Reduced Risk of Barrett's Esophagus in Statin Users: Case-Control Study and Meta-Analysis

Risk factors for Barrett's esophagus: Recent advances

Esophageal adenocarcinoma (EAC) is the most common malignant tumor of the esophagus in the West. During the past few decades, its morbidity has been increasing in China. Barrett's esophagus (BE) is defined as the replacement of normal squamous epithelium in the lower esophagus by metaplasia of columnar epithelium. BE is closely related to the occurrence of EAC. Knowledge regarding the risk factors for the occurrence and development of BE is of great significance for early screening and diagnosis of BE and prevention of EAC. In this paper, we review the clinical, demographics-related, lifestyle-related, and medications-related risk factors for BE to provide more valuable scientific evidence for the prevention and treatment of BE.

Role of Obesity, Physical Exercise, Adipose Tissue-Skeletal Muscle Crosstalk and Molecular Advances in Barrett's Esophagus and Esophageal Adenocarcinoma

Both obesity and esophageal adenocarcinoma (EAC) rates have increased sharply in the United States and Western Europe in recent years. EAC is a classic example of obesity-related cancer where the risk of EAC increases with increasing body mass index. Pathologically altered visceral fat in obesity appears to play a key role in this process. Visceral obesity may promote EAC by directly affecting gastroesophageal reflux disease and Barrett’s esophagus (BE), as well as a less reflux-dependent effect, including the release of pro-inflammatory adipokines and insulin resistance. Deregulation of adipokine production, such as the shift to an increased amount of leptin relative to “protective” adiponectin, has been implicated in the pathogenesis of BE and EAC. This review discusses not only the epidemiology and pathophysiology of obesity in BE and EAC, but also molecular alterations at the level of mRNA and proteins associated with these esophageal pathologies and the potential role of adipokines and myokines in these disorders. Particular attention is given to discussing the possible crosstalk of adipokines and myokines during exercise. It is concluded that lifestyle interventions to increase regular physical activity could be helpful as a promising strategy for preventing the development of BE and EAC.

Lifestyle interventions can reduce the risk of Barrett's esophagus: a systematic review and meta-analysis of 62 studies involving 250,157 participants

Background

Barrett's esophagus (BE) is a well‐established risk factor for esophageal adenocarcinoma. Our objective was to investigate the effectiveness of lifestyle interventions on BE risk.

Methods

We searched PubMed, Embase, and Web of Science up to 30 September 2020. The summary relative risks (RRs) and 95% confidence intervals (CIs) for the highest versus lowest categories of exposure were assessed. Analyses of subgroup, dose–response, sensitivity, and publication bias were conducted.

Results

Sixty‐two studies were included that involved more than 250,157 participants and 22,608 cases. Seven lifestyle factors were investigated: smoking, alcohol, body mass index (BMI), physical activity, sleep time, medication, and diet. We observed statistically significant increased BE risks for smoking (RR = 1.35, 95% CI = 1.16–1.57), alcohol intake (RR = 1.23, 95% CI = 1.13–1.34), body fatness (RR = 1.08, 95% CI = 1.03–1.13), less sleep time (RR = 1.76, 95% CI = 1.24–2.49), and proton pump inhibitors use (RR = 1.64, 95% CI = 1.17–2.29). Reduced risks of BE were found for aspirin (RR = 0.70, 95% CI = 0.58–0.84) and the intake of vitamin C (RR = 0.59, 95% CI = 0.44–0.80), folate (RR = 0.47, 95% CI = 0.31–0.71), and fiber (RR = 0.95, 95% CI = 0.93–0.97). The quality of most included studies was high and the subgroup analysis according to the quality score showed significant results (p < 0.05). There was no publication bias for smoking and alcohol. Although the analysis suggested significant evidence of publication bias for BMI, sensitivity analysis showed that the changes in the recalculated RRs were not significant.

Conclusions

The large meta‐analysis revealed that lifestyle modifications could reduce the risks of BE and, consequently, esophageal adenocarcinoma.

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.

