CSF-1R inhibitor, pexidartinib, sensitizes esophageal cancer to PD-1 immune checkpoint blockade in a rat model

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Background: Esophageal adenocarcinoma (EAC) is a leading cause of cancer deaths. Pexidartinib, is a multi-gene tyrosine kinase inhibitor, targeting FLT3, KIT and CSF1R. In particular, pexidartinib by targeting CSF-1R down modulates macrophage mediated pro-survival tumor signaling. Recently, CSF-1R inhibitors have successfully shown to enhance antitumor activity of PD-1/PD-L1 inhibitors by suppressing tumor immune evasion, in multiple solid tumors. Methods: Seventy-two rats underwent an end-to-side esophagojejunostomy to induce gastroesophageal reflux, resulting in EAC carcinogenesis. At 32 weeks postoperatively, tumor bearing animals were randomized to a dose of 30mg/kg of pexidartinib or vehicle control, 5 days on and 2 days off (14 day cycle), for a total of 3 cycles. A PD-1 inhibitor, AUNP-12, at a dose of 3mg/kg or placebo, was administered on day 12 of each cycle. At 38 weeks postoperatively animals were euthanized. Safety and efficacy was evaluated by objective health assessments, pre and posttreatment MRI, RT-PCR, immunofluorescent labeling and a serum cytokine assay. Results: The pexidartinib +/- PD-1 inhibitor (Px+P and Px-P) groups demonstrated no significant difference in daily weight change (p = 0.98) or in mortality (p = 0.59) when compared to vehicle control (V+P and V-P) groups. On post-mortem serum analysis AST (p = 0.01) and ALT (p = 0.001) were elevated, while albumin (p = 0.57) and BUN/creatinine ratio (p = 0.09) were reported within normal ranges, when comparing treatment to placebo groups. Pre to posttreatment, mean MRI tumor volume decreased by 37% and 54% in the Px-P and Px+P animals and increased by 147% and 88% in the V+P and V-P animals, respectively (p = < 0.0001). Overall response rate was 69% and 87% in Px-P and Px+P animals compared to 21% and 13% in V-P and V+P animals, respectively (p = < 0.0001). Downstream gene expression demonstrated upregulation of TNF-α (p = 0.003), IFN-γ (p = 0.002) and IL-6 (p = 0.0001) and downregulation of IL-13 (p = 0.051), IL-10 (p = 0.051), TGF-β (p = 0.024) and Arg-1 (p = 0.0003), in treatment vs. placebo animals. Increased apoptosis (Cas-3 p = 0.0005) and reduced proliferation (Ki-67 p = < 0.0001) were reported in the treatment animals. Higher CD3+CD8+ T cell densities and CD86/CD206 macrophage ratio was reported in treatment groups compared to placebo (p = < 0.0001). Serum cytokine levels significantly displayed upregulation of TNF-α and IFN-γ and downregulation of IL-4 and IL-10 in the treatment animals compared to the placebo. Conclusions: Overall, this study established a promising combinatorial strategy using a CSF-1R inhibitor to overcome resistance to PD-1/PD-L1 axis blockade in an esophageal cancer model, providing the rationale for future clinical strategies.

Safety and efficacy of immunotherapy in combination with epigenetic therapy in an esophageal adenocarcinoma model

