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

Is Helicobacter pylori infection protective against esophageal cancer?

Helicobacter pylori (H. pylori) infection affects a substantial proportion of the global population and causes various gastric disorders, including gastric cancer. Recent studies have found an inverse relationship between H. pylori infection and esophageal cancer (EC), suggesting a protective role against EC. This editorial focuses on the possible mechanisms underlying the role of H. pylori infection in EC and explores the role of gut microbiota in esophageal carcinogenesis and the practicality of H. pylori eradication. EC has two major subtypes: Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), which have different etiologies and risk factors. Gut microbiota can contribute to EC via inflammation-induced carcinogenesis, immunomodulation, lactagenesis, and genotoxin production. H. pylori infection is said to be inversely related to EAC, protecting against EAC by inducing atrophic gastritis, altering serum ghrelin levels, and triggering cancer cell apoptosis. Though H. pylori infection has no significant association with ESCC, COX-2-1195 polymorphisms and endogenous nitrosamine production can impact the risk of ESCC in H. pylori-infected individuals. There are concerns regarding a plausible increase in EC after H. pylori eradication treatments. However, H. pylori eradication is not associated with an increased risk of EC, making it safe from an EC perspective.

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

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

Prevalence of Helicobacter pylori infection among patients with esophageal carcinoma

BACKGROUND

Helicobacter pylori (H. pylori) is a widespread microorganism related to gastric adenocarcinoma (AC). In contrast, it has been reported that an inverse association exists between H. pylori infection and esophageal carcinoma. The mechanisms underlying this supposedly protective effect remain controversial.

AIM

To determine the prevalence of H. pylori infection in esophageal carcinoma patients, we performed a retrospective observational study of esophageal tumors diagnosed in our hospital.

METHODS

We retrospectively reviewed the prevalence of H. pylori infection in a cohort of patients diagnosed with esophageal carcinoma. Concomitant or previous proton pump inhibitor (PPI) usage was also recorded.

RESULTS

A total of 89 patients with esophageal carcinoma (69 males, 77.5%), with a mean age of 66 years (range, 26-93 years) were included. AC was the most frequent pathological variant (n = 47, 52.8%), followed by squamous cell carcinoma (n = 37, 41.6%). Fourteen ACs (29.8%) originated in the gastroesophageal junction and 33 (70.2%) in the esophageal body. Overall, 54 patients (60.7%) presented at stages III and IV. Previous H. pylori infection occurred only in 4 patients (4.5%), 3 with AC (6.3% of all ACs) and 1 with squamous cell carcinoma (2.7% of all squamous cell tumors). All patients with previous H. pylori infection had stage III-IV. Only one patient had received prior H. pylori eradication therapy, whereas 86 (96.6%) had received previous or concomitant PPI treatment.

CONCLUSION

In our cohort of patients, and after histologic evaluation of paraffin-embedded primary tumors, we found a very low prevalence of previous H. pylori infection. We also reviewed the medical history of the patients, concluding that the majority had received or were on PPI treatment. The minimal prevalence of H. pylori infection found in this cohort of patients with esophageal carcinoma suggests a protective role.

Risk of Esophageal Adenocarcinoma After Helicobacter pylori Eradication Treatment in a Population-Based Multinational Cohort Study

BACKGROUND & AIMS

Helicobacter pylori infection is associated with a decreased risk of esophageal adenocarcinoma, and the decreasing prevalence of such infection might contribute to the increasing incidence of this tumor. We examined the hypothesis that eradication treatment of H pylori increases the risk of esophageal adenocarcinoma.

METHODS

This population-based multinational cohort, entitled "Nordic Helicobacter Pylori Eradication Project (NordHePEP)," included all adults (≥18 years) receiving H pylori eradication treatment from 1995-2018 in any of the 5 Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) with follow-up throughout 2019. Data came from national registers. We calculated standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) by dividing the cancer incidence in the exposed cohort by that of the entire Nordic background populations of the corresponding age, sex, calendar period, and country. Analyses were stratified by factors associated with esophageal adenocarcinoma (ie, education, comorbidity, gastroesophageal reflux, and certain medications).

RESULTS

Among 661,987 participants who contributed 5,495,552 person-years after eradication treatment (median follow-up, 7.8 years; range, 1-24 years), 550 cases of esophageal adenocarcinoma developed. The overall SIR of esophageal adenocarcinoma was not increased (SIR = 0.89; 95% CI, 0.82-0.97). The SIR did not increase over time after eradication treatment, but rather decreased and was 0.73 (95% CI, 0.61-0.86) at 11-24 years after treatment. There were no major differences in the stratified analyses. The overall SIR of esophageal squamous cell carcinoma, calculated for comparison, showed no association (SIR = 0.99; 95% CI, 0.89-1.11).

CONCLUSIONS

This absence on an increased risk of esophageal adenocarcinoma after eradication treatment of H pylori suggests eradication is safe from a cancer perspective.

Role of the Microbiome in the Diagnosis and Management of Gastroesophageal Cancers

PURPOSE

Stomach and esophageal cancers are among the highest mortality from cancers worldwide. Microbiota has an interplaying role within the human gastrointestinal (GI) tract. Dysbiosis occurs when a disruption of the balance between the microbiota and the host happens. With this narrative review, we discuss the main alterations in the microbiome of gastroesophageal cancer, revealing its potential role in the pathogenesis, early detection, and treatment.

RESULTS

Helicobacter pylori plays a major role the development of a cascade of preneoplastic conditions ranging from atrophic gastritis to metaplasia and dysplasia, ultimately culminating in gastric cancer, while other pathogenic agents are Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli, and Lactobacillus. Campylobacter species (spp.)'s role in the progression of esophageal adenocarcinoma may parallel that of Helicobacter pylori in the context of gastric cancer, with other esophageal carcinogenic agents being Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. Moreover, gut microbiome could significantly alter the outcomes of chemotherapy and immunotherapy. The gut microbiome can be modulated through interventions such as antibiotics, probiotics, or prebiotics intake. Fecal microbiota transplantation has emerged as a therapeutic strategy as well.

CONCLUSIONS

Nowadays, it is widely accepted that changes in the normal gut microbiome causing dysbiosis and immune dysregulation play a role gastroesophageal cancer. Different interventions, including probiotics and prebiotics intake are being developed to improve therapeutic outcomes and mitigate toxicities associated with anticancer treatment. Further studies are required in order to introduce the microbiome among the available tools of precision medicine in the field of anticancer treatment.

Development of a Survival Nomogram for Esophageal Squamous Cell Carcinoma Patients: a Population-Based Analysis

PURPOSE

In this study, we developed a prognostic nomogram for esophageal squamous cell carcinoma (ESCC) patients.

