Pathophysiological mechanisms linking obesity and esophageal adenocarcinoma

Mitochondrial Ca2+ signaling is a hallmark of specific adipose tissue-cancer crosstalk

Obesity is associated with increased risk and worse prognosis of many tumours including those of the breast and of the esophagus. Adipokines released from the peritumoural adipose tissue promote the metastatic potential of cancer cells, suggesting the existence of a crosstalk between the adipose tissue and the surrounding tumour. Mitochondrial Ca2+ signaling contributes to the progression of carcinoma of different origins. However, whether adipocyte-derived factors modulate mitochondrial Ca2+ signaling in tumours is unknown. Here, we show that conditioned media derived from adipose tissue cultures (ADCM) enriched in precursor cells impinge on mitochondrial Ca2+ homeostasis of target cells. Moreover, in modulating mitochondrial Ca2+ responses, a univocal crosstalk exists between visceral adipose tissue-derived preadipocytes and esophageal cancer cells, and between subcutaneous adipose tissue-derived preadipocytes and triple-negative breast cancer cells. An unbiased metabolomic analysis of ADCM identified creatine and creatinine for their ability to modulate mitochondrial Ca2+ uptake, migration and proliferation of esophageal and breast tumour cells, respectively.

Risk reduction of non-hormonal cancers following bariatric surgery

Metabolic and bariatric surgery (MBS) is the most effective intervention for weight loss leading to significant resolution of obesity-related medical conditions. Recent literature has demonstrated risk reduction of certain cancer types after MBS. Studies have shown an overall reduction in the risk of hormonal cancer, such as breast and endometrial cancer. However, the association between bariatric surgery and the incidence of various types of non-hormonal cancer such as esophageal, gastric, liver, gallbladder, colorectal, pancreatic and kidney cancer remains contested. The aim of this study was to highlight obesity and its relationship to cancer development as well as bariatric surgery and its role in cancer reduction with focus on non-hormonal cancers.

Does leptin cause proximal gastric cancer in the obese? The role of serum leptin in the etiology of proximal gastric cancer

OBJECTIVES

The aim of the present study was to determine the correlation between obesity, serum levels of leptin and proximal gastric cancer.

METHODS

Sixty-four gastric cancer patients operated on with curative intent were included in the study. We determined the correlation between the preoperative serum levels of leptin and the tumor's location.

RESULTS

Serum leptin levels were correlated significantly with the proximal third location (p=0.04), gastric outlet obstructing tumors (p<0.0001), CRP levels (p=0.03) and BMI (p<0.0001). Patients with high serum levels of leptin had significantly more intestinal types of gastric cancer (p=0.033) and better differentiation (p=0.009). The linear regression model determined the proximal tumor location (beta: 0.467; p=0.045), BMI (beta: 0.657; p=0.001), high preoperative serum albumin (beta: 0.563; p=0.016) and the presence of pyloric stenosis (beta: 0.525; p=0.006) as related significantly to serum leptin levels. The Cox proportional hazard model identified age (HR: 0.003; 95 % CI: 0-0.794; p=0.041), preoperative serum levels of leptin (HR: 0.125; 95 % CI: 0.018-0.887; p=0.037) and the number of extracted LNs (HR: 0.001; 95 % CI: 0-0.677; p=0.038) as independent prognostic factors.

CONCLUSIONS

Serum levels of leptin were significantly elevated in patients with proximal gastric cancer, suggesting that the leptin's effect might be due to its systemic secretion. This might explain the higher incidence of proximal gastric cancer in obese patients. Elevated serum leptin levels were an independent prognostic factor.

ARID1A Deficiency Regulates Anti-Tumor Immune Response in Esophageal Adenocarcinoma

ARID1A, a member of the chromatin remodeling SWI/SNF complex, is frequently lost in many cancer types, including esophageal adenocarcinoma (EAC). Here, we study the impact of ARID1A deficiency on the anti-tumor immune response in EAC. We find that EAC tumors with ARID1A mutations are associated with enhanced tumor-infiltrating CD8+ T cell levels. ARID1A-deficient EAC cells exhibit heightened IFN response signaling and promote CD8+ T cell recruitment and cytolytic activity. Moreover, we demonstrate that ARID1A regulates fatty acid metabolism genes in EAC, showing that fatty acid metabolism could also regulate CD8+ T cell recruitment and CD8+ T cell cytolytic activity in EAC cells. These results suggest that ARID1A deficiency shapes both tumor immunity and lipid metabolism in EAC, with significant implications for immune checkpoint blockade therapy in EAC.

Dietary fat and lipid metabolism in the tumor microenvironment

Metabolic reprogramming has been considered a core hallmark of cancer, in which excessive accumulation of lipids promote cancer initiation, progression and metastasis. Lipid metabolism often includes the digestion and absorption of dietary fat, and the ways in which cancer cells utilize lipids are often influenced by the complex interactions within the tumor microenvironment. Among multiple cancer risk factors, obesity has a positive association with multiple cancer types, while diets like calorie restriction and fasting improve health and delay cancer. Impact of these diets on tumorigenesis or cancer prevention are generally studied on cancer cells, despite heterogeneity of the tumor microenvironment. Cancer cells regularly interact with these heterogeneous microenvironmental components, including immune and stromal cells, to promote cancer progression and metastasis, and there is an intricate metabolic crosstalk between these compartments. Here, we focus on discussing fat metabolism and response to dietary fat in the tumor microenvironment, focusing on both immune and stromal components and shedding light on therapeutic strategies surrounding lipid metabolic and signaling pathways.

Impact of Morbid Obesity on Post-esophagectomy Leak Rate: a NSQIP Analysis

BACKGROUND

Morbid obesity is becoming more prevalent and is a known risk factor for esophageal cancer. Esophagectomy in this population is technically more challenging than the non-obese, thus increasing the risks of surgery. This study hypothesizes that higher body mass index (BMI) is associated with higher anastomotic leak rates after esophagectomy.

