helicobacter pylori is not an etiological factor in patients with esophageal squamous cell carcinoma. We found a statistically significant negative correlation between esophageal squamous cell cancer and Helicobacter pylori infection. These findings may guide new strategies for esophageal squamous cell carcinoma therapy.

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.

Association of Helicobacter pylori infection with esophageal adenocarcinoma and squamous cell carcinoma: a meta-analysis

To evaluate the relationship of Helicobacter pylori and cytotoxin-associated gene A (CagA) positive strains with esophageal neoplasm, including esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), the authors conducted a meta-analysis using a predefined protocol. PubMed, Web of Science, China biology medical literature database, Wanfang, and China National Knowledge Infrastructure were searched for relevant articles from the first available year to April 8, 2013. The fixed or random effect pooled measure was selected based on heterogeneity among studies, which was evaluated using Q test and the I(2) of Higgins and Thompson. Metaregression was used to explore the sources of between-study heterogeneity. Publication bias was analyzed by Begg's funnel plot and Egger's regression test. The association was assessed by odds ratio (OR) with 95% confidence interval (CI). A total of 28 eligible studies were included in the meta-analysis. There was a significant inverse association between H. pylori infection (pooled OR, 0.57; 95% CI, 0.44-0.73) and EAC; CagA-positive H. pylori strains were less likely to be associated with EAC compared with CagA-negative strains (pooled OR, 0.64; 95% CI, 0.52-0.79). However, there was no statistically significant association between H. pylori/CagA-positive H. pylori strains infection and ESCC, and the pooled ORs were 1.16 (95% CI, 0.83-1.60) and 0.97 (95% CI, 0.79-1.19). But significant associations between CagA-positive H. pylori strains infection and ESCC risk were found in the stratified analysis of the study location (Asian and non-Asian), and the summary ORs were 0.74 (95% CI, 0.57-0.97) and 1.41 (95% CI, 1.02-1.94). H. pylori infection and CagA-positive strains are associated with decreased risk of EAC in the overall population. No significant association was found between H. pylori infection/CagA-positive strains and ESCC. But CagA-positive strains might have a positive association with ESCC in non-Asian population and an inverse association in Asian population.

Role of human papillomaviruses in esophageal squamous cell carcinoma

Esophageal cancer (EC) is responsible for almost half a million deaths worldwide annually and has a multifactorial etiology, which may account for its geographical variation in incidence. In the last 30 years the potential of human papillomaviruses (HPV) as oncogenes or co-factors in the tumorigenic process of esophageal squamous cell carcinoma (ESCC) has been widely studied. While the etiology of HPV in cervical and certain other anogenital and aerodigestive cancers has been established, results regarding its role in EC have been largely inconclusive. A causal association can be evaluated only with a case-control study, where normal controls are compared to ESCC cases for the presence of HPV. We reviewed all studies investigating ESCC tissue for HPV DNA and identified 139 that met our inclusion criteria, of which only 22 were case-control studies. Our results support previous findings of higher levels of HPV detection in high-risk ESCC regions than in areas of low risk. In addition, we confirm that the role of HPV in ESCC remains unclear, despite an accumulation of studies on the subject. The variations in investigative technique, study design and sample types tested may account for the lack of consistency in results. There is a need for a meta-analysis of all case-control studies to date, and for large, well-designed case-control studies with adequate power to investigate the association. The potential benefits of prophylactic HPV vaccines could be evaluated if HPV is identified as an etiological factor in EC, highlighting the need for further research in this area.

Incidence of esophageal carcinoma among Malays in North-Eastern Peninsular Malaysia: an area with an exceptionally low prevalence of Helicobacter pylori infection

BACKGROUND

Obesity, gastroesophageal reflux, and Barrett's esophagus have all been linked to esophageal adenocarcinoma. In addition, the decline in Helicobacter pylori (H. pylori) infection in affluent societies has also been suggested to be a major factor in the recent rise in the incidence of esophageal adenocarcinoma. If H. pylori infection has a protective role, populations with a naturally low prevalence of H. pylori infection such as the ethnic Malays of Northeastern Peninsular Malaysia should have high rates of esophageal adenocarcinoma.

AIM

To test this hypothesis, we investigated the incidence of esophageal carcinoma among the ethnic Malays of the state of Kelantan in Northeastern Peninsular Malaysia.

