Sex and Racial Disparity in Incidence of Esophageal Adenocarcinoma: Observations and Explanations

Mapping the adult human esophagus in vivo and in vitro

Many esophageal diseases can arise during development or throughout life. Therefore, well-characterized in vitro models and detailed methods are essential for studying human esophageal development, homeostasis and disease. Here, we (1) create an atlas of the cell types observed in the normal adult human esophagus; (2) establish an ancestrally diverse biobank of in vitro esophagus tissue to interrogate homeostasis and injury; and (3) benchmark in vitro models using the adult human esophagus atlas. We created a single-cell RNA sequencing reference atlas using fresh adult esophagus biopsies and a continuously expanding biobank of patient-derived in vitro cultures (n=55 lines). We identify and validate several transcriptionally distinct cell classes in the native human adult esophagus, with four populations belonging to the epithelial layer, including basal, epibasal, early differentiating and terminally differentiated luminal cells. Benchmarking in vitro esophagus cultures to the in vivo reference using single-cell RNA sequencing shows that the basal stem cells are robustly maintained in vitro, and the diversity of epithelial cell types in culture is dependent on cell density. We also demonstrate that cultures can be grown in 2D or as 3D organoids, and these methods can be employed for modeling the complete epithelial layers, thereby enabling in vitro modeling of the human adult esophagus.

AI-assisted discovery of an ethnicity-influenced driver of cell transformation in esophageal and gastroesophageal junction adenocarcinomas

Although Barrett's metaplasia of the esophagus (BE) is the only known precursor lesion to esophageal adenocarcinomas (EACs), drivers of cellular transformation in BE remain incompletely understood. We use an artificial intelligence-guided network approach to study EAC initiation and progression. Key predictions are subsequently validated in a human organoid model, in patient-derived biopsy specimens of BE, a case-control study of genomics of BE progression, and in a cross-sectional study of 113 patients with BE and EACs. Our model classified healthy esophagus from BE and BE from EACs in several publicly available gene expression data sets (n = 932 samples). The model confirmed that all EACs must originate from BE and pinpointed a CXCL8/IL8↔neutrophil immune microenvironment as a driver of cellular transformation in EACs and gastroesophageal junction adenocarcinomas. This driver is prominent in White individuals but is notably absent in African Americans (AAs). Network-derived gene signatures, independent signatures of neutrophil processes, CXCL8/IL8 expression, and an absolute neutrophil count (ANC) are associated with risk of progression. SNPs associated with changes in ANC by ethnicity (e.g., benign ethnic neutropenia [BEN]) modify that risk. Findings define a racially influenced immunological basis for cell transformation and suggest that BEN in AAs may be a deterrent to BE→EAC progression.

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.

Racial Disparities in Adherence to Quality Indicators in Barrett's Esophagus: An Analysis Using the GIQuIC National Benchmarking Registry

INTRODUCTION

Racial disparities in outcomes in esophageal adenocarcinoma are well established. Using a nationwide registry, we aimed to compare clinical and endoscopic characteristics of blacks and whites with Barrett's esophagus (BE) and adherence to defined quality indicators.

METHODS

We analyzed data from the Gastrointestinal Quality Improvement Consortium Registry between January 2012 and December 2019. Patients who underwent esophagogastroduodenoscopy with an indication of BE screening or surveillance, or an endoscopic finding of BE, were included. Adherence to recommended endoscopic surveillance intervals of 3-5 years for nondysplastic BE and adherence to Seattle biopsy protocol were assessed. Multivariate logistic regression was conducted to assess variables associated with adherence.

RESULTS

A total of 100,848 esophagogastroduodenoscopies in 84,789 patients met inclusion criteria (blacks-3,957 and whites-96,891). Blacks were less likely to have histologically confirmed BE (34.3% vs 51.7%, P < 0.01), had shorter BE lengths (1.61 vs 2.35 cm, P < 0.01), and were less likely to have any dysplasia (4.3% vs 7.1%, P < 0.01). Although whites were predominantly male (62.2%), about half of blacks with BE were female (53.0%). Blacks with nondysplastic BE were less likely to be recommended appropriate surveillance intervals (OR 0.78; 95% CI 0.68-0.89). Adherence rates to the Seattle protocol were modestly higher among blacks overall (OR 1.12, 95% CI 1.04-1.20), although significantly lower among blacks with BE segments >6 cm.