METHODS

This study is a retrospective review of patients undergoing esophagectomy in the National Surgical Quality Improvement Program (NSQIP) Targeted Esophagectomy database from 2016 to 2019. Patients were stratified by BMI < 35 versus BMI > 35, with the primary outcome being leak post-esophagectomy. Univariate analyses were performed for demographics and post-operative outcomes, and multivariate analyses were performed specifically for the primary outcome of anastomotic leak (all diagnoses and malignancy/dysplasia subgroup). This study was approved by the Institutional Review Board.

RESULTS

Of 4165 patients, 439 (10.5%) had a BMI > 35. Patients with BMI > 35 were often younger (mean age 60 vs 64 years, p < 0.001), White (p < 0.001), female (p < 0.001), non-smoker (p < 0.001), diabetic (p < 0.001), with hypertension (p < 0.001), and ASA ≥ 3 (p < 0.001). There were no differences between BMI groups with regard to indication for esophagectomy (malignancy/dysphasia vs other), conversion to open, mortality, or length of stay. The BMI > 35 cohort reported higher operative times (p < 0.001), open operative approach (p = 0.04), superficial surgical site infection (p < 0.001), return to operating room (p = 0.01), and leak (13.5% vs 10.1%, p = 0.01). BMI > 35 was not an independent predictor of leak for all diagnoses; however, the subgroup analysis of esophagectomy for malignancy/dysplasia demonstrated that BMI > 35 was predictive of leak (OR 1.42, 95% CI 1.05-1.91), as well as operative time and hypertension.

CONCLUSION

Patients with a BMI > 35 and who undergo esophagectomy have a higher rate of anastomotic leak. BMI > 35 was also an independent predictor of leak when esophagectomy was performed for malignancy/dysplasia, but not for all diagnoses. The risk of anastomotic leak should be considered in morbidly obese patients undergoing esophagectomy, particularly for malignancy.

Trends in Epidemiology of Esophageal Cancer in the US, 1975-2018

Importance

Esophageal cancer (EC) is the 7th most common cancer worldwide and 14th in the US. More data are needed to study the changing incidence patterns of its 2 primary histologic subtypes, squamous cell carcinoma of the esophagus (SCE) and adenocarcinoma of the esophagus (ACE).

Objective

To examine temporal trends in incidence rates of EC, ACE, and SCE from 1975 through 2018.

Design, Setting, and Participants

In this population-based cross-sectional study, data were derived from 9 Surveillance, Epidemiology, and End Results (SEER) registries from January 1975 through December 2018 and from all 21 registries for January 2000 through December 2018 for patients with a diagnosis of EC from 1975 through 2018 (International Classification of Disease-Oncology, Third Edition codes). Age-adjusted incidence rates (AAIRs) of EC, ACE, and SCE were calculated. The timing and magnitude of the annual percentage change (APC) in incidence were examined using Joinpoint regression analyses. Data analysis was started in 2021 and updated and completed in 2023.

Main Outcome and Measures

The APC for age-adjusted EC incidence rates as stratified by histology, anatomical location, stage, sex, age, race and ethnicity, and geographic region.

Results

A total of 47 648 patients with a diagnosis of EC were retained for analysis. These included 22 419 (47.1%) with a diagnosis of SCE, 22 217 (46.6%) with ACE, and 3012 (6.3%) with other subtypes. The AAIR for EC changed from 4.14 per 100 000 population in 1975 to 4.18 in 2018, AAIRs of SCE declined from 3.06 in 1975 to 1.15 in 2018 as well as for ACE, and AAIRs increased from 0.42 in 1975 to 2.78 in 2018. From 1975 through 2004, EC incidence significantly increased (APC, 0.53; 95% CI, 0.4 to 0.7) but significantly decreased (APC, -1.03; 95% CI, -1.3 to -0.7) from then until 2018. The APC of SCE significantly continued to decline (-2.80, 95% CI, -3.0 to -2.6), and ACE increased from 2000 to 2006 (APC, 2.51; 95% CI, 1.0 to 4.0) but has since stabilized from 2006 to 2018.

Conclusions and Relevance

The results of this cross-sectional study suggest that the incidence of EC modestly declined since 2004 and that the incidence of SCE continued to decline while the incidence rate of ACE plateaued for more than a decade. Understanding factors associated with plateaued rates of ACE may help inform public health interventions.

Obesity-induced changes in cancer cells and their microenvironment: Mechanisms and therapeutic perspectives to manage dysregulated lipid metabolism

Obesity has been closely related to cancer progression, recurrence, metastasis, and treatment resistance. We aim to review recent progress in the knowledge on the obese macroenvironment and the generated adipose tumor microenvironment (TME) inducing lipid metabolic dysregulation and their influence on carcinogenic processes. Visceral white adipose tissue expansion during obesity exerts systemic or macroenvironmental effects on tumor initiation, growth, and invasion by promoting inflammation, hyperinsulinemia, growth-factor release, and dyslipidemia. The dynamic relationship between cancer and stromal cells of the obese adipose TME is critical for cancer cell survival and proliferation as well. Experimental evidence shows that secreted paracrine signals from cancer cells can induce lipolysis in cancer-associated adipocytes, causing them to release free fatty acids and acquire a fibroblast-like phenotype. Such adipocyte delipidation and phenotypic change is accompanied by an increased secretion of cytokines by cancer-associated adipocytes and tumor-associated macrophages in the TME. Mechanistically, the availability of adipose TME free fatty acids and tumorigenic cytokines concomitant with the activation of angiogenic processes creates an environment that favors a shift in the cancer cells toward an aggressive phenotype associated with increased invasiveness. We conclude that restoring the aberrant metabolic alterations in the host macroenvironment and in adipose TME of obese subjects would be a therapeutic option to prevent cancer development. Several dietary, lipid-based, and oral antidiabetic pharmacological therapies could potentially prevent tumorigenic processes associated with the dysregulated lipid metabolism closely linked to obesity.

