Adenocarcinoma of the esophagus: role of obesity and diet

Obesity, Dietary Fats, and Gastrointestinal Cancer Risk-Potential Mechanisms Relating to Lipid Metabolism and Inflammation

Obesity is a major driving factor in the incidence, progression, and poor treatment response in gastrointestinal cancers. Herein, we conducted a comprehensive analysis of the impact of obesity and its resulting metabolic perturbations across four gastrointestinal cancer types, namely, oesophageal, gastric, liver, and colorectal cancer. Importantly, not all obese phenotypes are equal. Obese adipose tissue heterogeneity depends on the location, structure, cellular profile (including resident immune cell populations), and dietary fatty acid intake. We discuss whether adipose heterogeneity impacts the tumorigenic environment. Dietary fat quality, in particular saturated fatty acids, promotes a hypertrophic, pro-inflammatory adipose profile, in contrast to monounsaturated fatty acids, resulting in a hyperplastic, less inflammatory adipose phenotype. The purpose of this review is to examine the impact of obesity, including dietary fat quality, on adipose tissue biology and oncogenesis, specifically focusing on lipid metabolism and inflammatory mechanisms. This is achieved with a particular focus on gastrointestinal cancers as exemplar models of obesity-associated cancers.

Differential Expression of NEK Kinase Family Members in Esophageal Adenocarcinoma and Barrett's Esophagus

The incidence of esophageal adenocarcinoma (EAC) has risen rapidly during the past four decades, making it the most common type of esophageal cancer in the USA and Western countries. The NEK (Never in mitosis A (NIMA) related kinase) gene family is a group of serine/threonine kinases with 11 members. Aberrant expression of NEKs has been recently found in a variety of human cancers and plays important roles in tumorigenesis, progression, and drug-resistance. However, the expression of the NEKs in EAC and its precancerous condition (Barrett's esophagus, BE) has not been investigated. In the present study, we first analyzed the TCGA and 9 GEO databases (a total of 10 databases in which 8 contain EAC and 6 contain BE) using bioinformatic approaches for NEKs expression in EAC and BE. We identified that several NEK members, such as NEK2 (7/8), NEK3 (6/8), and NEK6 (6/8), were significantly upregulated in EAC as compared to normal esophagus samples. Alternatively, NEK1 was downregulated in EAC as compared to the normal esophagus. On the contrary, genomic alterations of these NEKs are not frequent in EAC. We validated the above findings using qRT-PCR and the protein expression of NEKs in EAC cell lines using Western blotting and in primary EAC tissues using immunohistochemistry and immunofluorescence. Our data suggest that frequent upregulation of NEK2, NEK3, and NEK7 may be important in EAC.

Novel evidence of obesity paradox in esophageal adenocarcinoma: perspective on genes that uncouple adiposity from dismal outcomes

Background: Obesity is a strong risk factor for esophageal adenocarcinoma (EAC). Nevertheless, not all the patients with EAC are obesity, and a substantial proportion of obesity patients don't suffer from poor prognoses. The mechanisms behind the “obesity paradox” that uncouple obesity from dismal outcomes in EAC are unclear. This study aimed to explore the “obesity-guarding” genes (OGG) profiles and their prognostic values in patients with EAC.

Methods: Gene expression data and clinical information of patients with EAC were downloaded from The Cancer Genome Atlas (TCGA) database. Enrichment analysis was used to explore the OGG functions and pathways. Cox regression analysis and nomogram model were performed to investigate the OGG prognostic values for overall survival (OS). In addition, relations between OGG and immune cells were assessed by the “CIBERSORT” algorithm and the Tumor IMmune Estimation Resource (TIMER) tool. Finally, the results were experimentally validated in real-world study.

Results: A total of 69 OGG were retrieved, and 17 significantly differentially expressed genes (SDEG) were identified between normal and EAC tissues. Enrichment analysis showed the OGG were enriched in the mitochondrion-related and various receptor pathways. Univariate Cox regression results showed that the MCM6, ATXN2 and CSK were significantly associated with OS (P=0.036, 0.039, 0.046, respectively). Multivariate Cox regression analysis showed MCM6 and CSK were independent prognostic genes for OS (P=0.025, 0.041, respectively). Nomogram demonstrated that the OGG had good predictive abilities for the 1-, 2-, and 3-year OS. Immunity analysis demonstrated that OGG were significantly associated with immune cells (P <0.05). In addition, clinical correlation analysis revealed that the OGG had significant relations with clinical parameters (P <0.05). The experiment results confirmed that the SDEG were significantly different between normal and EAC tissues (P <0.05).

Conclusions: We identified the OGG expression profiles that may uncouple obesity from poor survival in patients with EAC. They have prognostic values in predicting patients' OS, and may be exploited for prognostic biomarkers.

Lifestyle, WCRF/AICR Recommendations, and Esophageal Adenocarcinoma Risk: A Systematic Review of the Literature

One of the most notable changes in the epidemiology of esophageal cancer (EC) is the rising incidence and prevalence of esophageal adenocarcinoma (EAC) in developed countries. The aim of this systematic review was to collect and summarize all the available evidence regarding lifestyle, diet, and EAC risk. We searched the PubMed and Scopus databases in January 2021 for studies providing information about lifestyle, diet, WCRF/AICR recommendations, and EAC risk; published in English; without a time filter. The Newcastle-Ottawa Scale was used to assess risk of bias. The results are stratified by risk factor. A total of 106 publications were included. Half of the case-control studies were judged as high quality, whilst practically all cohort studies were judged as high quality. Body mass index and waist circumference were associated with increased EAC risk. Physical activity did not appear to have a significant direct role in EAC risk. A diet rich in fruit, vegetables, and whole grains appeared to be more protective than a Western diet. Alcohol does not seem to be related to EAC, whereas smokers, particularly heavy smokers, have an increased risk of EAC. Prevention remains the best option to avert EAC. Comprehensible and easy to follow recommendations should be provided to all subjects. Protocol ID number: CRD-42021228762, no funds received.

Impact of Obesity on Treatment Approach for Resectable Esophageal Cancer

BACKGROUND

With the prevalence of obesity and its known association with esophageal cancer, there is increasing need to understand how obesity affects treatment.

METHODS

Using The Society of Thoracic Surgeons General Thoracic Surgery Database, we retrospectively evaluated all patients who underwent esophagectomy with gastric conduit reconstruction between 2012 and 2016. Patients were categorized into five body mass index groups. Associations between body mass index and surgical technique, resection, lymphadenectomy, staging, and neoadjuvant treatment were evaluated using multivariable logistic regression models.

RESULTS

In all, 8547 patients were included in the analysis. Obese and morbidly obese patients were more likely to undergo open procedures compared with normal-weight patients (odds ratio [OR] 1.18, P = .016; and OR 1.45, P = .007), with longer operative times. Morbidly obese patients had a higher rate of intraoperative conversion from minimally invasive to open approaches (OR 3.75, P = .001). There were no differences in R0 resection or lymphadenectomy, and staging workup was similar. Obese patients were less likely to receive neoadjuvant therapy (OR 0.75, P = .048), and overweight and obese patients were less likely to receive preoperative radiation (OR 0.75, P = .017; and OR 0.71, P = .010). Analyzing by stage, overweight and obese patients with cT2N0 disease were less likely to receive neoadjuvant treatment (OR 0.54, P = .016; and OR 0.37, P < .001). There were no differences in neoadjuvant therapy for cT3 or node-positive disease.