METHODS

The pathology services in the state of Kelantan are provided by two main hospitals. The histopathological records of both hospitals were systematically examined to retrieve all cases of esophageal carcinoma diagnosed between 2004 and 2008. Incidence rates were determined based on the most recent population census.

RESULTS

The age-standardized incidence rates (per 100,000 population) of esophageal adenocarcinoma among Malay men and women were 0.75 and 0.69, respectively. The corresponding rates for squamous cell carcinoma of the esophagus were 0.66 and 1.34, respectively.

CONCLUSIONS

The low rates of adenocarcinoma and squamous cell carcinoma of the esophagus in the study area, despite the fact that H. pylori infection is virtually absent, does not support the hypothesis that the absence of H. pylori infection is a pivotal factor in the pathogenesis of these cancers.

Dietary habits and gastric cancer risk in north-west Iran

OBJECTIVES

North-west Iran is a high-risk area for gastric cancer (GC). Dietary practices may increase risk of GC. For the first time, the diet-GC association in this area was assessed using a validated food frequency questionnaire.

METHODS

Cases and controls were recruited in a population-based study. In addition to collecting dietary data using a food frequency questionnaire, Helicobacter pylori antibody level was measured. Multiple logistic regression models were used to estimate odds ratios for associations between dietary factors and GC among 286 cases and 304 controls.

RESULTS

A positive association was estimated for total fat intake (OR = 1.33/20 g, 95% CI: 1.12-1.57) and risk of GC. Inverse associations were observed for vitamin C, iron, and zinc intake and risk of GC and its subgroups (cardia, non-cardia). Fruits and vegetables consumption and refrigerator use showed inverse associations (OR = 0.72/100 g, 95% CI: 0.65-0.80 and OR = 0.75/10 years, 95% CI: 0.60-0.95, respectively). Positive association was observed among those who preferred fried food (OR = 2.21, 95% CI: 1.45-3.37) or consumed highly salted/roasted seeds (OR = 1.97, 95% CI: 1.13-3.43).

CONCLUSION

GC in north-west Iran is associated with dietary practices: foods, nutrients and food preparation habits.

Northwestern China: a place to learn more on oesophageal cancer. Part one: behavioural and environmental risk factors

Oesophageal squamous cell carcinoma (OSCC) remains a public health problem in many countries, especially in emerging and developing countries. Epidemiology of OSCC is characterized by marked differences in prevalence between countries/regions/ethnical groups. The highest incidence in the world is reached by populations living in specific areas of northwestern Xinjiang, China where age-adjusted mortality may reach 150 of 100 000. In fact, there are also marked differences among the various geographical areas and the various ethnic groups within the region, which suggests specific risk factors. Behavioural factors include those factors which are common to all 'high-risk populations', such as tobacco smoking and alcohol drinking. However, the very unusual sex ratio (1.2 : 1.0) and young age range of OSCC occurrence suggests the involvement of additional early risk factors shared by males and females, and which are different from those studied in other 'high-risk' areas of the world, including China, such as LinXian area. These include drinking very hot and salted tea, boiled with milk; a diet rich in meat, especially salted, dry and/or smoked meat, and dairy products; and a diet poor in fresh fruit and vegetables. The combination of hot drinks (such as milk, tea and soups) and high-degree spirit drinks, and hard food (bread, meat and cheese), together with poor oral hygiene and tooth loss, is likely to add mechanical injury of the oesophagus to other factors linked to climate characteristics of the area (drought) and dietary habits, which promote a sodium and nitrosamine-rich diet. Association of early and severe hypertension in the same populations at high risk of OSCC might likely raise more attention. Human papilloma virus (HPV) infection, and especially HPV 16/18 E6/E7, with gene mutations and association with p53 overexpression, may contribute to the extremely high incidence of OSCC observed in Xinjiang, and could be accessible to prevention. Infection may especially be a crucial additional factor in the Uygur population in which not only HPV infection but also infection with other oncogenic viruses, such as HHV8, are highly prevalent. Genetic polymorphism might interact with viruses and/or viral products to promote carcinogenesis. These observations in northwestern China suggest that usually neglected factors, such as sodium excess and viral infection, could be taken into more account when studying OSCC risk factors in other parts of the world, especially Europe.

Association between Helicobacter pylori seropositivity and digestive tract cancers

AIM

To explore the role of Helicobacter pylori (H pylori) infection on the risk of digestive tract cancers.

