A review of the epidemiology of Barrett's oesophagus and oesophageal adenocarcinoma

Etiologic factors for Barrett's esophagus: toward countermeasures in Asia

INTRODUCTION

Over the past several decades, Europe and the United States have experienced a rapid increase in esophageal adenocarcinoma. Research and countermeasures against Barrett's esophagus, its precancerous lesion, are progressing. Because esophageal adenocarcinoma has an extremely poor prognosis when diagnosed in an advanced stage, recommendations for early cancer detection have been made based on the various proven etiological factors of Barrett's esophagus and the actual cancer risk of Barrett's esophagus. In recent years, there have been indications of an increase in esophageal adenocarcinoma in Japan, and a similar trend of cancer will occur shortly in other Asian countries. Consequently, Asian countries must implement similar countermeasures against Barrett's esophagus and esophageal adenocarcinoma, referencing the knowledge gained thus far in Europe and the United States.

AREAS COVERED

This review summarizes the latest findings on the etiologic factors of Barrett's esophagus and discusses the differences between Westerners and Asians. The current status of Barrett's esophagus in Japan and other Asian countries is also summarized.

EXPERT OPINION

The etiological factors and cancer incidence of Barrett's esophagus in Asia diverge somewhat from those observed in Europe and America. Therefore, it is imperative to implement measures that are tailored to the actual circumstances of Asian people.

Causal association between dietary factors and esophageal diseases: A Mendelian randomization study

BACKGROUND

Using Mendelian randomization (MR) approach, our objective was to determine whether there was a causal association between dietary factors and gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), or esophageal cancer (EC).

METHODS

Genome-wide association study (GWAS) data for eighteen types of dietary intake were obtained from the UK Biobank. GWAS data for GERD, BE, and EC were sourced from the FinnGen consortium. We performed univariable and multivariable MR analysis to assess the cause effect between dietary factors and esophageal diseases. MR results were expressed as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Raw vegetable intake was associated with a lower risk of GERD (OR = 0.478; P = 0.011). On the contrary, cooked vegetable intake increased the risk of GERD (OR = 1.911; P = 0.024). Bread intake was associated with increased odds of BE (OR = 6.754; P = 0.007), while processed meat intake was associated with reduced risk of BE (OR = 0.210; P = 0.035). We also observed evidence that increased consumption of dried fruit (OR = 0.087; P = 0.022) and salt added to food (OR = 0.346; P = 0.045) could prevent EC. The results of multivariable MR showed that the protective effect of consumption of salt added to food on EC was no longer significant after adjusting for the consumption of dried fruit.

CONCLUSION

Vegetable consumption was associated with GERD, whereas consumption of bread and processed meat was associated with BE. Dried fruit intake was associated with a lower risk of EC, and the protective effect of consumption of salt added food on EC may also be mediated by consumption of dried fruit. Future research should be performed to investigate the mechanisms behind these cause-and-effect relationships to reduce the burden of disease caused by dietary habits.

The International Network on Oesophageal Atresia (INoEA) consensus guidelines on the transition of patients with oesophageal atresia-tracheoesophageal fistula

Oesophageal atresia-tracheoesophageal fistula (EA-TEF) is a common congenital digestive disease. Patients with EA-TEF face gastrointestinal, surgical, respiratory, otolaryngological, nutritional, psychological and quality of life issues in childhood, adolescence and adulthood. Although consensus guidelines exist for the management of gastrointestinal, nutritional, surgical and respiratory problems in childhood, a systematic approach to the care of these patients in adolescence, during transition to adulthood and in adulthood is currently lacking. The Transition Working Group of the International Network on Oesophageal Atresia (INoEA) was charged with the task of developing uniform evidence-based guidelines for the management of complications through the transition from adolescence into adulthood. Forty-two questions addressing the diagnosis, treatment and prognosis of gastrointestinal, surgical, respiratory, otolaryngological, nutritional, psychological and quality of life complications that patients with EA-TEF face during adolescence and after the transition to adulthood were formulated. A systematic literature search was performed based on which recommendations were made. All recommendations were discussed and finalized during consensus meetings, and the group members voted on each recommendation. Expert opinion was used when no randomized controlled trials were available to support the recommendation. The list of the 42 statements, all based on expert opinion, was voted on and agreed upon.