Translating Molecular Biology Discoveries to Develop Targeted Cancer Interception in Barrett's Esophagus

Esophageal adenocarcinoma (EAC) is a rapidly increasing lethal tumor. It commonly arises from a metaplastic segment known as Barrett's esophagus (BE), which delineates the at-risk population. Ample research has elucidated the pathogenesis of BE and its progression from metaplasia to invasive carcinoma; and multiple molecular pathways have been implicated in this process, presenting several points of cancer interception. Here, we explore the mechanisms of action of various agents, including proton pump inhibitors, non-steroidal anti-inflammatory drugs, metformin, and statins, and explain their roles in cancer interception. Data from the recent AspECT trial are discussed to determine how viable a multipronged approach to cancer chemoprevention would be. Further, novel concepts, such as the repurposing of chemotherapeutic drugs like dasatinib and the prevention of post-ablation BE recurrence using itraconazole, are discussed.

CANCER-ASSOCIATED ADIPOCYTES AND PROGNOSTIC VALUE OF PREOPERATIVE NEUTROPHIL-LYMPHOCYTE RATIO IN GASTRIC CANCER

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) turned out to be a routinely available marker capable to reflect the systemic inflammatory response created by a tumor. Gastric cancer (GC) grows in the anatomical vicinity of adipose tissue, which is also associated with low-grade inflammation.

AIM

To investigate the usefulness of the combined use of preoperative NLR and density of intratumoral cancer-associated adipocytes (CAAs) for predicting the disease outcome in GC patients.

MATERIALS AND METHODS

A total of 151 patients with GC were eligible for retrospective analysis between 2009 and 2015.NLR preoperative values were calculated. Perilipin expression in tumor tissue was examined immunohistochemically.

RESULTS

Low preoperative NLR is the most reliable prognostic factor for the favorable outcome for patients with low density of intratumoral CAAs. Patients with a high density of CCAs are at high risk of lethal outcomes independently of the value of preoperative NLR.

CONCLUSION

The results have clearly shown an association between preoperative NLR and the density of CAAs in the primary tumor of GC patients. The prognostic value of NLR is essentially modified by means of the individual density of intratumoral CAAs in GC patients.The elevated NLR could be of significant predictive potential for a negative prognosis for patients with tumors characterized by the high density of CAAs independently of BMI.

Health Complications of Obesity: 224 Obesity-Associated Comorbidities from a Mechanistic Perspective

Obesity is associated with a wide range of comorbidities that transverse multiple specialties in clinical medicine. The development of these comorbidities is driven by various mechanistic changes including chronic inflammation and oxidative stress, increased growth-promoting adipokines, insulin resistance, endothelial dysfunction, direct loading and infiltrative effect of adiposity, heightened activities of the renin-angiotensin-aldosterone system and sympathetic nervous system, impaired immunity, altered sex hormones, altered brain structure, elevated cortisol levels, and increased uric acid production, among others. Some of the comorbidities might develop secondary to one or more other comorbidities. Considering the obesity-associated comorbidities in the context of the mechanistic changes is helpful in understanding these conditions and in guiding treatment and future research.

A blood-based circulating microbial metagenomic panel for early diagnosis and prognosis of oesophageal adenocarcinoma

BACKGROUND

Emerging evidence indicates the potential clinical significance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in oesophageal adenocarcinoma (EAC) patients, particularly as novel non-invasive, early detection, surveillance and prognostic classifiers.

METHODS

Metagenome sequencing was performed on 81 serum specimens collected across EAC spectrum, with sequencing reads classified using Bracken and MetaPhlAn3. Followed by the Linear Discriminant Analysis effect size (LEfSe) method to identify microbial profiles between groups. Logistic regression and Kaplan-Meier analyses were used to build classifiers.

RESULTS

A significant loss of alpha and beta diversity was identified in serum specimens from EAC patients. We observed a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 (95% CI: 0.78-0.95; P < 0.001) and this panel in conjunction with the TNM stage was a robust predictor of overall survival (≥24 months; AUC = 0.84 (95% CI: 0.66-0.92; P = 0.006)).

CONCLUSION

This study firstly describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

TRANSLATIONAL RELEVANCE

Accumulating data indicates the clinical relevance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in patients with oesophageal adenocarcinoma (EAC). Herein, we performed metagenome sequencing in serum specimens from EAC patients 81 collected across EAC spectrum and observed a significant loss of alpha and beta diversity, with a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 and this panel, in conjunction with the TNM stage, was a robust predictor of overall survival. This study for the first time describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

Augmented CPT1A Expression Is Associated with Proliferation and Colony Formation during Barrett’s Tumorigenesis

Obesity is a known risk factor for the development of gastroesophageal reflux disease (GERD), Barrett’s Esophagus (BE) and the progression to esophageal adenocarcinoma. The mechanisms by which obesity contributes to GERD, BE and its progression are currently not well understood. Recently, changes in lipid metabolism especially in the context of a high fat diet have been linked to GERD and BE leading us to explore whether fatty acid oxidation plays a role in the disease progression from GERD to esophageal adenocarcinoma. To that end, we analyzed the expression of the rate-limiting enzyme, carnitine palmytoyltransferase 1A (CPT1A), in human tissues and cell lines representing different stages in the sequence from normal squamous esophagus to cancer. We determined uptake of palmitic acid, the most abundant fatty acid in human serum, with fluorescent dye-labeled lipids as well as functional consequences of stimulation with palmitic acid relevant to Barrett’s tumorigenesis, e.g., proliferation, characteristics of stemness and IL8 mediated inflammatory signaling. We further employed different mouse models including a genetic model of Barrett’s esophagus based on IL1β overexpression in the presence and absence of a high fat diet and deoxycholic acid to physiologically mimic gastrointestinal reflux in the mice. Together, our data demonstrate that CPT1A is upregulated in Barrett’s tumorigenesis and that experimental palmitic acid is delivered to mitochondria and associated with increased cell proliferation and stem cell marker expression.

International trends in esophageal cancer incidence rates by histological subtype (1990-2012) and prediction of the rates to 2030

BACKGROUND

We provide an up-to-date overview of recent international trends (1990-2012) and predicted trends (2013-2030) in the incidence rates of esophageal cancer.

