Nonsteroidal anti-inflammatory drug use associated with reduced incidence of adenocarcinomas of the esophagus and gastric cardia that overexpress cyclin D1: a population-based study

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.

Diagnosis and Management of Barrett's Esophagus: An Updated ACG Guideline

Barrett's esophagus (BE) is a common condition associated with chronic gastroesophageal reflux disease. BE is the only known precursor to esophageal adenocarcinoma, a highly lethal cancer with an increasing incidence over the last 5 decades. These revised guidelines implement Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the definition and diagnosis of BE, screening for BE and esophageal adenocarcinoma, surveillance of patients with known BE, and the medical and endoscopic treatment of BE and its associated early neoplasia. Important changes since the previous iteration of this guideline include a broadening of acceptable screening modalities for BE to include nonendoscopic methods, liberalized intervals for surveillance of short-segment BE, and volume criteria for endoscopic therapy centers for BE. We recommend endoscopic eradication therapy for patients with BE and high-grade dysplasia and those with BE and low-grade dysplasia. We propose structured surveillance intervals for patients with dysplastic BE after successful ablation based on the baseline degree of dysplasia. We could not make recommendations regarding chemoprevention or use of biomarkers in routine practice due to insufficient data.

Prevention Strategies for Esophageal Cancer-An Expert Review

Simple Summary

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

Abstract

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

Inhibition of the development of N-nitrosomethylbenzylamine-induced esophageal tumors in rats by strawberries and aspirin, alone and in combination

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of two subtypes of esophageal cancer, with high incidence and mortality rates in developing countries.

OBJECTIVE

The current study investigated the potential chemoprotective effects of strawberries and aspirin against the development of rat esophageal papillomas, the precursors to ESCC.

METHODS

Using a prevention model, we administered study diets to rats before, during, and after N-nitrosomethylbenzylamine (NMBA) treatment. The effects of the four diets were evaluated: the control diet, 5% strawberry powder in the control diet, 0.01% aspirin in the drinking water, and the combination of strawberries and aspirin. At week 25, we euthanized all the rats and collected their esophagi to quantify tumor incidence, multiplicity, and burden, as well as for molecular analysis.

RESULTS

Both strawberries and aspirin significantly decreased esophageal tumor multiplicity, with the combination causing the most robust suppression. Aspirin alone and the combination decreased the total tumor burden in the esophagus. None of the diets had a significant effect on tumor incidence or the expression of COX-1 and COX-2. Strawberries and aspirin, alone and in combination, significantly suppressed squamous epithelial cell proliferation (PCNA).

CONCLUSIONS

Strawberries, aspirin, and their combination exhibit chemoprotective effects against NMBA-induced esophageal tumors in rats.

Screening and Preventive Strategies in Esophagogastric Cancer

Gastric adenocarcinoma, esophageal adenocarcinoma, and esophageal squamous cell carcinoma are among the most prevalent and deadly of malignancies worldwide. Screening and prevention programs will be critical to finally improving outcomes in these diseases. For gastric adenocarcinoma, screening in high-risk populations has significantly reduced mortality. More research is needed on screening high-risk individuals in low-risk populations. For esophageal adenocarcinoma, work is needed to develop efficient and effective techniques in mass screening programs. For most Western populations, current screening is not cost effective. Avoiding environmental risk factors is critical to reducing the incidence of this deadly illness.

The Effects of Anti-inflammatory Drug Treatment in Gastric Cancer Prevention: an Update of a Meta-analysis

Gastric cancer has high incidence and fatality rates, making chemoprevention agents necessary. There is an ongoing debate about aspirin/nonsteroidal anti-inflammatory drugs (NSAIDs) use can significant reduce the risk of GC. We conducted a meta-analysis of existing studies evaluating the association of anti-inflammatory drug and GC. We performed a systematic literature search of PubMed, Web of Science, Embase, OVID, Cochrane Library and Clincialtrials.gov up to August 31, 2015. Either a fixed-effects or a random-effects model using was based on the result of homogeneity analysis. Subgroup, sensitivity, meta-regression, and publication bias analyses were evaluated. Forty-seven studies were finally included in this meta-analysis. The overall GC risk reduction benefit associated with anti-inflammatory drug use represented an RR of 0.78 (95% CI 0.71 to 0.85) and an adjusted RR of 0.74 (95% CI 0.71 to 0.77). Besides, the prevention benefit of aspirin/NSAIDs ingestion appeared to be confined to those patients with regiment of short or middle-term (≤5 years), high-frequency (>30 times per month) and low dose (<200 mg per day). Further, our data also suggest that COX-2 inhibitors use is a more effective approach in GC prevention (RR, 0.45; 95% CI, 0.29-0.70). In this meta-analysis, our finding support short or middle-term (≤5 years), high-frequency (>30 times per month) and low dose (<200 mg per day) aspirin/NSAIDs intake is a well method for GC prevention and also confirm the inverse association between aspirin/NSAIDs use and GC risk. Additionally, selective COX-2 inhibitors use probably a more effective approach to reduce GC risk.