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Background: There is a critical need to develop effective therapeutic approaches for patients with esophageal cancer, a leading cause of cancer mortality. Recently, immune checkpoint blockade (ICB) has demonstrated modest survival benefit in gastroesophageal cancer patients. Epigenetic therapies, including DNA methyltransferases (DNMT) and histone deacetylases (HDACs), have shown to enhance tumor immune recognition by directly upregulating antigen presentation and by activation of type-1 interferon response triggered by cytoplasmic double-stranded RNA, a phenomenon known as viral mimicry. In other cancer models, epigenetic therapy has shown early promise by enhancing the effectiveness of ICB via addictive antiproliferative effects, enhanced immune activation and reversal of T cell exhaustion towards a memory-effector T-cell phenotypes. Methods: Esophagojejunostomy was performed to induce gastroduodenojejunal reflux in rats, leading to development of EAC. At 32 weeks postop, animals were randomized into eight treatment and control groups: placebo ± radiation, epigenetic treatment ± radiation, immunotherapy treatment ± radiation, and concurrent epigenetic and immunotherapy ± radiation. Animals underwent three 14 day cycles of epigenetic treatment or placebo. Each cycle consisted of one week of DNMT treatment or placebo at a dose of 0.5mg/kg, followed by one week of HDAC treatment or placebo at a dose of 2mg/kg. Animals received one 3mg/kg dose of PD1 inhibitor or placebo on day 12 of each cycle. Safety and efficacy were evaluated via objective health assessments, change in tumor volume, immunofluorescent labeling and RT-PCR. Results: Seventy of 74 randomized animals reached study end-point with no significant differences in mortality observed across groups (p = 0.556). There were no significant differences in observed health scores or weights between all groups (p = 0.431 and p = 0.882, respectively). Pre to posttreatment, mean MRI tumor volume increased by 263.1% and 90.9% in the placebo and the placebo plus radiation groups, respectively. The largest tumor reduction was observed in the concurrent treatment groups, 84.5% and 61.8% with and without radiation, respectively. Additionally, independent epigenetic and immunotherapy treatments with or without radiation also exhibited decrease in tumor volume, but to a lesser extent than the concurrent regimens (p = 0.005). Immunofluorescent labeling demonstrated a significant increase in CD3+ CD8+ T cells in all treatment groups compared to placebo (p = < 0.001). Gene expression displayed upregulation of CD206 (p = 0.002), TNFα (p = < 0.001), and Arg1 (p = < 0.001) in treatment arms compared to placebo. Conclusions: This study establishes addictive antitumor efficacy and enhanced immune sensitization for a concurrently sequenced treatment, combining epigenetic therapy and radiation with immunotherapy, to treat EAC.

Agrin loss in Barrett's esophagus-related neoplasia and its utility as a diagnostic and predictive biomarker

PURPOSE

There is an unmet need for identifying novel biomarkers in Barrett's esophagus (BE) that could stratify patients with regards to neoplastic progression. We investigate the expression patterns of extracellular matrix (ECM) molecules in BE and BE-related neoplasia, and assess their value as biomarkers for the diagnosis of BE-related neoplasia and to predict neoplastic progression.

EXPERIMENTAL DESIGN

Gene expression analyses of ECM matrisome gene sets were performed using publicly available data on human BE, BE-related dysplasia, esophageal ADCA and normal esophagus. Immunohistochemical expression of basement membrane (BM) marker agrin (AGRN) and p53 was analyzed in biopsies of BE-related neoplasia from 321 patients in three independent cohorts.

RESULTS

Differential gene expression analysis revealed significant enrichment of ECM matrisome gene sets in dysplastic BE and ADCA compared with controls. Loss of BM AGRN expression was observed in both BE-related dysplasia and ADCA. The mean AGRN loss in BE glands was significantly higher in BErelated dysplasia and ADCA compared to non-dysplastic BE (NDBE; p<0.001; specificity=82.2% and sensitivity=96.4%). Loss of AGRN was significantly higher in NDBE samples from progressors compared to non-progressors (p<0.001) and identified patients who progressed to advanced neoplasia with a specificity of 80.2% and sensitivity of 54.8%. Moreover, the combination of AGRN loss and abnormal p53 staining identified progression to BE-related advanced neoplasia with a specificity and sensitivity of 86.5% and 58.7%.

CONCLUSIONS

We highlight ECM changes during BE progression to neoplasia. BM AGRN loss is a novel diagnostic biomarker that can identify NDBE patients at increased risk of developing advanced neoplasia.

Normative Ambulatory Reflux Monitoring Metrics for Laryngopharyngeal Reflux: A Systematic Review of 720 Healthy Individuals

OBJECTIVES

To review the normative data for acid, weakly acid, and nonacid proximal esophageal (PRE) and hypopharyngeal reflux (HRE) events in diagnosing laryngopharyngeal reflux (LPR) using ambulatory reflux monitoring.