DISCUSSION

The use of sex as a risk factor for BE screening may be inappropriate among blacks. Fewer blacks were recommended appropriate surveillance intervals, and blacks with longer segment BE were less likely to undergo Seattle biopsy protocol.

Current Status of Chemoprevention in Barrett's Esophagus

Candidates for chemoprevention in Barrett's esophagus have long been suggested and there has been observational data to support many drugs, including statins, hormone replacement therapy, metformin, proton pump inhibitor therapy, and aspirin. Proton pump inhibitor therapy and aspirin are the most promising agents. Data suggest that aspirin and proton pump inhibitor therapy can decrease the risk of neoplastic progression in Barrett's esophagus. Further, the combination of aspirin and proton pump inhibitor therapy decrease all-cause mortality by approximately 33%. Future guideline groups need to evaluate the evidence rigorously, but the combination of proton pump inhibitor therapy and aspirin is promising.

Sex-Specific Genetic Associations for Barrett's Esophagus and Esophageal Adenocarcinoma

BACKGROUND & AIMS

Esophageal adenocarcinoma (EA) and its premalignant lesion, Barrett's esophagus (BE), are characterized by a strong and yet unexplained male predominance (with a male-to-female ratio in EA incidence of up to 6:1). Genome-wide association studies (GWAS) have identified more than 20 susceptibility loci for these conditions. However, potential sex differences in genetic associations with BE/EA remain largely unexplored.

METHODS

Given strong genetic overlap, BE and EA cases were combined into a single case group for analysis. These were compared with population-based controls. We performed sex-specific GWAS of BE/EA in 3 separate studies and then used fixed-effects meta-analysis to provide summary estimates for >9 million variants for male and female individuals. A series of downstream analyses were conducted separately in male and female individuals to identify genes associated with BE/EA and the genetic correlations between BE/EA and other traits.

RESULTS

We included 6758 male BE/EA cases, 7489 male controls, 1670 female BE/EA cases, and 6174 female controls. After Bonferroni correction, our meta-analysis of sex-specific GWAS identified 1 variant at chromosome 6q11.1 (rs112894788, KHDRBS2-MTRNR2L9, PBONF = .039) that was statistically significantly associated with BE/EA risk in male individuals only, and 1 variant at chromosome 8p23.1 (rs13259457, PRSS55-RP1L1, PBONF = 0.057) associated, at borderline significance, with BE/EA risk in female individuals only. We also observed strong genetic correlations of BE/EA with gastroesophageal reflux disease in male individuals and obesity in female individuals.

CONCLUSIONS

The identified novel sex-specific variants associated with BE/EA could improve the understanding of the genetic architecture of the disease and the reasons for the male predominance.

Esophageal regenerative therapy using cell sheet technology

We have been conducting research on esophageal regenerative therapy using cell sheet technology. In particular, in the endoscopic field, we have pushed forward clinical research on endoscopic transplantation of cultured autologous oral mucosal epithelial cell sheets to esophageal ulcer after endoscopic submucosal dissection (ESD). We started research in this direction using animal models in 2004 and performed clinical research in 2012 in collaboration with Nagasaki University and Karolinska Institute. Although in full-circumferential cases it was difficult to prevent esophageal stricture after ESD, there were no complications and stricture could be suppressed. The cell sheet technology is still in its infancy. However, we are convinced that it has a high potential for application in various areas of gastrointestinal science. In this review, we focus on the pre-clinical and clinical trial results obtained and on the theoretical aspects of (1) stricture prevention, (2) esophageal tissue engineering research, and (3) endoscopic transplantation, and review the esophageal regenerative therapy by cell sheet technology.

Endoscopic features of esophageal adenocarcinoma derived from short-segment versus long-segment Barrett's esophagus

BACKGROUND AND AIM

The study aims to clarify the endoscopic features and clinicopathological differences in superficial Barret's esophageal adenocarcinoma (s-BEA) derived from short-segment Barrett's esophagus (SSBE) and long-segment Barrett's esophagus (LSBE).

METHODS

We reviewed data of 130 patients (141 lesions) with pathologically confirmed s-BEA (SSBE: 95 patients and 95 lesions; LSBE: 35 patients and 46 lesions). We analyzed endoscopic and clinicopathological features of s-BEA in patients with SSBE and LSBE.