Microbiome changes in esophageal cancer: implications for pathogenesis and prognosis

Esophageal cancer (EC) is an aggressive malignancy with a poor prognosis. Various factors, including dietary habits, and antacid and antibiotic use, have been shown to influence the esophageal microbiome. Conversely, enrichment and diversity of the esophageal microbiome can also impact its function. Recent studies have revealed prevalent changes in the esophageal microbiome among patients with EC, thus suggesting the potential contribution of the esophageal microbiome to EC development. Additionally, distinct microbiome compositions have been observed in patients with different responses to radiotherapy and chemotherapy, indicating the role of the esophageal microbiome in modulating treatment outcomes. In this review, we have examined previous studies on the esophageal microbiome in healthy individuals and patients with EC or other esophageal diseases, with a focus on identifying microbial communities associated with EC pathogenesis and prognosis. Understanding the role of the microbiome in EC may aid in early detection and optimized treatment strategies, ultimately leading to better outcomes for patients.

The Role of the Microbiota in Esophageal Cancer

Esophageal cancer is a major health problem, being the seventh most incidence cancer worldwide. Due to the often-late diagnosis and lack of efficient treatments, the overall 5-year survival is as low as 10%. Therefore, understanding the etiology and the mechanisms that drive the development of this type of cancer could improve the management of patients, increasing the chance of achieving a better clinical outcome. Recently, the microbiome has been studied as a putative etiological factor for esophageal cancer. Nevertheless, the number of studies tackling this issue is low, and the heterogeneity in the study design and data analysis has hindered consistent findings. In this work, we reviewed the current literature on the evaluation of the role of microbiota in the development of esophageal cancer. We analyzed the composition of the normal microbiota and the alterations found in precursor lesions, namely Barrett's esophagus and dysplasia, as well as in esophageal cancer. Additionally, we explored how other environmental factors can modify microbiota and contribute to the development of this neoplasia. Finally, we identify critical aspects to be improved in future studies, with the aim of refining the interpretation of the relationship between the microbiome and esophageal cancer.

Intestinal metaplasia in progression of Barrett's esophagus to esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has been increasing year by year. The prognosis of EAC is poor, and the 5-year survival rate is less than 20%. Barrett's esophagus (BE) is the only known precancerous lesion of EAC. BE with intestinal metaplasia (IM) has a higher risk of progressing to EAC. Exploring the mechanism of IM and finding targeted therapeutic targets for BE has become an important measure for tumor prevention. Bile acid reflux is considered an important factor in the occurrence of IM and promotes the progression of BE to EAC. However, the molecular regulatory mechanism of bile reflux induced IM and carcinogenesis remains unclear. This article reviews the environment, significance, and cell origin theory of IM, toxic effects of bile reflux, and molecular changes of IM progression to tumor, aiming to improve clinicians' understanding of IM in BE and provide evidence for early intervention of BE and prevention and treatment of EAC.

Esophageal cancer: Epidemiology, risk factors and screening

More than 600,000 people are diagnosed with esophageal cancer (EC) every year globally, and the five-year survival rate of EC is less than 20%. Two common histological subtypes of EC, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), have great geographical variations in incidence rates. About half of the world's EC was diagnosed in China and a majority of which belong to ESCC. Globally, the overall incidence rate of EC is decreasing. In some high-risk Asian regions, such as China, the incidence rate of ESCC has generally declined, potentially due to economic growth and improvement of diet habits. In some European high-income countries and the United States, the decline is mainly attributed to the decrease in smoking and drinking. The risk factors of EC are not well understood, and the importance of environmental and genetic factors in the pathogenesis is also unclear. The incidence and mortality of advanced EC can be reduced through early diagnosis and screening. White light endoscopy is still the gold standard in the current screening technology. This article reviews the epidemiology, risk factors, and screening strategies of EC in recent years to help researchers determine the most effective management strategies to reduce the risk of EC.