ACG Clinical Guideline: Diagnosis and Management of Barrett's Esophagus

Barrett's esophagus (BE) is among the most common conditions encountered by the gastroenterologist. In this document, the American College of Gastroenterology updates its guidance for the best practices in caring for these patients. These guidelines continue to endorse screening of high-risk patients for BE; however, routine screening is limited to men with reflux symptoms and multiple other risk factors. Acknowledging recent data on the low risk of malignant progression in patients with nondysplastic BE, endoscopic surveillance intervals are attenuated in this population; patients with nondysplastic BE should undergo endoscopic surveillance no more frequently than every 3-5 years. Neither routine use of biomarker panels nor advanced endoscopic imaging techniques (beyond high-definition endoscopy) is recommended at this time. Endoscopic ablative therapy is recommended for patients with BE and high-grade dysplasia, as well as T1a esophageal adenocarcinoma. Based on recent level 1 evidence, endoscopic ablative therapy is also recommended for patients with BE and low-grade dysplasia, although endoscopic surveillance continues to be an acceptable alternative. Given the relatively common recurrence of BE after ablation, we suggest postablation endoscopic surveillance intervals. Although many of the recommendations provided are based on weak evidence or expert opinion, this document provides a pragmatic framework for the care of the patient with BE.

Cyclooxygenase-2 expression is associated with poor overall survival of patients with gastric cancer: a meta-analysis

BACKGROUND

Cyclooxygenase-2 (COX-2) is believed to be involved in gastric carcinogenesis. However, it is still controversial whether COX-2 expression can be regarded as a prognostic factor for gastric cancer patients.

AIM

To obtain a more accurate relationship between COX-2 overexpression and prognosis in gastric cancer by meta-analysis.

METHOD

Relevant articles published up to May 2013 were searched by use of several keywords in electronic databases. Separate hazard ratio (HR) estimates and 95 % confidence intervals (95 % CI) for COX-2 overexpression and overall survival (OS) and disease-free survival (DFS) with gastric cancer were extracted. Combined HR with 95 % CI was calculated by use of Stata11.0 software to estimate the size of the effect. Publication bias testing and sensitivity analysis were also performed.

RESULTS

A total of 27 studies which included 3,891 gastric cancer patients were combined in the final analysis. Combined results suggested that COX-2 overexpression was associated with an unfavorable OS (HR 1.58, 95 % CI 1.36-1.84) but not DFS (HR 1.15, 95 % CI 0.93-1.43) among patients with gastric cancer. Publication bias was absent. Sensitivity analysis suggested that the results of this meta-analysis were robust.

CONCLUSIONS

The results of this meta-analysis suggest that high COX-2 expression may be an independent risk factor for poor OS of patients with gastric cancer. More large prospective studies are now needed to further clarify the prognostic value of COX-2 expression for DFS in gastric cancer.

Role of aspirin in chemoprevention of esophageal adenocarcinoma: a meta-analysis

OBJECTIVE

To identify whether regular aspirin use protects against esophageal adenocarcinoma (EA) and if so, the effect of the duration and frequency of drug exposure.

METHODS

Studies were selected from five journal/trial databases based on defined inclusion and exclusion criteria; most notably, the provision of multivariate EA odds ratios (ORs) in those taking regular aspirin. A subgroup analysis was then performed by stratifying the results according to the frequency and duration of aspirin use. The reliability of these investigations was assessed by calculating study heterogeneity and observing any elements of publication bias.

RESULTS

Nine studies were selected for the main analysis, of which five were included in the frequency analysis and three assessed the duration of aspirin use. Data pooling revealed a statistically significant EA OR of 0.671 (95% CI 0.526-0.856, P = 0.001) among all aspirin users, suggesting a protective effect. The results for duration and frequency did not reach statistical significance but nonetheless suggested possible benefits of longer, more frequent drug regimens that may be statistically confirmed by studies of larger sample sizes. Funnel plots and statistical tests demonstrated a minimal impact of publication bias on our results.

CONCLUSION

Aspirin use confers a significant protective effect against EA with a suggestion that the degree of protection may be increased by the longer duration and higher frequency of usage.

Nonsteroidal anti-inflammatory drug use reduces risk of adenocarcinomas of the esophagus and esophagogastric junction in a pooled analysis

BACKGROUND & AIMS

Regular use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) has been reported to reduce risks of esophageal adenocarcinoma (EAC) and esophagogastric junctional adenocarcinoma (EGJA). However, individual studies have been too small to accurately assess the effects of medication type, frequency, or duration of use. We performed a pooled analysis to investigate these associations.

METHODS

We performed a pooled analysis of 6 population-based studies within the Barrett's and Esophageal Adenocarcinoma Consortium to evaluate the association between NSAID use and the risk of EAC and EGJA, using uniform exposure definitions. We collected information from 6 studies (5 case-control and 1 cohort), with a total of 1226 EAC and 1140 EGJA cases, on aspirin and/or NSAID use. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariate adjusted logistic regression models and then pooled using a random effects meta-analysis model.