METHODS

Patients diagnosed with ESCC from the Surveillance, Epidemiology, and End Results (SEER) database (1975-2017) and a local hospital were enrolled in this retrospective cohort study. Prognoses were analyzed using the R language software, and the predictive power of the model was then assessed by the Harrell concordance index (C-index) and the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

RESULTS

In total, 2915 ESCC patients from SEER database were divided into training and validation cohorts. Multivariate analysis revealed that sex, marital status, tumor-node-metastasis (TNM) stage, surgery, chemotherapy, and radiation all showed a significant association with overall survival (OS) and cancer-specific survival (CSS) (also with tumor grade). These characteristics were employed to build a nomogram. The C-index of the nomogram for OS and CSS prediction was 0.743 and 0.748 for the training cohort, which were superior to the predictive power of the 7th TNM staging system. The AUCs of the nomogram for predicting 2- and 5-year OS were 0.805 and 0.812, respectively, and the AUCs for CSS were 0.811 and 0.821, respectively. ROC and calibration curves of data from the SEER internal validation set and of data from our hospital showed that this model had good accuracy for predicting the prognosis of ESCC patient.

CONCLUSION

The nomogram developed in this study provides a useful tool for accurately estimating OS and CSS for ESCC patients.

Obesity, obesities and gastrointestinal cancers

Obesity has been recognized to be increasing globally and is designated a disease with adverse consequences requiring early detection and appropriate care. In addition to being related to metabolic syndrome disorders such as type 2 diabetes, hypertension, stroke, and premature coronary artery disease. Obesity is also etiologically linked to several cancers. The non-gastrointestinal cancers are breast, uterus, kidneys, ovaries, thyroid, meningioma, and thyroid. Gastrointestinal (GI) cancers are adenocarcinoma of the esophagus, liver, pancreas, gallbladder, and colorectal. The brighter side of the problem is that being overweight and obese and cigarette smoking are mostly preventable causes of cancers. Epidemiology and clinical studies have revealed that obesity is heterogeneous in clinical manifestations. In clinical practice, BMI is calculated by dividing a person's weight in kilograms by the square of the person's height in square meters (kg/m2). A BMI above 30 kg/m2 (defining obesity in many guidelines) is considered obesity. However, obesity is heterogeneous. There are subdivisions for obesity, and not all obesities are equally pathogenic. Adipose tissue, in particular, visceral adipose tissue (VAT), is endocrine and abdominal obesity (a surrogate for VAT) is evaluated by waist-hip measurements or just waist measures. Visceral Obesity, through several hormonal mechanisms, induces a low-grade chronic inflammatory state, insulin resistance, components of metabolic syndrome, and cancers. Metabolically obese, normal-weight (MONW) individuals in several Asian countries may have BMI below normal levels to diagnose obesity but suffer from many obesity-related complications. Conversely, some people have high BMI but are generally healthy with no features of metabolic syndrome. Many clinicians advise weight loss by dieting and exercise to metabolically healthy obese with large body habitus than to individuals with metabolic obesity but normal BMI. The GI cancers (esophagus, pancreas, gallbladder, liver, and colorectal) are individually discussed, emphasizing the incidence, possible pathogenesis, and preventive measures. From 2005 to 2014, most cancers associated with overweight and Obesity increased in the United States, while cancers related to other factors decreased. The standard recommendation is to offer or refer adults with a body mass index (BMI) of 30 or more to intensive, multicomponent behavioral interventions. However, the clinicians have to go beyond. They should critically evaluate BMI with due consideration for ethnicity, body habitus, and other factors that influence the type of obesity and obesity-related risks. In 2001, the Surgeon General's ``Call to Action to Prevent and Decrease Overweight and Obesity'' identified obesity as a critical public health priority for the United States. At government levels reducing obesity requires policy changes that improve the food and physical activity for all. However, implementing some policies with the most significant potential benefit to public health is politically tricky. The primary care physician, as well as subspecialists, should identify overweight and Obesity based on all the variable factors in the diagnosis. The medical community should address the prevention of overweight and Obesity as an essential part of medical care as much as vaccination in preventing infectious diseases at all levels- from childhood, to adolescence, and adults.

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.

Relationship between pathogenic microorganisms and the occurrence of esophageal carcinoma based on pathological type: a narrative review

INTRODUCTION

Esophageal cancer (EC) is one of the most common malignant tumors of the upper gastrointestinal tract. The etiology of EC is complicated and increasing evidence has shown that microbial infection is closely related to the occurrence of various malignant tumors. Though many studies have been focused on this subject in recent years, the exact relationship between microbial infection and the occurrence of EC remains unclear.

AREAS COVERED

In this review, we searched all eligible literature reports, summarized the most recent studies in this research field, and analyzed the pathogenic microorganisms associated with EC, providing the latest evidence and references for the prevention of pathogenic microorganism-related EC.

EXPERT OPINION

In recent years, increasing evidence has shown that pathogenic microbial infections are closely associated with the development of EC. Therefore, it is necessary to describe in detail the relationship between microbial infection and EC and clarify its possible pathogenic mechanism, which will shed a light on clinical prevention and treatment of cancer caused by pathogenic microbial infection.

Current Status and Future Prospects for Esophageal Cancer

Esophageal cancer (EC) is the ninth most common cancer and the sixth leading cause of cancer deaths worldwide. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two main histological subtypes with distinct epidemiological and clinical features. While the global incidence of ESCC is declining, the incidence of EAC is increasing in many countries. Decades of epidemiologic research have identified distinct environmental exposures for ESCC and EAC subtypes. Recent advances in understanding the genomic aspects of EC have advanced our understanding of EC causes and led to using specific genomic alterations in EC tumors as biomarkers for early diagnosis, treatment, and prognosis of this cancer. Nevertheless, the prognosis of EC is still poor, with a five-year survival rate of less than 20%. Currently, there are significant challenges for early detection and secondary prevention for both ESCC and EAC subtypes, but Cytosponge™ is shifting this position for EAC. Primary prevention remains the preferred strategy for reducing the global burden of EC. In this review, we will summarize recent advances, current status, and future prospects of the studies related to epidemiology, time trends, environmental risk factors, prevention, early diagnosis, and treatment for both EC subtypes.

Cohort profile: Nordic Helicobacter Pylori eradication project (NordHePEP)

PURPOSE

This cohort description presents the Nordic Helicobacter Pylori Eradication Project (NordHePEP), a population-based cohort of patients having received eradication treatment for Helicobacter pylori (HP). The cohort is created with the main purpose of examining whether and to what extent HP eradication treatment influences the risk of gastrointestinal cancer.

PARTICIPANTS

NordHePEP includes all adults (aged ≥18 years) having been prescribed and dispensed HP eradication treatment according to the nationwide complete drug registries in any of the five Nordic countries (Denmark, Finland, Iceland, Norway, or Sweden) between 1994 and 2020 (start and end year varies between countries). We have retrieved and merged individual-level data from multiple national registries, including drug, patient, cancer, population, and death registries.

FINDINGS

The cohort includes 674,771 patients having received HP eradication treatment. During up to 23 years of follow-up, 59,292 (8.8%) participants were diagnosed with cancer (non-melanoma skin cancer excluded), whereof 15,496 (2.3%) in the gastrointestinal tract.

