Gastroesophageal reflux and cancer

Microflora composition in the gastrointestinal tract in patients with Barrett's esophagus

Background

The incidence of esophageal adenocarcinoma (EAC) has been increasing over the last 40 years. While Barrett's esophagus is a known risk factor for the development of EAC, the role of the microflora in the development of EAC is still largely unknown and is being investigated further by multiple centers. Our goal was to identify trends in microflora composition along various aspects of the upper gastrointestinal tract in patients with Barrett's esophagus.

Methods

After obtaining institutional review board approval, 12 patients agreed to participate in the study. While endoscopy was performed for surveillance Barrett's monitoring, additional biopsies of esophageal mucosa were taken from the (I) proximal esophagus, (II) mid-esophagus, (III) distal esophagus, and (IV) Barrett's esophagus. Additional swabs were also taken from the uvula and the endoscope used during the procedure. The swabs from the uvula and endoscope were obtained prior to the endoscope entering the stomach, to prevent exposing the endoscope to the acidic environment of the stomach. The most common bacterial elements were identified by amplifying sample DNA using a panel of 5 "universal" fusion primer pairs. The 400-500 base pair fragments created an overlap which covered 95% of the bacterial 16s gene.

Results

Throughout the esophagus, 34 bacterial genera were found which had a relative abundance of >1.0. Streptococcal genera were prevalent in all aspects of the esophagus, ranging from 16% to 70% of the bacterial community. Haemophilus genera were uniquely abundant in the Barrett's esophageal tissue but relatively absent elsewhere in the upper gastrointestinal tract. Overall, the percentage of Gram-positive organisms was much higher in the proximal than distal esophagus. The microflora pattern obtained from the uvula and endoscopic swabs did not correlate with any of the tissue biopsies along any aspect of the esophagus.

Conclusions

In patients with Barrett's esophagus, Streptococcal genera are widespread throughout the esophagus. Gram-positive genera tend to decrease as a percentage of overall flora distally. Obtaining a simple swab of the oropharynx or endoscope itself appears to be a poor substitute for tissue biopsy of esophageal mucosa when evaluating microflora patterns.

Proton pump inhibitors and histamine 2 blockers are associated with improved overall survival in patients with head and neck squamous carcinoma

It has been postulated that gastroesophageal reflux plays a role in the etiology of head and neck squamous cell carcinomas (HNSCC) and contributes to complications after surgery or during radiotherapy. Antacid medications are commonly used in patients with HNSCC for the management of acid reflux; however, their relationship with outcomes has not been well studied. Associations between histamine receptor-2 antagonists (H2RA) and proton pump inhibitors (PPI) use and treatment outcomes were determined in 596 patients with previously untreated HNSCC enrolled in our SPORE epidemiology program from 2003 to 2008 (median follow-up 55 months). Comprehensive clinical information was entered prospectively in our database. Risk strata were created on the basis of possible confounding prognostic variables (age, demographics, socioeconomics, tumor stage, primary site, smoking status, HPV16 status, and treatment modality); correlations within risk strata were analyzed in a multivariable model. Patients taking antacid medications had significantly better overall survival (OS; PPI alone: P < 0.001; H2RA alone, P = 0.0479; both PPI + H2RA, P = 0.0133). Using multivariable Cox models and adjusting for significant prognostic covariates, both PPIs and H2RAs used were significant prognostic factors for OS, but only H2RAs use for recurrence-free survival in HPV16-positive oropharyngeal patients. We found significant associations between the use of H2RAs and PPIs, alone or in combination, and various clinical characteristics. The findings in this large cohort study indicate that routine use of antacid medications may have significant therapeutic benefit in patients with HNSCC. The reasons for this association remain an active area of investigation and could lead to identification of new treatment and prevention approaches with agents that have minimal toxicities.