RESULTS

The distribution of lesions according to macroscopic findings were as follows (s-BEA in SSBE vs LSBE): flat type (0-IIb), 3.2% (3/95) vs 32.6% (15/46) (P < 0.001); accompanied type 0-IIb, 2.1% (2/95) vs 21.7% (10/46) (P < 0.001); and complex type (0-I + IIb, 0-IIa + IIc, etc.), 30.5% (29/95) vs 50.0% (23/46) (P = 0.025). Complex-type s-BEAs had high incidences of T1b invasions and poorly differentiated components (simple type: 22.5% [20/89] and 18.0% [16/89]; complex type: 59.6% [31/52] and 44.2% [23/52], P < 0.001 and P = 0.002, respectively). In SSBE, 72.6% (69/95) of lesions were located at the right anterior wall (P = 0.01). All flat-type or depressed-type lesions derived from SSBE were identified as reddish areas, whereas only 65.2% (15/23) from LSBE were identified as reddish areas (P < 0.001).

CONCLUSIONS

In LSBE, flat-type, accompanied-type 0-IIb, and complex-type lesions were significantly more prevalent. Furthermore, complex-type s-BEAs tended to have T1b invasions and poorly differentiated components. S-BEAs in LSBE should be more carefully evaluated on endoscopic appearance including flat-type and complex-type lesions than in SSBE.

Racial Disparity in the Sex Distribution, the Prevalence, and the Incidence of Dysplasia in Barrett's Esophagus

GOALS

Our aim was to study the prevalence of dysplasia and progression to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) in African Americans (AA) with Barrett's esophagus (BE) and compare it with that of non-Hispanic white (NHW) controls.

BACKGROUND

BE, a precursor of EAC, is a disease of predominantly white men and is uncommon in AA. The prevalence of dysplasia and progression to HGD and EAC in AA patients with BE is not clearly known.

STUDY

All AA or NHW patients with confirmed BE, that is specialized intestinal metaplasia, seen between 2002 and 2013 at our institution were included. Variables such as age, gender, medication use, the body mass index, the date of endoscopy, the hiatal hernia size, the BE length, and histologic findings were noted. Progression to HGD/EAC was evaluated.

RESULTS

Fifty-two AA and 2394 NHW patients with BE were identified. There was a higher percentage of women in the AA cohort (46.2%) than in the NHW cohort (24.9%, P<0.001). Nondysplastic BE was more prevalent in AA than in NHW (80.8% vs. 68.4%, P=0.058). In the surveillance cohort of 20 AA and 991 NHW, no racial differences in progression to HGD/EAC were observed during a median follow-up of 43 months.

CONCLUSIONS

This study includes the largest number of AA with histologically confirmed BE reported so far. About 46.2% of the AA cohort with BE in our study consisted of women. There was a trend toward a higher prevalence of nondysplastic BE in AA compared with NHW.

Constitutively Higher Level of GSTT2 in Esophageal Tissues From African Americans Protects Cells Against DNA Damage

BACKGROUND & AIMS

African American and European American individuals have a similar prevalence of gastroesophageal reflux disease (GERD), yet esophageal adenocarcinoma (EAC) disproportionately affects European American individuals. We investigated whether the esophageal squamous mucosa of African American individuals has features that protect against GERD-induced damage, compared with European American individuals.

METHODS

We performed transcriptional profile analysis of esophageal squamous mucosa tissues from 20 African American and 20 European American individuals (24 with no disease and 16 with Barrett's esophagus and/or EAC). We confirmed our findings in a cohort of 56 patients and analyzed DNA samples from patients to identify associated variants. Observations were validated using matched genomic sequence and expression data from lymphoblasts from the 1000 Genomes Project. A panel of esophageal samples from African American and European American subjects was used to confirm allele-related differences in protein levels. The esophageal squamous-derived cell line Het-1A and a rat esophagogastroduodenal anastomosis model for reflux-generated esophageal damage were used to investigate the effects of the DNA-damaging agent cumene-hydroperoxide (cum-OOH) and a chemopreventive cranberry proanthocyanidin (C-PAC) extract, respectively, on levels of protein and messenger RNA (mRNA).

RESULTS

We found significantly higher levels of glutathione S-transferase theta 2 (GSTT2) mRNA in squamous mucosa from African American compared with European American individuals and associated these with variants within the GSTT2 locus in African American individuals. We confirmed that 2 previously identified genomic variants at the GSTT2 locus, a 37-kb deletion and a 17-bp promoter duplication, reduce expression of GSTT2 in tissues from European American individuals. The nonduplicated 17-bp promoter was more common in tissue samples from populations of African descendant. GSTT2 protected Het-1A esophageal squamous cells from cum-OOH-induced DNA damage. Addition of C-PAC increased GSTT2 expression in Het-1A cells incubated with cum-OOH and in rats with reflux-induced esophageal damage. C-PAC also reduced levels of DNA damage in reflux-exposed rat esophagi, as observed by reduced levels of phospho-H2A histone family member X.