Statins as Potential Therapeutics for Esophageal Cancer

Esophageal cancer is a malignancy that has a poor prognosis, which is mainly due to patients presenting once the cancer is in the advances stages. Chemotherapy has been the mainstay for treating esophageal cancer. However, these agents are not consistently effective and fail to differentiate between the different subtypes of esophageal cancers. Targeted therapies have slowly been introduced into the clinical setting, and initial results seem to be promising. Nevertheless, these medications are not universally cheap and also have non-negligible side effects. Therefore, identifying other classes of drugs which could possess anti-esophageal cancer properties is appealing. In addition to expediting the research and development phases of drug discovery, these agents will have known side effect profiles. Statins are a class of cholesterol-lowering medications that have been prescribed for decades. There is a growing body of literature that has shown the anticancer properties of statins in the setting of various malignancies. Herein, we summarize and assimilate the current evidence pertaining to the potential anti-esophageal cancer benefits of statins. We also discuss the limitations of the published studies and consider the future role statins can play in treating patients with esophageal cancers.

Prevention Strategies for Esophageal Cancer-An Expert Review

Simple Summary

In the last decades, there has been a rapid increase in the incidence and prevalence of esophageal cancer in many countries around the world. Although several important risk factors have been identified, strong evidence-based preventive strategies are still lacking, and the prognosis of patients diagnosed with esophageal cancer remains poor, with an average survival rate of 5 years for only 20%. This review is an attempt to summarize the epidemiology and risk factors of EC and to highlight the unresolved aspects of current prevention strategies in order to plan more fruitful future initiatives aimed at ameliorating the disappointing prognosis of this kind of digestive tumor.

Abstract

In the last 30 years, we have witnessed a rapid increase in the incidence and prevalence of esophageal cancer in many countries around the word. However, despite advancements in diagnostic technologies, the early detection of this cancer is rare, and its prognosis remains poor, with only about 20% of these patients surviving for 5 years. The two major forms are the esophageal squamous cell carcinoma (ESCC), which is particularly frequent in the so-called Asian belt, and the esophageal adenocarcinoma (EAC), which prevails in Western populations. This review provides a summary of the epidemiological features and risk factors associated with these tumors. Moreover, a major focus is posed on reporting and highlighting the various preventing strategies proposed by the most important international scientific societies, particularly in high-risk populations, with the final aim of detecting these lesions as early as possible and therefore favoring their definite cure. Indeed, we have conducted analysis with attention to the current primary, secondary and tertiary prevention guidelines in both ESCC and EAC, attempting to emphasize unresolved research and clinical problems related to these topics in order to improve our diagnostic strategies and management.

Low Risk of Progression of Barrett's Esophagus to Neoplasia in Women

BACKGROUND AND AIMS

Men are at a higher risk for Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC), but little is known about BE progression to dysplasia and EAC in women. We performed a retrospective, multicenter cohort study to assess risk of BE progression to dysplasia and EAC in women compared with men. We also investigated comorbidities, medication use, and endoscopic features that contribute to sex differences in risk of BE progression.

METHODS

We collected data from large cohort of patients with BE seen at 6 centers in the United States and Europe, followed for a median 5.7 years. We obtained demographic information (age, sex, ethnicity), clinical history (tobacco use, body mass index, comorbidities), endoscopy results (procedure date, BE segment length), and histopathology findings. Neoplasia was graded as low-grade dysplasia, high-grade dysplasia (HGD), or EAC. Rates of disease progression between women and men were compared using χ2 analysis and the Student t test. Multivariable logistic regression was used to assess the association between sex and disease progression after adjusting for possible confounding variables.

RESULTS

Of the total 4263 patients in the cohort, 2145 met the inclusion criteria, including 324 (15%) women. There was a total of 34 (1.6%) incident EACs, with an overall annual incidence of 0.3% (95% confidence interval: 0.2%-0.4%). We found significant differences between women and men in annual incidence rates of EAC (0.05% for women vs. 0.3% in men; P=0.04) and in the combined endpoint of HGD or EAC (0.1% for women vs. 1.1% for men; P<0.001). Female gender was an independent predictor for reduced progression to HGD or EAC when rates of progression were adjusted for body mass index, smoking history, race, use of aspirin, nonsteroidal anti-inflammatory drugs, proton-pump inhibitors, or statins, hypertriglyceridemia, BE length, and histology findings at baseline (hazard ratio: 0.11; 95% confidence interval: 0.03-0.45; P=0.002).

CONCLUSIONS

In a multicenter study of men versus women with BE, we found a significantly lower risk of disease progression to cancer and HGD in women. The extremely low risk of EAC in women with BE (0.05%/y) indicates that surveillance endoscopy may not be necessary for this subgroup of patients with BE.