FUTURE PLANS

We will analyse HP eradication treatment in relation to gastrointestinal cancer risk. Standardised incidence ratios will be calculated as the observed cancer incidence in the cohort divided by the expected cancer incidence, derived from the background population of the corresponding age, sex, and calendar year.

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.

Implications of Gut Microbiota in Epithelial-Mesenchymal Transition and Cancer Progression: A Concise Review

Advancement in the development of molecular sequencing platforms has identified infectious bacteria or viruses that trigger the dysregulation of a set of genes inducing the epithelial-mesenchymal transition (EMT) event. EMT is essential for embryogenesis, wound repair, and organ development; meanwhile, during carcinogenesis, initiation of the EMT can promote cancer progression and metastasis. Recent studies have reported that interactions between the host and dysbiotic microbiota in different tissues and organs, such as the oral and nasal cavities, esophagus, stomach, gut, skin, and the reproductive tract, may provoke EMT. On the other hand, it is revealed that certain microorganisms display a protective role against cancer growth, indicative of possible therapeutic function. In this review, we summarize recent findings elucidating the underlying mechanisms of pathogenic microorganisms, especially the microbiota, in eliciting crucial regulator genes that induce EMT. Such an approach may help explain cancer progression and pave the way for developing novel preventive and therapeutic strategies.

Effects of Helicobacter pylori infection in gastrointestinal tract malignant diseases: From the oral cavity to rectum

Helicobacter pylori (H. pylori) has infected approximately fifty percent of humans for a long period of time. However, improvements in the public health environment have led to a decreased chance of H. pylori infection. However, a high infection rate is noted in populations with a high incidence rate of gastric cancer (GC). The worldwide fraction of GC attributable to H. pylori is greater than 85%, and a high H. pylori prevalence is noted in gastric mucosa-associated lymphoid tissue lymphoma patients. These results indicate that the majority of GC cases can be prevented if H. pylori infection is eliminated. Because H. pylori exhibits oral-oral or fecal-oral transmission, the relationship between this microorganism and other digestive tract malignant diseases has also attracted attention. This review article provides an overview of H. pylori and the condition of the whole gastrointestinal tract environment to further understand the correlation between the pathogen and the host, thus allowing improved realization of disease presentation.

Lower Incidence of Hepatobiliary Cancer in Helicobacter pylori-Infected Persons: A Cohort Study of 53.633 Persons

BACKGROUND AND AIMS

Helicobacter pylori (HP) is known to be involved in intestinal carcinogenesis. As regards hepatobiliary cancers, there are few and inconsistent reports. We investigated HP infection and its association with the incidence of hepatobiliary cancers in a large cohort study. The cohort's appropriateness for the purpose was gauged by its ability to identify the established risk relation to gastric cancer.

METHODS

This historical study was performed in the Central Denmark Region. Patients were included from primary healthcare after being tested for HP infection with a urea breath test. Patients' diagnoses, age, gender, and country of birth were obtained from Danish national administrative registries. Cox regression was used to compare incidences of hepatobiliary and gastric cancer between HP-positive and HP-negative persons, adjusting for confounding variables.

RESULTS

A total of 53,633 persons were included and 10,553 were tested HP-positive. They were followed for a median of 4.6 years (total 250,515 person-years). We found 64 hepatobiliary cancers, with a markedly lower incidence in HP-positive persons; HR = 0.27 (95% CI 0.11-0.68). A higher incidence of gastric cancer in HP-positive persons was confirmed (HR = 1.99 (95% CI 1.35-2.94)).

CONCLUSION

The incidence of hepatobiliary cancers was remarkably lower in HP-infected persons after adjusting for age, gender, cirrhosis, alcohol-related diagnoses, chronic viral hepatitis, and country of origin. We found no methodological cause for this unexpected finding, and the pathogenic links between the infection and cancer remain to be identified. Our results must be confirmed in a similar cohort.

Epidemiology of Helicobacter pylori

In many countries alike, the time trends of gastric cancer, gastric and duodenal ulcer, ulcerative colitis, Crohn's disease, and colorectal cancer are characterized by similar birth-cohort patterns. Mortality from these diagnoses rose in cohorts born during the 19th century and then fell in subsequent cohorts born during the 20th century.

Effects of Helicobacter pylori Infection on the Oral Microbiota of Reflux Esophagitis Patients

The human oral microbiota plays a vital role in maintaining metabolic homeostasis. To explore the relationship between Helicobacter pylori (Hp) and reflux esophagitis, we collected 86 saliva samples from reflux esophagitis patients (RE group) and 106 saliva samples from healthy people (C group) for a high-throughput sequencing comparison. No difference in alpha diversity was detected between the RE and the C groups, but beta diversity of the RE group was higher than the C group. Bacteroidetes was more abundant in the RE group, whereas Firmicutes was more abundant in the C group. The linear discriminant analysis effect size analysis demonstrated that the biomarkers of the RE group were Prevotella, Veillonella, Leptotrichia, and Actinomyces, and the biomarkers of the C group were Lautropia, Gemella, Rothia, and Streptococcus. The oral microbial network structure of the C group was more complex than that of the RE group. Second, to explore the effect of Hp on the oral microbiota of RE patients, we performed the ¹⁴C-urea breath test on 45 of the 86 RE patients. We compared the oral microbiota of 33 Hp-infected reflux esophagitis patients (REHpp group) and 12 non-Hp-infected reflux esophagitis patients (REHpn group). No difference in alpha diversity was observed between the REHpn and REHpp groups, and beta diversity of the REHpp group was significantly lower than that of the REHpn group. The biomarkers in the REHpp group were Veillonella, Haemophilus, Selenomonas, Megasphaera, Oribacterium, Butyrivibrio, and Campylobacter; and the biomarker in the REHpn group was Stomatobaculum. Megasphaera was positively correlated with Veillonella in the microbial network of the REHpp group. The main finding of this study is that RE disturbs the human oral microbiota, such as increased beta diversity. Hp infection may inhibit this disorderly trend.

Predictive Model for Overall Survival and Cancer-Specific Survival in Patients with Esophageal Adenocarcinoma

Objective

Recent years, there has been a rapid increase in the incidence of esophageal adenocarcinoma (EAC), while the prognosis for patients diagnosed remains poor and has slightly improved.

Methods

We extracted 6,466 cases with detailed demographical characteristics including age at diagnosis, sex, ethnicity, marital status, and clinical features, involving tumor grade and stage at diagnosis and treatment modalities (radiation therapy, chemotherapy, and surgery) from the Surveillance, Epidemiology, and End Results (SEER) (1975–2017) dataset. They were further randomly divided into the training and validating cohorts. Univariate and multivariate Cox analyses were conducted to determine significant variables for construction of nomogram. The predictive power of the model was then assessed by Harrell concordance index (C-index) and the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

Results

Multivariate analysis revealed that age, marital status, insurance, tumor grade, TNM stage, surgery, and chemotherapy all showed a significant association with overall survival (OS) and cancer-specific survival (CSS). These characteristics were employed to build a nomogram. Particularly, the discrimination of nomogram for OS and CSS prediction in the training set were excellent (C-index = 0.762, 95% CI: 0.754–0.770 and C-index = 0.774, 95% CI: 0.766–0.782). The AUC of the nomogram for predicting 2- and 5-year OS was 0.834 and 0.853 and CSS was 0.844 and 0.866. Similar results were observed in the internal validation set.