DATA SOURCES

PubMed, Cochrane Library, and Scopus.

REVIEW METHODS

A literature search was conducted about the normative data for PRE and HRE on multichannel intraluminal impedance-pH monitoring (MII-pH), hypopharyngeal-esophageal MII-pH (HEMII-pH), or oropharyngeal pH monitoring using PICOTS (population, intervention, comparison, outcome, timing, and setting) and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statements. Outcomes reviewed included device characteristics, impedance/pH sensor placements, study duration, number/average and percentiles of PRE or HRE occurrence, and the event characteristics (pH, composition, and position).

RESULTS

Of 154 identified studies, 18 met criteria for analysis, including 720 healthy individuals. HEMII-pH, MII-pH, and oropharyngeal pH monitoring were used in 7, 6, and 5 studies, respectively. The definition and inclusion/exclusion criteria of healthy individuals varied substantially across studies, with 6 studies considering only digestive symptoms to exclude potential LPR patients. Substantial heterogeneity across studies was noted, including impedance/pH sensor placements/configurations and definitions of composition (liquid, gas, mixed) and type (acid, weakly acid, nonacid) of PRE/HRE. The 95th percentile thresholds were 10 to 73 events for PRE, 0 to 10 events for HRE on HEMII-pH, and 40 to 128 for events with pH <6.0 on oropharyngeal pH monitoring. Most HREs were nonacid and occurred upright. The mean HRE among healthy individuals was 1.

CONCLUSION

The low number of studies and the heterogeneity in inclusion criteria, definitions, and characterization of PRE and HRE limit the establishment of consensual normative criteria for LPR on ambulatory reflux monitoring. Future large multicenter studies are needed.

Swallow-induced syncope after magnetic sphincter augmentation: a case report and physiologic explanation

Swallow-induced syncope is a rare cause of syncope that occurs during or immediately after swallowing. This phenomenon has been reported in association with few esophageal pathologies and the likely explanation is a vagal reflex during deglutition that results in inhibition of the cardiac conduction system. This report describes a case of swallow-induced syncope related to the implantation of a magnetic sphincter augmenting (MSA) device. Two episodes of syncope after food bolus occurred with the device in place and upon removal of the device, the patient had no further episodes of syncope. Vagal stimulation from distention of the esophagus or vagus nerve contact irritation by the implant are the potential explanation for syncope in this patient. Although this is an extremely rare complication of magnetic sphincter device augmentation, it is one that physicians should be cognizant of given the dangers of syncope events.

Multifactorial dysphagia: Azygos vein aneurysm (AVA) and esophagogastric junction outflow obstruction (EGJOO)

Introduction

Vascular impingement of the esophagus is a rare cause of dysphagia, and is most commonly due to aortic arch anomalies such as arterial lusoria. Dysphagia resultant from venous compression is even further less likely.

Presentation of case

We present a highly unusual case of dysphagia secondary to a large aneurysm of the azygous vein near its confluence with the superior vena cava, which was managed with endovascular modalities. Despite initial treatment success, patient reported some intermittent solid food dysphagia, and was also found to have esophagogastric junction outflow obstruction (EGJOO) on high resolution impedance manometry (HRIM) which was successfully managed with surgical myotomy and partial fundoplication.

Discussion

The azygos vein has an intimate anatomic relationship with the esophagus as it traverses the posterior mediastinum. Because of this anatomic association, the azygos vein may present a point of esophageal obstruction in the setting of significant pathology.

Conclusion

This case highlights the possibility of multifactorial causes of dysphagia, and that HRIM is a key aspect of this workup. Additionally we discuss the pertinent anatomy, diagnosis, and treatments for azygos vein aneurysm and EGJOO.

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Vascular impingement of the esophagus is a rare cause of dysphagia.

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This type of dysphagia is most commonly due to aortic arch anomalies such as arterial lusoria.

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The azygos vein may present a point of esophageal obstruction in the setting of significant pathology.

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Endovascular therapy in selected patients can provide resolution of dysphagia in patients with azygos vein aneurysm.

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There is possibility of multifactorial causes of dysphagia, and high resolution manometry is a key aspect of this workup.