RESULTS

Compared with nonusers, individuals who have used NSAIDs had a statistically significant reduced risk of EAC (OR, 0.68; 95% CI, 0.56-0.83); they also appeared to have a reduced risk of EGJA (OR, 0.83; 95% CI, 0.66-1.03). Similar reductions in risk were observed among individuals who took aspirin or nonaspirin NSAIDs. The highest levels of frequency (daily or more frequently) and duration (≥10 years) of NSAID use were associated with an approximately 40% reduction in risk of EAC, with ORs of 0.56 (95% CI, 0.43-0.73; P(trend) < .001) and 0.63 (95% CI, 0.45-0.90; P(trend) = .04), respectively.

CONCLUSIONS

Although reverse causation could, in part, explain the inverse association observed between NSAID use and EAC risk, our pooled analysis suggests a possible role for NSAIDs in prevention of adenocarcinomas of the esophagus and esophagogastric junction.

Chemoprevention of esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) is rising rapidly in Western countries, and effective chemoprevention for this malignancy is lacking. Endoscopic surveillance of patients with Barrett's esophagus is currently employed to diagnose EAC at earlier stages, but this strategy has several limitations. Non-steroidal anti-inflammatory drugs and proton pump inhibitors are the most promising agents for prevention of EAC, and a randomized controlled trial of aspirin and esomeprazole is ongoing. Other agents under investigation include green tea, berries, and antioxidants. Cost-effectiveness analyses have shown that chemopreventive agents need to be highly effective at preventing EAC in order to have benefit beyond endoscopic surveillance.

Meta-analysis on the relationship between nonsteroidal anti-inflammatory drug use and gastric cancer

Although nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, show chemopreventive effects on several types of cancer, their role in the development of gastric cancer remains controversial. The objective of this study is to assess the quantitative association between NSAIDs and gastric cancer by meta-analysis using both crude data and adjusted data. A search of Medline, Embase, Web of science, and citations from relevant articles was conducted for eligible articles published up to March 2009. A meta-analysis was developed. Pooled risk ratio and odds ratio with 95% confidence intervals were calculated, based on both crude and adjusted data from the selected studies and using random or fixed effects models based on heterogeneity analysis. Overall, 21 individual epidemiological studies (13 case-control studies with 29 560 participants and 8 cohort studies with 2 199 227 participants) were examined. The summary crude and adjusted risk ratios were 0.89 (0.83-0.97) and 0.81 (0.73-0.89) when the case-control and cohort studies were pooled, respectively. Significant protective effects of NSAIDs against gastric cancer appeared in all subgroups (study design, type of drug, site of cancer, and sample source), but only the site of cancer and sample source can substantially influence the estimate of effect. The chemopreventive effect of NSAIDs in gastric cancer was stronger based on the adjusted data than that based on crude data. Therefore, we conclude that NSAID use is associated with a decrease in the development of gastric cancer. The associations were more obvious after we adjusted for several risk factors that are known to contribute to the development of gastric cancer.

Epidemiology of adenocarcinoma of the esophagus, gastric cardia, and upper gastric third

The incidence of adenocarcinoma of the esophagus and esophagogastric junction (gastric cardia) has risen rapidly over the past three decades in the United States and northern Europe. This increase had been most dramatic among White males. The majority of these cancers arise from Barrett's esophagus. However, less than 10% of the patients with esophageal adenocarcinoma were known to have Barrett's esophagus before. Current evidence indicates that gastroesophageal reflux and obesity are major risk factors for adenocarcinoma of the esophagus. Abdominal obesity, more prevalent in males, and independent of body mass index, seems to be associated with an increased risk of esophageal adenocarcinoma but not of cardia adenocarcinoma. This observation may explain the high male:female ratio observed in esophageal adenocarcinoma. Tobacco use has also been found as a possible risk factor for adenocarcinoma of the esophagus and gastric cardia. Infection with Helicobacter pylori and the use of nonsteroidal anti-inflammatory drugs might reduce the risk. On the other hand, low intake of fruits, vegetables, and cereal fibers seem to increase the risk of esophageal adenocarcinoma. Currently, there is no evidence that strongly supports any specific strategy to screen a subgroup of the population at risk for adenocarcinoma of the esophagus or esophagogastric junction. Future strategies to decrease obesity and tobacco use might help to reduce the burden of esophageal adenocarcinoma at least partially.