CONCLUSIONS

We found GSTT2 to protect esophageal squamous cells against DNA damage from genotoxic stress and that GSTT2 expression can be induced by C-PAC. Increased levels of GSTT2 in esophageal tissues of African American individuals might protect them from GERD-induced damage and contribute to the low incidence of EAC in this population.

Factors Associated With Recurrence of Barrett's Esophagus After Radiofrequency Ablation

BACKGROUND & AIMS

Radiofrequency ablation (RFA) is effective treatment for Barrett's esophagus (BE). However, some patients have recurrence after complete eradication of intestinal metaplasia (CEIM). We investigated the incidence of and factors associated with BE recurrence, with or without neoplasia, after RFA and CEIM using data from the national Veterans Affairs (VA) healthcare system.

METHODS

We performed a retrospective cohort study of Veterans with BE treated by RFA from 2005 through 2016 with follow-up endoscopy. Subjects were followed until BE recurrence, neoplasia, death until October 2016. CEIM, BE recurrence, and factors associated with recurrence were identified by review of medical records. We calculated incidence rates of BE recurrence, with and without neoplasia, after CEIM and identified predictors using Cox proportional hazards models.

RESULTS

We identified 430 Veterans with BE who were treated with RFA; of these 337 achieved CEIM (78.4%). Most were men (98.6%), White (83.7%), and 66.0% had baseline dysplasia. Of those with CEIM, 98 patients (29.1%) had recurrence of BE during a total 906.0 patient-years of follow-up (median 1.9 years) after CEIM (incidence, 10.8%/patient-year). Dysplasia developed in 20 patients (2.2%/patient-year) and cancer in 3 patients (0.3%/patient-year). Baseline dysplasia (hazard ratio [HR], 1.71; 95% CI, 1.03-2.84) and long-segment BE (HR, 1.59; 95% CI, 1.01-2.51) increased risk of BE recurrence whereas treatment at high-volume RFA facilities reduced risk of BE recurrence (for quartile 4 vs quartile 1: HR, 0.19; 95% CI, 0.05-0.68).

CONCLUSIONS

In a nationwide VA system study of outcomes of RFA for BE, we associated baseline dysplasia, long-segment BE, and treatment at low-volume RFA centers with recurrence of BE after CEIM. The findings call for performing these procedures in high-volume centers.

The Association Between Statin Use After Diagnosis and Mortality Risk in Patients With Esophageal Cancer: A Retrospective Cohort Study of United States Veterans

OBJECTIVE

Statins may reduce mortality from esophageal cancer by both reducing incidence but also improving prognosis. However, prior studies of statin use and mortality have reported conflicting results.

METHODS

We identified 7882 patients with esophageal adenocarcinoma (EAC) and 3868 with esophageal squamous cell carcinoma (ESCC) from the VA Central Cancer Registry diagnosed between 2002 and 2016. We identified prescriptions for statins that were filled before and after cancer diagnosis. Time-dependent Cox regression models were used to calculate hazard ratios (HR) and 95% CIs for mortality risk. We used a time-varying exposure to avoid immortal-time bias and a 3 month lag (following patients from 3 months after cancer diagnosis) to reduce reverse causation. A sensitivity analysis was conducted varying the lag duration between date of cancer diagnosis and start of follow-up.

RESULTS

Statin use after diagnosis was recorded in 27.4% of EAC and 17.1% of ESCC patients. In EAC patients, statin use after diagnosis was associated with a decreased risk of cancer specific (HR, 0.79; 95% CI 0.70-0.88) and all-cause mortality (HR, 0.80; 95% CI 0.74-0.86). Similarly, statin use after diagnosis of ESCC was associated with a decreased risk of cancer specific (HR, 0.77; 95% CI 0.63-0.92) and all-cause mortality (HR, 0.83; 95% CI 0.74-0.95). The inverse associations were attenuated towards the null with a 6-month lag.

CONCLUSIONS

Post-diagnosis statin use was associated with reduced mortality in esophageal cancer patients; however, the effect may be partially due to reverse causality as patients with poor prognosis are unlikely to initiate statin therapy.

