Ali H. Zaidi

A utility of peroral endoscopic myotomy (POEM) across the spectrum of esophageal motility disorders

BackgroundPeroral endoscopic myotomy (POEM) has been performed as a novel endoscopic procedure to treat achalasia with favorable outcome. The objective of this study was to assess the outcome of POEM in our initial series and to assess the safety and efficacy of POEM in a variety of esophageal motility-related clinical problems.MethodsThis is a retrospective cross-sectional study involving all patients with esophageal motility disorders defined by the Chicago classification, who had undergone consideration for POEM at our institution. Validated questionnaires such as gastroesophageal reflux disease health-related quality of life (GERD-HRQL), reflux symptom index (RSI) and achalasia disease-specific health-related quality of life were obtained pre- and postoperatively.ResultsFrom January 2013 to October 2014, a total of 35 POEMs (achalasia nxa0=xa025, non-achalasia nxa0=xa010) were performed on 33 patients (female nxa0=xa020, male nxa0=xa013, mean age 56.9xa0years). There was no mortality. The rate of inadvertent mucosotomy was 17.1xa0%. The rate of complications requiring interventions was 5.7xa0%. During a mean follow-up period of 7xa0months (range 0.5–17), 92xa0% of patients with achalasia and 75xa0% of those with non-achalasia motility disorders had a symptomatic improvement in dysphagia. Chest pain was completely resolved in all patients with achalasia (8/8) and 80xa0% of patients with non-achalasia (4/5). The GERD-HRQL, RSI and dysphagia scores significantly improved after POEM in patients with achalasia. There was a significant improvement in GERD-HRQL and RSI scores, and a trend toward lower dysphagia score in patients with non-achalasia.ConclusionsThe outcome of POEM to treat achalasia and non-achalasia motility disorders is consistent with previous studies. Potential benefit of POEM includes not only its flexibility to adjust the length and location of myotomy but also the ability to extend myotomy proximally without thoracoscopy or thoracotomy. POEM can be combined with laparoscopic procedures and used as “salvage” for localized esophageal dysmotility.

Evaluation of a 4‐protein serum biomarker panel—biglycan, annexin‐A6, myeloperoxidase, and protein S100‐A9 (B‐AMP)—for the detection of esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is associated with a dismal prognosis. The identification of cancer biomarkers can advance the possibility for early detection and better monitoring of tumor progression and/or response to therapy. The authors present results from the development of a serum‐based, 4‐protein (biglycan, myeloperoxidase, annexin‐A6, and protein S100‐A9) biomarker panel for EAC.

Associations of microbiota and toll-like receptor signaling pathway in esophageal adenocarcinoma

BackgroundToll-like receptors (TLRs) recognize known molecules from microbes and have an established role in tumorigenesis. Using a rat model of esophageal adenocarcinoma, and human clinical samples, we investigated genes central to TLR-mediated signal transduction and characterized the esophageal microbiome across the spectrum of esophageal adenocarcinoma carcinogenesis.MethodsWe surgically induced bile/acid reflux in rats and their esophagi were harvested at 40xa0weeks post-surgery. Tissue samples from the model were selected for gene expression profiling. Additionally, for rat and human samples microbiome analysis was performed using PCR-ESI-MS-TOF technology with validation by fluorescence in situ hybridization.ResultsGene expression results in the rat model indicated a significant upregulation of TLRs 1-3, 6, 7 and 9 in EAC compared to normal epithelium. PCR-ESI-MS-TOF analysis revealed a prevalence of Escherichia coli in Barrett’s esophagus (60xa0%) and esophageal adenocarcinoma (100xa0%), which was validated by fluorescence in situ hybridization. In the human clinical samples, Streptococcus pneumonia was detected in high abundance in gastroesophageal reflux disease and Barrett’s esophagus (50–70xa0%) in comparison to tumor adjacent normal epithelium, dysplasia, and esophageal adenocarcinoma (20–30xa0%). E. coli was detected in the Barrett’s esophagus and esophageal adenocarcinoma groups but was absent in the tumor adjacent normal epithelium, dysplasia, and the gastroesophageal reflux disease groups.ConclusionsWe demonstrated an association between the TLR signaling pathway and E. coli hinting towards possible early molecular changes being mediated by microbes in the rat model of esophageal adenocarcinoma carcinogenesis. Studies on human clinical samples also corroborate results to some extent; however, a study with larger sample size is needed to further explore this association.