METHODS

In total, 199 oral squamous-cell carcinoma (SCC), 317 esophageal SCC, 196 gastric cardia and non-cardia adenocarcinoma and 240 colon adenocarcinoma patients were recruited for serum tests of H pylori infection. Two hospital- and one community-based control groups were used for the comparisons. H pylori seropositivity was determined by an enzyme linked immunosorbent assay method against H pylori IgG.

RESULTS

Presence of H pylori infection was significantly inversely associated with esophageal SCC [adjusted odds ratio (AOR): 0.315-0.472, all P-value < 0.05] but positively associated with gastric adenocarcinoma (both cardia and non-cardia) (AOR: 1.636-3.060, all P-value < 0.05) in comparison to the three control groups. Similar results were not found in cancers of the oral cavity and colon.

CONCLUSION

Our findings support the finding that H pylori seropositivity is inversely associated with esophageal SCC risk, but increases the risk of gastric cardia adenocarcinoma.

Polymorphism in COX-2 modifies the inverse association between Helicobacter pylori seropositivity and esophageal squamous cell carcinoma risk in Taiwan: a case control study

Background

Overexpression of Cyclooxygenase-2 (COX-2) was observed in many types of cancers, including esophageal squamous cell carcinoma (ESCC). One functional SNP, COX-2 -1195G/A, has been reported to mediate susceptibility of ESCC in Chinese populations. In our previous study, the presence of Helicobacter pylori (H. pylori) was found to play a protective role in development of ESCC. The interaction of COX-2 and H. pylori in gastric cancer was well investigated. However, literature on their interaction in ESCC risk is scarce. The purpose of this study was to evaluate the association and interaction between COX-2 single nucleotide polymorphism (SNP), H. pylori infection and the risk of developing ESCC.

Methods

One hundred and eighty patients with ESCC and 194 controls were enrolled in this study. Personal data regarding related risk factors, including alcohol consumption, smoking habits and betel quid chewing, were collected via questionnaire. Genotypes of the COX-2 -1195 polymorphism were determined by PCR-based restriction fragment length polymorphism. H. pylori seropositivity was defined by immunochromatographic screening test. Data was analyzed by chi-squared tests and polytomous logistics regression.

Results

In analysis adjusting for the covariates and confounders, H. pylori seropositivity was found to be inversely association with the ESCC development (adjusted OR: 0.5, 95% CI: 0.3 – 0.9). COX-2 -1195 AA homozygous was associated with an increased risk of contracting ESCC in comparison with the non-AA group, especially among patients with H. pylori seronegative (adjusted OR ratio: 2.9, 95% CI: 1.2 – 7.3). The effect was strengthened among patients with lower third ESCC (adjusted OR ratio: 6.9, 95% CI 2.1 – 22.5). Besides, H. pylori seropositivity conveyed a notably inverse effect among patients with COX-2 AA polymorphism (AOR ratio: 0.3, 95% CI: 0.1 – 0.9), and the effect was observed to be enhanced for the lower third ESCC patients (AOR ratio: 0.09, 95% CI: 0.02 – 0.47, p for multiplicative interaction 0.008)

Conclusion

H. pylori seropositivity is inversely associated with the risk of ESCC in Taiwan, and COX-2 -1195 polymorphism plays a role in modifying the influence between H. pylori and ESCC, especially in lower third esophagus.

Macroscopic extent of gastric mucosal atrophy: increased risk factor for esophageal squamous cell carcinoma in Japan

Background

We aimed to estimate whether the macroscopic extent of gastric mucosal atrophy is associated with a risk for esophageal squamous cell carcinoma using a case-control study in Japanese subjects, a population known to have a high prevalence of CagA-positive H. pylori infection.

Methods

Two hundred and fifty-three patients who were diagnosed as having esophageal squamous cell carcinoma, and 253 sex- and age-matched controls were enrolled in the present study. The macroscopic extent of gastric mucosal atrophy was evaluated based on the Kimura and Takemoto Classification. A conditional logistic regression model with adjustment for potential confounding factors was used to assess the associations.

Results

Body gastritis, defined endoscopically, was independently associated with an increased risk for esophageal squamous cell carcinoma.

Conclusion

Our findings suggest that macroscopic body gastritis may be a risk factor for esophageal squamous cell carcinoma in Japan. Further studies are needed to confirm these findings.