METHODS

We used data from the Cancer Incidence in Five Continents (CI5plus) database that contains annual incidence data by cancer site, age, and sex as well as corresponding populations. The age-standardized esophageal cancer incidence rates of each country were calculated and plotted from 1990 through 2012 and were predicted to 2030 using a Bayesian age-period-cohort model.

RESULTS

Globally, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) showed opposing trends between 1990 and 2012; ESCC showed a decreasing trend, with an AAPC of - 1.5 (95% CI - 2.4, - 0.7), yet EAC showed an increasing trend, with an AAPC of 5.2 (95% CI 4.2, 6.2). The increasing trend in EAC was commonly observed in high-income countries. The predicted trend to 2030 indicated that most countries will continue to experience a decreasing trend or a stable trend in esophageal cancer incidence, except Denmark, the Netherlands, and the UK, where the overall esophageal cancer incidence rates, mainly driven by EAC, are predicted to increase.

CONCLUSIONS

Decreasing trends in ESCC have been observed worldwide in both low- and middle-income countries and high-income countries, which may have been offset by increasing trends in EAC in high-income countries. The changing patterns of these two main subtypes of esophageal cancer may call for interventions, especially innovative interventions, to address obesity, GERD, and Barrett's esophagus.

Esophageal squamous cell carcinoma and adenocarcinoma in Malaysia - Pooled data from upper gastrointestinal centers in a multiethnic Asian population

BACKGROUND

Esophageal cancer is the sixth leading cause of cancer death worldwide with considerable geographical histological variation There is a paucity of data in esophageal cancer in demographics, histology, and survival among the multi-ethnic Malaysian population. This paper is a review of esophageal cancer epidemiology and survival among esophageal cancer patients from data collected by the Malaysian Upper Gastrointestinal Surgical Society.

METHODS

This is a multicenter retrospective observational study of esophageal cancer patients from six upper gastrointestinal surgical centers in Malaysia between 2005 and 2019. Patient characteristics, histological type and stage were compared and survival analyzed.

RESULTS

There were 820 patients with esophageal cancer included, where 442 (53.9 %) cases had squamous cell carcinoma (SCC) and 378 (46.1 %) had adenocarcinomas (AC). Malays were the predominant ethnicity with AC (66.7 %) while Indians were the ethnic majority (74.6 %) with SCC. Majority of patients (56.8 %) presented as stage IV disease. Overall, the 1-, 3-, and 5-years' survival were 35.8 %, 13.8 % and 11.0 %, respectively. Surgical resection with curative intent yielded the best 5-year survival (29.4 %). Intervention in stage IV AC yielded superior survival when compared to SCC (median survival, 7.9 months vs 4.8 months; p, 0.018) Our series demonstrated an increase in AC to SCC over the last 15 years.

CONCLUSIONS

There was an ethnic preponderance seen between different histology in this region, not previously discussed. An increase in AC was observed over the last 15 years. Late diagnosis seen in most patients imparts poor prognosis as curative surgery affords the best outcome.

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.

The ambiguous role of obesity in oncology by promoting cancer but boosting antitumor immunotherapy

Obesity is nowadays considered a pandemic which prevalence's has been steadily increasingly in western countries. It is a dynamic, complex, and multifactorial disease which propitiates the development of several metabolic and cardiovascular diseases, as well as cancer. Excessive adipose tissue has been causally related to cancer progression and is a preventable risk factor for overall and cancer-specific survival, associated with poor prognosis in cancer patients. The onset of obesity features a state of chronic low-grade inflammation and secretion of a diversity of adipocyte-derived molecules (adipokines, cytokines, hormones), responsible for altering the metabolic, inflammatory, and immune landscape. The crosstalk between adipocytes and tumor cells fuels the tumor microenvironment with pro-inflammatory factors, promoting tissue injury, mutagenesis, invasion, and metastasis. Although classically established as a risk factor for cancer and treatment toxicity, recent evidence suggests mild obesity is related to better outcomes, with obese cancer patients showing better responses to treatment when compared to lean cancer patients. This phenomenon is termed obesity paradox and has been reported in different types and stages of cancer. The mechanisms underlying this paradoxical relationship between obesity and cancer are still not fully described but point to systemic alterations in metabolic fitness and modulation of the tumor microenvironment by obesity-associated molecules. Obesity impacts the response to cancer treatments, such as chemotherapy and immunotherapy, and has been reported as having a positive association with immune checkpoint therapy. In this review, we discuss obesity's association to inflammation and cancer, also highlighting potential physiological and biological mechanisms underlying this association, hoping to clarify the existence and impact of obesity paradox in cancer development and treatment.

OUP accepted manuscript

Background

Accumulating evidence suggests a survival benefit after curative oesophageal cancer surgery in women compared with men. The aim of this study was to explore sex disparities in survival after surgery with curative intent in patients with oesophageal cancer.

Methods

This was a population-based cohort study, including all patients with oesophageal or gastric cancer who underwent surgery with a curative intent between 2006 and 2017 in Sweden. Female versus male mortality rate ratio (MRR) and excess mortality rate ratio (EMRR) were used as measures of survival. Two different parametric models were designed to account for potential confounders. Patients with gastric cancer were used as a comparison group as no differences in survival between sexes were expected among these patients.

Results

A total of 1301 patients underwent resection for oesophageal adenocarcinoma and 305 patients for oesophageal squamous cell carcinoma. Women had a lower EMRR (0.76, 95 per cent c.i. 0.58 to 1.01, P = 0.056; 0.52, 95 per cent c.i. 0.32 to 0.84, P = 0.007 respectively) in both histological subtypes. The effect was more profound in early clinical stages, in patients receiving neoadjuvant treatment, and without postoperative complications. No sex-related difference was observed in survival of patients with gastric cancer.

Conclusions

Women undergoing resection for oesophageal carcinoma have better survival compared with men.