Acid suppression medications reduce risk of oesophageal adenocarcinoma in Barrett's oesophagus: a nested case-control study in US male veterans

BACKGROUND

Proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) may reduce the risk of oesophageal adenocarcinoma (OAC) in Barrett's oesophagus; however, current epidemiologic studies are inconclusive.

AIM

To evaluate the independent effects of PPIs and H2RAs on risk of OAC in patients with Barrett's oesophagus.

METHODS

We conducted a nested case-control study of male veterans diagnosed with Barrett's oesophagus. Cases with incident OAC were matched by incidence density sampling on birth year and Barrett's diagnosis date to controls with Barrett's oesophagus who did not develop OAC. We identified prescription medication usage 1 year prior to Barrett's oesophagus diagnosis to 3 months prior to the OAC diagnosis. Odds ratios (OR) and 95% CI were estimated using conditional logistic regression.

RESULTS

Compared with 798 controls, the 300 cases were less likely to use PPIs (90.0% vs 94.5%, P = 0.01) and H2RAs (19.7% vs 25.7%, P = 0.04). In the multivariable model including the use of statins, H2RAs, aspirin and nonsteroidal anti-inflammatory drugs, PPI use was associated with 41% lower risk of OAC (OR 0.59, 95% CI 0.35-0.99). While risk reduction of OAC was stronger for high-dose PPIs (omeprazole daily dose >40 mg, adjusted OR 0.11, 95% 0.04-0.36), we did not find a dose-response relationship with PPI duration (P trend = 0.45). Likewise, H2RA use was independently associated with 30% lower risk of OAC (OR 0.70, 95% CI 0.50-0.99).

CONCLUSION

Use of PPIs and H2RAs among patients with Barrett's oesophagus are associated with lower risk of OAC. Further clinical trials are needed to confirm this possible chemopreventive effect.

Menopausal hormone therapy and the risk of esophageal and gastric cancer

A protective effect of female sex hormones has been suggested to explain the male predominance in esophageal and gastric adenocarcinoma, but evidence is lacking. We aimed to test whether menopausal hormone therapy (MHT) decreases the risk of these tumors. For comparison, esophageal squamous cell carcinoma was also assessed. This population-based matched cohort study included all women who had ever used systemic MHT in Sweden in 2005-2012. A comparison cohort of non-users of MHT was matched to the MHT-users regarding age, parity, thrombotic events, hysterectomy, diabetes, obesity, smoking-related diseases and alcohol-related diseases. Individuals with any previous cancer were excluded. Data on MHT use, cancer, comorbidity and mortality were collected from well-established Swedish nationwide registers. Odds ratios (OR) with 95% confidence intervals (CI) were calculated using conditional logistic regression. Different MHT regimens and age groups were compared in sub-group analyses. We identified 290,186 ever-users and 870,165 non-users of MHT. Ever-users had decreased ORs of esophageal adenocarcinoma (OR = 0.62, 95% CI 0.45-0.85, n = 46), gastric adenocarcinoma (OR = 0.61, 95% CI 0.50-0.74, n = 123) and esophageal squamous cell carcinoma (OR = 0.57, 95% CI 0.39-0.83, n = 33). The ORs were decreased for both estrogen-only MHT and estrogen and progestin combined MHT, and in all age groups. The lowest OR was found for esophageal adenocarcinoma in MHT-users younger than 60 years (OR = 0.20, 95% CI 0.06-0.65). Our study suggests that MHT-users are at a decreased risk of esophageal and gastric adenocarcinoma and also of esophageal squamous cell carcinoma. The mechanisms behind these associations remain to be elucidated.

Risk Profiles for Barrett's Esophagus Differ between New and Prevalent, and Long- and Short-Segment Cases

Background

Previous studies on Barrett’s esophagus (BE) risk factors have had differing case definitions and control groups. The purpose of this study was to examine differences in risk factors between newly diagnosed vs. prevalent BE, long- vs. short-segment BE, and endoscopy-only BE without specialized intestinal metaplasia (SIM).

Methods

We conducted a cross-sectional study among eligible patients scheduled for elective esophagogastroduodenoscopy (EGD) and patients eligible for screening colonoscopy, recruited from primary care clinics at a Veterans Affairs center. All participants completed a survey on demographics, gastroesophageal reflux disease (GERD) symptoms and medication use prior to undergoing study EGD. We compared BE cases separately to two control groups: 503 primary care controls and 1353 endoscopy controls. Associations between risk factors and differing BE case definitions were evaluated with multivariate logistic regression models.