CONCLUSIONS

Higher body mass index is associated with increased use of open versus minimally invasive esophagectomy and intraoperative conversion. Whereas staging workup and oncologic outcomes of surgery are similar, overweight and obese patients with cT2N0 disease are less likely to undergo neoadjuvant treatments.

Dietary vitamin B intake and the risk of esophageal cancer: a meta-analysis

BACKGROUND

Several epidemiology studies have explored the association between dietary B vitamins' intake and the risk of esophageal cancer (EC). However, the results remain inconclusive. Thus, we conducted a systematic review with meta-analysis to evaluate such association.

METHODS

Literature retrieval was performed using PubMed (Medline), ScienceDirect, and Cochrane Library electronic databases for all studies published from database inception to December 2017.

RESULTS

The meta-analysis included 19 studies and showed an overall decreased risk of EC (OR=0.77, 95% CI: 0.68-0.87) in association with multivitamin B (ie, B1, B2, B3, B5, B6, B9, and B12) dietary intake. In a subgroup analysis based on vitamin B subclass, B1, B3, B6, and B9 vitamins were associated with decreased EC risk (vitamin B1: OR=0.68, 95% CI: 0.56-0.82; vitamin B3: OR=0.70, 95% CI: 0.53-0.94; vitamin B6: OR=0.64, 95% CI: 0.49-0.83; and vitamin B9: OR=0.69, 95% CI: 0.55-0.86). By contrast, no association was detected between dietary vitamin B2 and vitamin B5 intake and EC risk (vitamin B2: OR=0.86, 95% CI: 0.64-1.16; vitamin B5: OR=0.49, 95% CI: 0.20-1.20), whereas a potential non-linear dose-response association was found between dietary vitamin B12 intake and EC risk. A statistically significant, inverse association was observed for an increase of 100 µg/day in supplemental vitamin B6 and B9 and EC risk (vitamin B6: OR=0.98, 95% CI: 0.98-0.99; vitamin B9: OR= 0.89; 95% CI: 0.86-0.94).

CONCLUSION

These findings support that vitamin B may have an influence on carcinogenesis of the esophagus. Vitamin B1, B3, B6, B9 showed a decreased risk of EC, and vitamin B12 showed an increased risk of EC.

Cruciferous Vegetables and Risk of Cancers of the Gastrointestinal Tract

Cancers of the oropharyngeal tissues, oesophagus, stomach, and colorectum are amongst the most common causes of death from cancer throughout the world. Higher consumption of fruits and vegetables is thought to be protective, and cruciferous vegetables are of particular interest because of their unique role as a source of biologically active glucosinolate breakdown products. A literature review of primary studies and meta-analyses indicates that higher consumption of cruciferous vegetables probably reduces the risk of colorectal and gastric cancers by approximately 8% and 19%, respectively. Some studies support the hypothesis that the protective effect against colorectal cancer is modified by genetic polymorphisms of genes regulating the expression of enzymes of the glutathione S-transferase family, but due to contradictory findings the evidence is currently inconclusive. Despite these promising findings, future epidemiological research on the protective effects of cruciferous plants will depend critically upon accurate measurement of dietary exposure, both to the vegetables themselves, and to their active constituents. The development of sensitive chemical assays has facilitated the measurement of urinary excretion of isothiocyanate metabolites as an objective biomarker of intake, but sampling strategies need to be optimized in order to assess long-term exposures at the population level.

Coffee consumption and risk of esophageal cancer incidence: A meta-analysis of epidemiologic studies

BACKGROUND

In epidemiologic studies, association between coffee consumption and esophageal cancer risk is inconsistent.

OBJECTIVE

The aim of tjis study was to evaluate the effect of coffee on esophageal cancer by combining several similar studies.

METHODS

We conducted a meta-analysis for association of coffee intake and esophageal cancer incidence. Eleven studies, including 457,010 participants and 2628 incident cases, were identified. A relative risk (RR, for cohort study) or odds ratio (OR, for case-control study) of heavy coffee drinkers was calculated, compared with light coffee drinkers or non-drinkers. The analysis was also stratified by cancer types (esophageal squamous cell carcinoma and esophageal adenocarcinoma), sex, and geographic region.

RESULTS

The summarized OR of having esophageal cancer in heavy coffee drinkers was 0.93 (95% confidence interval [CI]: 0.73-1.12), compared with light coffee drinkers. When stratified by sex, pathologic type of esophageal cancer, and type of epidemiologic study, we did not find any association of coffee consumption and esophageal cancer incidence. However, an inverse association between coffee consumption and incidence of esophageal cancer was found in East Asia participants with OR of 0.64 (95% CI: 0.44-0.83), but not in Euro-America participants (OR = 1.05; 95% CI: 0.81-1.29).

CONCLUSION

There is a protective role of coffee consumption against esophageal cancer in East Asians, but not in Euro-Americans.

Intakes of citrus fruit and risk of esophageal cancer: A meta-analysis

Esophageal cancer (EC) is the eighth most common cancer and the sixth most frequent cause of cancer death in the whole world. Many studies have investigated the association between citrus fruit intake and the risk of EC, but the results are inconsistent and not analyzed by category. We aimed to perform a meta-analysis of studies to evaluate the incidence between citrus fruit consumption and subtypes of esophageal cancer and derive a more precise estimation.Through searches of PubMed, OVID, and Web of Science we updated 1988 systematic review up to April 2016. Based on an inclusion and exclusion criteria, conventional meta-analysis according to DerSimonian and Laird method was used for the pooling of the results. Random-effect models were used to calculate subgroups.Twenty-five English articles (20 case-control studies and 5 cohort studies) comprising totally 5730 patients of esophageal cancer would be suitable for use in this study. The result indicated the inverse associations between intakes of citrus fruit and EC (relative risk [RR] = 0.65, 95% confidence interval [CI] 0.56-0.75, I  = 51.1%, P = .001), Esophageal squamous cell carcinoma (ESCC) (RR = 0.59, 95% CI 0.47-0.76, I  = 60.7%, P = .002), no significant relationship between citrus fruit and esophageal adenocarcinoma (EAC) (RR = 0.86, 95% CI 0.74-1.01, I  = 0.0%, P = .598).This meta-analysis indicates that intakes of citrus fruit significantly reduce the risk of ESCC and is no obvious relationship with EAC. Further studies about constituents in citrus fruit and its mechanism are warranted.

Esophageal Cancer: Recent advances

Esophageal carcinoma has, over the past decade, undergone a sea of change, not only in its pathological distribution, but also in the diagnosis, staging and subsequent management. Although the advent of better imaging techniques has helped in diagnosing patients at an earlier period, the majority of them have unresectable disease at the time of presentation. Despite aggressive treatment protocols involving either one or a combination of the options of surgery, radiation, and chemotherapy, the five-year survival remains dismal in the order of 10 to 15%. The two most commonly used surgical techniques for resecting the esophagus, the Ivor Lewis and the trans-hiatal esophagectomy, have similar results in terms of morbidity, mortality and, more importantly, five-year survival following resection. There has been an increasing interest in the surgical treatment of carcinoma esophagus by a minimally invasive approach, as meta-analysis of clinical series have shown that a faster recovery time without any statistically significant difference in the in-hospital mortality or morbidity when compared to conventional surgery. Nonrandomized studies suggest that patients receiving neoadjuvant chemo-radiation have a five year survival advantage compared with those treated with surgery alone, especially if they had a complete histological response to the preoperative regimen. Lastly, palliative procedures, form the mainstay of management of patients with non-resectable disease.