Improvement of water and sanitation for developing countries

William Checkley and colleagues rightly identified that inadequate water and sanitation is associated with poor childhood health. Provision of water and sanitation to disadvantaged sectors therefore might be one of the most reliable policies to reduce poverty and lower the burden of diarrhoea in developing countries. This fact is further emphasised by Rebecca Dillingham and Richard Guerrant who suggest the need for immediate investment in measures known to alleviate the devastating societal costs of inadequate water poor sanitation and early childhood diarrhoea. An effective prevention programme however will have to integrate a selection of proven interventions along with those found to be effective for a particular region. For example fly control with insecticide if necessary may be recommended along with improvement of water and sanitation in situations where high fly density is associated with a high incidence of diarrhoea. (excerpt)

Smoothened Inhibition Leads to Decreased Proliferation and Induces Apoptosis in Esophageal Adenocarcinoma Cells

The Hedgehog (Hh) pathway is known to be active in Barretts carcinogenesis. Therefore, we evaluated the efficacy and underlying mechanisms of inhibition of cancer cell growth by the smoothened (Smo) antagonist BMS-833923 in esophageal adenocarcinoma (EAC) cell lines. Cell proliferation and apoptosis were evaluated by flow cytometry, Western blotting, immunofluorescence, and quantitative reverse transcription polymerase chain reactions. Results showed that the Smo antagonist led to reduced Hh pathway activity, resulting in decreased cell proliferation and induction of apoptosis via the intrinsic pathway in the esophageal cancer cells. In conclusion, the Smo antagonist may have application as an EAC chemotherapeutic agent.

Prognostic value and targeted inhibition of survivin expression in esophageal adenocarcinoma and cancer-adjacent squamous epithelium.

Background Survivin is an inhibitor of apoptosis and its over expression is associated with poor prognosis in several malignancies. While several studies have analyzed survivin expression in esophageal squamous cell carcinoma, few have focused on esophageal adenocarcinoma (EAC) and/or cancer-adjacent squamous epithelium (CASE). The purpose of this study was 1) to determine the degree of survivin up regulation in samples of EAC and CASE, 2) to evaluate if survivin expression in EAC and CASE correlates with recurrence and/or death, and 3) to examine the effect of survivin inhibition on apoptosis in EAC cells. Methods Fresh frozen samples of EAC and CASE from the same patient were used for qRT-PCR and Western blot analysis, and formalin-fixed, paraffin-embedded tissue was used for immunohistochemistry. EAC cell lines, OE19 and OE33, were transfected with small interfering RNAs (siRNAs) to knockdown survivin expression. This was confirmed by qRT-PCR for survivin expression and Western blot analysis of cleaved PARP, cleaved caspase 3 and survivin. Survivin expression data was correlated with clinical outcome. Results Survivin expression was significantly higher in EAC tumor samples compared to the CASE from the same patient. Patients with high expression of survivin in EAC tumor had an increased risk of death. Survivin expression was also noted in CASE and correlated with increased risk of distant recurrence. Cell line evaluation demonstrated that inhibition of survivin resulted in an increase in apoptosis. Conclusion Higher expression of survivin in tumor tissue was associated with increased risk of death; while survivin expression in CASE was a superior predictor of recurrence. Inhibition of survivin in EAC cell lines further showed increased apoptosis, supporting the potential benefits of therapeutic strategies targeted to this marker.

A Tissue Systems Pathology Assay for High-Risk Barrett's Esophagus

Background: Better methods are needed to predict risk of progression for Barretts esophagus. We aimed to determine whether a tissue systems pathology approach could predict progression in patients with nondysplastic Barretts esophagus, indefinite for dysplasia, or low-grade dysplasia. Methods: We performed a nested case–control study to develop and validate a test that predicts progression of Barretts esophagus to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC), based upon quantification of epithelial and stromal variables in baseline biopsies. Data were collected from Barretts esophagus patients at four institutions. Patients who progressed to HGD or EAC in ≥1 year (n = 79) were matched with patients who did not progress (n = 287). Biopsies were assigned randomly to training or validation sets. Immunofluorescence analyses were performed for 14 biomarkers and quantitative biomarker and morphometric features were analyzed. Prognostic features were selected in the training set and combined into classifiers. The top-performing classifier was assessed in the validation set. Results: A 3-tier, 15-feature classifier was selected in the training set and tested in the validation set. The classifier stratified patients into low-, intermediate-, and high-risk classes [HR, 9.42; 95% confidence interval, 4.6–19.24 (high-risk vs. low-risk); P < 0.0001]. It also provided independent prognostic information that outperformed predictions based on pathology analysis, segment length, age, sex, or p53 overexpression. Conclusion: We developed a tissue systems pathology test that better predicts risk of progression in Barretts esophagus than clinicopathologic variables. Impact: The test has the potential to improve upon histologic analysis as an objective method to risk stratify Barretts esophagus patients. Cancer Epidemiol Biomarkers Prev; 25(6); 958–68. ©2016 AACR.

Hypopharyngeal pepsin and Sep70 as diagnostic markers of laryngopharyngeal reflux: preliminary study.