Conclusion

We have successfully established a novel nomogram for predicting OS and CSS in EAC patients with good accuracy, which can help clinicians predict the survival of individual patient survival and provide optimal treatment strategies.

Association of Helicobacter pylori and gastric atrophy with adenocarcinoma of the esophagogastric junction in Taixing, China

Gastric atrophy caused by Helicobacter pylori infection was suggested to influence the risk of adenocarcinoma of the esophagogastric junction (AEGJ), however, the evidence remains limited. We aimed to examine the associations of H. pylori infection and gastric atrophy (defined using serum pepsinogen [PG] I to PGII ratio) with AEGJ risk, based on a population-based case-control study in Taixing, China (2010-2014), with 349 histopathologically confirmed AEGJ cases and 1859 controls. We explored the potential effect modification by H. pylori serostatus and sex on the association of serum PGs with AEGJ risk. We used unconditional logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). H. pylori seropositivity was associated with an elevated AEGJ risk (OR = 1.95, 95% CI: 1.47-2.63). Neither CagA-positive nor VacA-positive strains dramatically changed this association. Gastric atrophy (PGI/PGII ratio ≤4) was positively associated with AEGJ risk (OR = 2.36, 95% CI: 1.72-3.22). The fully adjusted ORs for AEGJ progressively increased with the increasing levels of PGII (P-trend <.001). H. pylori showed nonsignificant effect modification (P-interaction = .385) on the association of gastric atrophy with AEGJ. In conclusion, H. pylori and gastric atrophy were positively associated with AEGJ risk. These results may contribute evidence to the ongoing research on gastric atrophy-related cancers and guide the prevention and control of AEGJ.

The Role of Microbiota in Gastrointestinal Cancer and Cancer Treatment: Chance or Curse?

The gastrointestinal (GI) tract is home to a complex and dynamic community of microorganisms, comprising bacteria, archaea, viruses, yeast, and fungi. It is widely accepted that human health is shaped by these microbes and their collective microbial genome. This so-called second genome plays an important role in normal functioning of the host, contributing to processes involved in metabolism and immune modulation. Furthermore, the gut microbiota also is capable of generating energy and nutrients (eg, short-chain fatty acids and vitamins) that are otherwise inaccessible to the host and are essential for mucosal barrier homeostasis. In recent years, numerous studies have pointed toward microbial dysbiosis as a key driver in many GI conditions, including cancers. However, comprehensive mechanistic insights on how collectively gut microbes influence carcinogenesis remain limited. In addition to their role in carcinogenesis, the gut microbiota now has been shown to play a key role in influencing clinical outcomes to cancer immunotherapy, making them valuable targets in the treatment of cancer. It also is becoming apparent that, besides the gut microbiota's impact on therapeutic outcomes, cancer treatment may in turn influence GI microbiota composition. This review provides a comprehensive overview of microbial dysbiosis in GI cancers, specifically esophageal, gastric, and colorectal cancers, potential mechanisms of microbiota in carcinogenesis, and their implications in diagnostics and cancer treatment.

The Role of Microbiota in the Pathogenesis of Esophageal Adenocarcinoma

Simple Summary

Esophageal adenocarcinoma has a poor 5-year survival rate and is among the highest mortality cancers. Changes in the esophageal microbiome have been associated with cancer pathogenesis; however, the molecular mechanism remains obscure. This review article critically analyzes the molecular mechanisms through which microbiota may mediate the development and progression of esophageal adenocarcinoma and its precursors-gastroesophageal reflux disease and Barrett’s esophagus. It summarizes changes in esophageal microbiome composition in normal and pathologic states and subsequently discusses the role of altered microbiota in disease progression. The potential role of esophageal microbiota in protecting against the development of esophageal adenocarcinoma is also discussed. By doing so, this article highlights specific directions for future research developing microbiome-mediated therapeutics for esophageal adenocarcinoma.

Abstract

Esophageal adenocarcinoma (EAC) is associated with poor overall five-year survival. The incidence of esophageal cancer is on the rise, especially in Western societies, and the pathophysiologic mechanisms by which EAC develops are of extreme interest. Several studies have proposed that the esophageal microbiome may play an important role in the pathophysiology of EAC, as well as its precursors—gastroesophageal reflux disease (GERD) and Barrett’s esophagus (BE). Gastrointestinal microbiomes altered by inflammatory states have been shown to mediate tumorigenesis directly and are now being considered as novel targets for both cancer treatment and prevention. Elucidating molecular mechanisms through which the esophageal microbiome potentiates the development of GERD, BE, and EAC will provide a foundation on which new therapeutic targets can be developed. This review summarizes current findings that elucidate the molecular mechanisms by which microbiota promote the pathogenesis of GERD, BE, and EAC, revealing potential directions for additional research on the microbiome-mediated pathophysiology of EAC.

Global burden and epidemiology of Barrett oesophagus and oesophageal cancer

Oesophageal cancer is a global health problem; in 2018 there were more than 572,000 people newly diagnosed with oesophageal cancer worldwide. There are two main histological subtypes of oesophageal cancer, oesophageal adenocarcinoma (EAC) and oesophageal squamous cell carcinoma (ESCC), and there has been a dramatic shift in its epidemiology. While the incidence of EAC and its precursor lesion, Barrett oesophagus, has increased in Western populations over the past four decades, the incidence of ESCC has declined in most parts of the world over the same period. ESCC still accounts for the vast majority of all oesophageal cancer cases diagnosed worldwide each year. Prognosis for patients with oesophageal cancer is strongly related to stage at diagnosis. As most patients are diagnosed with late-stage disease, overall 5-year survival for oesophageal cancer remains <20%. Knowledge of epidemiology and risk factors for oesophageal cancer is essential for public health and clinical decisions about risk stratification, screening and prevention. The goal of this Review is to establish the current epidemiology of oesophageal cancer, with a particular focus on the Western world and the increasing incidence of EAC and Barrett oesophagus.

The complexity of cancer origins at the gastro-oesophageal junction

Chronic acid-biliary reflux and Helicobacter pylori infection are instrumental environmental drivers of cancer initiation and progression in the upper gastrointestinal tract. Remarkably, although these environmental carcinogens are quite dissimilar, the tumour progression cascade these carcinogens engender is highly comparable. For this reason, studies of malignant progression occurring at the anatomic borderland between the oesophagus and the stomach have traditionally lumped junctional adenocarcinomas with either oesophageal adenocarcinoma or gastric adenocarcinoma. Whilst studies have revealed remarkable epidemiological and genetic similarities of these cancers and their associated premalignant conditions, these works have also revealed some key differences. This highlights that further scientific effort demands a dedicated focus on the understanding of the cell-cell interaction between the epithelium and the local microenvironment in this anatomic region. We here review available evidence with regards to tumour progression occurring at the gastro-oesophageal junction and contrast it with available data on cancer evolution in the metaplastic oesophagus and distal stomach.