Dietary impact on esophageal cancer in humans: a review

Foods and the risk of esophageal cancer.

Dietary fat intake and risk of esophageal carcinoma: a meta-analysis of observational studies

Dietary fat intake is potentially associated with the onset of esophageal carcinoma (EC), but evidence from observational studies has remained unclear. This study aimed to evaluate the role of fat intake in the development of esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). A systematic search was conducted in PubMed and Web of Science to identify all relevant studies. Study-specific relative risks (RR) for the highest versus the lowest intake categories and 95% confidence intervals (CI) were pooled using a random-effects model. Seventeen case-control studies (2058 EAC cases, 1581 ESCC cases and 11696 controls) and two prospective cohort studies (494, 978 participants and 630 EAC cases and 215 ESCC cases) were identified. In EAC, the RRs (95% CI) were 1.69 (1.14–2.50) for total fat intake, 1.88 (1.28–2.77) for saturated fat (SFA) intake, 1.04 (0.86–1.27) for polyunsaturated fat (PUFA) intake and 1.70 (1.01–2.84) for monounsaturated fat (MUFA) intake. In ESCC, the RRs (95% CI) were 1.12 (0.84–1.51) for total fat, 1.38 (0.91–2.08) for SFA, 0.95 (0.55–1.62) for PUFA and 1.04 (0.65–1.66) for MUFA. In conclusion, total fat, SFA and MUFA intake were associated with EAC risk, but fat intake showed no significant association with ESCC risk. Large-scale prospective cohort studies are needed to confirm our findings.

Low vitamin B12 increases risk of gastric cancer: A prospective study of one-carbon metabolism nutrients and risk of upper gastrointestinal tract cancer

Previous studies have found associations between one-carbon metabolism nutrients and risk of several cancers, but little is known regarding upper gastrointestinal tract (UGI) cancer. We analyzed prediagnostic serum concentrations of several one-carbon metabolism nutrients (vitamin B12, folate, vitamin B6, riboflavin and homocysteine) in a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study of male smokers, which was undertaken in Finland between 1985 and 1988. We conducted a nested case-control study including 127 noncardia gastric adenocarcinoma (NCGA), 41 esophagogastric junctional adenocarcinoma and 60 esophageal squamous cell carcinoma incident cases identified within ATBC. Controls were matched to cases on age, date of serum collection and follow-up time. One-carbon nutrient concentrations were measured in fasting serum samples collected at baseline (up to 17 years prior to cancer diagnosis). Odds ratios and 95% confidence intervals (CI) were calculated using conditional logistic regression. Lower prediagnostic vitamin B12 concentrations at baseline were associated with a 5.8-fold increased risk of NCGA (95% CI = 2.7-12.6 for lowest compared to highest quartile, p-trend <0.001). This association remained in participants who developed cancer more than 10 years after blood collection, and after restricting the analysis to participants with clinically normal serum vitamin B12 (>300 pmol/L). In contrast, pepsinogen I, a known serologic marker of gastric atrophy, was not associated with NCGA in this population. As vitamin B12 absorption requires intact gastric mucosa to produce acid and intrinsic factor, our findings suggest vitamin B12 as a possible serologic marker for the atrophic gastritis that precedes NCGA, one more strongly associated with subsequent NCGA than pepsinogen.

An age-period-cohort analysis of obesity and incident esophageal adenocarcinoma among white males

The incidence of esophageal adenocarcinoma (EAC) has increased in recent decades. Increases in incidence have been attributed to changes in the prevalence of risk factors for EAC; however, the extent to which these changes explain increases in EAC incidence has not been studied in detail. We used age-period-cohort analysis to estimate changes in the incidence of EAC among white males by age, time period, and birth cohort. Incidence rates per 100,000 individuals were analyzed from 1973 to 2012. Hierarchical Poisson models were used to estimate age, period, and cohort effects, whereby age-specific incidence rates were nested within periods and cohorts. The prevalence of obesity for each time period and birth cohort was included in the model as a fixed-effect. Incidence increased with advancing age (β = 0.12, P < 0.01). There were significant period and birth cohort effects, although the period effect was much larger than the cohort effect. The period effect decreased dramatically when obesity was included as a fixed effect, while the small cohort effect remained unchanged. Results suggest much of the increase in the incidence of EAC can be attributed to a period effect, which may be due to changes in the prevalence of obesity over time.

Terrein performs antitumor functions on esophageal cancer cells by inhibiting cell proliferation and synergistic interaction with cisplatin

Terrein is a bioactive fungal metabolite isolated from Aspergillus terreus. Besides being a melanogenesis inhibitor, previous studies have revealed that terrein has antiproliferative effects on a number of types of cancer tumors. In the present study, the inhibitory effect of terrein on esophageal cancer was evaluated and the possible underlying mechanisms were investigated. The results revealed that terrein inhibited the proliferation of Eca109 esophageal cancer cells in a dose- and time-dependent manner. Mechanistically, terrein treatment led to the G₂/M phase arrest of Eca109 cells by indirectly regulating cyclin B1 and phosphorylating the cell division cycle protein 2 genes. Notably, terrein exhibited a synergistic effect on Eca109 cells when combined with cisplatin, which is a commonly used chemotherapeutic drug. Taken together, these findings indicate that terrein suppresses the proliferation of esophageal cancer cells, and may prove to be a novel therapeutic approach for the treatment of esophageal cancer via inhibiting the proliferation of cancer cells.

Clinicopathological features and prognosis of patients <45 years old with esophageal adenocarcinoma comparing to other age groups

BACKGROUND

To analyze the clinicopathological features and prognosis of younger patients with esophageal adenocarcinoma (EAC).

METHODS

A total of 2,601 patients diagnosed with EAC between 1988 and 2011 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. All patients underwent primary tumor resection and regional lymphadenectomy without preoperative radiotherapy. The patients were into four age groups (<45, 45-59, 60-74, ≥75), with 94, 813, 1,272 and 422 patients in each group respectively.

RESULTS

Patients in the age <45 group were more likely to have lymph node (LN) metastasis (P=0.002), postoperative radiotherapy (P<0.001) and advanced T and N stage (P=0.003, 0.014) compared to the other three groups. We then conducted two Cox proportional hazards model adjusted for the sex, race, number of LNs examined, histological grade, postoperative radiation. The hazard ratio (HR) was higher in patients <45 y and the survival rate were paradoxically lower compared to the patients between 45-60 years old (P=0.046, 0.039).

CONCLUSIONS

The patients <45 y had the most aggressive clinicopathological features of EAC and poorer survival rate after radical esophagectomy.

The oesophageal microbiome: an unexplored link in obesity-associated oesophageal adenocarcinoma

The influence of diets rich in saturated fats and simple sugars on the intestinal microbiota plays a central role in obesity. Being overweight or obese predisposes individuals to several diseases including oesophageal adenocarcinoma (OAC), which develops through a cascade of events starting with gastro-oesophageal reflux disease, progressing to Barrett's oesophagus (BO), and then OAC. A range of mechanisms for the increased risk of OAC in obese individuals have been proposed; however, a role for the oesophageal microbiota has been largely ignored. This is despite the fact that it is clear that the composition of the oesophageal microbiota shifts with the development of OAC. Given the well-established impact that unhealthy diets have on the intestinal microbiota, it is plausible that exposure to unhealthy foods, and the ensuing obesity, would result in an imbalance in the oesophageal microbiota. It is also likely that these changes may mimic the changes observed in the intestinal microbiota (i.e. increase in short-chain fatty acid (SCFA) producers and bile acid biosynthesis). The modulation of SCFAs and bile acids in the oesophagus by diet could promote the transdifferentiation from squamous to intestinal-like columnar cells observed in BO, given that intestinal cells proliferate in the presence of SCFAs.