Patient-derived organoids as a platform for modeling a patient's response to chemoradiotherapy in esophageal cancer

3D patient-derived organoids (PDOs) have been utilized to evaluate potential therapies for patients with different cancers. However, the use of PDOs created from treatment-naive patient biopsies for prediction of clinical outcomes in patients with esophageal cancer has not yet been reported. Herein we describe a pilot prospective observational study with the goal of determining whether esophageal cancer PDOs created from treatment naive patients can model or predict clinical outcomes. Endoscopic biopsies of treatment-naive patients at a single tertiary care center were used to generate esophageal cancer PDOs, which were treated with standard-of-care chemotherapy, gamma-irradiation, and newer non-standard approaches, such as proton beam therapy or two small molecule inhibitors. Clinical outcomes of patients following neoadjuvant treatment were compared to their in vitro PDO responses, demonstrating the PDO's ability to mirror clinical response, suggesting the value of PDOs in prediction of clinical response to new therapeutic approaches. Future prospective clinical trials should test the use of pre-treatment PDOs to identify specific, targeted therapies for individual patients with esophageal adenocarcinoma.

Obesity, Cancer, and Risk Reduction with Bariatric Surgery

The prevalence of noncommunicable diseases has increased dramatically in North America and throughout the world and is expected to continue increasing in coming years. Obesity has been linked to several types of cancers and is associated with increased morbidity and mortality following cancer diagnosis. Bariatric surgery has emerged as the prominent model to evaluate the effects of intentional weight loss on cancer incidence and outcomes. Current literature, comprising prospective cohort investigations, indicates site-specific reductions in cancer risk with select bariatric procedures. Future research is required to establish evidence-based indications for bariatric surgery in the context of cancer prevention.

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.

Construction and Evaluation of a Risk Score Model for Autophagy-Related Genes in Esophageal Adenocarcinoma

Background

Several studies have suggested the importance of autophagy during esophageal adenocarcinoma (EAC) development. This study aimed to explore the autophagy-related genes correlated with overall survival in patients with EAC.

Material/Methods

The RNA-seq expression profiles and clinical data of patients with EAC were screened using The Cancer Genome Atlas (TCGA) database. Screening of autophagy-related genes was conducted using the human autophagy database (HADb). Bioinformatic analysis was conducted and included the following: univariate cox, lasso regression, and multivariate cox regression analysis; building overall survival assessment of the prognosis model; drawing the model of receiver operating characteristic (ROC) curve and determining the area under the curve; and a C-index reliability index assessment model through Kaplan-Meier screening of statistically significant genes in the model. The screening results were verified via Oncomine differential expression analysis. Gene set enrichment analysis (GSEA) was further used to analyze the molecular biological functions and related pathways of the gene model.

Results

Through cox regression and ROC analysis, the model showed that the risk score could accurately and independently predict the prognosis of EAC. The screening identified 4 genes: DAPK1, BECN1, ATG5, and VAMP7. GSEA showed that the high and low expression levels of the 4 genes were mainly enriched in biological functions, such as cell production and regulation, and metabolic pathways that maintain cell activity.

Conclusions

Our research found that autophagy was involved in the process of EAC development and that several autophagy-related genes may provide prognostic information and clinical application value for patients with EAC.

Quercetin as an anticancer agent: Focus on esophageal cancer

Esophageal cancer (EC) is regarded as the sixth highest contributor to all cancer-related mortality, worldwide. In spite of advances in the treatment of EC, currently used methods remain ineffective. Quercetin, as a dietary antioxidant, is a plant flavonol from the flavonoid group of polyphenols, and can be found in numerous vegetables, fruits, and herbs. Quercetin can affect the processes of cancer-related diseases via cell proliferation inhibitory effects, potential apoptosis effects, and antioxidant properties. Of the various types of cancer, the use of quercetin has now become prominent in the treatment of EC. In this review, we discuss how quercetin may be an important supplement for the prevention, treatment, and management of EC, owing to its natural origin, and low-cost relative to synthetic cancer drugs. However, most findings cited in the current study are based on in vitro and in vivo studies, and thus, further human-based research is necessitated. PRACTICAL APPLICATIONS: In spite of advances in the treatment of esophageal cancer, currently used methods remain ineffective, therefore, an alternative or complementary therapy is required. Quercetin, as a dietary antioxidant, can affect the processes of cancer-related diseases via cell proliferation inhibitory effects, potential proapoptotic functions, and antioxidant properties. Quercetin may be an important supplement for the prevention, treatment, and management of EC, owing to its natural origin. The low cost of quercetin as supplement or dietary intake, relative to synthetic cancer drugs, is an advantage of the compound which should be considered.

Primary impact of Gli1 on radioresistance in esophageal cancer

Radioresistance is the primary cause for the low efficacy of radiotherapy in the treatment of esophageal cancer (EC). Increasing evidence has demonstrated that the Sonic Hedgehog (Shh) signaling pathway may be involved in the pathology of various tumors, including EC. The present study aimed to examine the association between radioresistance in EC and the Sonic Hedgehog pathway, and to determine whether a downstream transcription factor of the Shh pathway, glioma-associated oncogene family zinc finger 1 (Gli1), serves a primary role in radioresistance. The radiation-resistant cell line Eca109R was established by repeated low dose (cumulative dose 60 Gy) irradiation of the human EC cell line Eca109. The level of cell radiosensitivity was determined by colony formation assay, and the localization of Gli1 was detected using immunofluorescence. Western blotting was used to determine the protein expression levels of Gli1, Shh, patched 1 (Ptch) and smoothened frizzled class receptor (Smo) in the two cell lines. Significantly higher levels of Gli1 were identified in the Eca109R cell line compared with those inEca109 cells (P<0.05). Additionally, western blotting analysis demonstrated an increased expression level of the Gli1, Shh, Ptch and Smo proteins in Eca109R, compared with Eca109 cells (P<0.05). Overexpression of Gli1 in the parental cell line led to decreased levels of radiosensitivity and radiosensitivity of the radioresistant cell line was restored through knockdown of Gli1. The present study demonstrated that Gli1 may be associated with the development of radioresistance in EC.