Aurora kinase A in gastrointestinal cancers: time to target

Gastrointestinal (GI) cancers are a major cause of cancer-related deaths. During the last two decades, several studies have shown amplification and overexpression of Aurora kinase A (AURKA) in several GI malignancies. These studies demonstrated that AURKA not only plays a role in regulating cell cycle and mitosis, but also regulates a number of key oncogenic signaling pathways. Although AURKA inhibitors have moved to phase III clinical trials in lymphomas, there has been slower progress in GI cancers and solid tumors. Ongoing clinical trials testing AURKA inhibitors as a single agent or in combination with conventional chemotherapies are expected to provide important clinical information for targeting AURKA in GI cancers. It is, therefore, imperative to consider investigations of molecular determinants of response and resistance to this class of inhibitors. This will improve evaluation of the efficacy of these drugs and establish biomarker based strategies for enrollment into clinical trials, which hold the future direction for personalized cancer therapy. In this review, we will discuss the available data on AURKA in GI cancers. We will also summarize the major AURKA inhibitors that have been developed and tested in pre-clinical and clinical settings.

Zinc salts provide a novel, prolonged and rapid inhibition of gastric acid secretion

OBJECTIVES

The overproduction of acid and the associated illnesses linked to hypersecretion have a lifetime prevalence of 25-35% in the United States. Although a variety of pharmaceutical agents have been used to reduce the production of acid, alarming new evidence questions the long-term efficacy and safety of the agents. These issues coupled with the delayed onset of action and the return of symptoms in over 60% of the patients is less than satisfactory. The purpose of this study was to determine whether administration of a zinc salt could lead to a rapid and sustained increase in gastric pH in both animals and in humans and provide a new rapid acid suppression therapy.

METHODS

Intracellular pH was measured with 2',7'-bis-(2-carboxyethyl)-5-and-6-carboxy-fluorescein in both human and rat gastric glands following an acid load±a secretagogue. In a separate series of studies, whole stomach acid secretion was monitored in rats. A final study used healthy human volunteers while monitoring with a gastric pH measurement received placebo, zinc salt, or a zinc salt and proton pump inhibitor (PPI).

RESULTS

We demonstrate that exposure to ZnCl(2) immediately abolished secretagogue-induced acid secretion in isolated human and rat gastric glands, and in intact rat stomachs. Chronic low-dose zinc exposure effectively inhibited acid secretion in whole stomachs and isolated glands. In a randomized cross-over study in 12 volunteers, exposure to a single dose of ZnCl(2) raised intragastric pH for over 3  h, including a fast onset of effect.

CONCLUSIONS

Our findings demonstrate that zinc offers a novel rapid and prolonged therapy to inhibit gastric acid secretion in human and rat models.

Effort, safety, and findings of routine preoperative endoscopic evaluation of morbidly obese patients undergoing bariatric surgery

BACKGROUND

Obesity is becoming an epidemic health problem and is associated with concomitant diseases, such as sleep apnea syndrome and gastroesophageal reflux disease (GERD). There is no standardized diagnostic workup for the upper gastrointestinal tract in obese patients; many patients have no upper gastrointestinal symptoms, and few data are available on safety of endoscopy in morbidly obese patients.

METHODS

Sixty-nine consecutive diagnostic upper gastrointestinal endoscopies in morbidly obese patients (26 men, 43 women; mean age 43.4 +/- 10.9 years) were prospectively evaluated from January to December 2008 in an outpatient setting before bariatric procedures. Sedation was administered with propofol. Data on sedation, critical events, and examination times were recorded, as well as pathological findings.

RESULTS

The patients' mean body mass index was 47.6 +/- 7.9 (range, 35.1-73.3) kg/m(2); 17.4% reported GERD symptoms. The mean duration of the endoscopy procedure (including sedation) was 20.3 +/- 9.3 (range, 5-50) min, and the whole procedure (including preparation and postprocessing) took 58.2 +/- 19 (range, 20-120) min. The mean propofol dosage was 380 +/- 150 (range, 80-900) mg. Two patients had critical events that required bronchoscopic intratracheal O(2) insufflation due to severe hypoxemia (<60% SaO: (2)). Nearly 80% of patients had pathological findings in the upper gastrointestinal tract. Only 20% reported upper gastrointestinal symptoms. Pathologic conditions were found in the esophagus in 23.2% of the patients, in the stomach in 78.2%, and in the duodenum in 11.6%. The prevalence of Helicobacter pylori infection was 8.7%.