Association between infection with Campylobacter species, poor oral health and environmental risk factors on esophageal cancer: a hospital-based case-control study in Thailand

Background

Previous studies have shown the association between Campylobacter species infection and that environmental factors, poor oral hygiene in particular, are linked to an increased risk of esophageal cancer (EC). However, no study has reported on these factors in Thailand. Thus, this study’s objective was to evaluate the impact of the relationship between Campylobacter infection and environmental factors on EC incidence in the population of Thailand.

Methods

Data from a case–control study were collected from 105 newly diagnosed EC cases and 105 controls recruited from 2007 to 2017. Infection with Campylobacter spp. was detected in the formalin-fixed paraffin-embedded (FFPE) tissue of EC taken from gastroesophageal biopsy specimens obtained from the participants, and evaluated using TaqMan^® real-time PCR. Multivariable logistic regression was performed to calculate the odds ratios (ORs) and perform data analysis.

Results

Smoking, alcohol use, a family history of cancer, history of gastroesophageal reflux disease, poor oral hygiene and Campylobacter spp. infection were shown to be significant risk factors for EC (p  <  0.05). The combination of poor oral hygiene and infection with Campylobacter spp. constituted significant risk for EC (p  <  0.001). In addition, the risk of EC in subjects co-infected with C. rectus and C. concisus that practiced poor oral hygiene was even higher and was significant (ORadj  =  4.7; 95% CI 2.41–9.98; p  =  0.003).

Conclusions

In Thailand, the major risk factors for EC are smoking status, alcohol drinking, family history of cancer, GERD, poor oral hygiene and Campylobacter spp. infection. This study found Campylobacter spp. prevalence to be associated with EC and appears to be enhanced by poor oral hygiene, suggesting that a combination of poor oral hygiene and Campylobacter species infection may together act as an important etiological risk factor for EC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-021-00561-3.

Diagnostic Performance of Artificial Intelligence-Based Models for the Detection of Early Esophageal Cancers in Barret's Esophagus: A Meta-Analysis of Patient-Based Studies

Introduction Barret's esophagus (BE) is a precursor of adenocarcinoma of the esophagus. The detection of high-grade dysplasia and adenocarcinoma at an early stage can improve survival but is very challenging. Artificial intelligence (AI)-based models have been claimed to improve diagnostic accuracy. The aim of the current study was to carry out a meta-analysis of papers reporting the results of artificial intelligence-based models used in real-time white light endoscopy of patients with BE to detect early esophageal adenocarcinoma (EEAC). Methods This meta-analysis was registered with the International Prospective Register of Systematic Reviews (PROSPERO; Reg No. CRD42021246148) and its conduction and reporting followed the Preferred Reporting Items for Systematic Review and Meta-Analysis of Diagnostic Test Accuracy (PRISMA-DTA) statement guidelines. All peer-reviewed and preprint original articles that reported the sensitivity and specificity of AI-based models on white light endoscopic imaging as an index test against the standard criterion of histologically proven early oesophageal cancer on the background of Barret's esophagus reported as per-patient analysis were considered for inclusion. There was no restriction on type and year of publication, however, articles published in the English language were searched. The search engines used included Medline, PubMed, EMBASE, EMCARE, AMED, BNI, and HMIC. The search strategy included the following keywords for all search engines: ("Esophageal Cancer" OR "Esophageal Neoplasms" OR " Oesophageal Cancer" OR "Oesophageal Neoplasms" OR "Barrett's Esophagus" OR "Barrett's Oesophagus") And ("Artificial Intelligence" OR "Deep Learning" OR "Machine Learning" OR "Convolutional Network"). This search was conducted on November 30, 2020. Duplicate studies were excluded. Studies that reported more than one dataset per patient for the diagnostic accuracy of the AI-based model were included twice. Quantitative and qualitative data, including first author, year of publication, true positives (TP), false negatives (FN), false positives (FP), true negatives (TN), the threshold of the index test, and country where the study was conducted, were extracted using a data extraction sheet. The Quality Appraisal for Diverse Studies 2 (QUADS-2) tool was used to assess the quality of each study. Data were analyzed using MetaDTA, interactive online software for meta-analysis of diagnostic studies. The diagnostic performance of the meta-analysis was assessed by a summary receiver operating characteristics (sROC) plot. A meta-analysis tree was constructed using MetaDTA software to determine the effect of cumulative sensitivity and specificity on surveillance of patients with BE in terms of miss rate and overdiagnosis. Results The literature search revealed 171 relevant records. After removing duplicates, 117 records were screened. Full-text articles of 28 studies were assessed for eligibility. Only three studies reporting four datasets met the inclusion criteria. The summary sensitivity and specificity of AI-based models were 0.90 (95% CI, 0.83- 0.944) and 0.86 (95% CI, 0.781-0.91), respectively. The area under the curve for all the available evidence was 0.88. Conclusion Collective evidence for the routine usage of AI-based models in the detection of EEAC is encouraging but is limited by the low number of studies. Further prospective studies reporting the patient-based diagnostic accuracy of such models are required.