Dietary Fat Intake and Risk of Gastric Cancer: A Meta-Analysis of Observational Studies

BACKGROUND AND OBJECTIVES

Consumption of dietary fat has been reported to be associated with gastric cancer risk, but the results of epidemiologic studies remain inconsistent. We conducted a meta-analysis to summarize the evidence regarding the association between dietary fat intake and gastric cancer risk.

METHODS

A comprehensive search of PubMed and EMBASE was performed to identify observational studies providing quantitative estimates between dietary fat and gastric cancer risk. Random effects model was used to calculate the summary relative risk(SRR) in the highest versus lowest analysis. Categorical dose-response analysis was conducted to quantify the association between dietary fat intake and gastric cancer risk. Heterogeneity among studies was evaluated using I2 and tau2(between study variance)statistics. Subgroup analysis and publication bias analysis were also performed.

RESULTS

Twenty-two articles were included in the meta-analysis. The SRR for gastric cancer was 1.18 for individuals with highest intake versus lowest intake of total fat (95% confidence interval [CI]: 0.999-1.39; n = 28; P< 0.001; tau2 = 0.12; I2 = 69.5%, 95% CI: 55%-79%) and 1.08 with a daily increase in total fat intake (20 g/d) (95%CI: 1.02-1.14; n = 6; P = 0.09; tau2 = 0.002; I2 = 46.8%, 95% CI: 0%-79%). Positive association between saturated fat intake (SRR = 1.31; 95%CI: 1.09-1.58;n = 18;P<0.001; tau2 = 0.08; I2 = 60.6%, 95% CI: 34%-76%), inverse association between polyunsaturated fat intake (SRR = 0.77; 95%CI: 0.65-0.92; n = 16; P = 0.003; tau2 = 0.06; I2 = 56.2%, 95% CI: 23%-75%) and vegetable fat intake (SRR = 0.55; 95%CI: 0.41-0.74; n = 4;P = 0.12; tau2 = 0.04; I2 = 48.6%, 95% CI: 0%-83%), and no association between monounsaturated fat intake (SRR = 1.00; 95%CI: 0.79-1.25; n = 14; P< 0.001; tau2 = 0.10; I2 = 63.0%, 95% CI: 34%-79%) and animal fat intake (SRR = 1.10; 95%CI: 0.90-1.33; n = 6; P = 0.13;tau2 = 0.02; I2 = 42.0%, 95% CI: 0%-70%) and gastric cancer risk were observed.

CONCLUSIONS

Our results suggest that intake of total fat is potentially positively associated with gastric cancer risk, and specific subtypes of fats account for different effects. However, these findings should be confirmed by further well-designed cohort studies with detailed dietary assessments and strict control of confounders.

Citrus Fruit Intake Substantially Reduces the Risk of Esophageal Cancer: A Meta-Analysis of Epidemiologic Studies

Many epidemiologic studies indicate a potential association between fruit and vegetable intake and various cancers. The purpose of this meta-analysis is to investigate the association between citrus fruit intake and esophageal cancer risk. The authors conducted a comprehensive search on PubMed, EMBASE, and the Cochrane Library from inception until July 2014. Studies presenting information about citrus intake and esophageal cancer were analyzed. The authors extracted the categories of citrus intake, study-specific odds ratio or relative risk, and the P value and associated 95% confidence intervals for the highest versus lowest dietary intake of citrus fruit level. The association was quantified using meta-analysis of standard errors with a random-effects model. Thirteen case-control studies and 6 cohort studies were eligible for inclusion. Citrus intake may significantly reduce risk of esophageal cancer (summary odds ratio = 0.63; 95% confidence interval = 0.52-0.75; P = 0), without notable publication bias (intercept = -0.79, P = 0.288) and with significant heterogeneity across studies (I = 52%). The results from epidemiologic studies suggest an inverse association between citrus fruit intake and esophageal cancer risk. The significant effect is consistent between case-control and cohort studies. Larger prospective studies with rigorous methodology should be considered to validate the association between citrus fruits and esophageal cancer.

Risk factors of early proximal gastric carcinoma in Chinese diagnosed using WHO criteria

OBJECTIVE

The incidence of proximal gastric carcinoma (PGC) is rising worldwide for unknown reasons. Herein we compare the risk factors of early PGC with distal gastric carcinoma (DGC) in patients treated at a single tertiary hospital in China.

METHODS

Risk factors of 379 consecutive surgically resected early gastric carcinoma (EGC) diagnosed according to the 2010 World Health Organization criteria were studied by reviewing their medical records and esophagogastroduodenoscopy/biopsy findings and interviewing patients and family members for the patients' history of environmental toxin exposure (ETE), dietary habits, family (FCH) and personal cancer history (PCH) and survival. Differences between PGC (n = 115), DGC (n = 264) and age-matched and gender-matched controls (n = 225) were compared.

RESULTS

Proportion of early PGC in all EGC patients was increased significantly (P < 0.05). The independent risk factors for both PGC and DGC identified by multivariate analysis were intake of preserved food and little fruit, and gastric mucosal intestinal metaplasia and atrophy (all P < 0.05). Advanced age (odds ratio [OR] 9.83, P < 0.01), PCH (OR 5.09, P < 0.05), a high body mass index (>24 kg/m(2) ) (OR 2.79, P < 0.01) and ETE (OR 2.31, P < 0.05) were independent risk factors for PGC, but not male gender, tobacco or alcohol abuse, hiatus hernia, gastroesophageal reflux disease or columnar-lined esophagus. In contrast, FCH (OR 2.34, P < 0.01) and Helicobacter pylori infection (OR 2.81, P < 0.001) were independent risk factors for DGC.

CONCLUSION

Independent risk factors for PGC in Chinese patients differ from those of DGC or esophageal adenocarcinoma, supporting the classification of PGC as a separate gastric carcinoma entity in the Chinese populations.

A dietary pattern rich in lignans, quercetin and resveratrol decreases the risk of oesophageal cancer

Dietary lignans, quercetin and resveratrol have oestrogenic properties, and animal studies suggest that they synergistically decrease cancer risk. A protective effect of lignans on the development of oesophageal cancer in humans has recently been demonstrated, and the present study aimed to test whether these three phytochemicals synergistically decrease the risk of oesophageal cancer. Data from a Swedish nationwide population-based case-control study that recruited 181 cases of oesophageal adenocarcinoma (OAC), 158 cases of oesophageal squamous-cell carcinoma (OSCC), 255 cases of gastro-oesophageal junctional adenocarcinoma (JAC) and 806 controls were analysed. Exposure data were collected through face-to-face interviews and questionnaires. The intake of lignans, quercetin and resveratrol was assessed using a sixty-three-item FFQ. Reduced-rank regression was used to assess a dietary pattern, and a simplified dietary pattern score was categorised into quintiles on the basis of the distribution among the control subjects. Unconditional multivariable logistic regression provided OR with 95% CI, adjusted for all the potential risk factors. A dietary pattern rich in lignans, quercetin and resveratrol was mainly characterised by a high intake of tea, wine, lettuce, mixed vegetables, tomatoes, and whole-grain bread and a low intake of milk. There were dose-dependent associations between simplified dietary pattern scores and all types of oesophageal cancer (all P for trend < 0.05). On comparing the highest quintiles with the lowest, the adjusted OR were found to be 0.24 (95% CI 0.12, 0.49) for OAC, 0.31 (95% CI 0.15, 0.65) for OSCC, and 0.49 (95% CI 0.28, 0.84) for JAC. The results of the present study indicate that a dietary pattern characterised by the intake of lignans, quercetin and resveratrol may play a protective role in the development of oesophageal cancer in the Swedish population.