Cellular prion protein regulates the differentiation and function of adipocytes through autophagy flux

The role of autophagy modulation in adipogenic differentiation and the possible autophagy modulators targeting adipogenesis remain unclear. In this study, we investigated whether normal cellular prion protein (PrP<C>) is involved in the modulation of autophagy and affects adipogenic differentiation in vivo and in vitro. Surprisingly, autophagy flux signals were activated in the adipose tissue of prion protein-deficient mice and PrP<C>-deleted 3T3-L1 adipocytes. The activation of autophagy flux mediated by PrP<C> deletion was confirmed in the adipose tissue via transmission electron microscopy. Adipocyte differentiation factors were highly induced in prion protein-deficient adipose tissue and 3T3-L1 adipocytes. In addition, deletion of prion protein significantly increased visceral fat volume, body fat weight, adipocyte cell size, and body weight gain in Prnp-knockout mice and increased lipid accumulation in PrP<C> siRNA-transfected 3T3-L1 cells. However, the overexpression of prion protein using adenovirus inhibited the autophagic flux signals, lipid accumulation, and the PPAR-γ and C/EBP-α mRNA and protein expression levels in comparison to those in the control cells. Our results demonstrated that deletion of normal prion protein accelerated adipogenic differentiation and lipid accumulation mediated via autophagy flux activation.

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.

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

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

Baseline Metabolic Risk Score and Postsurgical Esophageal Cancer-Specific Mortality: The Fujian Prospective Investigation of Cancer (FIESTA) Study

Backgrounds: Compelling evidence has emerged to support a close relationship between metabolic syndrome and esophageal cancer (EC). Aims: Using five baseline metabolism-related markers, we constructed a metabolic risk score (MRS), aiming to test whether MRS can improve the prediction of postsurgical EC-specific mortality over traditional demographic and clinicopathologic characteristics. Methods: Total 2535 EC patients who received three-field lymphadenectomy were enrolled from January 2000 to December 2010, and they were followed up until December 2015. Results: All EC patients were randomly split into derivation group (n=1512, 60%) and validation group (n=1014, 40%). MRS was generated in derivation group by adopting the Framingham 'points' system and shrinkage method, and it ranged from -9 to 17. EC-specific mortality risk increased with the increase of MRS, and adjusted estimates were more obvious in patients with upper tertile (MRS>6) than patients with lower MRS (≤2) in either derivation (hazard ratio [HR]=2.28, 95% confidence interval [CI]: 1.90-2.73, P<0.001) or validation group (HR=2.11, 95% CI: 1.66-2.67, P<0.001) or both groups (HR=2.37, 95% CI: 1.95-2.88, P<0.001). In Kaplan-Meier curve, cumulative survival rates differed significantly across tertiles of MRS. Further analysis indicated that MRS can improve classification accuracy and discriminatory ability over clinicopathologic parameters. Conclusions: Our findings supported the usefulness of baseline MRS in predicting the prognosis of postsurgical EC-specific mortality.

Worldwide incidence, mortality and time trends for cancer of the oesophagus

The incidence and mortality trends of oesophageal cancer are changing significantly across the world with considerable heterogeneity between sex, histological types, ethnic patterns and geographical distribution. Recent oesophageal cancer incidence and mortality trends have been analysed using data available from the WHO mortality database, the GLOBOCAN 2012 database and the Cancer Incidence in Five Continents database managed by the International Agency for Research on Cancer. Huge geographical variation is an epidemiological characteristic of oesophageal cancer, with the highest incidence rates observed in Eastern Asia and in Eastern and Southern Africa and the lowest rates observed in Western Africa. The variation is to the order of more than 21 times between the lowest-incidence and the highest-incidence countries. Although the incidence of squamous cell carcinoma is increasing globally, its incidence rates are decreasing in the USA and a few European countries. However, the decrease in the incidence of squamous cell carcinomas in these countries has been accompanied by a marked increase in adenocarcinoma incidence rates. There is a significant sex variation as well, with men being affected three to four times more commonly than women worldwide. The observed trends reflect significant global variations in the incidence and mortality of oesophageal cancers on the basis of sex, geographical distribution, ethnicity and histology. These epidemiological factors related to oesophageal cancers point out a possibly significant role of molecular epidemiological factors (genetic susceptibility and response to treatment) with major differences likely between the characteristics of Asian and Western populations.

Obesity-associated digestive cancers: A review of mechanisms and interventions

The prevalence of obesity has steadily increased over the past few decades. Previous studies suggest that obesity is an oncogenic factor and that over 20% of all cancers are obesity-related. Among such cancers, digestive system malignancies (including esophageal adenocarcinomas, colorectal cancers, and cancers of the gastric cardia, liver, and pancreas) are reported most frequently. While the 5-year survival rates of cancers of the breast and prostate are 90%, that rate is only 45% for digestive cancers. In this review, the mechanisms of obesity-associated digestive cancers are discussed, with an emphasis on obesity-related gene mutations, insulin and insulin-like growth factor signaling pathways, chronic inflammation, and altered adipokine levels. Evidence that these factors often function interdependently rather than independently in carcinogenesis is presented. Recommended interventions that may reduce the burden of obesity-associated digestive cancers, such as participation in physical activity, diet modulation, and calorie restriction, are also described.