Global prevalence of Barrett's oesophagus and oesophageal cancer in individuals with gastro-oesophageal reflux: a systematic review and meta-analysis

OBJECTIVES

Chronic gastro-oesophageal reflux might lead to the development of Barrett's oesophagus (BO) or even oesophageal adenocarcinoma. There has been no definitive systematic review and meta-analysis of data to estimate global prevalence of BO or oesophageal adenocarcinoma in individuals with gastro-oesophageal reflux.

DESIGN

We searched MEDLINE, Embase and Embase Classic to identify cross-sectional surveys that reported prevalence of BO or oesophageal adenocarcinoma in adults with gastro-oesophageal reflux. We extracted prevalence for all studies, both for endoscopically suspected and histologically confirmed cases. We calculated pooled prevalence according to study location, symptom frequency and sex, as well as ORs with 95% CIs.

RESULTS

Of the 4963 citations evaluated, 44 reported prevalence of endoscopically suspected and/or histologically confirmed BO. Prevalence of BO among individuals with gastro-oesophageal reflux varied according to different geographical regions ranging from 3% to 14% for histologically confirmed BO with a pooled prevalence of 7.2% (95% CI 5.4% to 9.3%), whereas pooled prevalence for endoscopically suspected BO was 12.0% (95% CI 5.5% to 20.3%). There was heterogeneity in many of our analyses. Prevalence of BO was significantly higher in men, both for endoscopically suspected (OR=2.1; 95% CI 1.6 to 2.8) and histologically confirmed BO (OR=2.3; 95% CI 1.7 to 3.2). Dysplasia was present in 13.9% (95% CI 8.9% to 19.8%) of cases of histologically confirmed BO, 80.7% of which was low-grade.

CONCLUSION

The prevalence of Barrett's oesophagus among individuals with gastro-oesophageal reflux varied strikingly among countries, broadly resembling the geographical distribution of gastro-oesophageal reflux itself. Prevalence of BO was significantly higher in men.