Epidemiology of esophageal cancer: Orient to Occident. Effects of chronology, geography and ethnicity

Esophageal adenocarcinoma (EAC) has been rapidly increasing in Western countries during the past half century, especially in white men. Esophageal squamous cell carcinoma (ESCC) used to be the dominant type of esophageal malignancy both in Western and Asian countries. The rapid increase of EAC in Western countries has occurred in parallel with an increased prevalence of gastroesophageal reflux disease (GERD) and its major determinant, obesity. Such an increase in EAC has not yet been observed in Asia, despite a recent increase in prevalence of GERD. In this mini-review, we analyze possible factors influencing such east-west ('Orient to Occident') differences, particularly possible roles of ethnicity and environmental factors, such as Helicobacter pylori infection and nutritional factors, and how these might interact with socioeconomic differences. Development of Barrett's esophagus and esophageal adenocarcinoma appears to be strongly affected by ethnic factors, with populations resident at the west end of the Eurasian continent, such as Anglo-Celtics, being more prone to both conditions. On the other hand, ethnic groups from the eastern and southern ends of Eurasia, such as Chinese, Koreans and Japanese, and Africans might be more prone to developing esophageal squamous cell carcinoma. Future trends will also be discussed.

Helicobacter pylori and esophageal cancer risk: a meta-analysis

We conducted this meta-analysis to examine the association between Helicobacter pylori and esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma. We searched the PubMed database, the ISI database, and the references of the selected articles. Case-control or nested case-control studies were selected if they used serology or endoscopic methods to detect H. pylori in the stomach and if control subjects were not restricted to upper gastrointestinal tract cancer or peptic ulcer disease patients. A total of 19 studies were used for this analysis. Summary odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using the DerSimonian-Laird method. Q statistics and I(2) statistics were calculated to examine heterogeneity. Subgroup analyses were conducted by CagA status. For EAC, the summary OR (95% CI) was 0.56 (0.46-0.68). There was little heterogeneity among studies (I(2) = 15%). Further analysis showed that colonization with CagA-positive strains was inversely associated with EAC risk (OR, 0.41; 95% CI, 0.28-0.62) but colonization with CagA-negative strains was not (OR, 1.08; 95% CI, 0.76-1.53). For esophageal squamous cell carcinoma, the summary OR (95% CI) was 1.10 (0.78-1.55). However, there was substantial heterogeneity among studies (I(2) = 73%), with statistically significant associations in both directions. Our results suggest an inverse association between CagA-positive H. pylori colonization and risk of EAC. The prominent decline of H. pylori colonization in the past few decades may be partly responsible for the recent increase in EAC incidence in Western countries.

Environmental causes of esophageal cancer

This article reviews the environmental risk factors and predisposing conditions for the two main histologic types of esophageal cancer. Tobacco smoking, excessive alcohol consumption, drinking maté, low intake of fresh fruits and vegetables, achalasia, and low socioeconomic status increase the risk of esophageal squamous cell carcinoma. Results of investigations on other potential risk factors, including opium consumption, intake of hot drinks, eating pickled vegetables, poor oral health, and exposure to human papillomavirus, polycyclic aromatic hydrocarbons, N-nitroso compounds, acetaldehyde, and fumonisins are discussed. Gastroesophageal reflux, obesity, tobacco smoking, hiatal hernia, achalasia, and, probably, absence of H pylori in the stomach increase the risk of esophageal adenocarcinoma. Results of studies investigating other factors are also discussed.

Risk factors and gene expression in esophageal cancer

Esophageal cancer is a significant worldwide health problem because of its poor prognosis and high incidence in certain parts of the world. Tobacco smoke and alcohol consumption are significant risk factors for esophageal squamous cell carcinoma, whereas frequent gastroesophageal reflux and subsequent inflammatory reactions play a role in causing the adenocarcinoma. Esophageal carcinogenesis involves multiple genetic alterations. A large body of knowledge has been generated regarding molecular alterations associated with esophageal carcinogenesis. These alterations include aberrant cell cycle control, DNA repair, cellular enzymes, growth factor receptors, and nuclear receptors. This chapter reviews the most frequent gene alterations and their correlation with risk factors as well as the prevention strategies in esophageal cancer.

Apoptotic effect of Helicobacter pylori on oesophageal squamous-cell carcinoma cells in vitro

BACKGROUND

The relationship between Helicobacter pylori (Hp) infection and oesophageal squamous-cell carcinoma (ESCC) risk is still inconclusive. Our previous study found an inverse association between the two, but its mechanism is still unknown. Thus, we conducted in vitro studies to clarify the issue.