Epidemiology of Barrett's Esophagus and Esophageal Adenocarcinoma: Implications for Screening and Surveillance

In the United States, the incidence of esophageal adenocarcinoma increased markedly since the 1970s with a recent stabilization. Despite evolving screening and surveillance strategies to diagnose, risk triage, and intervene in Barrett's esophagus patients to prevent esophageal adenocarcinoma, most cases present with advanced disease and poor resultant survival. Epidemiologic studies have identified the main risk factors for these conditions, including increasing age, male sex, white race, gastroesophageal reflux disease, abdominal obesity, cigarette smoking, and lack of infection with Helicobacter pylori. This review summarizes the current epidemiologic evidence with implications for screening and surveillance in Barrett's esophagus and esophageal adenocarcinoma.

Epidemiology of esophageal cancer: update in global trends, etiology and risk factors

Esophageal cancer is the eighth most common type of cancer worldwide and constitutes the sixth leading cause of cancer deaths. It is characterized by its high mortality rate, poor prognosis at time of diagnosis and variability based on geographic location. Present day, the prevalence of esophageal cancer is in transition. Although esophageal squamous cell carcinoma continues to be the most prevalent type worldwide, esophageal adenocarcinoma is quickly becoming the most prevalent type in developed countries. Risk factors for the development of esophageal squamous cell carcinoma include low socioeconomic status, consumption of tobacco, alcohol, hot beverages, and nitrosamines. Additionally, micronutrient deficiencies have also been linked to the development of esophageal squamous cell cancer. These include vitamin C, vitamin E, and folate. With respect to esophageal adenocarcinoma, risk factors include Barrett's esophagus, gastroesophageal reflux disease, obesity, and tobacco consumption. Screening for esophageal cancer will likely play an essential role in prevention, and consequently, mortality in the future. Present day, there are no established guidelines for esophageal squamous cell cancer screening. Guidelines for esophageal adenocarcinoma are more well established but lack concrete evidence in the form of randomized controlled trials. This review will discuss the epidemiology, risk factors, and current prevention strategies for esophageal cancer in depth. It is our aim to raise awareness on the aforementioned topics to increase public health efforts in eradicating this disease.

Upper Gastrointestinal Cancer in China: Spatial Epidemiologic Evidence from Screening Areas

Upper gastrointestinal cancer (UGIC) including esophageal cancer and gastric cancer, which has been a significant burden in China. Few studies have explored the spatial pattern and association of incidence and mortality using nationwide data. This study aims to explore the spatial pattern and association of incidence and mortality between esophageal cancer and gastric cancer, and identify high-risk areas of the cancers to provide scientific evidence for tailoring endoscopic screening programs. We collected UGIC data in 2014 from a National Cancer Report, and then adopted methods of correlation analysis and spatial statistics to identify high-risk areas on the cancers and to explore the pattern. The results show a spatial autocorrelation on the spatial distribution of incidence and mortality of esophageal and gastric cancers, and the relative risks were from 2.52 (95% CI (confidence interval), 2.37-2.67; P < 0.001) to 3.80 (95% CI, 3.46-4.18; P < 0.001) in primary risk areas, respectively. Moreover, esophageal cancer shows an upward and then downward trend from west to east, and from south to north, yet gastric cancer exhibits an upward and then downward trend only from south to north. This study indicates habitants in overlapping risk areas have heavier cancer burdens, and suggests esophageal cancer and gastric cancer have a significant correlation. Therefore, more endoscopic screening attention should focus on overlapping risk areas.

The Cancer-Immune Set Point in Oesophageal Cancer

Immunotherapy has achieved long-term disease control in a proportion of cancer patients, but determinants of clinical benefit remain unclear. A greater understanding of antitumor immunity on an individual basis is needed to facilitate a precision oncology approach. A conceptual framework called the "cancer-immune set point" has been proposed to describe the equilibrium between factors that promote or suppress anticancer immunity and can serve as a basis to understand the variability in clinical response to immune checkpoint blockade. Oesophageal cancer has a high mutational burden, develops from pre-existing chronic inflammatory lesions and is therefore anticipated to be sensitive to immune checkpoint inhibition. However, both tumour- and patient-specific factors including the immune microenvironment, the microbiome, obesity, and host genetics contribute to an immune set point that confers a lower-than-expected response to checkpoint blockade. Immunotherapy is therefore currently confined to latter lines of treatment of advanced disease, with no reliable predictive biomarker of response. In this review, we examine oesophageal cancer in the context of the cancer-immune set point, discuss factors that contribute to response to immunotherapeutic intervention, and propose areas requiring further investigation to improve treatment response.

Helicobacter pylori eradication treatment and the risk of Barrett's esophagus and esophageal adenocarcinoma

BACKGROUND

Helicobacter pylori (H. pylori) is associated with lower risks of Barrett's esophagus and esophageal adenocarcinoma, but whether H. pylori eradication increases the risk of these conditions is unknown. This study aimed to test the hypothesis that H. pylori eradication leads to gradually increased risks of Barrett's esophagus and esophageal adenocarcinoma over time, while esophageal squamous cell carcinoma was assessed for comparison reasons.

MATERIAL AND METHODS

This Swedish nationwide, population-based cohort study in 2005-2012 used data from the Swedish Prescribed Drug Registry to assess eradication treatment for H. pylori. Barrett's esophagus was identified from the Swedish Patient Registry, and esophageal adenocarcinoma and squamous cell carcinoma from the Swedish Cancer Registry. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by dividing the observed risk in the H. pylori eradication treatment cohort by the expected risk derived from the Swedish population of the same age, sex, and calendar period.

RESULTS

The cohort included 81 919 patients having had eradication treatment. For Barrett's esophagus (n = 178), the overall SIR was increased (SIR 3.67, 95% CI 3.15-4.25), but the SIRs slightly decreased over time after eradication treatment. For esophageal adenocarcinoma (n = 11), the overall SIR was 1.26 (95% CI 0.62-2.26), and the SIRs did not increase over time. The SIRs of esophageal squamous cell carcinoma (n = 10) were not influenced by eradication treatment.

CONCLUSIONS

This study did not provide any evidence of an increasing risk of Barrett's esophagus or esophageal adenocarcinoma (or esophageal squamous cell carcinoma) over time after eradication treatment for H. pylori.

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.

Combined elevation of TRIB2 and MAP3K1 indicates poor prognosis and chemoresistance to temozolomide in glioblastoma

Introduction

Glioblastoma (GBM) is the most lethal primary malignant brain tumor in adults with poor survival due to acquired therapeutic resistance and rapid recurrence. Currently, the standard clinical strategy for glioma includes maximum surgical resection, radiotherapy, and temozolomide (TMZ) chemotherapy; however, the median survival of patients with GBM remains poor despite these comprehensive therapies. Therefore, the identification of new prognostic biomarkers is urgently needed to evaluate the malignancy and long‐term outcome of glioma.