Integrated PPI- and WGCNA-Retrieval of Hub Gene Signatures Shared Between Barrett's Esophagus and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) is a deadly cancer with high mortality rate, especially in economically advanced countries, while Barrett's esophagus (BE) is reported to be a precursor that strongly increases the risk of EAC. Due to the complexity of these diseases, their molecular mechanisms have not been revealed clearly. This study aims to explore the gene signatures shared between BE and EAC based on integrated network analysis. We obtained EAC- and BE-associated microarray datasets GSE26886, GSE1420, GSE37200, and GSE37203 from the Gene Expression Omnibus and ArrayExpress using systematic meta-analysis. These data were accompanied by clinical data and RNAseq data from The Cancer Genome Atlas (TCGA). Weighted gene co-expression network analysis (WGCNA) and differentially expressed gene (DEG) analysis were conducted to explore the relationship between gene sets and clinical traits as well as to discover the key relationships behind the co-expression modules. A differentially expressed gene-based protein-protein interaction (PPI) complex was used to extract hub genes through Cytoscape plugins. As a result, 403 DEGs were excavated, comprising 236 upregulated and 167 downregulated genes, which are involved in the cell cycle and replication pathways. Forty key genes were identified using modules of MCODE, CytoHubba, and CytoNCA with different algorithms. A dark-gray module with 207 genes was identified which having a high correlation with phenotype (gender) in the WGCNA. Furthermore, five shared hub gene signatures (SHGS), namely, pre-mRNA processing factor 4 (PRPF4), serine and arginine-rich splicing factor 1 (SRSF1), heterogeneous nuclear ribonucleoprotein M (HNRNPM), DExH-Box Helicase 9 (DHX9), and origin recognition complex subunit 2 (ORC2), were identified between BE and EAC. SHGS enrichment denotes that RNA metabolism and splicosomes play a key role in esophageal cancer development and progress. We conclude that the PPI complex and WGCNA co-expression network highlight the importance of phenotypic identifying hub gene signatures for BE and EAC.

Genetic variants in the ZNF208 gene are associated with esophageal cancer in a Chinese Han population

Previous studies showed an association between the ZNF208 gene and gastric cancer. In this study, we investigated the association between single nucleotide polymorphisms (SNPs) in ZNF208 and the risk of esophageal cancer in a Chinese Han population. We conducted a case-control study that included 386 cases and 495 controls. Five SNPs were selected from previous genome-wide association studies and genotyped using the Sequenom MassARRAY platform. Unconditional logistic regression was used to calculate odds ratios and 95% confidence intervals after adjustment for age and gender. Logistic regressionl analysis showed that two SNPs (rs8103163 and rs7248488) were associated with an increased risk of esophageal cancer under different inheritance models after Bonferroni correction. Haplotype analysis suggested that the four variants comprised one block, and that the G_rs2188972C_rs2188971C_rs8103163C_rs7248488 haplotype was significantly correlated with an increased risk of esophageal cancer. Our data indicate that variants in ZNF208 are contribute to the susceptibility to esophageal cancer in a Chinese Han population.

The Characteristics of Postprandial Proximal Gastric Acid Pocket in Gastroesophageal Reflux Disease

Background

Postprandial proximal gastric acid pocket (PPGAP) plays important roles in gastroesophageal reflux disease (GERD). In this study, we analyzed the characteristics of PPGAP in GERD.

Material/Methods

There were 17 normal participants and 20 GERD patients who completed a gastroesophageal reflux disease questionnaire (GerdQ) and underwent a gastroscopy, a high-resolution manometry, an esophageal 24-hour pH monitoring, and a station pull-through pH monitoring to assess their symptomatic degree, endoscopic change, acid exposure, and PPGAP.

Results

PPGAP was present in all participants. Compared with normal participants, the PPGAP in GERD patients was significantly different, thus the disappearing time was significantly later (p<0.001), the lasting time was significantly longer (p<0.001), the length was significantly longer (p<0.001), and the lowest pH and the mean pH were significantly lower (p<0.001). The length of PPGAP in GERD patients was positively correlated with GerdQ score (p<0.05). The disappearing time, the lasting time, and the length of PPGAP in GERD patients was positively correlated with the DeMeester score (p<0.01). The lowest pH and the mean pH of PPGAP in GERD patients was negatively correlated with the DeMeester score (p<0.001).

Conclusions

PPGAP was generally present. PPGAP in GERD patients had characteristics of long time period, long length, and high acidity. Its length was positively correlated with subjective symptomatic degree. Its period, length, and acidity were positively correlated with the objective acid exposure. PPGAP seems to be the originator of acid reflux events and plays important roles in GERD.