Combinatorial chemoprevention reveals a novel smoothened-independent role of GLI1 in esophageal carcinogenesis

Reflux-induced injury promotes esophageal adenocarcinoma, one of the most rapidly increasing, highly lethal cancers in Western countries. Here, we investigate the efficacy of a combinatorial chemoprevention strategy for esophageal adenocarcinoma and characterize the underlying molecular mechanisms. Specifically, our approach involves the use of ursodeoxycholic acid (Urso) due to its ability to decrease injury-inducing bile salts in combination with Aspirin to mitigate the consequences of injury. We find that Urso-Aspirin combination reduces the risk of adenocarcinoma in vivo in animals with reflux, decreases the proliferation of esophageal adenocarcinoma cells, and downregulates a key cell cycle regulator, CDK2. Mechanistically, using cell growth, luciferase reporter, expression, and chromatin immunoprecipitation assays, we identify GLI1, a Hedgehog-regulated transcription factor, as a novel target of Urso-Aspirin combination. We show that GLI1 is upregulated during esophageal carcinogenesis, and GLI1 can bind to the CDK2 promoter and activate its expression. Although the Urso-Aspirin combination downregulates GLI1, the GLI1 overexpression not only abrogates the effect of this combination on proliferation but it also restores CDK-2 expression. These findings support that the chemopreventive effect of the Urso-Aspirin combination occurs, at least in part, through a novel GLI1-CDK2-dependent mechanism. To further understand the regulation of CDK2 by GLI1, both pharmacologic and RNAi-mediated approaches show that GLI1 is a transcriptional activator of CDK2, and this regulation occurs independent of Smoothened, the central transducer of the Hedgehog canonical pathway. Collectively, these results identify a novel GLI1-to-CDK2 pathway in esophageal carcinogenesis, which is a bona fide target for effective combinatorial chemoprevention with Urso and Aspirin.

Aspirin use and the risk of gastric cancer: a meta-analysis

PURPOSE

Studies investigating the association between aspirin use and gastric cancer risk have reported conflicting results. The objective of this study was to quantitatively summarize the evidence for such a relationship.

RESULTS

Two investigators independently searched the Medline, PubMed, Embase, and Academic Search Premier (EBSCO) databases. Fourteen studies with a total number of 5,640 gastric cancer cases were identified. Most of the study populations were Caucasian. The combined results based on all studies showed there was no statistically significant difference between aspirin use and gastric cancer risk (odds ratio (OR) = 0.80, 95% confidence intervals (CI) = 0.54-1.19). When stratifying by study designs and gender, results were similar except for cohort and randomized controlled trial (RCT) studies (OR = 0.72, 95% CI = 0.62-0.84). When stratifying by location and Helicobacter pylori (H. pylori) infection, we observed there were lower risks in noncardia gastric cancer (OR = 0.62, 95% CI = 0.55-0.69) and H. pylori-infected individuals (OR = 0.62, 95% CI = 0.42-0.90) for aspirin users. Among Caucasians, there were lower risks for noncardia gastric cancer (OR = 0.73, 95% CI = 0.62-0.87) and H. pylori-infected individuals (OR = 0.62, 95% CI = 0.42-0.90) also.

CONCLUSIONS

This meta-analysis indicated that regular use of aspirin may be associated with reduced risk of noncardia gastric cancer, especially among Caucasians; for H. pylori-infected subjects the result was similar.

Distinct role of Kruppel-like factor 11 in the regulation of prostaglandin E2 biosynthesis

Kruppel-like factor (KLF) proteins are emerging as key regulators of lipid metabolism, diabetes, and the biosynthesis of immunological cytokines. However, their role in the synthesis of prostaglandins, widely known biochemical mediators that act in a myriad of cell biological processes remain poorly understood. Consequently, in this study a comprehensive investigation at the cellular, biochemical, and molecular levels reveal that KLF11 inhibits prostaglandin E(2) synthesis via transcriptional silencing of the promoter of its biosynthetic enzyme, cytosolic phospholipase A2alpha. Mechanistically, KLF11 accomplishes this function by binding to the promoter via specific GC-rich sites and recruiting the Sin3-histone deacetylase chromatin remodeling complex. Further functional characterization reveals that this function of KLF11 can be reversed by epidermal growth factor receptor-AKT-mediated post-translational modification of threonine 56, a residue within its Sin3-binding domain. This is the first evidence supporting a relevant role for any KLF protein in doing both: transcriptionally inhibiting prostaglandin biosynthesis and its reversibility by an epidermal growth factor receptor-AKT signaling-mediated posttranslational mechanisms.