CONCLUSIONS

Upper gastrointestinal endoscopy can be performed safely. However, careful monitoring and anesthesiological support are required for patients with concomitant diseases and those receiving sedation. Because 80% of the patients with pathological findings were asymptomatic, every morbidly obese patient should undergo endoscopy before bariatric surgery because there may be findings that might change the surgical strategy.

Management of complications after laparoscopic Nissen's fundoplication: a surgeon's perspective

Introduction

Gastro-oesophageal reflux disease (GORD) is a common problem in the Western countries, and the interest in the minimal access surgical approaches to treat GORD is increasing. In this study, we would like to discuss the presentations and management of complications we encountered after Laparoscopic Nissen's fundoplication in our District General NHS Hospital. The aim is to recognise these complications at the earliest stage for effective management to minimise the morbidity and mortality.

Methods

301 patients underwent laparoscopic treatment for GORD by a single consultant surgeon in our NHS Trust from September 1999. The data was prospectively collected and entered into a database. The data was retrospectively analysed for presentations for complications and their management.

Results

Surgery was completed laparoscopically in all patients, except in five, where the operation was technically difficult due to pre-existing conditions. The complications we encountered during surgery and follow-up period were major intra-operative bleeding (n = 1, 0.33%), severe post-operative nausea and vomiting (n = 1, 0.33%), wound infection (n = 3, 1%), port-site herniation (n = 1, 0.33%), wrap-migration (n = 2, 0.66%), wrap-ischaemia (n = 1, 0.33%), recurrent regurgitation (n = 4, 1.32%), recurrent heartburn (n = 29, 9.63%), tension pneumothorax (n = 2, 0.66%), surgical emphysema (n = 8, 2.66%), and port-site pain (n = 4, 1.33%).

Conclusion

Minimal access approach to treat GORD has presented with some specific and unique complications. It is important to recognise these complications at the earliest possible stage as some of these patients may present in an acute setting requiring emergency surgery. All members of the department, and not just the members of the specialised team, should be aware about these complications to minimise the morbidity and mortality.

Comparison of glutathione S-transferase-Pi expression at mRNA levels in oesophageal mucosa using RT-PCR-ELISA in individuals with reflux diseases, adenocarcinoma and squamous cell carcinoma

OBJECTIVES

To develop a RT-PCR technique coupled with Enzyme Linked Immunosobant Assay (ELISA) i.e. RT-PCR-ELISA for measurement of class-Pi glutathione S-transferase (GST-P)-specific mRNA in esophageal diseases.

METHODS

In this study, 66 esophageal tissue biopsies diagnosed as non-erosive reflux disease (NERD), gastroesophageal reflux disease (GERD), adenocarcinoma (ADC), and squamous cell carcinoma (SCC) were used. Standardization of the RT-PCR-ELISA was carried out using specific GST-Pi and beta-actin primers, biotin labeled probe, DIG-labeling RT-PCR and anti-DIG-HRP conjugate.

RESULTS

The results of RT-PCR-ELISA based on OD ratio of GST-Pi mRNA/beta-actin showed that there was no significant difference in GST-Pi expression in normal, NERD and GERD samples. Overexpression of GST-Pi in malignant tissues (ADC and SCC) was distinguishable. The OD ratio of GST-Pi mRNA expression to beta-actin mRNA was 1.17+/-0.13 and 1.3+/-0.13 in ADC and SCC samples, respectively, which is significantly higher (P<0.05) than matching control (0.78+/-0.06 and 0.85+/-0.07).

CONCLUSIONS

RT-PCR-ELISA showed that GST-Pi expression was not altered in GERD and NERD esophagus, whereas, in ADC and SCC samples, it was significantly higher (P<0.05) as compared to inflamed and normal tissues.