Leptin activates Akt in oesophageal cancer cells via multiple atorvastatin-sensitive small GTPases

Obesity is a risk factor for Barrett’s oesophagus and oesophageal adenocarcinoma. Adipose tissue secretes the hormone leptin. Leptin is a growth factor for several cell types, including Barrett’s cells and oesophageal adenocarcinoma cells. Statins are associated with reduced rates of Barrett’s oesophagus and oesophageal cancer and exhibit anti-cancer effects in vitro. The mechanisms of these effects are not fully established. We have examined the effects of leptin and the lipid-soluble statin, atorvastatin, on signalling via monomeric GTP-binding proteins and Akt. Proliferation and apoptosis were assessed in OE33 cells. Akt activity was quantified by cell-based ELISA and in vitro kinase assay. Specific small-molecule inhibitors and a dominant-negative construct were used to reduce Akt activity. Small GTPases were inhibited using transfection of dominant-negative plasmids, prenylation inhibitors and pretreatment with atorvastatin. Leptin stimulated Akt activity and cell proliferation and inhibited camptothecin-induced apoptosis in an Akt-sensitive manner. Leptin induced phosphorylation of Bad and FOXO1 in an Akt-sensitive manner. Leptin activated Ras, Rac, RhoA and cdc42. Transfection of dominant-negative plasmids confirmed that leptin-induced Akt activation required Ras, RhoA cdc42 but not Rac. Atorvastatin inhibited leptin-induced activation of Ras, RhoA, cdc42 and Akt. Co-treatment with mevalonate prevented these effects of atorvastatin. The protein kinase Akt is essential to the growth-promoting and anti-apoptotic effects of leptin in oesophageal adenocarcinoma cells. Akt is activated via Ras-, Rho- and cdc42-dependant pathways. Atorvastatin reduces leptin-induced Akt activation by inhibiting prenylation of small GTPases. This may explain the reduced incidence of oesophageal adenocarcinoma in statin-users.

Chronic High-Fat Diet Induces Early Barrett's Esophagus in Mice through Lipidome Remodeling

Esophageal adenocarcinoma (EAC) incidence has been rapidly increasing, potentially associated with the prevalence of the risk factors gastroesophageal reflux disease (GERD), obesity, high-fat diet (HFD), and the precursor condition Barrett’s esophagus (BE). EAC development occurs over several years, with stepwise changes of the squamous esophageal epithelium, through cardiac metaplasia, to BE, and then EAC. To establish the roles of GERD and HFD in initiating BE, we developed a dietary intervention model in C57/BL6 mice using experimental HFD and GERD (0.2% deoxycholic acid, DCA, in drinking water), and then analyzed the gastroesophageal junction tissue lipidome and microbiome to reveal potential mechanisms. Chronic (9 months) HFD alone induced esophageal inflammation and metaplasia, the first steps in BE/EAC pathogenesis. While 0.2% deoxycholic acid (DCA) alone had no effect on esophageal morphology, it synergized with HFD to increase inflammation severity and metaplasia length, potentially via increased microbiome diversity. Furthermore, we identify a tissue lipid signature for inflammation and metaplasia, which is characterized by elevated very-long-chain ceramides and reduced lysophospholipids. In summary, we report a non-transgenic mouse model, and a tissue lipid signature for early BE. Validation of the lipid signature in human patient cohorts could pave the way for specific dietary strategies to reduce the risk of BE in high-risk individuals.

The relationship between metabolic syndrome and increased risk of Barrett's esophagus: an updated systematic review and meta-analysis

BACKGROUND

The relationship between metabolic syndrome (MetS) and Barrett's esophagus (BE) is still a challenging issue, and inconsistent results have been reported in different studies. Therefore, this study was conducted to determine the relationship between MetS and BE.

METHODS

In this study, we followed the MOOSE protocol and results were reported according to the PRISMA guidelines. All study steps were performed independently by two authors. If necessary, the dispute was resolved by consultation with a third author. The search strategy is designed to find published studies. Comprehensive search was done in the following databases until July 2019: Cochrane Library, PubMed/Medline, Web of Science, Science Direct, EMBASE, Scopus, CINAHL, EBSCO, and Google Scholar search engine. All analyses were performed using Comprehensive Meta-Analysis Software Ver.2, while p-value lower than 0.05 was considered significant.