Histopathological Assessment for Esophageal Adenocarcinoma

In the World Health Organization (WHO) classification, adenocarcinoma of esophagus comprises preinvasive type (dysplasia), adenocarcinoma, adenoid cystic carcinoma, adenosquamous carcinoma, and mucoepidermoid carcinoma. For adenocarcinoma, it is important to determine the grading of the cancer and histological variants such as signet ring adenocarcinoma. In the current day management of esophageal adenocarcinoma by neoadjuvant therapy, the histology of the cancer and the lymph nodal status may change after the therapy. Tumor regression grading systems could be used to assess the response to the neoadjuvant therapy in esophageal adenocarcinoma.

Abdominal diameter index is a stronger predictor of prevalent Barrett's esophagus than BMI or waist-to-hip ratio

Abdominal obesity is associated with gastroesophageal reflux disease (GERD) and Barrett's esophagus (BE). Increased body mass index (BMI) and waist-to-hip ratio (WHR) have been associated with BE. Abdominal diameter index (ADI, sagittal abdominal diameter divided by thigh circumference) was previously shown to be a more accurate predictor of incident cardiovascular disease compared to other measurements. Our aim is to examine whether abdominal diameter index was a more accurate predictor of prevalent BE compared to other anthropometric measurements. We conducted a case-control study of patients presenting to our institution. Our study population was consecutive Caucasian men with a known history of BE, and we recruited control patients who had GERD without BE. Both groups completed a questionnaire about demographics, smoking, and medications and underwent a series of anthropometric body measurements using standardized measuring tools. BMI, waist-to-hip ratio, and abdominal diameter index were calculated. Thirty-one BE patients and 27 control patients were recruited. The BE cohort were older and had a higher rate of hiatal hernia. The mean abdominal diameter index for patients with BE was 0.65 ± 0.07 and without BE was 0.60 ± 0.07 (p = 0.01). The predictive value of abdominal diameter index was analyzed using a receiver-operator characteristic (ROC) curve and was a more powerful predictor of BE than waist-to-hip ratio or BMI (AUROC = 0.70 vs. 0.60 vs. 0.52, respectively). Using a cut-point abdominal diameter index value of 0.60, abdominal diameter index had a sensitivity of 77.4% and a specificity of 63.0% for the presence of BE. When controlling for age, smoking status, and BMI, an abdominal diameter index ≥0.60 was a significant independent risk factor for BE (OR = 5.7, 95% CI = 1.29-25.4). In this pilot study, the abdominal diameter index appears to be a more powerful predictor of the presence of BE than BMI and waist-to-hip ratio and remained the only significant predictor of BE in multivariate analysis. We propose further validation of abdominal diameter index before inclusion in future prediction tools for BE.

Clinicopathological features of Siewert type II adenocarcinoma: comparison of gastric cardia adenocarcinoma and Barrett's esophageal adenocarcinoma following endoscopic submucosal dissection

OBJECTIVES

Siewert type II esophagogastric junction adenocarcinoma encompasses both gastric cardia adenocarcinoma (GCA) and Barrett's esophageal adenocarcinoma (BEA) due to short-segment Barrett's esophagus. We compared these two types of Siewert type II esophagogastric junction adenocarcinoma in terms of background factors and clinical outcomes of endoscopic submucosal dissection (ESD).

METHODS

We enrolled 139 patients (142 lesions) who underwent ESD from 2006 to 2014 at our institution. Background factors evaluated were age, sex, body mass index, hypertension, hyperlipidemia, hyperuricemia, diabetes mellitus, smoking, drinking, double cancer, and endoscopic findings. Clinical outcomes evaluated were procedure time, en bloc resection rate, curative resection rate, and adverse events.

RESULTS

There were 87 GCA lesions (61.2%) and 55 BEA lesions. Features of BEA [55 lesions (38.8%)] included a younger age, small diameter, and a protruding type, along with a high frequency of esophageal hiatal hernia and less mucosal atrophy. There were no significant differences in lifestyle-related background factors between the GCA and BEA groups. Curative resection rate was greater for GCA (81%) than for BEA (66%) (P = 0.01). There were no serious adverse events in either group. Among the factors for noncurative resection, lymphovascular invasion and depth of invasion were greater for BEA (33.3 vs. 7 and 20.7 vs. 8.2%, respectively (P < 0.01). Of the noncured patients, 70% underwent additional surgery and none had postoperative lymph node metastasis.