Immunogenomic features of pathologic response to neoadjuvant immune checkpoint blockade in esophageal cancer

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Background: Improving immunotherapy efficacy remains an unmet need in esophagogastric cancer and a deeper understanding of tumor and immune system dynamics during therapy may tailor immuno-oncology approaches. Methods: We performed whole exome sequencing (WES) and bulk RNA sequencing (RNAseq) of 70 serial tumor samples from 23 patients with stage II/III esophageal/gastroesophageal junction (E/GEJ) cancer treated on a phase 1B clinical trial with neoadjuvant nivolumab with or without relatlimab (anti-LAG-3) and chemoradiation followed by surgery (NCT03044613; CA209-906). Pathologic response was measured by tumor regression at the time of resection. Median follow up was 23 months post-surgery. Serial tumor samples were collected prior to therapy, after 2 cycles of induction immune checkpoint blockade (ICB), and at the time of resection. Twenty-two baseline tumor/normal DNA pairs were analyzed by WES and 48 serial tumor samples were analyzed by RNAseq. WES data was analyzed to identify somatic mutations, generate tumor mutation burden (TMB) estimates and assess the fraction of expressed mutations in conjunction with RNAseq data. Immune cell subset composition was determined by RNAseq data deconvolution by CIBERSORT and gene set enrichment analyses were performed utilizing GSEA. B-cell density was inferred by immunoglobulin rearrangements detected by RNAseq. Results: Gene set enrichment expression analyses revealed an upregulation of effector pro-inflammatory cytokines after induction ICB. Interferon-gamma, interferon-alpha and TNF-alpha related genes were significantly upregulated after induction ICB compared to baseline (p < 0.0001). In contrast, significant downregulation of E2F targets (p = 0.002), G2M checkpoint genes (p = 0.005) and DNA damage repair genes (p = 0.004) was observed post ICB; enrichment analyses were independent of response to therapy and treatment arm. While TMB was not predictive of pathologic response (p = 0.22), patients with tumors harboring a higher number of expressed mutations were more likely to achieve a pathologic complete response (pCR; p = 0.026). RNAseq deconvolution analyses revealed a higher B-cell density post ICB induction in tumors with pCR (p = 0.018). Furthermore, an increased baseline content of intra-tumoral activated M1 macrophages differentiated tumors from patients achieving a pCR (p = 0.0034), which was further exemplified post induction ICB. Conclusions: Neoadjuvant immunotherapy induces an inflammatory immune response in the tumor microenvironment that is linked with tumor elimination and pathologic response. Our findings highlight the importance of nuanced multi-omics analyses to understand the wiring of response to immunotherapy and guide therapy for E/GEJ cancer.

Gastric remnant mesentero-axial volvulus following Roux-en-Y esophagojejunostomy: A rare complication

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Acute gastric volvulus is characterized by abnormal rotation of the stomach by more than 180°, creating a closed loop obstruction with the risk of strangulation, necrosis and perforation.

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Diagnosis of gastric volvulus is challenging due to non-specific presentation and rarity of this clinical condition.

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The diagnosis is even more challenging in patients with altered anatomy and requires high index of suspicion.

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Extensive gastric mobilization is a key step in several foregut and bariatric surgeries.

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This mobilization will leave the stomach with no attachments posteriorly and along the greater curvature, increasing the likelihood of volvulus.

Introduction

Acute gastric volvulus is a surgical emergency with a mortality as high as 15–20%. The rarity of gastric volvulus requires high index of clinical suspicion especially in the patients with altered anatomy, to allow immediate surgical intervention and reduce the morbidity and mortality.

Presentation of case

We present an unusual case of gastric remnant volvulus several months following Roux-en-Y esophagojejunostomy performed in an obese patient for severe, recurrent gastroesophageal reflux disease (GERD) and failed prior fundoplication. The patient was treated with gastropexy and Stamm gastrostomy tube.