RESULTS

In 14 studies with a sample size of 108,416, MetS significantly increased the risk of BE (OR = 1.354; 95% CI: 1.145-1.600; P < 0.001; Heterogeneity: I2 = 81.95%; P < 0.001). Sensitivity analysis by omitting one study showed that overall estimates are still robust. Subgroup analysis was significant for continent (P < 0.001) and MetS diagnostic criteria (P = 0.043), but was not significant for variables of study type (P = 0.899), study setting (P = 0.115), control groups (P = 0.671) and quality of studies (P = 0.603). The Begg (P = 0.912) and Egger's (P = 0.094) tests were not significant; therefore, the publication bias did not play a role in the results.

CONCLUSION

MetS increases the risk of BE compared to control groups. The results of this study can help health practitioners by identifying a treatable risk factor for the most important risk factor for esophageal carcinoma (ie, BE). Future studies should examine whether treatment for MetS reduces the risk of BE.

Clinical course of gastroesophageal reflux disease and impact of treatment in symptomatic young patients

In symptomatic young patients with gastroesophageal reflux symptoms, early identification of progressive gastroesophageal reflux disease (GERD) is critical to prevent long-term complications associated with hiatal hernia, increased esophageal acid and nonacid exposure, release of proinflammatory cytokines, and development of intestinal metaplasia, endoscopically visible Barrett's esophagus, and dysplasia leading to esophageal adenocarcinoma. Progression of GERD may occur in asymptomatic patients and in those under continuous acid-suppressive medication. The long-term side effects of proton-pump inhibitors, chemopreventive agents, and radiofrequency ablation are contentious. In patients with early-stage disease, when the lower esophageal sphincter function is still preserved and before endoscopically visible Barrett's esophagus develops, novel laparoscopic procedures, such as magnetic and electric sphincter augmentation, may have a greater role than conventional surgical therapy. A multidisciplinary approach to GERD by a dedicated team of gastroenterologists and surgeons might impact the patients' lifestyle, the therapeutic choices, and the course of the disease. Biological markers are needed to precisely assess the risk of disease progression and to tailor surveillance, ablation, and management.

Statins and gastroesophageal reflux disease: A meta-analysis

Background/Objectives

Gastroesophageal reflux disease (GERD) is one of the common gastrointestinal disorders worldwide. Recent epidemiologic studies have suggested that use of statins may lower the risk of GERD although the results from different studies were inconsistent. This systematic review and meta-analysis were conducted with the aim to summarize all available data.

Methods

A systematic literature review was performed using MEDLINE and EMBASE database from inception to December 2017. Cohort, case-control, and cross-sectional studies that compared the risk of GERD among statin users versus nonusers were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

Results

A total of 4 studies (1 case control, 1 cohort, and 2 cross-sectional studies) with 14,505 participants met the eligibility criteria and were included in the meta-analysis. The risk of GERD among statin users was numerically lower than nonusers with the pooled OR of 0.89 but the result did not achieve statistical significance (95% CI, 0.60-1.33). The statistical heterogeneity in this study was moderate (I² = 54%).

Conclusions

The current meta-analysis found that the risk of GERD was numerically lower among statin users although the pooled result did not reach statistical significance. Therefore, more studies are still needed to further clarify this potential benefit of statins.

Interactive decision support for esophageal adenocarcinoma screening and surveillance

BACKGROUND

A key barrier to controlling esophageal adenocarcinoma (EAC) is identifying those most likely to benefit from screening and surveillance. We aimed to develop an online educational tool, termed IC-RISC™, for providers and patients to estimate more precisely their absolute risk of developing EAC, interpret this estimate in the context of risk of dying from other causes, and aid in decision-making.

RESULTS

U.S. incidence and mortality data and published relative risk estimates from observational studies and clinical trials were used to calculate absolute risk of EAC over 10 years adjusting for competing risks. These input parameters varied depending on presence of the key precursor, Barrett's esophagus. The open source application works across common devices to gather risk factor data and graphically illustrate estimated risk on a single page. Changes to input data are immediately reflected in the colored graphs. We used the calculator to compare the risk distribution between EAC cases and controls from six population-based studies to gain insight into the discrimination metrics of current practice guidelines for screening, observing that current guidelines sacrifice a significant amount of specificity to identify 78-86% of eventual cases in the US population.