Aims

To further investigate prognostic biomarkers and potential therapeutic targets for GBM.

Results

In this study, we identified tribbles pseudokinase 2 (TRIB2) as one of the genes that is most correlated with pathological classification, radioresistance, and TMZ resistance in glioma. Additionally, the expression of mitogen‐activated protein kinase kinase kinase 1 (MAP3K1) showed a strong correlation with TRIB2. Moreover, a combined increase in TRIB2 and MAP3K1 was observed in GBM and indicated a poor prognosis of patients with glioma. Finally, enriched TRIB2 expression and MAP3K1 expression were shown to be associated with resistance to TMZ and radiotherapy.

Conclusion

Combined elevation of TRIB2 and MAP3K1 could be novel prognostic biomarkers and potential therapeutic targets to evaluate the malignancy and long‐term outcomes of GBM.

Alteration of the esophageal microbiota in Barrett's esophagus and esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased in recent decades, and its 5-year survival rate is less than 20%. As a well-established precursor, patients with Barrett's esophagus (BE) have a persistent risk of progression to EAC. Many researchers have already identified some factors that may contribute to the development of BE and EAC, and the identified risks include gastroesophageal reflux (GER), male sex, older age, central obesity, tobacco smoking, Helicobacter pylori (H. pylori) eradication, and the administration of proton pump inhibitors (PPIs) and antibiotics. The human gut harbors trillions of microorganisms, the majority of which are bacteria. These microorganisms benefit the human host in many ways, such as helping in digestion, assisting in the synthesis of certain vitamins, promoting the development of the gastrointestinal immune system, regulating metabolism and preventing invasion by specific pathogens. In contrast, microbial dysbiosis may play important roles in various diseases, such as inflammation and cancers. The composition of the microbiota located in the normal esophagus is relatively conserved without distinct microbial preferences in the upper, middle and lower esophagus. Six major phyla constitute the esophageal microbiota, including Firmicutes, Bacteroides, Actinobacteria, Proteobacteria, Fusobacteria and TM7, similar to the oral microbiota. Streptococcus dominates the esophageal microbiota. However, the microbiota varies in different esophageal diseases compared to that in the healthy esophagus. The type I microbiota, which is primarily composed of gram-positive bacteria, is closely associated with the normal esophagus, while type II microbiota has enriched gram-negative bacteria and is mainly associated with the abnormal esophagus. These increased gram-negative anaerobes/microaerophiles include Veillonella, Prevotella, Haemophilus, Neisseria, Granulicatella and Fusobacterium, many of which are associated with BE. The microbial diversity in the esophagus is decreased in EAC patients, and Lactobacillus fermentum is enriched compared to that in controls and BE patients. Furthermore, the microbiota may be associated with BE and EAC by interacting with their risk factors, including central obesity, GER, H. pylori, administration of PPIs and antibiotics. Therefore, a large gap in research must be bridged to elucidate the associations among these factors. Some studies have already proposed several potential mechanisms by which the microbiota participates in human carcinogenesis by complicated interactions with the human host immune system and signaling pathways. The activation of the LPS-TLR4-NF-κB pathway may contribute to inflammation and malignant transformation. This exciting field of gastrointestinal microbiota allows us to unravel the mystery of carcinogenesis from another perspective. Further studies are needed to explore whether the microbiota changes before or after disease onset, to improve our understanding of the pathogenesis, and to find novel targets for prevention, diagnosis and therapy, which could offer more cost-effective and relatively safe choices.

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.

Prognostic Significance of MicroRNAs in Glioma: A Systematic Review and Meta-Analysis

PURPOSE

Different microRNAs (miRs) have been demonstrated to relate with the outcome of glioma patients, while the conclusions are inconsistent. We perform a meta-analysis to clarify the relationship between different miRs and prognosis of glioma.

METHODS

Related studies were retrieved from PubMed, Embase, and Cochrane Library. Pooled hazard ratios (HRs) of different miRs expression for survival and 95% confidence intervals (CIs) were calculated using random-effects model.

RESULTS

A total of 15 miRs with 4708 glioma patients were ultimately included. Increased expression of miR-15b (HR, 1.584; 95% CI, 1.199-2.092), 21 (HR, 1.591; 95% CI, 1.278-1.981), 148a (HR, 1.122; 95% CI, 1.023-1.231), 196 (HR, 1.877; 95% CI, 1.033-3.411), 210 (HR, 1.251; 95% CI, 1.010-1.550), and 221 (HR, 1.269; 95% CI, 1.054-1.527) or decreased expression of miR-106a (HR, 0.809; 95% CI, 0.655-0.998) and 124 (HR, 0.833; 95% CI, 0.729-0.952) was correlated with poor outcome of glioma patients.

CONCLUSIONS

miR-15b, 21, 148a, 196, 210, 221, 106a, and 124 are valuable biomarkers for the prognosis of glioma which might be used in clinical settings.

Systematic review: the etiology of esophageal squamous cell carcinoma in low-income settings

Esophageal carcinoma causes over 380 000 deaths per year, ranking sixth worldwide in mortality amongst all malignancies. Globally, the squamous cell subtype is most common and accounts for 80% of esophageal cancers. Nonetheless, esophageal squamous cell carcinoma is much more poorly understood than esophageal adenocarcinoma, including what is driving such high prevalences, why it often presents in young patients, and shows such marked geographical delineations Areas covered: The current literature was searched for articles focusing on aetiopathogenesis of squamous cell esophageal carcinoma via a systematic review, particularly in low-resource settings. This was supplemented by papers of interest known to the authors. Expert commentary: Current putative mechanisms include polycyclic aromatic hydrocarbons, nitrosamines, acetaldehyde, cyclo-oxygenase-2 pathways, androgen and their receptor levels, as well as smoking & alcohol, micronutrient deficiencies and diet, mycotoxins, thermal damage, oral hygiene and microbiotal factors, inhaled smoke, viral infections such as HPV, and chronic irritative states. Etiology is likely multifactorial and varies geographically. Though smoking and alcohol play a predominant role in high-income settings, there is strong evidence that mycotoxins, diet and temperature effects may play an under-recognized role in low and middle-income settings.

Risk factors for oesophageal cancer

The two main histological subtypes of oesophageal cancer, squamous cell carcinoma and adenocarcinoma, have distinct risk factor profiles. For oesophageal squamous cell carcinoma, tobacco smoking and excess alcohol use are the main risk factors. For adenocarcinoma, gastro-oesophageal reflux disease and obesity are main risk factors, whereas tobacco smoking is a moderately strong risk factor and infection with Helicobacter pylori decreases the risk. Dietary factors may influence the risk of both types of oesophageal cancer. Genetic factors are involved in the aetiology, but their influence is generally low. The striking male predominance in oesophageal adenocarcinoma is unexplained, although sex hormones may play a role. Risk prediction models combining information on multiple risk factors have shown promising potential in identifying high-risk individuals for targeted prevention and early detection, which should prompt further studies. More high-quality research efforts are warranted for better understanding of the aetiology of oesophageal cancer, particularly in developing countries.