A case-control study of glycemic index, glycemic load and dietary fiber intake and risk of adenocarcinomas and squamous cell carcinomas of the esophagus: the Australian Cancer Study

Background

Glycemic index (GI) and glycemic load (GL) have been investigated as etiologic factors for some cancers, but epidemiological data on possible associations between dietary carbohydrate intake and esophageal cancer are scant. This study examined the association between GI, GL, and other dietary carbohydrate components and risk of adenocarcinomas and squamous cell carcinoma of the esophagus accounting for established risk factors.

Methods

We analyzed data from a population-based Australian case-control study (2002-05) comprising 299 adenocarcinoma (EAC), 337 gastro-esophageal junction adenocarcinoma (EGJAC), 245 squamous cell carcinoma (ESCC), and 1507 controls sampled from a population registry. Dietary information was obtained using a 135-item food frequency questionnaire (FFQ); GI and GL were derived from an Australian GI database. Multivariable logistic regression models were used to derive odds ratios (ORs).

Results

All three case groups tended to have a lower intake of fiber, and significantly higher intake of fat, total energy, and alcohol (ESCC only) compared to controls. GI was unrelated to all histological types. Higher GL was not associated with risk of EAC and EGJAC, but was inversely associated with risk of ESCC (adjusted model, p_trend = 0.006), specifically among men where we observed a 58% reduced risk of ESCC in the highest versus the lowest quartile. Increased intake of total carbohydrates and starch was related to similarly large risk reductions of ESCC. Fiber intake was strongly and inversely associated with risk of EAC, EGJAC and ESCC (all p_trend ≤0.001), indicating risk reductions of 28%-37% per 10 g/day.

Conclusions

This study suggests a reduced risk of esophageal SCC with higher GL level particularly in men, but provides no evidence for the role of GI in the development of esophageal cancer. In addition, increased fiber intake appears to be associated with lower risk of all histological types of esophageal cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-877) contains supplementary material, which is available to authorized users.

The role of obesity in oesophageal cancer development

The incidence of oesophageal adenocarcinoma has increased dramatically in the developed world in the last half century. Over approximately the same period there has been an increase in the prevalence of obesity. Multiple epidemiological studies and meta-analyses have confirmed that obesity, especially abdominal, visceral obesity, is a risk factor for gastro-oesophageal reflux, Barrett's oesophagus and oesophageal adenocarcinoma. Although visceral obesity enhances gastro-oesophageal reflux, the available data also show that visceral obesity increases the risk of Barrett's oesophagus and adenocarcinoma via reflux-independent mechanisms. Several possible mechanisms could link obesity with the risk of oesophageal adenocarcinoma in addition to mechanical effects increasing reflux. These include reduced gastric Helicobacter pylori infection, altered intestinal microbiome, factors related to lifestyle, the metabolic syndrome and associated low-grade inflammation induced by obesity and the secretion of mediators by adipocytes which may directly influence the oesophageal epithelium. Of these adipocyte-derived mediators, increased leptin levels have been independently associated with progression to oesophageal adenocarcinoma and in laboratory studies leptin enhances malignant behaviours in cell lines. Adiponectin is also secreted by adipocytes and levels decline with obesity: decreased serum adiponectin levels are associated with malignant progression in Barrett's oesophagus and experimentally adiponectin exerts anticancer effects in Barrett's cell lines and inhibits growth factor signalling. At present there are no proven chemopreventative interventions that may reduce the incidence of obesity-associated oesophageal cancer: observational studies suggest that the combined use of a statin and aspirin or another cyclo-oxygenase inhibitor is associated with a significantly reduced cancer incidence in patients with Barrett's oesophagus.

Current strategies in chemoradiation for esophageal cancer

Chemoradiotherapy (CRT) has an important role in the treatment of esophageal cancer in both the inoperable and the pre-operative settings. Pre-operative chemoradiation therapy is generally given to 41.4-50.4 Gy with platinum or paclitaxel based chemotherapy. The most common definitive dose in the U.S. is 50-50.4 Gy. New advances in CRT for esophageal cancer have come from looking for ways to minimize toxicity and maximize efficacy. Recent investigations for minimizing toxicity have focused advanced radiation techniques such as IMRT and proton therapy, have sought to further define normal tissue tolerances, and have examined the use of tighter fields with less elective clinical target volume coverage. Efforts to maximize efficacy have included the use of early positron emission tomography (PET) response directed therapy, molecularly targeted therapies, and the use of tumor markers that predict response.

Intakes of folate, methionine, vitamin B6, and vitamin B12 with risk of esophageal and gastric cancer in a large cohort study

BACKGROUND

Nutrients in the one-carbon metabolism pathway may be involved in carcinogenesis. Few cohort studies have investigated the intakes of folate and related nutrients in relation to gastric and esophageal cancer.

METHODS

We prospectively examined the association between self-reported intakes of folate, methionine, vitamin B6, and vitamin B12 and gastric and esophageal cancer in 492,293 men and women.

RESULTS

We observed an elevated risk of esophageal squamous cell carcinoma with low intake of folate (relative risk (95% confidence interval): Q1 vs Q3, 1.91 (1.17, 3.10)), but no association with high intake. Folate intake was not associated with esophageal adenocarcinoma, gastric cardia adenocarcinoma, or non-cardia gastric adenocarcinoma. The intakes of methionine, vitamin B6, and vitamin B12 were not associated with esophageal and gastric cancer.

CONCLUSION

Low intake of folate was associated with increased risk of esophageal squamous cell carcinoma.

Procyanidin induces apoptosis of esophageal adenocarcinoma cells via JNK activation of c-Jun

Procyanidins are polymeric flavanols found in fruits and vegetables and have shown anticarcinogenic/chemopreventive properties. We previously showed that oligomeric procyanidin extracted from apples induced cell cycle arrest and apoptosis in esophageal adenocarcinoma (OA) cells. To understand the mechanism of action, we determined transcriptomic changes induced by procyanidin in OA cells. Pathway analysis implicated mitogen-activated protein kinase signaling pathways in eliciting these responses. Procyanidin induced the activation of JNK and p38 and the phosphorylation and expression of c-Jun. Inhibition of JNK but not p38 kinase activity prevented the procyanidin-induced phosphorylation and expression of c-Jun. Knockdown of the expression of JNK1, JNK2, or JUN diminished procyanidin-induced effects on cell proliferation and apoptosis. c-Jun is a component of the transcription factor AP-1 and AP-1 binding sites are overrepresented in the promoters of procyanidin-induced genes. This indicates that JNK activation of c-Jun by procyanidin leads to the induction of apoptosis of OA cells and suggests a role for a c-Jun-mediated transcriptional program. These data provide a mechanistic understanding of how procyanidin specifically targets a distinct pathway involved in the induction of apoptosis in OA cells and will inform future studies investigating its use as a chemopreventive/therapeutic agent.