CONCLUSIONS

This educational tool provides a simple and rapid means to graphically communicate risk of EAC in the context of other health risks, facilitates "what-if" scenarios regarding potential preventative actions, and can inform discussions regarding screening, surveillance and treatment options. Its generic architecture lends itself to being easily extended to other cancers with distinct pathways and/or intermediate stages, such as hepatocellular cancer. IC-RISC™ extends current qualitative clinical practice guidelines into a quantitative assessment, which brings the possibility of preventative actions being offered to persons not currently targeted for screening and, conversely, reducing unnecessary procedures in those at low risk. Prospective validation and application to existing well-characterized cohort studies are needed.

Barrett oesophagus

Barrett oesophagus (BE), the only known histological precursor of oesophageal adenocarcinoma (EAC), is a condition in which the squamous epithelium of the oesophagus is replaced by columnar epithelium as an adaptive response to gastro-oesophageal reflux. EAC has one of the fastest rising incidences of cancers in Western countries and has a dismal prognosis. BE is usually detected during endoscopic examination, and diagnosis is confirmed by the histological presence of intestinal metaplasia. Advances in genomics and transcriptomics have improved our understanding of the pathogenesis and malignant progression of intestinal metaplasia. As the majority of EAC cases are diagnosed in individuals without a known history of BE, screening for BE could potentially decrease disease-related mortality. Owing to the pre-malignant nature of BE, endoscopic surveillance of patients with BE is imperative for early detection and treatment of dysplasia to prevent further progression to invasive EAC. Developments in endoscopic therapy have resulted in a major shift in the treatment of patients with BE who have dysplasia or early EAC, from surgical resection to endoscopic resection and ablation. In addition to symptom control by optimization of lifestyle and pharmacological therapy with proton pump inhibitors, chemopreventive strategies based on NSAIDs and statins are currently being investigated for BE management.

Systematic Review and Meta-analysis: Use of Statins Is Associated with a Reduced Incidence of Oesophageal Adenocarcinoma

PURPOSE

Laboratory studies have suggested that statins may have useful anti-cancer effects against Barrett's epithelial cancer lines. A variety of effects have been reported in clinical studies.

METHODS

We performed a systematic review and meta-analysis of the association between statin use and the development of oesophageal cancer. Multiple databases were searched for studies reporting the association of statin use and oesophageal cancer. Meta-analysis on the relationship between statin use and cancer incidence was performed.

RESULTS

Twenty publications met eligibility criteria, yielding 22 datasets for meta-analysis. All were observational studies. Population-level studies included 372,206 cancer cases and 6,086,906 controls. Studies examining adenocarcinoma development in Barrett's oesophagus included 1057 cancers and 17,741 controls. In patients with Barrett's oesophagus, statin use was associated with a reduced incidence of adenocarcinoma (pooled adjusted odds ratio (OR) 0.59 (95% confidence intervals 0.50-0.68)), with no heterogeneity between 11 studies. Population-based studies demonstrated more heterogeneity but showed that statin use was associated with a lower incidence of both oesophageal adenocarcinoma (OR 0.57 (0.43-0.76)) and all oesophageal cancers (OR 0.82 (0.7-0.88)). Information on statin type, dose, and duration was reported too infrequently for statistical analysis but individual studies showed a tendency to a dose- and duration-dependant decrease in cancer incidence.

CONCLUSIONS

Statin use is associated with a significantly lower incidence of oesophageal adenocarcinoma. This is seen in both Barrett's cohorts and general populations. Further studies should focus on drug, dose, and duration and the interaction with other risk and preventative factors.

Introduction: Esophageal Adenocarcinoma: Updates of Current Status

Esophageal and esophagogastric adenocarcinoma is highly prevalent in the Western populations and is a major cause of cancer-related morbidity and mortality worldwide. The incidence of esophageal adenocarcinoma is rapidly rising in the Western populations. The major predisposing diseases and pathogenesis (gastro-esophageal reflux disease, Barrett esophagus, and dysplasia) of the cancer are well known. There is an urgent need for works of the multidisciplinary teams (clinical, pathological, the molecular biology and translational research) for improved outcomes of patients with this cancer.

Do Statins Increase the Risk of Esophageal Conditions? Findings from Four Propensity Score-Matched Analyses

BACKGROUND AND OBJECTIVE

Statins are commonly used medications. Whereas some observational studies suggested an association of statin use with Barrett's esophagus and some upper gastrointestinal symptoms, there is a dearth of data on the association of statins and common esophageal conditions such as gastroesophageal reflux disease and esophagitis. The aim of this study is to examine the association of statins with esophageal conditions.