Potential impact of Helicobacter pylori-related metabolic syndrome on upper and lower gastrointestinal tract oncogenesis

Both Helicobacter pylori infection and metabolic syndrome present significant global public health burdens. Metabolic syndrome is closely related to insulin resistance, the major underlying mechanism responsible for metabolic abnormalities, and Helicobacter pylori infection has been proposed to be a contributing factor. There is growing evidence for a potential association between Helicobacter pylori infection and insulin resistance, metabolic syndrome and related morbidity, including abdominal obesity, type 2 diabetes mellitus, dyslipidemia, hypertension, all of which increase mortality related to cardio-cerebrovascular disease, neurodegenerative disorders, nonalcoholic fatty liver disease and malignancies. More specifically, insulin resistance, metabolic syndrome and hyperinsulinemia have been associated with upper and lower gastrointestinal tract oncogenesis. Apart from cardio-cerebrovascular, degenerative diseases and nonalcoholic fatty liver disease, a number of studies claim that Helicobacter pylori infection is implicated in metabolic syndrome-related Barrett's esophagus and esophageal adenocarcinoma development, gastric and duodenal ulcers and gastric oncogenesis as well as lower gastrointestinal tract oncogenesis. This review summarizes evidence on the potential impact of Helicobacter pylori-related metabolic syndrome on gastroesophageal reflux disease-Barrett's esophagus-esophageal adenocarcinoma, gastric atrophy-intestinal metaplasia-dysplasia-gastric cancer and colorectal adenoma-dysplasia-colorectal cancer sequences. Helicobacter pylori eradication might inhibit these oncogenic processes, and thus further studies are warranted.

Barrett's Esophagus and Esophageal Adenocarcinoma: How Common Are They Really?

Since the early 1970s, the incidence of esophageal adenocarcinoma (EA) has increased dramatically in most Western populations while the incidence of esophageal squamous cell carcinoma has decreased. As a result, EA has become the predominant subtype of esophageal cancer in North America and Europe and is an important contributor to overall cancer mortality. Barrett's esophagus (BE), a metaplastic columnar epithelium of the distal esophagus, is the known precursor lesion for EA. EA and BE occur more frequently in white men over 50 years old, as well as in people with frequent symptoms of gastroesophageal reflux, in smokers, and in people who are obese. Conversely, EA and BE are less common in persons using nonsteroidal anti-inflammatory drugs and in person with Helicobacter pylori infection. The 5-year survival rate for patients with EA, although generally poor, has improved during the past decade, and long-term survival is increasingly possible for patients with early or locally advanced disease. This review combines a synthesis of published studies with an analysis of data from the United States National Cancer Institute's Surveillance, Epidemiology, and End Results program to discuss the change in incidence of EA and summarize current knowledge of risk factors.

Customization of therapy for gastroesophageal adenocarcinoma patients

Gastroesophageal adenocarcinomas (GEACs) remain a global health problem. These are most often diagnosed at advanced stage and the estimated 5-year relative survival rate is about 5%. Although cure is not possible for patients with advanced GEAC, systemic therapy (chemotherapy or biochemotherapy) can palliate symptoms, improve survival and provide a better quality of life. One of the most promising options for some patients with advanced stage GEAC is immunotherapy, which can result in durable responses. Numerous phase III trials evaluating targeted therapies in different lines are ongoing and it is hoped that better biomarkers will emerge to identify patients who can benefit from targeted agents and immunotherapy in the future. Surgery remains as the corner stone for localized GEAC and adjunctive therapies can increase the survival rates by about 10%. The high toxicity and low completion rates of adjuvant therapy led to the strategies of preoperative treatment. With the results of ongoing pre-operative therapy trials we will be able to determine the optimal adjunctive approach for resectable GEAC.

Maintenance proton pump inhibition therapy and risk of oesophageal cancer

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Modifiable factors and esophageal cancer: a systematic review of published meta-analyses

There are marked differences in the etiology of the major histological types of esophageal cancer (EC)-squamous cell carcinomas (ESCC) and adenocarcinomas (EAC). This study aimed to summarize the current scientific knowledge on modifiable risk factors for EC, by histological type, through a systematic review of meta-analyses referenced in PubMed and ISI Web of Knowledge. We identified 100 meta-analyses on risk factors for ESCC (n = 54), EAC (n = 43), or EC (n = 51). ESCC risk significantly increased with alcohol and maté drinking, smoking, red and processed meat consumption and human papillomavirus infection, while it was negatively associated with body mass index and consumption of fruit, vegetables, white meat, folate, and some carotenoids. Cessation of drinking and smoking significantly reduced ESCC risk. For EAC, an increased risk was reported for smoking, body mass index, and red and processed meat consumption, while risk decreased with Helicobacter pylori infection, low/moderate alcohol drinking, physical activity, and consumption of fruit, vegetables, folate, fiber, beta-carotene, and vitamin C. Differences in results between meta-analyses and mechanisms underlying some of the associations found are discussed. This work reinforces the importance of a separate assessment of EC subtypes to allow for a proper evaluation of incidence trends and planning of prevention/control interventions.

The Epidemiology of Esophageal Adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased in many Western countries and is higher in men than women. Some risk factors for EAC have been identified-mainly gastroesophageal reflux disease, Barrett's esophagus, obesity, and tobacco smoking. It is not clear whether interventions to address these factors can reduce risk of EAC, although some evidence exists for smoking cessation. Although consumption of alcohol is not associated with EAC risk, other exposures, such as physical activity, nutrition, and medication use, require further study. Genetic variants have been associated with risk for EAC, but their overall contribution is low. Studies are needed to investigate associations between risk factors and the molecular subtypes of EAC. The prognosis for patients with EAC has slightly improved, but remains poor-screening and surveillance trials of high-risk individuals are needed.

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

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

Helicobacter pylori serological biomarkers of gastric cancer risk in the MCC-Spain case-control Study

BACKGROUND

Helicobacter pylori infection is one of the main risk factors for non-cardia gastric cancer. However, only a minority of infected persons develop the disease. This study aims at identifying H. pylori related serological biomarkers of risk for gastric cancer.

METHODS

Incident gastric cancer cases and population controls (age, sex and region frequency-matched) from the MCC-Spain multicase-control Study were included. Seroreactivities against 16H. pylori proteins were determined using multiplex serology. Infection was defined as seropositivity against≥4 proteins. Relation of serological results to non-cardia and cardia gastric cancer was assessed using multivariable mixed logistic regression and principal components analysis.

RESULTS

Seroprevalence was 88% among 2071 controls, 95% among 202 non-cardia gastric cancer cases (OR=1.9 (95% CI: 1.0-3.6)) and 85% among 62 cardia cancer cases (OR=0.5 (95% CI: 0.3-1.1)). In infected subjects, seropositivity for UreA, HP231, NapA and Cagδ was associated with lower non-cardia gastric cancer risk, while seropositivity for CagA and VacA was associated with higher risk. Seropositivity for CagA and seronegativity for Cagδ maintained the association after additional adjustment by serostatus of significant proteins. We identified two antibody reactivity patterns: the "virulent-pattern", related to a threefold higher risk of non-cardia gastric cancer and the "non-virulent pattern", related to a 60% decreased risk (4th vs. first quartile).