MATERIALS AND METHODS

One ESCC (CE 81T/VGH) cell line was co-cultured with Hp, using one gastric adenocarcinoma (AGS) cell line as the control. Hp-induced cell apoptosis was determined by flow cytometry, terminal transferase-mediated dUTP nick end labelling (TUNEL) assay and staining; caspase-3 protein expressions in cell lysates were detected by Western immunoblot.

RESULTS

Increased apoptosis was found in CE 81T/VGH, but not in AGS cells, by flow cytometry and TUNEL assay after being co-cultured with Hp at the multiplicity of infection of 1/100 (but not at 1/400) for 36 h. The amount of activated caspase-3 (17/19 kDa) also increased in CE 81T/VGH, but not in AGS cells, after co-culturing with Hp at MOI of 1/100 for 36 h. The results were confirmed by triplicate experiments in which the different apoptotic assays remained consistent.

CONCLUSIONS

Our study provides indirect evidence of the inverse association between Hp infection and ESCC risk, which is possibly due to Hp-induced apoptosis in ESCC cells. A further in vivo study is necessary to confirm our findings.

Helicobacter pylori infection and oesophageal cancer risk: association studies via evidence-based meta-analyses

AIMS

Infection of Helicobacter pylori, a major cause of various gastric diseases, has been reported to play a role in the process of tumorigenesis and progression of gastric carcinoma. Some studies have been devoted to the relationship between H. pylori infection and oesophageal cancer and have yielded conflicting results. Whether infection of H. pylori is a risk factor for this cancer remains uncertain. In this study we aimed to evaluate the association of H. pylori infection with oesophageal cancer risk.

MATERIALS AND METHODS

The associated literature was acquired through deliberate searching and selected based on the established inclusion criteria for publications, then the extracted data were further analysed by systematic meta-analyses.

RESULTS

In total, 195 articles were identified, of which 12 case-control studies concerning oesophageal cancer were selected. Oesophageal adenocarcinoma risk for H. pylori infection was 0.58-fold (95% confidence interval 0.48-0.70) (Z=5.79, P<0.01) compared with the controls. Oesophageal squamous cell carcinoma risk was 0.80-fold (95% confidence interval 0.45-1.43) (Z=0.75, P>0.05) compared with the controls. Compared with CagA-negative H. pylori, CagA-positive H. pylori markedly decreased oesophageal cancer risk.

CONCLUSION

The pooled data suggest infection of H. pylori as a possible preventive factor for oesophageal adenocarcinoma and failed to suggest a significant association between H. pylori infection and oesophageal squamous cell carcinoma.

Potential influence of interleukin-1 haplotype IL-1 beta-511*T-IL-1RN*1 in conferring low risk to middle third location of esophageal cancer: a case-control study

Interleukin (IL)-1 gene polymorphisms affect several inflammatory diseases, including cancer. Therefore, we studied genetic association of biallelic (-511C>T) polymorphism of IL-1 beta and 86-bp VNTR polymorphism of IL-1RN in 159 patients with esophageal cancer (EC) and 194 age- and gender-matched healthy controls. Genetic analysis for IL-1 polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism. The frequencies of IL-1 beta (-511C>T) and IL-1RN (variable number tandem repeat) genotypes, alleles, and haplotypes did not differ significantly between patients and controls. However, IL-1 beta -511TT genotype and T1+ haplotype combination illustrated low risk for disease at the middle third location of the tumor (odds ratio [OR] = 0.27; 95% confidence interval [CI] = 0.11-0.62; p = 0.002; OR = 0.462; 95% CI = 0.253-0.845, p = 0.01). In conclusion, subjects with IL-1 beta -511TT genotype or IL-1 beta*T-IL-1RN*1 (T1) haplotype had lower risk for middle third tumor location of EC in a northern Indian population.

Relationship between Helicobacter pylori infection and esophageal neoplasia: a meta-analysis

BACKGROUND & AIMS

Helicobacter pylori is an important causative factor in gastric carcinogenesis. However, its role in extragastric gastrointestinal malignancies, such as esophageal cancer, is controversial. The aim of this study was to explore the relationship of H. pylori infection and H. pylori cagA-positive strain with this malignancy by performing meta-analysis of all relevant studies.

METHODS

Extensive MEDLINE English language medical literature searches for human studies were performed through February 2007 with suitable keywords. Pooled estimates were obtained by using fixed or random-effects model as appropriate. Heterogeneity between studies was evaluated with the Cochran Q test, whereas the likelihood of publication bias was assessed by constructing funnel plots. Their symmetry was estimated by the Begg and Mazumdar adjusted rank correlation test.