IntroductionThe management of laryngopharyngeal reflux (LPR) has been challenging. Hypopharyngeal multichannel intraluminal impedance (HMII) has shown to increase the sensitivity in diagnosing LPR. The objective of this study is to investigate the potential use of pepsin and Sep70 as diagnostic tools for detection of LPR in combination with HMII.Materials and methodsTissue samples of hypopharynx, distal esophagus, and gastric cardia were collected from patients with LPR symptoms regardless of gastroesophageal reflux (GERD) diagnosis and underwent HMII to detect LPR and high esophageal reflux (HER: reflux 2xa0cm distal to upper esophageal sphincter) events. Patients were classified into two groups based on the presence of abnormal proximal exposure (APE), which was defined as LPR ≥1/day and/or HER ≥5/day: (1) positive-APE and (2) negative-APE. Patients with typical GERD symptoms without LPR symptoms who did not undergo HMII were used as a “control” GERD group. Protein was isolated from tissue samples and Western blot analysis of pepsin and Sep70 was performed. Pepsinogen was used as a control to differentiate pepsin from pepsinogen. Relative quantitation was performed using Image Studio Lite Software with normalization against the internal actin of each blot.ResultsFrom October 2012 to September 2013, 55 patients underwent HMII. Of 55, 20 patients underwent biopsies from hypopharynx (17 positive-APE and 3 negative-APE). Ten patients with typical GERD symptoms were identified from tissue bank as a “control” GERD group. Pepsin was detected in distal esophagus and hypopharynx in all groups without significant difference among groups. However, Sep70 in distal esophagus and hypopharynx was significantly depleted in the positive-APE group compared to the other groups (pxa0=xa00.032 and 0.002, respectively).ConclusionDepletion of Sep70 with the presence of pepsin in the hypopharynx may indicate cellular injury in laryngopharynx due to constant proximal reflux. However, the normative data for these markers have to be validated.

Establishing Magnetic Resonance Imaging as an Accurate and Reliable Tool to Diagnose and Monitor Esophageal Cancer in a Rat Model

Objective To assess the reliability of magnetic resonance imaging (MRI) for detection of esophageal cancer in the Levrat model of end-to-side esophagojejunostomy. Background The Levrat model has proven utility in terms of its ability to replicate Barrett’s carcinogenesis by inducing gastroduodenoesophageal reflux (GDER). Due to lack of data on the utility of non-invasive methods for detection of esophageal cancer, treatment efficacy studies have been limited, as adenocarcinoma histology has only been validated post-mortem. It would therefore be of great value if the validity and reliability of MRI could be established in this setting. Methods Chronic GDER reflux was induced in 19 male Sprague-Dawley rats using the modified Levrat model. At 40 weeks post-surgery, all animals underwent endoscopy, MRI scanning, and post-mortem histological analysis of the esophagus and anastomosis. With post-mortem histology serving as the gold standard, assessment of presence of esophageal cancer was made by five esophageal specialists and five radiologists on endoscopy and MRI, respectively. Results The accuracy of MRI and endoscopic analysis to correctly identify cancer vs. no cancer was 85.3% and 50.5%, respectively. ROC curves demonstrated that MRI rating had an AUC of 0.966 (p<0.001) and endoscopy rating had an AUC of 0.534 (pu200a=u200a0.804). The sensitivity and specificity of MRI for identifying cancer vs. no-cancer was 89.1% and 80% respectively, as compared to 45.5% and 57.5% for endoscopy. False positive rates of MRI and endoscopy were 20% and 42.5%, respectively. Conclusions MRI is a more reliable diagnostic method than endoscopy in the Levrat model. The non-invasiveness of the tool and its potential to volumetrically quantify the size and number of tumors likely makes it even more useful in evaluating novel agents and their efficacy in treatment studies of esophageal cancer.

MicroRNA signature characterizes primary tumors that metastasize in an esophageal adenocarcinoma rat model.

Objective To establish a miRNA signature for metastasis in an animal model of esophageal adenocarcinoma (EAC). Background The incidence of esophageal adenocarcinoma (EAC) has dramatically increased and esophageal cancer is now the sixth leading cause of cancer deaths worldwide. Mortality rates remain high among patients with advanced stage disease and esophagectomy is associated with high complication rates. Hence, early identification of potentially metastatic disease would better guide treatment strategies. Methods The modified Levrat’s surgery was performed to induce EAC in Sprague-Dawley rats. Primary EAC and distant metastatic sites were confirmed via histology and immunofluorescence. miRNA profiling was performed on primary tumors with or without metastasis. A unique subset of miRNAs expressed in primary tumors and metastases was identified with Ingenuity Pathway Analysis (IPA) along with upstream and downstream targets. miRNA-linked gene expression analysis was performed on a secondary cohort of metastasis positive (n=5) and metastasis negative (n=28) primary tumors. Results The epithelial origin of distant metastasis was established by IF using villin (VIL1) and mucin 5AC (MUC5AC) antibodies. miRNome analysis identified four down-regulated miRNAs in metastasis positive primary tumors compared to metastasis negative tumors: miR-92a-3p (p=0.0001), miR-141-3p (p=0.0022), miR-451-1a (p=0.0181) and miR133a-3p (p=0.0304). Six target genes identified in the top scoring networks by IPA were validated as significantly, differentially expressed in metastasis positive primary tumors: Ago2, Akt1, Kras, Bcl2L11, CDKN1B and Zeb2. Conclusion In vivo metastasis was confirmed in the modified Levrat’s model. Analysis of the primary tumor identified a distinctive miRNA signature for primary tumors that metastasized.