CONCLUSIONS

In our population, people seropositive for H. pylori were characterized by two patterns of antibody reactivity against H. pylori proteins: 1) Combined high seroreactivity against several proteins, associated with a lower non-cardia gastric cancer risk, and 2) High seroreactivity against CagA and VacA, associated with an increased risk.

The role of intestinal bacteria in the development and progression of gastrointestinal tract neoplasms

More than 100 trillion microorganisms inhabit the human intestinal tract and play important roles in health conditions and diseases, including cancer. Accumulating evidence demonstrates that specific bacteria and bacterial dysbiosis in the gastrointestinal tract can potentiate the development and progression of gastrointestinal tract neoplasms by damaging DNA, activating oncogenic signaling pathways, producing tumor-promoting metabolites such as secondary bile acids, and suppressing antitumor immunity. Other bacterial species have been shown to produce short-chain fatty acids such as butyrate, which can suppress inflammation and carcinogenesis in the gastrointestinal tract. Consistent with these lines of evidence, clinical studies using metagenomic analyses have shown associations of specific bacteria and bacterial dysbiosis with gastrointestinal tract cancers, including esophageal, gastric, and colorectal cancers. Emerging data demonstrate that intestinal bacteria can modulate the efficacy of cancer chemotherapies and novel targeted immunotherapies such as anti-CTLA4 and anti-CD274 therapies, the process of absorption, and the occurrence of complications after gastrointestinal surgery. A better understanding of the mechanisms by which the gut microbiota influence tumor development and progression in the intestine would provide opportunities to develop new prevention and treatment strategies for patients with gastrointestinal tract cancers by targeting the intestinal microflora.

The Troublesome Epidemiology of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus and esophageal adenocarcinoma diagnoses have increased markedly in recent decades. Recent research with patients diagnosed with Barrett's esophagus (the only known precursor for esophageal adenocarcinoma) and esophageal adenocarcinoma has identified several modifiable and nonmodifiable potential risk factors. Consistent risk factors for both disorders include increasing age, male sex, white non-Hispanic race/ethnicity, gastroesophageal reflux disease, lack of infection with Helicobacter pylori, smoking, abdominal obesity, and a Western diet. The authors present detailed discussions of these risk factors along with possible explanations for some apparent discrepancies and ideas for future study.

Impact of mutations in Toll-like receptor pathway genes on esophageal carcinogenesis

Esophageal adenocarcinoma (EAC) develops in an inflammatory microenvironment with reduced microbial diversity, but mechanisms for these influences remain poorly characterized. We hypothesized that mutations targeting the Toll-like receptor (TLR) pathway could disrupt innate immune signaling and promote a microenvironment that favors tumorigenesis. Through interrogating whole genome sequencing data from 171 EAC patients, we showed that non-synonymous mutations collectively affect the TLR pathway in 25/171 (14.6%, PathScan p = 8.7x10-5) tumors. TLR mutant cases were associated with more proximal tumors and metastatic disease, indicating possible clinical significance of these mutations. Only rare mutations were identified in adjacent Barrett's esophagus samples. We validated our findings in an external EAC dataset with non-synonymous TLR pathway mutations in 33/149 (22.1%, PathScan p = 0.05) tumors, and in other solid tumor types exposed to microbiomes in the COSMIC database (10,318 samples), including uterine endometrioid carcinoma (188/320, 58.8%), cutaneous melanoma (377/988, 38.2%), colorectal adenocarcinoma (402/1519, 26.5%), and stomach adenocarcinoma (151/579, 26.1%). TLR4 was the most frequently mutated gene with eleven mutations in 10/171 (5.8%) of EAC tumors. The TLR4 mutants E439G, S570I, F703C and R787H were confirmed to have impaired reactivity to bacterial lipopolysaccharide with marked reductions in signaling by luciferase reporter assays. Overall, our findings show that TLR pathway genes are recurrently mutated in EAC, and TLR4 mutations have decreased responsiveness to bacterial lipopolysaccharide and may play a role in disease pathogenesis in a subset of patients.

Prevalence of Helicobacter pylori Infection in Patients with Squamous Cell Carcinoma of the Oesophagus. A Descriptive Case Series Study

INTRODUCTION

Helicobacter pylori is an important causative factor in gastric carcinogenesis; its role in extra-gastric gastrointestinal malignancies such as oesophageal cancer is controversial. H. pylori is thought to cause extensive gastric atrophy associated with squamous cell carcinoma of the oesophagus. We conducted a study to determine the prevalence of H. pylori infection in patients with squamous cell carcinoma of the oesophagus.

METHOD

We collected biopsies from the antrum and corpus of 59 patients with confirmed squamous cell carcinoma of the oesophagus, two from each area. These were then examined by an experienced histopathologist using methylene blue staining for the presence of H. pylori.

RESULTS

H. pylori was found in 30 (51 %) of the patients, a prevalence similar to that of the general population in South Africa. Five patients were found to have associated intestinal metaplasia, and all but two had chronic inflammation.

CONCLUSION

The prevalence of H. pylori in our patients with squamous cell carcinoma of the oesophagus is 51 %, similar to that previously reported in the general population.

Globular adiponectin inhibits leptin-stimulated esophageal adenocarcinoma cell proliferation via adiponectin receptor 2-mediated suppression of UHRF1

Esophageal adenocarcinoma (EAC) is one of the most common malignancies in the world which is associated the increased prevalence of obesity. In the context of obesity, leptin can directly contribute to progression of EAC. Adiponectin inhibits leptin-induced oncogenic signaling in EAC cells. However, the exact molecular mechanisms linking obesity, adipokines, and EAC remain far from completely understood. In the present study, we tested the role of ubiquitin-like with PHD and ring finger domains 1 (UHRF1) in adiponectin-induced protective effects against leptin-induced EAC cell proliferation. We found that globular adiponectin (gAD) significantly inhibited leptin-induced increase of cell proliferation and decrease of apoptosis in OE 19 cells. Moreover, leptin-induced increase of UHRF1 expression was suppressed by gAD. Compared with normal controls, UHRF1 expression was markedly increased in EAC tissues and cell lines. Silence of UHRF1 increased the expression of cleaved caspase 3 and 9 and Bax, reduced the expression of Bcl-2, promoted apoptosis, and inhibited cell proliferation in OE 19 cells. Overexpression of UHRF1 significantly blocked gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of adiponectin receptor 1/2 (AdipoR1/2) could inhibit gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of AdipoR2, but not AdipoR1, suppressed gAD-induced decrease of UHRF1 expression in leptin-treated cells. The results indicated that gAD inhibited the prooncogenic effects of leptin via AdipoR2-mediated suppression of UHRF1. Our study provides novel insights into the role of UHRF1 in the development of EAC and the mechanism of antitumor effect of gAD.