RESULTS

In adenocarcinoma patients there were inverse significant relationships with both the H. pylori prevalence (pooled odds ratio [OR], 0.52; 95% confidence interval [CI], 0.37-0.73; P < .001) and the prevalence of H. pylori cagA-positive strain (pooled OR, 0.51; 95% CI, 0.31-0.82; P = .006). Similarly in patients with Barrett's esophagus there were inverse significant relationships (pooled OR, 0.64; 95% CI, 0.43-0.94; P = .025 and pooled OR, 0.39; 95% CI, 0.21-0.76; P = .005, respectively). In patients with squamous cell carcinoma there were no significant relationships with both H. pylori prevalence (pooled OR, 0.85; 95% CI, 0.55-1.33; P = .48) and the prevalence of H. pylori cagA-positive strains (pooled OR, 1.22; 95% CI, 0.7-2.13; P = .48).

CONCLUSIONS

The results showed an inverse statistically significant relationship of H. pylori infection with both esophageal adenocarcinoma and Barrett's esophagus, which might suggest a protective role of the infection in these entities. On the contrary, no statistically significant relationship with squamous cell carcinoma was found.

Helicobacter pylori and CagA seropositivity and its association with gastric and oesophageal carcinoma

OBJECTIVE

Helicobacter pylori infection is an established risk factor for non-cardia gastric adenocarcinoma. Infection with H. pylori strains harbouring the cagA pathology island may augment this association. H. pylori infection may at the same time reduce the risk for oesophageal carcinoma. However, prospective data on the association between CagA seropositivity and gastric or oesophageal carcinomas are limited. The purpose of this study was to investigate whether CagA seropositivity among H. pylori seropositive subjects is associated with gastric or oesophageal carcinomas.

MATERIAL AND METHODS

A nested case-control study was performed in the Malmö Preventive Medicine cohort consisting of 32,906 middle-aged subjects. Tumour cases were identified by the Swedish National Cancer Registry. The Western blot method Helicoblot 2.1 was used to detect H. pylori and CagA seropositivity.

RESULTS

Non-cardia gastric adenocarcinoma was associated with H. pylori seropositivity, odds ratio 17.8 (95% CI: 4.2-74.8; 67 cases). The odds ratio for CagA seropositivity among H. pylori seropositive subjects was 9.7 (95% CI: 1.5-infinity). No significant associations were found between cardia gastric adenocarcinoma and H. pylori or CagA seropositivity among H. pylori seropositive subjects; odds ratios were 1.5 (95% CI: 0.51-4.8) and 2.7 (95% CI: 0.38-infinity), respectively (24 cases). Oesophageal adenocarcinoma and oesophageal squamous cell carcinoma were not significantly associated with H. pylori seropositivity or with CagA seropositivity among H. pylori seropositive subjects; the odds ratios associated with oesophageal adenocarcinoma were 0.46 (95% CI: 0.07-2.6) and 0.38 (95% CI: 0.02-24), respectively. Corresponding odds ratios for oesophageal squamous cell carcinoma were 0.44 (95% CI: 0.15-1.2; 37 cases) and 2.0 (95% CI: 0.24-infinity), respectively.

CONCLUSIONS

CagA seropositivity among H. pylori seropositive subjects is a risk factor for non-cardia gastric adenocarcinoma.

Extensive gastric atrophy: an increased risk factor for superficial esophageal squamous cell carcinoma in Japan

OBJECTIVES

A recent study in Sweden has reported that gastric atrophy is associated with an increased risk for esophageal squamous cell carcinoma. However, this finding needs to be confirmed in other ethnic groups due to the wide geographic variation of this cancer.

OBJECTIVES

To investigate whether gastric atrophy is associated with a risk for esophageal squamous cell carcinoma using a case-control study in Japanese subjects, a population known to have a high prevalence of H. pylori infection and accompanying gastric atrophy.

METHODS

Seventy-three patients who had undergone endoscopic mucosal resection for superficial esophageal squamous cell carcinoma, and 73 sex- and age-matched controls, were enrolled prospectively. Gastric fundic atrophy was evaluated by histology of biopsy specimens and serum pepsinogen I level (cutoff level 25 ng/mL). Conditional logistic regression model with adjustment for potential confounding factors was used to assess the associations.