Urinary prostaglandin E2 metabolite and gastric cancer risk in the Shanghai women's health study

Chronic inflammation has been implicated in the etiology of gastric cancer. Prostaglandin E(2) (PGE(2)) is one of the major end-products of the cyclooxygenase-2 pathway, an enzyme that is an important mediator of inflammation. Using a novel method of quantifying the primary urinary metabolite of PGE(2) (PGE-M; 11alpha-hydroxy-9,15-dioxo-2,3,4,5-tetranorprostane-1,20-dioic acid), we evaluated urinary PGE-M concentrations in association with subsequent risk of development of gastric cancer in the Shanghai Women's Health Study, a large population-based prospective cohort, using a nested case-control study design. Controls were matched (1:1) to 153 gastric cancer cases by menopausal status; age, time, and date of sample collection; time interval since last meal; and availability of urine sample. Odds ratios (95% confidence intervals) were calculated using conditional logistic regression adjusted for potential confounders. Baseline urinary PGE-M levels were slightly higher among gastric cancer cases with a median of 6.4 ng/mg creatinine (interquartile range, 3.4-11.2) compared with 5.4 ng/mg creatinine among controls (interquartile range, 2.8-9.0), but this difference was not statistically significant (P = 0.34, Wilcoxon). With increasing quartiles of urinary PGE-M levels, the odds ratios (95% confidence intervals) for risk of gastric cancer increased in quartiles 2 to 4: 1.00 (0.48-2.08), 1.40 (0.67-2.91), and 1.98 (0.95-4.13), with a statistically significant test for trend (P = 0.04). The association persisted after additional adjustment for Helicobacter pylori status and was slightly strengthened among non-nonsteroidal anti-inflammatory drug users, subjects with positive H. pylori status, and for cases diagnosed within 46 months after study enrollment. Our findings suggest that higher levels of urinary PGE-M, a marker of inflammation, may be associated with gastric cancer risk.

Cigarette smoking, body mass index, gastro-esophageal reflux disease, and non-steroidal anti-inflammatory drug use and risk of subtypes of esophageal and gastric cancers by P53 overexpression

A number of risk factors for esophageal and gastric cancers have emerged, yet little is known whether risk factors map to molecular tumor markers such as overexpression of the tumor suppressor TP53. Using a US multicenter, population-based case-control study (170 cases of esophageal adenocarcinomas, 147 gastric cardia adenocarcinomas, 220 non-cardia gastric adenocarcinomas, and 112 esophageal squamous cell carcinomas), we examined whether the risk associated with cigarette smoking, body mass index (BMI), gastroesophageal reflux disease (GERD), and non-steroidal anti-inflammatory drug (NSAID) use varied by P53 overexpression. We defined P53 overexpression through immunohistochemistry of paraffin-embedded tumor tissues, using cutpoints based on percent of cells positive. Polytomous logistic regression was used to assess differences between each case group (defined by tumor subtype and P53 expression) and the control group by risk factors. The proportion of cases overexpressing P53 by tumor subtype was 72% for esophageal adenocarcinoma, 69% for gastric cardia adenocarcinoma, 52% for non-cardia gastric adenocarcinoma, and 67% for esophageal squamous cell carcinoma. For most tumor subtypes, we found little difference in risk factors by tumor P53 overexpression. For non-cardia gastric cancer however, an association with cigarette smoking was suggested for tumors that do not overexpress P53, whereas larger BMI was related to adenocarcinomas that overexpress P53 versus no overexpression. Overall, this study did not find a clear relationship between P53 protein overexpression and the known risk factors for subtypes of esophageal and gastric cancers. Further research on these tumors is needed to identify molecular markers associated with variations in the risk factor profiles.

Nonsteroidal anti-inflammatory drugs and risk of esophageal and gastric adenocarcinomas in Los Angeles County

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) use has been associated with a reduced risk of colon cancer; further epidemiologic data appear consistent for stomach and esophageal adenocarcinomas. Yet, data on potential confounding effects by upper gastrointestinal tract (UGI) disorders on adenocarcinomas of the UGI are limited.

METHODS

This study recruited newly diagnosed patients with esophageal adenocarcinoma (n = 220), gastric cardia adenocarcinoma (n = 277), or distal gastric adenocarcinoma (n = 441) as well as 1,356 control subjects in Los Angeles County. Unconditional multivariable logistic regression analyses were done to evaluate the association between regular NSAID use, at least two pills per week for 1 month, and these cancers.

RESULTS

Duration of regular use of aspirin and non-aspirin NSAIDs was associated with reduced relative odds of distal gastric adenocarcinoma [>5 years use versus no regular use: odds ratio (OR), 0.61; 95% confidence interval, 0.40-0.92; P(trend) = 0.009] and esophageal adenocarcinoma (OR, 0.60; 95% confidence interval, 0.38-0.95; P(trend) = 0.04) in multivariable models that included history of UGI disorders and other potential confounding factors. Daily regular use was also associated with statistically significant reduced ORs of these two tumor types. No significant heterogeneity in risk estimates was noted after stratification by history of UGI disorders for any of the sites studied. However, irregular users of NSAIDs also had reduced risk of these cancers when compared with nonusers.

CONCLUSIONS

Results from this study support an inverse association between regular NSAID use and risk of esophageal and distal gastric adenocarcinomas in individuals with and without a history of UGI disorders with long duration and daily use, providing the greatest risk reduction. Reduced risk in irregular users suggests that factors other than an effect on cyclooxygenase may also be important.