Analysis of Preoperative Metabolic Risk Factors Affecting the Prognosis of Patients with Esophageal Squamous Cell Carcinoma: The Fujian Prospective Investigation of Cancer (FIESTA) Study

Some metabolic factors have been shown to be associated with an increased risk of esophageal cancer; however the association with its prognosis is rarely reported. Here, we assessed the prediction of preoperative metabolic syndrome and its single components for esophageal cancer mortality by analyzing a subset of data from the ongoing Fujian prospective investigation of cancer (FIESTA) study. Between 2000 and 2010, patients who underwent three-field lymphadenectomy were eligible for inclusion. Blood/tissue specimens, demographic and clinicopathologic data were collected at baseline. Metabolic syndrome is defined by the criteria proposed by Chinese Diabetes Society. In this study, analysis was restricted to esophageal squamous cell carcinoma (ESCC) due to the limited number of other histological types. The median follow-up in 2396 ESCC patients (males/females: 1822/574) was 38.2months (range, 0.5-180months). The multivariate-adjusted hazard ratio (HR) of metabolic syndrome for ESCC mortality was statistically significant in males (HR, 95% confidence interval, P: 1.45, 1.14-1.83, 0.002), but not in females (1.46, 0.92-2.31, 0.107). For single metabolic components, the multivariate-adjusted HRs were significant for hyperglycemia (1.98, 1.68-2.33, <0.001) and dyslipidemia (1.41, 1.20-1.65, <0.001) in males and for hyperglycemia (1.76, 1.23-2.51, <0.001) in females, independent of clinicopathologic characteristics and obesity. In tree-structured survival analysis, the top splitting factor in both genders was tumor-node-metastasis stage, followed by regional lymph node metastasis. Taken together, our findings demonstrate that preoperative metabolic syndrome was a significant independent predictor of ESCC mortality in males, and this effect was largely mediated by glyeolipid metabolism disorder.

Is Obesity Associated with Barrett's Esophagus and Esophageal Adenocarcinoma?

Barrett's esophagus is a premalignant condition portending increased risk of esophageal adenocarcinoma. Given the significant morbidity and mortality of esophageal adenocarcinoma, identification of risk factors for Barrett's esophagus and esophageal adenocarcinoma is crucial. There are a plethora of studies investigating the relationship of obesity with these pathologies. Recent studies reveal that this relationship may specifically be with central adiposity. Increased cell turnover and eventual carcinogenesis is likely precipitated by increased intragastric pressure but also is affected by the complex interplay of increased insulin resistance in patients with increased fat tissue. Further studies are warranted to evaluate if weight loss can decrease progression of Barrett's esophagus.

Correlation between NAD(P)H: quinone oxidoreductase 1 C609T polymorphism and increased risk of esophageal cancer: evidence from a meta-analysis

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphisms have been reported to influence the risk for esophageal cancer (EC) in many studies. However, the results remain controversial and ambiguous. We performed a meta-analysis, which included 13 independent studies with a total of 2357 subjects, to examine the association between NQO1 C609T polymorphism and EC. The association was assessed by five different gene models. The overall analysis suggested that the variant allele and genotypes were significantly related to increased risk of EC (odds ratio [OR] T versus C = 1.15, 95% confidence interval [CI] 0.95-1.40, probability of rejection [POR] = 0.014; OR TT versus CC = 1.32, 95% CI 1.01-1.73, POR = 0.045; OR TC versus CC = 1.32, 95% CI 0.98-1.21, POR = 0.128; OR TT + TC versus CC = 1.10, 95% CI 1.00-1.20, POR = 0.05; OR TT versus CC + TC = 1.26, 95% CI 0.95-1.57, POR = 0.103). Sensitivity analysis confirmed the reliability of these findings. Our study shows that individuals carrying the NQO1 C609T variant allele and genotypes are more susceptible to EC.

The combination effects of body acupuncture and auricular acupressure compared to sham acupuncture for body weight control: study protocol for a randomized controlled trial

BACKGROUND

Obesity is an increasingly prevalent chronic condition that is associated with serious morbidity and mortality. Excess body weight is a risk factor contributing to diseases such as hypertension, heart disease, hypercholesterolaemia, diabetes mellitus, cerebrovascular disease, gall bladder disease, and some types of cancer. Almost all the Western anti-obesity drugs have adverse effects or body weight is regained upon cessation of therapy. Recent studies have found that acupuncture had a similar efficacy as the Western anti-obesity drugs with fewer reported adverse effects. However, these conclusions were limited due to the small sample size and low quality of methodologies of these studies. Therefore, we design this study to explore the effectiveness and safety of acupuncture on weight control.

METHODS/DESIGN

This is a pilot single-blinded, randomized, sham-controlled trial on acupuncture for body weight control. Seventy-two participants are randomly assigned to the acupuncture group or the control group. Tianshu (ST-25), Daheng (SP-15), Daimai (GB-26), Qihai (CV-6), Zhongwan (CV-12), Zusanli (ST-36), Fenglong (ST-40), and Sanyinjiao (SP-6) are selected as acupuncture points. For the acupuncture group, disposable acupuncture needles will be inserted at a depth of 10-25 mm into the points and electrical stimulation with dense-disperse waves at 50 Hz and 10 V will be applied on the abdominal points. The bodily needles will be retained for 30 minutes. For subjects assigned to the control group, Streitberger's non-invasive acupuncture needles will be applied to serve as the sham control at the same acupoints with the same stimulation modality, except that the needles are only adhered to the skin instead of inserted. The duration of the treatment is 8 weeks with two sessions per week, and the follow-up period is 8 weeks. The primary outcome is the change in body weight before and after treatment. The secondary outcomes include changes in body mass index, waist circumference, hip circumference, and body fat percentage during the treatment and follow-up period.

DISCUSSION

The study will compare the efficacy and safety of acupuncture with sham acupuncture on weight control, in the hope of obtaining evidence for utilizing acupuncture for body weight control.

TRIAL REGISTRATION

NCT02516878 . Registered on 30 July 2015.

Evolving role of adiponectin in cancer-controversies and update

Adiponectin (APN), an adipokine produced by adipocytes, has been shown to have a critical role in the pathogenesis of obesity-associated malignancies. Through its receptor interactions, APN may exert its anti-carcinogenic effects including regulating cell survival, apoptosis and metastasis via a plethora of signalling pathways. Despite the strong evidence supporting this notion, some work may indicate otherwise. Our review addresses all controversies critically. On the whole, hypoadiponectinaemia is associated with increased risk of several malignancies and poor prognosis. In addition, various genetic polymorphisms may predispose individuals to increased risk of obesity-associated malignancies. We also provide an updated summary on therapeutic interventions to increase APN levels that are of key interest in this field. To date efforts to manipulate APN levels have been promising, but much work remains to be done.