Results

For comparisons with primary care controls, early onset frequent GERD symptoms were more strongly associated with risk of long-segment BE (OR 19.9; 95% CI 7.96–49.7) than short-segment BE (OR 8.54; 95% CI 3.85–18.9). Likewise, the inverse association with H. pylori infection was stronger for long-segment BE (OR, 0.45; 95% CI, 0.26–0.79) than short-segment BE (OR, 0.71; 95% CI, 0.48–1.05). GERD symptoms and H. pylori infection was also more strongly associated with prevalent BE than newly diagnosed BE. Few differences were observed between BE cases and endoscopy controls. Endoscopy-only BE was associated with GERD symptoms (OR 2.25, 95% CI 1.32–3.85) and PPI/H2RA use (OR 4.44; 95% CI 2.61–7.54) but to a smaller degree than BE with SIM.

Conclusion

We found differences in the strength and profiles of risk factors for BE. The findings support that epidemiological studies of BE should make a distinction between long and short, new and prevalent, endoscopy-only and BE with SIM as well as type of controls.

Nonsteroidal Anti-Inflammatory Drug Use is Not Associated With Reduced Risk of Barrett's Esophagus

OBJECTIVES

Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced risk of esophageal adenocarcinoma. Epidemiological studies examining the association between NSAID use and the risk of the precursor lesion, Barrett's esophagus, have been inconclusive.

METHODS

We analyzed pooled individual-level participant data from six case-control studies of Barrett's esophagus in the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON). We compared medication use from 1,474 patients with Barrett's esophagus separately with two control groups: 2,256 population-based controls and 2,018 gastroesophageal reflux disease (GERD) controls. Study-specific odds ratio (OR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression models and were combined using a random-effects meta-analytic model.

RESULTS

Regular (at least once weekly) use of any NSAIDs was not associated with the risk of Barrett's esophagus (vs. population-based controls, adjusted OR=1.00, 95% CI=0.76-1.32, I²=61%; vs. GERD controls, adjusted OR=0.99, 95% CI=0.82-1.19, I²=19%). Similar null findings were observed among individuals who took aspirin or non-aspirin NSAIDs. We also found no association with highest levels of frequency (at least daily use) and duration (≥5 years) of NSAID use. There was evidence of moderate between-study heterogeneity; however, associations with NSAID use remained non-significant in "leave-one-out" sensitivity analyses.

CONCLUSIONS

Use of NSAIDs was not associated with the risk of Barrett's esophagus. The previously reported inverse association between NSAID use and esophageal adenocarcinoma may be through reducing the risk of neoplastic progression in patients with Barrett's esophagus.

Inverse Association Between Gluteofemoral Obesity and Risk of Barrett's Esophagus in a Pooled Analysis

BACKGROUND & AIMS

Gluteofemoral obesity (determined by measurement of subcutaneous fat in the hip and thigh regions) could reduce risks of cardiovascular and diabetic disorders associated with abdominal obesity. We evaluated whether gluteofemoral obesity also reduces the risk of Barrett's esophagus (BE), a premalignant lesion associated with abdominal obesity.

METHODS

We collected data from non-Hispanic white participants in 8 studies in the Barrett's and Esophageal Adenocarcinoma Consortium. We compared measures of hip circumference (as a proxy for gluteofemoral obesity) from cases of BE (n = 1559) separately with 2 control groups: 2557 population-based controls and 2064 individuals with gastroesophageal reflux disease (GERD controls). Study-specific odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using individual participant data and multivariable logistic regression and combined using a random-effects meta-analysis.

RESULTS

We found an inverse relationship between hip circumference and BE (OR per 5-cm increase, 0.88; 95% CI, 0.81-0.96), compared with population-based controls in a multivariable model that included waist circumference. This association was not observed in models that did not include waist circumference. Similar results were observed in analyses stratified by frequency of GERD symptoms. The inverse association with hip circumference was statistically significant only among men (vs population-based controls: OR, 0.85; 95% CI, 0.76-0.96 for men; OR, 0.93; 95% CI, 0.74-1.16 for women). For men, within each category of waist circumference, a larger hip circumference was associated with a decreased risk of BE. Increasing waist circumference was associated with an increased risk of BE in the mutually adjusted population-based and GERD control models.

CONCLUSIONS

Although abdominal obesity is associated with an increased risk of BE, there is an inverse association between gluteofemoral obesity and BE, particularly among men.

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.