Clinical significance of prostaglandin E synthase expression in gastric cancer tissue

Studies have linked microsomal prostaglandin E synthase (mPGES)-1 with gastric cancer. The purpose of this study was to determine mPGES-1, mPGES-2, and cytosolic PGES (cPGES) expression in gastric cancer and to evaluate the correlation between mPGES-1 and mPGES-2 expression and clinicopathological factors and cyclooxygenase-2 expression. PGES protein expression was examined by Western blot in gastric cancer cell lines and in biopsy samples from patients with gastric cancer. mPGES-1, mPGES-2, and cPGES protein localizations were examined immunohistochemically in 129 archival gastric cancer surgical resections. mPGES-1 protein expression was found in gastric cancer biopsies and cancer cell lines with differentiated or undifferentiated adenocarcinoma. There was no mPGES-1 expression in nonneoplastic biopsies. All cell lines and tissue samples expressed mPGES-2 and cPGES. Immunohistochemical analysis showed cancer cells expressed mPGES-1 in 47% of cases. mPGES-2 immunoreactivity was seen both in nonneoplastic glandular epithelium and cancer cells; however, cancer cell immunoreactivity was significantly more pronounced in 29% of cases. cPGES expression was constitutive both in nonneoplastic and neoplastic tissues, with no significant variation among cases. mPGES-1 and mPGES-2 expression correlated with cyclooxygenase-2 expression. mPGES-1 and mPGES-2 expression, and tumor-node-metastasis stage had independent prognostic significance under multivariate analysis in patients with gastric cancer overall and in patients with differentiated cancers. However, only tumor-node-metastasis stage and mPGES-2 expression retained independent prognostic significance in patients with poorly differentiated cancers. mPGES-1 and mPGES-2 correlate with clinicopathological factors and may be valuable prognostic factors in gastric cancer.

Cyclooxygenase-2 (cox-2) and the inflammogenesis of cancer

Cohesive scientific evidence from molecular, animal, and human investigations supports the hypothesis that aberrant induction of COX-2 and up-regulation of the prostaglandin cascade play a significant role in carcinogenesis, and reciprocally, blockade of the process has strong potential for cancer prevention and therapy. Supporting evidence includes the following: [1] expression of constitutive COX-2-catalyzed prostaglandin biosynthesis is induced by most cancer-causing agents including tobacco smoke and its components (polycylic aromatic amines, heterocyclic amines, nitrosamines), essential polyunsaturated fatty acids (unconjugated linoleic acid), mitogens, growth factors, proinflammatory cytokines, microbial agents, tumor promoters, and other epigenetic factors, [2] COX-2 expression is a characteristic feature of all premalignant neoplasms, [3] COX-2 expression is a characteristic feature of all malignant neoplasms, and expression intensifies with stage at detection and cancer progression and metastasis, [4] all essential features of carcinogenesis (mutagenesis, mitogenesis, angiogenesis, reduced apoptosis, metastasis, and immunosuppression) are linked to COX-2-driven prostaglandin (PGE-2) biosynthesis, [5] animal studies show that COX-2 up-regulation (in the absence of genetic mutations) is sufficient to stimulate the transformation of normal cells to invasive cancer and metastatic disease, [6] non-selective COX-2 inhibitors, such as aspirin and ibuprofen, reduce the risk of human cancer and precancerous lesions, and [7] selective COX-2 inhibitors, such as celecoxib, reduce the risk of human cancer and precancerous lesions at all anatomic sites thus far investigated. Results confirming that COX-2 blockade is effective for both cancer prevention and therapy have been tempered by observations that some COX2 inhibitors pose a risk to the cardiovascular system, and more studies are needed in order to determine if certain of these drugs can be taken at dosages that prevent cancer without increasing cardiovascular risk. It is emphasized that the "inflammogenesis model of cancer" is not mutually exclusive and may in fact be synergistic with the accumulation of somatic mutations in tumor suppressor genes and oncogenes or epigenetic factors in the development of cancer.

Trends in the incidence of adenocarcinoma of the oesophagus and cardia in the Netherlands 1989-2003

Over the 15-year period 1989–2003, the incidence of oesophagus–cardia adenocarcinoma in the Netherlands rose annually by 2.6% for males and 1.2% for females. This was the net outcome of annual increases in the incidence of adenocarcinoma of the oesophagus (ACO) of 7.2% for males and 3.5% for females and annual declines in the incidence of adenocarcinoma of the gastric cardia (AGC) of more than 1% for both genders. Nonlinear cohort patterns were found in females with ACO and for both genders in AGC; a nonlinear period pattern was observed only in males with AGC. These differing epidemiological patterns for ACO and AGC do not support a common aetiology. Proposed underlying factors for the rise in ACO incidence appear to have little effect on AGC incidence. This and the secular decline in smoking among males may have led to the decline in AGC incidence.

Association of common polymorphisms in inflammatory genes with risk of developing cancers of the upper aerodigestive tract

OBJECTIVES

The purpose of this study was to investigate the role of polymorphisms of genes involved in inflammation in the risk of cancers of the upper aerodigestive tract (UADT).