Diet and lifestyle factors and risk of subtypes of esophageal and gastric cancers: classification tree analysis

PURPOSE

Although risk factors for squamous cell carcinoma of the esophagus and adenocarcinomas of the esophagus (EA), gastric cardia (GC), and other (noncardia) gastric (OG) sites have been identified, little is known about interactions among risk factors. We sought to examine interactions of diet, other lifestyle, and medical factors with risks of subtypes of esophageal and gastric cancers.

METHODS

We used classification tree analysis to analyze data from a population-based case-control study (1095 cases, 687 controls) conducted in Connecticut, New Jersey, and western Washington State.

RESULTS

Frequency of reported gastroesophageal reflux disease symptoms was the most important risk stratification factor for EA, GC, and OG, with dietary factors (EA, OG), smoking (EA, GC), wine intake (GC, OG), age (OG), and income (OG) appearing to modify the risk of these cancer sites. For esophageal squamous cell carcinoma, smoking was the most important risk stratification factor, with gastroesophageal reflux disease, income, race, noncitrus fruit, and energy intakes further modifying risk.

CONCLUSION

Various combinations of risk factors appear to interact to affect risk of each cancer subtype. Replication of these data mining analyses are required before suggesting causal pathways; however, the classification tree results are useful in partitioning risk and mapping multilevel interactions among risk variables.

The role of obesity in gastrointestinal cancer: evidence and opinion

There is increasing recognition of the impact of being overweight and obese on the development of cancers at diverse sites including the gastrointestinal tract. Large epidemiological studies indicate that up to 14% of tumours may be related to obesity. Pathophysiological mechanisms underpinning this association are not well understood and so are discussed in this review.

Carcinogenesis of Barrett's esophagus: a review of the clinical literature

Barrett's esophagus (BE) is a premalignant condition of esophageal adenocarcinoma (EAC). Although the incidence of BE has risen rapidly in the West, it is rare in Asia despite a recent increase in the prevalence of gastroesophageal reflux disease. Controversies over the definition of BE are presented because most cases show short-segment BE, especially ultra-short BE, in Asia. Here we review possible risk factors for the development of EAC, particularly possible roles of ethnicity, specialized intestinal metaplasia (SIM), BE length, and environmental factors, such as Helicobacter pylori infection and obesity. Additionally, we summarize recent studies on the effect of chemoprevention including proton pump inhibitors, nonsteroidal anti-inflammatory drugs or aspirin in order to reduce the risk of neoplastic progression in BE patients. Although substantial knowledge of risk factors of dysplasia/EAC in BE is shown, the risk for neoplastic development may be influenced by geographic variation, study population, the presence or absence of SIM or dysplasia at baseline, and the small number of BE patients investigated. Recently, the efficiency of surveillance for BE patients has been discussed from the standpoint of cost-effectiveness. It may be too difficult to draw conclusions because no randomized clinical trials of BE surveillance have been performed.

Locoregional failure rate after preoperative chemoradiation of esophageal adenocarcinoma and the outcomes of salvage strategies

PURPOSE

The primary purpose of surveillance of patients with esophageal adenocarcinoma (EAC) and/or esophagogastric junction adenocarcinoma after local therapy (eg, chemoradiotherapy followed by surgery or trimodality therapy [TMT]) is to implement a potentially beneficial salvage therapy to overcome possible morbidity/mortality caused by locoregional failure (LRF). However, the benefits of surveillance are not well understood. We report on LRFs and salvage strategies in a large cohort.

PATIENTS AND METHODS

Between 2000 and 2010, 518 patients with EAC who completed TMT were analyzed for the frequency of LRF over time and salvage therapy outcomes. Standard statistical techniques were used.

RESULTS

For 518 patients, the median follow-up time was 29.3 months (range, 1 to 149 months). Distant metastases (with or without LRF) occurred in 188 patients (36%), and LRF only occurred in 27 patients (5%). Eleven of 27 patients had lumen-only LRF. Most LRFs (89%) occurred within 36 months of surgery. Twelve patients had salvage chemoradiotherapy, but only five survived more than 2 years. Four patients needed salvage surgery, and three who survived more than 2 years developed distant metastases. The median overall survival of 27 patients with LRF was 17 months, and 10 patients (37%) survived more than 2 years. Thus, only 2% of all 518 patients benefited from surveillance/salvage strategies.

CONCLUSION

Our surveillance strategy, which is representative of many others currently being used, raises doubts about its effectiveness and benefits (along with concerns regarding types and times of studies and costs implications) to patients with EAC who have LRF only after TMT. Fortunately, LRFs are rare after TMT, but the salvage strategies are not highly beneficial. Our data can help develop an evidence-based surveillance strategy.

Dietary fiber and the risk of precancerous lesions and cancer of the esophagus: a systematic review and meta-analysis

Dietary fiber has several anticarcinogenic effects and is thought to be protective against esophageal cancer. The aim of this systematic review was to quantify the association between dietary fiber and the risk of esophageal cancer by investigating histological subtypes of esophageal cancer and the stage at which fiber may influence the carcinogenic pathway. Systematic search strategies were used to identify relevant studies, and adjusted odds ratios (ORs) were combined using random-effects meta-analyses to assess the risk of cancer when comparing extreme categories of fiber intake. Ten relevant case-control studies were identified within the timeframe searched. Pooled estimates from eight studies of esophageal adenocarcinoma revealed a significant inverse association with the highest fiber intakes (OR 0.66; 95% confidence interval [CI] 0.44-0.98). Two studies also identified protective effects of dietary fiber against Barrett's esophagus. Similar, though nonsignificant, associations were observed when results from five studies of fiber intake and risk of squamous cell carcinoma were combined (OR 0.61; 95%CI 0.31-1.20). Dietary fiber is associated with protective effects against esophageal carcinogenesis, most notably esophageal adenocarcinoma. Potential methods of action include modification of gastroesophageal reflux and/or weight control.

Minimally invasive esophagectomy is safe in patients with previous gastric bypass

BACKGROUND

The prevalence of morbid obesity in the United States has been steadily increasing, and there is an established relationship between obesity and the risk of developing certain cancers. Patients who have undergone prior gastric bypass (GB) and present with newly diagnosed esophageal cancer represent a new and challenging cohort for surgical resection of their disease. We present our case series of consecutive patients with previous GB who underwent minimally invasive esophagectomy (MIE).

METHODS

Retrospective review of consecutive patients with a history of GB who underwent a MIE for esophageal cancer between July 2010 and August 2012.

RESULTS

Five patients were identified with a mean age of 57 years. Mean follow-up was 9.1 months. Four patients had undergone laparoscopic GB, and 1 patient had an open GB. Two patients received neoadjuvant chemoradiation therapy for locally advanced disease. Minimally invasive procedures were thoracoscopic/laparoscopic esophagectomy with cervical anastomosis in 4 patients and colonic interposition in 1 patient. Mean operative time was 6 hours and 52 minutes. Median length of stay was 7 days. There was no mortality. Postoperative complications occurred in 3 patients and included pneumonia/respiratory failure, recurrent laryngeal nerve injury, and pyloric stenosis. All patients are alive and disease free at last follow-up.