Discussion

Gastric volvulus is a rare phenomenon, in which the stomach rotates around the short (mesentero-axial) or longitudinal (organo-axial) axes. Diagnosis of gastric volvulus is challenging due to non-specific presentation and rarity of this clinical condition. The diagnosis of volvulus in patients with altered anatomy is even more challenging, requiring a high index of suspicion, and heavily relies on cross sectional imaging.

Conclusion

Extensive gastric mobilization is a key step in several foregut and bariatric surgeries, this will leave the stomach with no attachments posteriorly and along the greater curvature and increases the likelihood of volvulus.

Intratumoral immunotherapy with STING agonist, ADU-S100, induces CD8+ T-cell mediated anti-tumor immunity in an esophageal adenocarcinoma model

BACKGROUND

Esophageal adenocarcinoma (EAC) is a deadly disease with limited treatment options. STING is a transmembrane protein that activates transcription of interferon genes, resulting in stimulation of APCs and enhanced CD8+ T-cell infiltration. The present study evaluates STING agonists, alone and in combination with radiation to determine durable anticancer activity in solid tumors.

MATERIALS AND METHODS

Esophagojejunostomy was performed on rats to induce reflux leading to the development of EAC. At 32 weeks post operatively, rats received intratumorally either 50 μg STING (ADU-S100) or placebo (PBS), +/- 16Gy radiation. Drug activity was evaluated by pre- and post- treatment MRI, histology, immunofluorescence and RT-PCR.

RESULTS

Mean MRI tumor volume decreased by 30.1% and 50.8% in ADU-S100 and ADU-S100 + radiation animals and increased by 76.7% and 152.4% in placebo and placebo + radiation animals, respectively (P < 0.0001). Downstream gene expression, pre- to on- and post- treatment, demonstrated significant upregulation of IFNβ, TNFα, IL-6, and CCL-2 in the treatment groups vs. placebo. On- or post- treatment, radiation alone, ADU-S100 alone, and ADU-S100 + radiation groups demonstrated enhanced PD-LI expression, induced by upregulation of CD8+ T-cells (p < 0.01).

CONCLUSIONS

ADU-S100 +/- radiation exhibits potent antitumor activity and a promising immunomodulatory profile in a de novo EAC.

Efficacy of Magnetic Sphincter Augmentation Across the Spectrum of GERD Disease Severity

BACKGROUND

The performance and durability of various types of fundoplication are variable when stratified by disease severity. To date, magnetic sphincter augmentation (MSA) has not been evaluated in this context. We designed this study to determine the efficacy of MSA in the treatment of severe GERD.

STUDY DESIGN

Guided by previous studies, a DeMeester score (DMS) ≥ 50 was used as a cutoff point to define severe reflux disease. Subjects were divided into 2 groups using this cutoff, and outcomes of severe cases were compared with those with less severe disease (DMS < 50).

RESULTS

A total of 334 patients underwent MSA. Patients with severe disease had a higher mean preoperative DMS compared with those with mild to moderate GERD (79.2 [53.2] vs 22.8 [13.7], p < 0.0001). At a mean postoperative follow-up of 13.6 (10.4) months, there was no difference between the mean GERD Health-Related Quality of Life (HRQL) total scores in patients with severe disease compared with those with less severe GERD (8.8 [10] vs 9.2 [10.8], p = 0.9204). Postoperative mean DMS was not different between groups (17.3[23.0] vs 14.1[33.9], p = 0.71), and there was no difference in the prevalence of esophagitis (p = 0.52). Patients with severe disease were less likely to be free from use of proton pump inhibitors after surgery (85% vs 93.1%, p = 0.041). There were similar rates of postoperative dysphagia (10% vs 14%, p = 0.42) and need for device removal (3% vs 5%, p = 0.7463).

CONCLUSIONS

MSA is an effective treatment in patients with severe GERD and leads to significant clinical improvement across the spectrum of disease severity, with few objective outcomes being superior in patients with mild-to-moderate reflux disease.

Measurement of outflow resistance imposed by magnetic sphincter augmentation: defining normal values and clinical implication

Introduction

No manometric criteria have been defined to select patients for magnetic sphincter augmentation (MSA). The first step to establish such criteria is to measure the outflow resistance at esophagogastric junction (EGJ) imposed by MSA. This resistance needs to be overcome by the esophageal contraction in order for the esophagus to empty and to avoid postoperative dysphagia. This study was designed to measure the outflow resistance caused by MSA in patients free of postoperative dysphagia.