METHODS

We have evaluated the role of polymorphisms in key genes related to inflammation, namely IL1B (rs1143627), COX2/PTGS2 (rs5275), and IL8 (rs4073) in a large case-control study comprising 811 UADT cancer cases and 1,083 controls.

RESULTS

An association was observed for squamous cell carcinoma of the pharynx for a polymorphism in the promoter of the IL1B gene, with an OR of 2.39 (95% CI = 1.19-4.81) for the homozygotes for the minor allele A promoter polymorphism of IL8 was associated with decreased risk of laryngeal cancer, with an OR of 0.70 (95% CI = 0.50-0.98) for carriers of the minor allele.

CONCLUSIONS

To our knowledge, this is the first report on the role of these polymorphisms with respect to UADT carcinogenesis. Our results suggest that inflammation-related polymorphisms play a role, albeit minor, in the risk of developing cancers of the upper aerodigestive tract.

Nonsteroidal anti-inflammatory drugs and the esophageal inflammation-metaplasia-adenocarcinoma sequence

Observational studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of esophageal adenocarcinoma, but it is not known at what stage they may act in the esophageal inflammation-metaplasia-adenocarcinoma sequence. In an all-Ireland case-control study, we investigated the relationship between the use of NSAIDs and risk of reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. Patients with esophageal adenocarcinoma, long-segment Barrett's esophagus and population controls were recruited from throughout Ireland. Esophagitis patients were recruited from Northern Ireland only. Data were collected on known and potential risk factors for esophageal adenocarcinoma and on the use of NSAIDs, including aspirin, at least 1 year before interview. Associations between use of NSAIDs and the stages of the esophageal inflammation-metaplasia-adenocarcinoma sequence were estimated by multiple logistic regression. In total, 230 reflux esophagitis, 224 Barrett's esophagus, and 227 esophageal adenocarcinoma and 260 population controls were recruited. Use of aspirin and NSAIDs was associated with a reduced risk of Barrett's esophagus [odds ratio [OR; 95% confidence interval (95% CI)], 0.53 (0.31-0.90) and 0.40 (0.19-0.81), respectively] and esophageal adenocarcinoma [OR (95% CI), 0.57 (0.36-0.93) and 0.58 (0.31-1.08), respectively]. Barrett's esophagus and esophageal adenocarcinoma patients were less likely than controls to have used NSAIDs. Selection or recall bias may explain these results and the results of previous observational studies indicating a protective effect of NSAIDs against esophageal adenocarcinoma. If NSAIDs have a true protective effect on the esophageal inflammation-metaplasia-adenocarcinoma sequence, they may act early in the sequence.

p27 downregulation and metallothionein overexpression in gastric cancer patients are associated with a poor survival rate

BACKGROUND AND OBJECTIVES

As a significant number of curatively treated gastric cancer patients will ultimately relapse, there is an urgent need to investigate new prognostic markers for identification of high-risk patients. In this study, we investigated the possible role of molecular markers involved in cell cycle regulation (B1 and D3 cyclins, and p27) and cell protection (metallothionein, MT) in predicting tumor behavior and clinical outcome in gastric cancer patients.

METHODS

Analysis of the above indicators was performed by immunohistochemistry on 73 gastric cancer patient samples and 25 normal gastric mucosa specimens.

RESULTS

Normal gastric mucosa cells displayed low expressions of B1 and D3 cyclins and MT, and intense p27 staining. Conversely, gastric tumor cells showed higher cyclin D3 and MT, and lower p27 expressions. B1 cyclin expressions were not different between normal and tumor tissue. p27 and MT expressions were altered in almost all cancer samples, and were strongly correlated with tumor progression. Advanced extent of the primary tumor, nodal metastasis, low p27, and high MT expressions were the best combination of variables for prediction of poor clinical outcome. Each marker predicted outcome better than staging based on tumor-node (TNM) system. Survival and recurrence rates decreased as molecular alterations increased. Finally, molecular profile determination correctly predicted the prognosis in patients with same TNM stage.

CONCLUSIONS

p27 and MT expressions strongly correlated with clinical outcome allowing to identify an unfavorable group of patients that may benefit from tailored treatments. The role of B1 and D3 cyclins in gastric cancer remains to be elucidated.

Epidemiology of esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma has risen rapidly over the past 25 years in the United States as well as in several Western European countries. This increase had been most dramatic among white males. The majority of these cancers arise from a background of premalignant Barrett esophagus. However, less than 10% of the patients with esophageal adenocarcinoma were known to have Barrett esophagus previously. It is uncertain which risk factors contribute to the increasing incidence of esophageal adenocarcinoma, although gastroesophageal reflux disease, cigarette smoking, and obesity have been implicated. Whereas infection with Helicobacter pylori and use of non-steroidal anti-inflammatory drugs are associated with reduced risk, low intakes of fruit, vegetables, and cereal fibers seem to increase the risk of esophageal adenocarcinoma. Presently there is no evidence that strongly supports any specific strategy to screen a subgroup of the population at risk for Barrett esophagus and adenocarcinoma of the esophagus.