METHODS

This is a retrospective cohort study using regional military healthcare data (1 October, 2003 to 1 March, 2012). The primary analyses evaluated the odds of: esophagitis; symptoms of esophagitis; gastroesophageal reflux disease/dyspepsia; and esophageal complications of gastroesophageal reflux disease in four propensity score-matched cohorts of statin users and non-users (propensity score-overall, propensity score-healthy, propensity score-women, and propensity score-men cohorts). Secondary and sensitivity analyses were performed.

RESULTS

In the propensity score-overall cohort (n = 12,684), statin users were more likely to be diagnosed with esophagitis (odds ratio 1.11, 95% confidence interval 1.01-1.22) and gastroesophageal reflux disease/dyspepsia (odds ratio 1.18, 95% confidence interval 1.10-1.27) compared with non-users. Similar findings were seen in the propensity score-healthy cohort and in the propensity score-men cohort. In the propensity score-women cohort, the odds of esophagitis was higher among statin users compared with non-users (odds ratio 1.16, 95% confidence interval 1.02-1.32) but other outcomes were not different. In sensitivity analyses, which excluded patients with obesity, statin use was not associated with an increased odds ratio of gastroesophageal reflux disease/dyspepsia.

CONCLUSION

Statin therapy was associated with higher odds of being diagnosed with esophagitis and gastroesophageal reflux disease/dyspepsia. Further study is warranted to elucidate the potential role of statins in these commonly diagnosed esophageal conditions.

Additional Benefits of Routine Drugs on Gastrointestinal Cancer: Statins, Metformin, and Proton Pump Inhibitors

BACKGROUND

Commonly used medications including statins, metformin, and proton pump inhibitors (PPIs) effectively reduce the risk of esophageal, gastric, and colorectal cancer (CRC).

SUMMARY

A number of observational studies and meta-analyses have shown that long-term statin use significantly reduces the incidence of gastrointestinal (GI) cancer. Moreover, statin use after GI cancer diagnosis has been significantly associated with better prognosis in large-scale cohort studies. Metformin was rigorously evaluated in a population-based study and meta-analysis, and was found to have an unexpected benefit in the prevention and prolonged survival of CRC patients with type 2 diabetes mellitus. In contrast, few studies have demonstrated the chemopreventive effect of metformin for esophageal and gastric cancer. Recent observational studies have demonstrated that PPIs effectively reduce the progression of nondysplastic Barrett's esophagus into esophageal adenocarcinoma in a dose-dependent manner. However, the association between chronic PPI use and CRC or gastric cancer risk is still controversial. It was expected that these 3 routinely used medicines would show a synergistic effect with conventional systemic chemotherapy in advanced GI cancers. However, recent phase III studies failed to show significantly better outcomes. Key Messages: Further studies are needed to identify "additional" anticancer effects of these commonly used medicines.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Determination of risk for Barrett's esophagus and esophageal adenocarcinoma

PURPOSE OF REVIEW

The incidence of esophageal adenocarcinoma and its precursor, Barrett's esophagus, have increased greatly over the past 40 years and continue to rise. This report summarizes the most recent data on the risk factors for Barrett's esophagus and esophageal adenocarcinoma.

RECENT FINDINGS

Other factors, highly correlated with increasing trends for obesity, are the dominant driver of the increase in incidence of esophageal adenocarcinoma, interacting with gastroesophageal reflux disease symptoms. Abdominal obesity, independently of gastroesophageal reflux disease symptoms, is associated with increased risk of Barrett's esophagus and this association is likely mediated by high levels of leptin and insulin. Use of aspirin, nonsteroidal anti-inflammatory drugs, statins, and proton pump inhibitors are associated with a reduced risk of Barrett's esophagus as well as lower risk of neoplastic progression in patients with Barrett's esophagus. An increasing number of genetic loci have been associated with risk of Barrett's esophagus and esophageal adenocarcinoma.

SUMMARY

Recent advances in identifying risk factors and reporting of more precise estimates of effect for the main risk factors will positively impact clinical risk stratification efforts for Barrett's esophagus and esophageal adenocarcinoma. Large pooling studies are underway to derive and validate reliable clinical risk models.