CONCLUSIONS

Siewert type II adenocarcinoma encompasses two types of cancers with different etiologies: GCA and BEA. Although there are no significant differences in lifestyle-related background factors between GCA and BEA, BEA is a risk factor for noncurative resection via ESD.

Alcohol consumption pattern and risk of Barrett's oesophagus and erosive oesophagitis: an Italian case-control study

Knowledge about the association between alcohol and Barrett's oesophagus and reflux oesophagitis is conflicting. In this case-control study we evaluated the role of specific alcoholic beverages (red and white wine, beer and liquors) in 339 Barrett's oesophagus and 462 oesophagitis patients compared with 619 endoscopic controls with other disorders, recruited in twelve Italian endoscopic units. Data on alcohol and other individual characteristics were obtained from structured questionnaires. No clear, monotonic significant dose-response relationship was pointed out for red wine. However, a generalised U-shaped trend of Barrett's oesophagus/oesophagitis risk due to red wine consumption particularly among current drinkers was found. Similar results were also found for white wine. Liquor/spirit consumption seemed to bring about a 1·14-2·30 risk excess, although statistically non-significant, for current Barrett's oesophagus/oesophagitis drinkers. Statistically significant decreasing dose-response relationships were found in Barrett's oesophagus for frequency and duration of beer consumption. Similar, but less clear downward tendencies were also found for oesophagitis patients. In conclusion, although often not statistically significant, our data suggested a reduced risk of Barrett's oesophagus and oesophagitis with a low/moderate intake of wine and beer consumption. A non-significant increased risk of Barrett's oesophagus/oesophagitis was observed with a higher intake of any type of heavy alcohol consumption, but no conclusion can be drawn owing to the high number of non-spirit drinkers and to the small number of drinkers at higher alcohol intake levels.

Pathology of esophageal cancer and Barrett's esophagus

Esophageal cancer is a serious malignancy with high mortality. The two common distinctive pathologic subtypes of esophageal cancer are squamous cell carcinoma and adenocarcinoma. These differ with regards to etiology, ethnic distribution, pathogenesis, and location in the esophagus. The precursor lesions are also unique to each subtype. Squamous cell carcinoma is more common in East Asia, is linked to smoking and tobacco use, more commonly involves the middle esophagus, and the precursor lesion is squamous dysplasia. Adenocarcinoma is more common in the United States and certain European countries, associated with obesity and gastroesophageal reflux disease (GERD), more commonly involves the distal esophagus, and the precursor lesion is Barrett's esophagus. Endoscopic surveillance with biopsy evaluation is the standard of care in high-risk groups. Endoscopic ablative therapies for early cancers have lower morbidity than surgery. Despite increased awareness, identification of high-risk groups and endoscopic surveillance, a large proportion of patients present with advanced cancers. Surgery and chemoradiation, either in neo-adjuvant or adjuvant setting, is the usual treatment for patients with advanced but resectable esophageal cancers. The prognosis and further management largely depends upon the pathologic tumor-node-metastasis (TNM) staging provided by the American Joint Committee on Cancer (AJCC) and the International Union against Cancer. Currently, the 7th edition of TNM staging system is being applied for prognostication and this is more focused on pathologic evaluation. Eighth edition of AJCC/UICC TNM staging has been introduced and will be implemented for clinical use in 2018.