RESULTS

Gastric atrophy, defined histologically or serologically, was independently associated with an increased risk for esophageal squamous cell carcinoma and the risk seemed to increase with the progression of the atrophy. Multivariate odds ratio (95% confidence interval) for histological fundic atropy, fundic intestinal metaplasia, and serological atrophy are 4.2 (1.5-11.7), 10.7 (2.3-50.4), and 8.2 (2.2-30.4), respectively.

CONCLUSIONS

Gastric atrophy, a newly recognized risk factor for esophageal squamous cell carcinoma in Sweden, is likely to be a risk factor in other areas. Further studies are warranted to explore the causal relationship.

Helicobacter pylori and oesophageal and gastric cancers in a prospective study in China

In a cohort of 29,584 residents of Linxian, China, followed from 1985 to 2001, we conducted a case-cohort study of the magnitude of the association of Helicobacter pylori seropositivity with cancer risk in a random sample of 300 oesophageal squamous cell carcinomas, 600 gastric cardia adenocarcinomas, all 363 diagnosed gastric non-cardia adenocarcinomas, and a random sample of the entire cohort (N=1050). Baseline serum was evaluated for IgG antibodies to whole-cell and CagA H. pylori antigens by enzyme-linked immunosorbent assay. Risks of both gastric cardia and non-cardia cancers were increased in individuals exposed to H. pylori (Hazard ratios (HRs) and 95% confidence intervals=1.64; 1.26-2.14, and 1.60; 1.15-2.21, respectively), whereas risk of oesophageal squamous cell cancer was not affected (1.17; 0.88-1.57). For both cardia and non-cardia cancers, HRs were higher in younger individuals. With longer time between serum collection to cancer diagnosis, associations became stronger for cardia cancers but weaker for non-cardia cancers. CagA positivity did not modify these associations. The associations between H. pylori exposure and gastric cardia and non-cardia adenocarcinoma development were equally strong, in contrast to Western countries, perhaps due to the absence of Barrett's oesophagus and oesophageal adenocarcinomas in Linxian, making all cardia tumours of gastric origin, rather than a mixture of gastric and oesophageal malignancies.

Etiological study of esophageal squamous cell carcinoma in an endemic region: a population-based case control study in Huaian, China

BACKGROUND

Continuous exposure to various environmental carcinogens and genetic polymorphisms of xenobiotic-metabolizing enzymes (XME) are associated with many types of human cancers, including esophageal squamous cell carcinoma (ESCC). Huaian, China, is one of the endemic regions of ESCC, but fewer studies have been done in characterizing the risk factors of ESCC in this area. The aims of this study is to evaluate the etiological roles of demographic parameters, environmental and food-borne carcinogens exposure, and XME polymorphisms in formation of ESCC, and to investigate possible gene-gene and gene-environment interactions associated with ESCC in Huaian, China.

METHODS

A population based case-control study was conducted in 107 ESCC newly diagnosed cases and 107 residency- age-, and sex-matched controls in 5 townships of Huaian. In addition to regular epidemiological and food frequency questionnaire analyses, genetic polymorphisms of phase I enzymes CYP1A1, CYP1B1, CYP2A6, and CYP2E1, and phase II enzymes GSTM1, GSTT1, GSTP1, and microsomal epoxide hydrolase (EPHX) were assessed from genomic DNA using PCR based techniques.

RESULTS

Consuming acrid food, fatty meat, moldy food, salted and pickled vegetables, eating fast, introverted personality, passive smoking, a family history of cancer, esophageal lesion, and infection with Helicobacter pylori were significant risk factors for ESCC (P < 0.05). Regular clean up of food storage utensils, green tea consumption, and alcohol abstinence were protective factors for ESCC (P < 0.01). The frequency of the GSTT1 null genotype was higher in cases (59.4%) compared to controls (47.2%) with an odds ratio (OR) of 1.68 and 95% confidence interval (CI) from 0.96 to 2.97 (P = 0.07), especially in males (OR = 2.78; 95% CI = 1.22-6.25; P = 0.01). No associations were found between polymorphisms of CYP1A1, CYP1B1, CYP2A6, CYP2E1, GSTM1, GSTP1, and EPHX and ESCC (P > 0.05).

CONCLUSION

Our results demonstrated that dietary and environmental exposures, some demographic parameters and genetic polymorphism of GSTT1 may play important roles in the development of ESCC in Huaian area, China.