CONCLUSIONS

Minimally invasive esophagectomy after prior GB is well tolerated, is technically feasible, and has acceptable oncologic and perioperative outcomes. We conclude that precise endoscopic evaluation before bariatric surgery in patients with gastroesophageal reflux disease is essential, as is the necessity for continuing postsurgical surveillance in patients with known Barrett's esophagitis and for early evaluation in patients who develop new symptoms of gastroesophageal reflux disease after bariatric surgery.

Meat, fish, and esophageal cancer risk: a systematic review and dose-response meta-analysis

Risk factors for esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are well defined, while the role of diet in these conditions remains controversial. To help elucidate the role of particular dietary components, major bibliographic databases were searched for published studies (1990-2011) on associations between esophageal cancer risk (EC) and consumption of various types of meat and fish. Random-effects models and dose-response meta-analyses were used to pool study results. Subgroup analyses were conducted by histological subtype, study design, and nationality. Four cohorts and 31 case-control studies were identified. The overall pooled relative risk (RR) of EC and the confidence intervals (CIs) for the groups with the highest versus the lowest levels of intake were as follows: 0.99 (95% CI: 0.85-1.15) for total meat; 1.40 (95%CI: 1.09-1.81) for red meat; 1.41 (95%CI: 1.13-1.76) for processed meat; 0.87 (95%CI: 0.60-1.24) for poultry; and 0.80 (95%CI: 0.64-1.00) for fish. People with the highest levels of red meat intake had a significantly increased risk of ESCC. Processed meat intake was associated with increased risk of EAC. These results suggest that low levels of red and processed meat consumption and higher levels of fish intake might reduce EC risk.

Screening and risk stratification for Barrett's esophagus: how to limit the clinical impact of the increasing incidence of esophageal adenocarcinoma

Barrett's esophagus (BE) and gastroesophageal reflux disease are the strongest risk factors for esophageal adenocarcinoma. To reduce the clinical impact of this disease, endoscopic screening to detect BE has been proposed and nonendoscopic diagnostic techniques are under investigation. Because screening would result in new diagnoses of BE and additional costs related to endoscopic surveillance, novel tools for risk stratification are also warranted. Dysplasia is the gold standard for risk stratification. Molecular biomarkers may provide a more objective and reproducible estimation of the individual risk, and further prospective studies are required as a prelude to introducing biomarkers into routine clinical practice.

Human papillomavirus (HPV) infection and the risk of esophageal squamous cell carcinoma

There is currently no consensus on the relationship between human papillomavirus (HPV) infection and the pathogenic process of esophageal squamous cell carcinoma (ESCC). Therefore, a retrospective study was performed to explore the association between HPV infection and ESCC, where 225 patients with diagnosed ESCC and 224 matched controls were enrolled in the study and stratified according to smoking and alcohol consumption. Enzyme-linked immunosorbent assay was used to determine seropositivity to HPV by the detection of either IgG or IgM anti-HPV antibodies. In the non-smoking and non-alcohol-consuming subgroup, the incidence of ESCC of HPV seropositive subjects was similar with that of HPV seronegative subjects (P= 0.737, odds ratio [OR] 1.14, 95% confidence interval [CI] 0.54-2.40). However, in the smoking subgroup, there was a significant difference in the incidence of ESCC between HPV seropositive subjects and HPV seronegative subjects (P= 0.009, OR 2.22, 95% CI 1.22-4.04). In addition, there was a significantly higher association of the development of ESCC in HPV seropositive patients that smoke and drink than those that do not (P < 0.001, OR 10.31, 95% CI 4.04-26.29). Therefore, HPV infection is not an independent risk factor for developing ESCC in the non-smoking and non-alcohol-consuming group. For smokers, however, HPV infection increases the risk of the incidence of ESCC.

Body mass index in relation to oesophageal and oesophagogastric junction adenocarcinomas: a pooled analysis from the International BEACON Consortium

BACKGROUND

Previous studies suggest an association between obesity and oesophageal (OA) and oesophagogastric junction adenocarcinomas (OGJA). However, these studies have been limited in their ability to assess whether the effects of obesity vary by gender or by the presence of gastro-oesophageal reflux (GERD) symptoms.

METHODS

Individual participant data from 12 epidemiological studies (8 North American, 3 European and 1 Australian) comprising 1997 OA cases, 1900 OGJA cases and 11 159 control subjects were pooled. Logistic regression was used to estimate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between body mass index (BMI, kg/m(2)) and the risk of OA and OGJA. Random-effects meta-analysis was used to combine these ORs. We also investigated effect modification and synergistic interaction of BMI with GERD symptoms and gender.

RESULTS

The association of OA and OGJA increased directly with increasing BMI (P for trend <0.001). Compared with individuals with a BMI <25, BMI ≥40 was associated with both OA (OR 4.76, 95% CI 2.96-7.66) and OGJA (OR 3.07, 95% CI 1.89-4.99). These associations were similar when stratified by gender and GERD symptoms. There was evidence for synergistic interaction between BMI and GERD symptoms in relation to OA/OGJA risk.

CONCLUSIONS

These data indicate that BMI is directly associated with OA and OGJA risk in both men and women and in those with and without GERD symptoms. Disentangling the relationship between BMI and GERD will be important for understanding preventive efforts for OA and OGJA.

Association of dietary fat intakes with risk of esophageal and gastric cancer in the NIH-AARP diet and health study

The aim of our study was to investigate whether intakes of total fat and fat subtypes were associated with esophageal adenocarcinoma (EAC), esophageal squamous cell carcinoma (ESCC), gastric cardia or gastric noncardia adenocarcinoma. From 1995-1996, dietary intake data was reported by 494,978 participants of the NIH-AARP cohort. The 630 EAC, 215 ESCC, 454 gastric cardia and 501 gastric noncardia adenocarcinomas accrued to the cohort. Cox proportional hazards regression was used to examine the association between the dietary fat intakes, whilst adjusting for potential confounders. Although apparent associations were observed in energy-adjusted models, multivariate adjustment attenuated results to null [e.g., EAC energy adjusted hazard ratio (HR) and 95% confidence interval (95% CI) 1.66 (1.27-2.18) p for trend <0.01; EAC multivariate adjusted HR (95% CI) 1.17 (0.84-1.64) p for trend = 0.58]. Similar patterns were also observed for fat subtypes [e.g., EAC saturated fat, energy adjusted HR (95% CI) 1.79 (1.37-2.33) p for trend <0.01; EAC saturated fat, multivariate adjusted HR (95% CI) 1.27 (0.91-1.78) p for trend = 0.28]. However, in multivariate models an inverse association for polyunsaturated fat (continuous) was seen for EAC in subjects with a body mass index (BMI) in the normal range (18.5-<25 kg/m(2)) [HR (95% CI) 0.76 (0.63-0.92)], that was not present in overweight subjects [HR (95% CI) 1.04 (0.96-1.14)], or in unstratified analysis [HR (95% CI) 0.97 (0.90-1.05)]. p for interaction = 0.02. Overall, we found null associations between the dietary fat intakes with esophageal or gastric cancer risk; although a protective effect of polyunsaturated fat intake was seen for EAC in subjects with a normal BMI.