Risk factors for Barrett's esophagus

Barrett's esophagus (BE) is a well-recognized precursor of esophageal adenocarcinoma (EAC) and is defined as ≥1 cm segment of salmon-colored mucosa extending above the gastroesophageal junction into the tubular esophagus with biopsy confirmation of metaplastic replacement of the normal squamous epithelium by intestinal-type columnar epithelium. The incidence of both BE and EAC has been increasing over the past few decades. As a result, preventing the development of BE by identifying and understanding its modifiable and non-modifiable risk factors may help reduce the incidence of EAC. Over the recent past, a tremendous amount of progress has been made towards improving our knowledge of risk factors and pathogenesis of BE. This article reviews the evidence for the various risk factors for developing BE.

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

BACKGROUND

Use of statins has been associated with a reduced incidence of esophageal adenocarcinoma in population-based studies. However there are few studies examining statin use and the development of Barrett's esophagus.

AIM

The purpose of this study was to examine the association between statin use and the presence of Barrett's esophagus in patients having their first gastroscopy.

METHODS

We have performed a case-control study comparing statin use between patients with, and without, an incident diagnosis of non-dysplastic Barrett's esophagus. Male Barrett's cases (134) were compared to 268 male age-matched controls in each of two control groups (erosive gastro-esophageal reflux and dyspepsia without significant upper gastrointestinal disease). Risk factor and drug exposure were established using standardised interviews. Logistic regression was used to compare statin exposure and correct for confounding factors. We performed a meta-analysis pooling our results with three other case-control studies.

RESULTS

Regular statin use was associated with a significantly lower incidence of Barrett's esophagus compared to the combined control groups [adjusted OR 0.62 (95 % confidence intervals 0.37-0.93)]. This effect was more marked in combined statin plus aspirin users [adjusted OR 0.43 (95 % CI 0.21-0.89)]. The inverse association between statin or statin plus aspirin use and risk of Barrett's was significantly greater with longer duration of use. Meta-analysis of pooled data (1098 Barrett's, 2085 controls) showed that statin use was significantly associated with a reduced risk of Barrett's esophagus [pooled adjusted OR 0.63 (95 % CI 0.51-0.77)].

CONCLUSIONS

Statin use is associated with a reduced incidence of a new diagnosis of Barrett's esophagus.

Bardoxolone Methyl Prevents Mesenteric Fat Deposition and Inflammation in High-Fat Diet Mice

Mesenteric fat belongs to visceral fat. An increased deposition of mesenteric fat contributes to obesity associated complications such as type 2 diabetes and cardiovascular diseases. We have investigated the therapeutic effects of bardoxolone methyl (BARD) on mesenteric adipose tissue of mice fed a high-fat diet (HFD). Male C57BL/6J mice were administered oral BARD during HFD feeding (HFD/BARD), only fed a high-fat diet (HFD), or fed low-fat diet (LFD) for 21 weeks. Histology and immunohistochemistry were used to analyse mesenteric morphology and macrophages, while Western blot was used to assess the expression of inflammatory, oxidative stress, and energy expenditure proteins. Supplementation of drinking water with BARD prevented mesenteric fat deposition, as determined by a reduction in large adipocytes. BARD prevented inflammation as there were fewer inflammatory macrophages and reduced proinflammatory cytokines (interleukin-1 beta and tumour necrosis factor alpha). BARD reduced the activation of extracellular signal-regulated kinase (ERK) and Akt, suggesting an antioxidative stress effect. BARD upregulates energy expenditure proteins, judged by the increased activity of tyrosine hydroxylase (TH) and AMP-activated protein kinase (AMPK) and increased peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and uncoupling protein 2 (UCP2) proteins. Overall, BARD induces preventive effect in HFD mice through regulation of mesenteric adipose tissue.

Microbiome and potential targets for chemoprevention of esophageal adenocarcinoma

Esophageal cancer is one of the deadliest cancers, with a dismal prognosis. It is increasingly recognized that esophageal cancer is a heterogeneous disease. It can be subdivided into two distinct groups: squamous cell carcinoma and adenocarcinoma, based on histological appearance. In the Western world, the incidence of squamous cell carcinoma was considerably higher than esophageal adenocarcinoma (EA) until the 1990s when, due to a dramatic increase, the incidence of EA surpassed that of squamous cell carcinoma. EA typically follows a well-established stepwise evolution from chronic inflammation due to reflux esophagitis (RE) that progresses to metaplasia (Barrett's esophagus [BE]) to dysplasia, which often culminates in EA. The pathophysiology of EA is complex and involves diverse factors, including gastroesophageal reflux, gastric acid secretion, dysfunction of the antireflux barrier, gastric emptying disturbances, and abnormalities in esophageal defense mechanisms. The current understanding of the etiology of EA is mainly derived from epidemiological studies of risk factors such as cigarette smoking, obesity, gastroesophageal reflux disorders (GERD), and low fruit and vegetable consumption. Numerous studies have been done, but the factors that drive the dynamic increase in the incidence of EA remain elusive. The advent of widespread antibiotic use occurred in the 1950s, preceding the surge of EA. Based on this temporal sequence, it has been hypothesized that antibiotics alter the microbiome to which the esophagus is exposed in patients who have GERD and that chronic exposure to this abnormal microbiome (ie, changes in species diversity or abundance) accounts for the increase in EA. If changes in the proposed factors alter the stepwise progression (RE-BE-dysplasia-EA), they may represent potential targets for chemoprevention. New discoveries will help improve our understanding of the biology and pathogenesis of these cancers, and aid in finding novel therapeutic targets.

Predictors of Progression to High-Grade Dysplasia or Adenocarcinoma in Barrett's Esophagus

The prevalence of esophageal adenocarcinoma is increasing dramatically. Barrett's esophagus remains the most well-established risk factor for the development of esophageal adenocarcinoma. There are multiple clinical, endoscopic, and pathologic factors that increase the risk of neoplastic progression to high-grade dysplasia or esophageal adenocarcinoma in Barrett's esophagus. This article reviews both risk and protective factors for neoplastic progression in patients with Barrett's esophagus.