Methods

Records of the patients who underwent MSA in our institution were reviewed. A group of MSA patients with excellent functional outcome, who were free of clinically significant postoperative dysphagia, were selected. These patients then underwent high-resolution impedance manometry (HRIM) at a target date of 1 year after surgery. The outflow resistance was measured by the esophageal intrabolus pressure (iBP) recorded 2 cm proximal to the lower esophageal sphincter (LES).

Results

The study population consisted of 43 patients. HRIM was performed at mean of 20.4 (10.4) months after surgery. The mean (SD) amplitude of the iBP was 13.5 (4.3) before surgery and increased to 19.1 (5.6) after MSA (p < 0.0001). Patients with a smaller size LINX device (≤ 14 beads) had a similar iBP when compared to those with a larger device (> 15 beads) [19.7 (4.5) vs. 18.4 (5.9), p = 0.35]. There was a significant correlation between the iBP and % incomplete bolus clearance [Spearman R: 0.44 (95% CI 0.15–0.66), p = 0.0032]. The 95th percentile value for iBP after MSA was 30.4 mmHg.

Conclusion

The EGJ outflow resistance measured by iBP is increased after MSA. The upper limit of normal for iBP is 30 mmHg in this cohort of patients who were free of dysphagia after MSA. This degree of resistance needs to be overcome by distal esophageal contraction and will likely be requisite to prevent persistent postoperative dysphagia.

Esophageal Squamous Cell Carcinoma After Radiofrequency Catheter Ablation Thermal Injury

Radiofrequency ablation is a common treatment for atrial fibrillation, and esophageal complications are exceedingly rare. This report describes the case of a patient with no other known cancer risk factors who had esophageal squamous cell carcinoma that developed at the site of esophageal thermal injury, which occurred during a radiofrequency catheter ablation procedure.

COVID-19 outbreak and surgical practice: The rationale for suspending non-urgent surgeries and role of testing modalities

One-hundred years after the 1918-19 H1N1 flu pandemic and 10 years after the 2009 H1N1 flu pandemic, another respiratory virus has now inserted itself into the human population. Severe acute respiratory syndrome coronavirus has become a critical challenge to global health with immense economic and social disruption. In this article we review salient aspects of the coronavirus disease 2019 (COVID-19) outbreak that are relevant to surgical practice. The emphasis is on considerations during the pre-operative and post-operative periods as well as the utility and limitations of COVID-19 testing. The focus of the media during this pandemic is centered on predictive epidemiologic curves and models. While epidemiologists and infectious disease physicians are at the forefront in the fight against COVID-19, this pandemic is also a "stress test" to evaluate the capacity and resilience of our surgical community in dealing with the challenges imposed to our health system and society. As recently pointed out by Dr. Anthony Fauci, the virus decides the timelines in the models. However, the models can also change based on our decisions and behavior. It is our role as surgeons, to make every effort to bend the curves against the virus' will.

COVID-19 outbreak and endoscopy: Considerations in patients encountered in a foregut surgery practice

Severe acute respiratory syndrome coronavirus has become a critical challenge to global health. Since the arrival of coronavirus disease 2019 in the United States, several government agencies and professional societies have issued guidelines to healthcare systems and medical providers. Endoscopy is a substantial portion of the practice of many general surgeons in the United States. With upper endoscopy, manipulation of the upper aerodigestive tract can turn the droplets to an aerosolized form and increase the likelihood of transmission and therefore is considered a high-risk procedure. In this article we review some aspects of the coronavirus disease 2019 outbreak that are relevant to practice of surgical endoscopy. The emphasis of this communication is on the mode of transmission, previous experiences during other coronavirus outbreaks and society guidelines. We then highlight the changes that we have made to our practice to incorporate these factors to improve the safety of patients, health care providers, and community as a whole.