The association between obesity factor and esophageal caner

Accumulating epidemiological studies have supported the link between increased body mass index, central obesity and esophageal adenocarcinoma. This association appears stronger than that for other types of obesity-related cancers. Central obesity or visceral fat, more often observed in men, is much more strongly associated with adenocarcinoma than body mass index alone, possibly contributing to the imbalance of disease occurrence between the sexes. Potential mechanisms underlying the association between obesity and esophageal adenocarcinoma have been recently identified, including the insulin-like growth factor pathway, adipokines and sex hormone disturbances. These findings are summarized in this review; however, more research is warranted before these mechanisms are conclusively established.

A meta-analysis of body mass index and esophageal and gastric cardia adenocarcinoma

BACKGROUND

The incidence rates of esophageal and gastric cardia adenocarcinoma (EGCA) have increased over recent years in several countries, and overweight/obesity has been suggested to play a major role in these trends. In fact, higher body mass index (BMI) has been positively associated with EGCA in several studies.

MATERIAL AND METHODS

We conducted a meta-analysis of case-control and cohort studies on the BMI and EGCA updated to March 2011. We estimated overall relative risks (RRs) and 95% confidence intervals (CI) for BMI between 25 and 30 and BMI ≥ 30 kg/m(2), when compared with normo-weight subjects, using random-effects models.

RESULTS

We identified 22 studies, including almost 8000 EGCA cases. The overall RR was 1.71 (95% CI 1.50-1.96) for BMI between 25 and 30, and was 2.34 (95% CI 1.95-2.81) for BMI ≥ 30 kg/m(2). The continuous RR for an increment of 5 kg/m(2) of BMI was 1.11 (95% CI 1.09-1.14). The association was stronger for esophageal adenocarcinoma (RR for BMI ≥ 30 kg/m(2) = 2.73, 95% CI 2.16-3.46) than for gastric cardia adenocarcinoma (RR for BMI ≥ 30 kg/m(2) = 1.93, 95% CI 1.52-2.45). No substantial differences emerged across strata of sex and geographic areas.

CONCLUSION

Overweight and obesity are strongly related to EGCA, particularly to espophageal adenocarcinoma.

Epidermal growth factor receptor expression in esophageal adenocarcinoma: relationship with tumor stage and survival after esophagectomy

Background and Aims. Esophageal adenocarcinoma (EA) is an aggressive tumor with increasing incidence in occidental countries. Several prognostic biomarkers have been proposed, including epidermal growth factor receptor (EGFR). The aim of this study was to assess whether EGFR expression predicts EA staging and patient survival. Methods. In this historical cohort, consecutive patients with EA managed between 2000 and 2010 were considered eligible for the study. Surgical specimens of patients treated with transhiatal esophagectomy were evaluated to establish EGFR expression and tumor differentiation. Staging was classified according with tumor-node-metastasis (TNM) system. Survival was determined according to either medical register or patient's family contact. Results. Thirty-seven patients who underwent esophagectomy without presurgical chemotherapy or radiotherapy were studied. EGFR expression was found in 16 patients (43%). EGFR expression was more frequent as higher was the TNM (I and II = 0% versus III = 47% versus IV = 100%; P < 0.001). Average survival in months was significantly shorter in the group of patients with EGFR expression (10.5 versus 21.7; P = 0.001). Conclusions. In patients with esophageal adenocarcinoma treated with transhiatal esophagectomy, EGFR expression was related to higher TNM staging and shorter survival. EGFR expression might be assumed as a prognostic marker for esophageal adenocarcinoma.

Failure patterns in patients with esophageal cancer treated with definitive chemoradiation

BACKGROUND

Local failure after definitive chemoradiation therapy for unresectable esophageal cancer remains problematic. Little is known about the failure pattern based on modern-day radiation treatment volumes. We hypothesized that most local failures would be within the gross tumor volume (GTV), where the bulk of the tumor burden resides.

METHODS

We reviewed treatment volumes for 239 patients who underwent definitive chemoradiation therapy and compared this information with failure patterns on follow-up positron emission tomography (PET). Failures were categorized as within the GTV, the larger clinical target volume (CTV, which encompasses microscopic disease), or the still larger planning target volume (PTV, which encompasses setup variability) or outside the radiation field.

RESULTS

At a median follow-up time of 52.6 months (95% confidence interval, 46.1-56.7 months), 119 patients (50%) had experienced local failure, 114 (48%) had distant failure, and 74 (31%) had no evidence of failure. Of all local failures, 107 (90%) were within the GTV, 27 (23%) were within the CTV, and 14 (12%) were within in the PTV. On multivariate analysis, GTV failure was associated with tumor status (T3/T4 vs T1/T2; odds ratio, 6.35; P = .002), change in standardized uptake value on PET before and after treatment (decrease >52%: odds ratio, 0.368; P = .003), and tumor size (>8 cm, 4.08; P = .009).

CONCLUSIONS

Most local failures after definitive chemoradiation for unresectable esophageal cancer occur in the GTV. Future therapeutic strategies should focus on enhancing local control.

Clinical implications of molecular changes in pediatric Barrett's esophagus

Barrett's esophagus (BE) is a preneoplastic condition that predisposes to esophageal adenocarcinoma. Although data on the occurrence of BE in children are limited, recent studies have suggested an increase in the pediatric population. BE is thought to be a complex disease in which individual genetic predisposition interacts with environmental stimuli. Early premalignant clones produce biological and genetic heterogeneity, resulting in stepwise changes in differentiation, proliferation, and apoptosis, allowing disease progression under selective pressure. The value of endoscopic surveillance biopsy for dysplasia and carcinoma in patients with BE is controversial. Thus, the recognition of early and objective alternative risk markers, less susceptible of sampling error, will be of relevance in the management of BE patients. The possibility of performing molecular genetics on paraffin-embedded biopsies will expand our understanding of the natural history of BE and may lead to the use of biomarkers to inform treatment strategies.

Tobacco smoking increases the risk of high-grade dysplasia and cancer among patients with Barrett's esophagus

BACKGROUND & AIMS

Esophageal adenocarcinoma arises from Barrett's esophagus (BE); patients with this cancer have a poor prognosis. Identification of modifiable lifestyle factors that affect the risk of progression from BE to esophageal adenocarcinoma might prevent its development. We investigated associations among body size, smoking, and alcohol use with progression of BE to neoplasia.

METHODS

We analyzed data from patients with BE identified from the population-based Northern Ireland BE register, diagnosed between 1993 and 2005 with specialized intestinal metaplasia (n = 3167). Data on clinical, demographic, and lifestyle factors related to diagnosis of BE were collected from hospital case notes. We used the Northern Ireland Cancer Registry to identify which of these patients later developed esophageal adenocarcinoma, adenocarcinomas of the gastric cardia, or esophageal high-grade dysplasia. Cox proportional hazards models were used to associate lifestyle factors with risk of progression.

RESULTS

By December 31, 2008, 117 of the patients with BE developed esophageal high-grade dysplasia or adenocarcinomas of the esophagus or gastric cardia. Current tobacco smoking was significantly associated with an increased risk of progression (hazard ratio = 2.03; 95% confidence interval, 1.29-3.17) compared with never smoking, and across all strata of smoking intensity. Alcohol consumption was not related to risk of progression. Measures of body size were infrequently reported in endoscopy reports, and body size was not associated with risk of progression.

CONCLUSIONS

Smoking tobacco increases the risk of progression to cancer or high-grade dysplasia 2-fold among patients with BE, compared with patients with BE that have never smoked. Smoking cessation strategies should be considered for patients with BE.