Advances in Barrett's esophagus and esophageal adenocarcinoma

Despite advances in diagnosis and therapy, esophageal adenocarcinoma remains an aggressive and usually lethal tumor. This review focuses on the epidemiology of esophageal adenocarcinoma and its presumed precursor lesion, Barrett's esophagus; the pathogenesis of the cancer; advances in treatment of adenocarcinoma and Barrett's esophagus; and strategies for cancer prevention. Emphasis is placed on recent literature. Although the absolute number of cases of adenocarcinoma in the United States is still small, the incidence of this cancer has increased dramatically in the last 40 years, and adenocarcinoma is now the predominant form of esophageal cancer in this country. Recent evidence suggests that Barrett's esophagus is more prevalent in asymptomatic individuals than previously appreciated. The pathogenesis of Barrett's esophagus is poorly understood. Given that some subjects will have repeated bouts of severe erosive esophagitis and never develop Barrett's esophagus, host factors must play an important role. The utility of neoadjuvant radiation and chemotherapy in those with adenocarcinoma, although they are widely practiced, is not of clear benefit, and some authorities recommend against it. Ablative therapies, as well as endoscopic mucosal resection, hold promise for those with superficial cancer or high-grade dysplasia. Most series using these modalities feature relatively short follow-up, and longer-term data will be necessary to better describe the effects of these therapies. The value of chemoprevention in subjects with dysplastic Barrett's esophagus by use of cyclooxygenase 2 inhibitors, nonsteroidal anti-inflammatory drugs, or proton pump inhibitors is unknown. Similarly, although endoscopic screening is widely practiced, its value in patients with chronic gastroesophageal reflux disease symptoms is of unproven value, and recommending bodies are divided as to its practice.

Nicotine and gastric cancer

About 60 components in cigarette smoke are considered to be carcinogens, namely polycyclic aromatic hydrocarbons, nitrosamines, aromatic amine, trace metals, as well as nicotine. Nicotine is considered to be one of the active components in cigarette smoke, and its association with tumorigenesis is enigmatic. Nonsteroidal antiinflammatory drugs are widely accepted as antitumor agents to treat patients with cancer by inhibiting cyclooxygenase-2 activity. Stimulation of tumor growth by nicotine involves different processes of cell proliferation and angiogenesis. Study results, with the use of animal xenograft models and cell culture systems, show that nicotine stimulates the progression of tumor growth, through a cyclooxygenase-2-dependent pathway. On the basis of these findings, nicotine seems to be a potent mitogenic agent in modulating tumor cell proliferation, and selective cyclooxygenase-2 inhibitors are promising antitumor agents for gastric cancer in smokers.

Overexpression of 5-Lipoxygenase in Rat and Human Esophageal Adenocarcinoma and Inhibitory Effects of Zileuton and Celecoxib on Carcinogenesis

PURPOSE

Aberrant arachidonic acid (AA) metabolism, especially through the cyclooxygenase (Cox) and 5-lipoxygenase (5-Lox) pathways, has been suggested to play an important role in the development of esophageal adenocarcinoma (EAC). The purpose of this study was to investigate the expression of 5-Lox in EAC of a rat model and in human samples as well as the chemopreventive effects of zileuton (a specific 5-Lox inhibitor) and celecoxib (a specific Cox2 inhibitor) in the rat EAC model.

EXPERIMENTAL DESIGN

5-Lox expression in EAC of a rat esophagogastroduodenal anastomosis model and of humans was examined with immunohistochemistry. A chemoprevention study was designed to test whether zileuton and celecoxib could suppress aberrant AA metabolism and esophageal adenocarcinogenesis.

RESULTS

With immunohistochemistry, we found that 5-Lox was overexpressed during esophageal adenocarcinogenesis in our rat model and in humans. In the chemoprevention study, EAC incidence was reduced in a dose-dependent manner from 68.8% (11 of 16) to 44.4% (8 of 18; P > 0.05) and 31.3% (5 of 16; P < 0.05) by 500 and 1,000 ppm zileuton, respectively, and to 33.3% (7 of 21; P < 0.05) and 20% (3 of 15; P < 0.05) by 500 and 1,000 ppm celecoxib, respectively. With isobolographic analysis, zileuton and celecoxib, both at a dose of 500 ppm, had an additive effect by reducing the tumor incidence to 16.7% (3 of 18, P < 0.01). Leukotriene B4 and prostaglandin E2 levels in the esophageal tissues were also significantly reduced by zileuton and celecoxib.

CONCLUSIONS

This study clearly demonstrated that 5-Lox and Cox2 play important roles in the development of EAC. Both zileuton and celecoxib had inhibitory effects on esophageal adenocarcinogenesis through inhibition on their respective enzymes of AA metabolism.