A novel gene signature for predicting response to chemoradiotherapy in locally advanced esophageal adenocarcinoma

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Background: While neoadjuvant chemoradiotherapy (CRT) has emerged as an important treatment modality in patients with locally advanced esophageal adenocarcinoma (EAC), ~60%-70% of patients do not respond to such treatments; but are exposed to their toxicity nonetheless. This highlights the clinical need for the development of biomarkers that can robustly predict response to CRT and spare others from the toxicity and expense associated with these treatments. Herein, we systematically and comprehensively identified a biomarker signature that predicts response to neoadjuvant therapy in EAC patients. Methods: A cohort of 31 EAC patients treated with chemotherapy or chemoradiotherapy was assembled, with a majority of patients receiving carboplatin, paclitaxel and concurrent radiotherapy. Specifically, we performed a capture based targeted sequencing in paired biopsy specimens obtained at baseline and 3-6 weeks post-treatment. In addition, we also analyzed the predictive potential of a panel of immune-related genes (TIM3, LAG3, IDO1 and CXCL9) in these matched pre- and post-treatment tissues. Results: In our cohort, based upon pathologic response to neoadjuvant CRT, 8 EAC patients were categorized as non-responders, while 23 were deemed as responders to CRT. Among responders, the most frequently mutated genes were MKI67, SYNE1, PCLO, RECQL4, MSH3, NOTCH2, ILR7, CIITA, LRRK2 and EML4, and the overall tumor mutation burden (TMB) was significantly reduced for these genes in post-treatment samples ( P=5.73E-03). Similarly, in non-responders NLRP1, MAP3K1, ASMTL, and ALK harbored frequent mutations, and the TMB was significantly reduced for these genes in post-treatment samples ( P=5.57E-03). We compared responders and non-responders from the pre-treatment samples and identified differentially mutated genes including EPHA5, ZNF217, RELN, PALB2 and MYO18A. Similarly, responders had all four immune-related genes significantly up-regulated in post-treatment samples than pre-treatment samples. We constructed a risk-stratification model that comprised of mutational score from 5 differentially mutated genes, together with 4 immune-related genes, which achieved an AUC of 0.96 in predicting response to CRT in EAC patients ( P=1.03E-04). Conclusions: Using a systematic biomarker discovery approach, we have developed a novel biomarker signature that robustly predicts response to CRT in EAC patients and has a significant potential for personalized management of locally advanced EAC patients.

A novel gene signature for predicting response to chemoradiotherapy in esophageal adenocarcinoma

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Background: While neoadjuvant chemoradiotherapy (CRT) has emerged as an important treatment modality in patients with locally advanced esophageal adenocarcinoma (EAC), ~60%-70% of patients do not respond to such treatments; but are exposed to their toxicity nonetheless. This highlights the clinical need for the development of biomarkers that can robustly predict response to CRT and spare others from the toxicity and expense associated with these treatments. Herein, we systematically identified a biomarker signature that predicts response to CRT in EAC patients. Methods: Using a clinical-trial driven cohort of 25 EAC patients treated with 5- fluorouracil plus carboplatin and concurrent radiation therapy, we performed whole-exome sequencing (WES) in paired biopsy specimens obtained at baseline and 3-6 weeks post-treatment. In addition, we also analyzed the predictive potential of a panel of immune-related genes (TIM3, LAG3, IDO1 and CXCL9) in these matched tissues. Results: In our cohort, based upon RECIST criteria, 14 EAC patients were categorized as non-responders, while 11 were deemed as responders to CRT. Among responders, the most frequently mutated genes were NOTCH1, NOTCH2, NOTCH3, and MLL2; and the overall tumor mutation burden (TMB) was significantly reduced for these genes in post-treatment specimens (P<0.001). In contrast, in non-responders, NFE2L2, KEAP1, FAT1, FAT2, FAT3 and PIK3CA, harbored frequent mutations. Similarly, all four immune-related genes were significantly up-regulated in post-treatment specimens (p<0.05-0.001). Interestingly, the progression-free survival was significantly greater in patients with lower TMB (64.1%, p=0.04) and increased immunogenic scoring (62.7%, p=0.01). We finally constructed a risk-stratification model that comprised of mutational scores from 10 most frequently mutated genes, together with 4 immune-related genes, which achieved an AUC of 0.83 in predicting response to CRT in EAC patients. Conclusions: Using a systematic biomarker discovery approach, we have developed a novel biomarker signature that robustly predicts response to CRT in EAC patients and has a significant potential for personalized management of EAC patients.