Dietary fruit, vegetable, fat, and red and processed meat intakes and Barrett's esophagus risk: a systematic review and meta-analysis

The relationships between dietary fruit, vegetable, fat, and red and processed meat intakes and Barrett’s esophagus (BE) risk remain inconclusive. We conducted a systematic review and meta-analysis to summarize the available evidence on these issues. PubMed, EMBASE and the Cochrane Library were searched for studies published from inception through October 2015. A total of eight studies were included in this analysis. Fruit intake was not associated with BE risk (OR = 0.65, 95% CI = 0.37–1.13), but vegetable intake was strongly associated with BE risk (OR = 0.45, 95% CI = 0.29–0.71). Saturated fat, red meat and processed meat intakes were not associated with BE risk with OR = 1.25 (95% CI = 0.82–1.91), OR = 0.85 (95% CI = 0.61–1.17) and OR = 1.03 (95% CI = 0.73–1.46), respectively. Dietary vegetable not fruits intake may be associated with decreased BE risk. Fat and red and processed meat intakes may not contribute to an increased BE risk. Well-designed, large prospective studies with better established dose-response relationships are needed to further validate these issues.

Oral Bisphosphonates and Upper Gastrointestinal Cancer Risks in Asians with Osteoporosis: A Nested Case-Control Study Using National Retrospective Cohort Sample Data from Korea

Background

Bisphosphonate can irritate the gastrointestinal mucosa and increase the risk of esophageal or gastric cancer. The relatively high prevalence of upper gastrointestinal cancers and the widespread use of bisphosphonate in Korea call for further investigation. We conducted a case-control study to evaluate the risk of esophageal or gastric cancer after exposure to oral bisphosphonates in Korean patients with osteoporosis.

Methods

We used the National Health Insurance Service-National Sample Cohort database of Korea from 2002 to 2013. Among osteoporotic patients (>40 years), cases were defined as incident diagnosis of esophageal or gastric cancer between 2006 and 2013. For each case, four controls were matched for age, sex, and income level by type of insurance. We categorized bisphosphonate use as non-user, recent user, past user, and past and recent user, depending on prescription in two periods (1 to 2 years and 2 to 4 years prior to the index date). We also assessed the duration of bisphosphonate use by measuring cumulative duration of exposure (CDE). To examine the association between oral bisphosphonates and esophageal or gastric cancer, we estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) using conditional logistic regression analysis, adjusting for concomitant diseases.

Results

A total of 1,708 cases and 6,832 controls were identified. The aORs (95% CIs) of recent, past, and continuous bisphosphonate use compared to non-users were 1.18 (0.93–1.51), 1.04 (0.83–1.29), and 1.25 (0.95–1.58)), respectively. In addition, no significant association was observed by CDE, even when different outcome definitions were applied.

Conclusions

This study did not prove an increased risk of esophageal or gastric cancer risk associated with bisphosphonate use, with respect to both risk windows and duration of exposure, in an Asian population-based, real-world setting.

Polymorphisms in genes in the androgen pathway and risk of Barrett's esophagus and esophageal adenocarcinoma

The strong male predominance in Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) remains inadequately explained, but sex hormones might be involved. We hypothesized that single nucleotide polymorphisms (SNPs) in the androgen pathway influence risk of developing BE and EAC. This genetic-epidemiological analysis included 14 studies from Australia, Europe and North America. Polymorphisms in 16 genes coding for the androgen pathway were analyzed using a gene-based approach: versatile gene-based test association study. This method evaluates associations between a trait and all SNPs within a specific gene rather than each SNP marker individually as in a conventional GWAS. The data were stratified for sex, body-mass index, waist-to-hip ratio, tobacco smoking and gastroesophageal reflux status. Included were data from 1,508 EAC patients, 2,383 BE patients and 2,170 control participants. SNPs within the gene CYP17A1 were associated with risk of BE in the sexes combined (p = 0.002) and in males (p = 0.003), but not in females separately (p = 0.3). This association was found in tobacco smokers (p = 0.003) and in BE patients without reflux (p = 0.004), but not in nonsmokers (p = 0.2) or those with reflux (p = 0.036). SNPs within JMJD1C were associated with risk of EAC in females (p = 0.001). However, none of these associations replicated in a subsequent sample. Fourteen other genes studied did not reach statistically significant levels of association with BE, EAC or the combination of BE and EAC, after correcting for the number of genes included in the analysis. In conclusion, genetic variants in the androgen-related genes CYP17A1 and JMJD1C might be associated with risk of BE and EAC, respectively, but replication data with larger sample sizes are needed.