Extracellular Matrix Degradation Products Downregulate Neoplastic Esophageal Cell Phenotype

IMPACT STATEMENT

Extracellular matrix (ECM) biomaterials were used to treat esophageal cancer patients after cancer resection and promoted regrowth of normal mucosa without recurrence of cancer. The present study investigates the mechanisms by which these materials were successful to prevent the cancerous phenotype. ECM downregulated neoplastic esophageal cell function (proliferation, metabolism), but normal esophageal epithelial cells were unaffected in vitro, and suggests a molecular basis (downregulation of PI3K-Akt, cell cycle) for the promising clinical results. The therapeutic effect appeared to be enhanced using homologous esophageal ECM. This study suggests that ECM can be further investigated to treat cancer patients after resection or in combination with targeted therapy.

The Dynamic and Transient Immune Microenvironment in Locally Advanced Esophageal Adenocarcinoma Post Chemoradiation

OBJECTIVE

The aim of this study was to assess the impact of chemoradiation on the immune microenvironment to influence and optimally design future neoadjuvant clinical trials.

SUMMARY BACKGROUND DATA

Programmed death (PD)-1 inhibitors in metastatic gastroesophageal cancer have demonstrated response rates of approximately 25% in programmed death ligand-1 (PD-L1+) tumors. Unfortunately, the majority of patients do not respond. Therefore, a rationale strategy of combining immunotherapeutic agents with chemoradiation in earlier stage esophageal cancer may prevent metastatic disease in patients.

METHODS

To determine the effects of chemoradiation on resected esophageal adenocarcinomas, we examined the immune microenvironment pre- and post-chemoradiation using immunohistochemistry, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), and functional analysis of tumor-infiltrating lymphocytes. Additionally, to assess the duration and dependency of radiation-induced PD-L1 upregulation, a surgical rat reflux model of esophageal adenocarcinoma is used. First, tumor-bearing animals were dosed with single-fraction 13Gy or 16Gy radiation to determine safety, dose correlation, and PD-L1 upregulation using qRT-PCR post-radiation. Next, longitudinal PD-L1 expression levels within individual animals were determined using serial endoscopic biopsies at baseline, 1, 5, and 9 weeks post 16Gy radiation.

RESULTS

The majority of cancers displayed enhanced interferon γ and activated CD8+ T lymphocytes at the tumor stroma interface. These tumors also demonstrated enhanced upregulation of PD-L1 and multiple other immune checkpoints including TIM3, GITR, IDO1, LAG3, OX40, and KIR. The animal model results indicated PD-L1 upregulation is dose-dependent and transiently elevated post radiation exposure.

CONCLUSIONS

Collectively, these findings provide insights into the evolving immune landscape after chemoradiation and have significant implications for neoadjuvant trial designs that will combine radiotherapy with immune checkpoint inhibitors.

Comparison of surgical payer costs and implication on the healthcare expenses between laparoscopic magnetic sphincter augmentation (MSA) and laparoscopic Nissen fundoplication (LNF) in a large healthcare system

Introduction

Magnetic sphincter augmentation (MSA) is a promising antireflux surgical treatment. The cost associated with the device may be perceived as a drawback by payers, which may limit the adoption of this technique. There are limited data regarding the cost of MSA in the management of reflux disease. The aims of the study were to report the clinical outcome and quality of life measures in patients after MSA and to compare the pharmaceutical and procedure payer costs and the disease-related and overall expense of MSA compared to laparoscopic Nissen fundoplication (LNF) from a payer perspective.

Methods and procedures

This prospective observational study was performed in conjunction with the region’s largest health insurance company. Data were collected on patients who underwent MSA over a 2-year period beginning in September 2015 at the study network hospitals. The LNF comparison group was procured from members’ claims data of the payer. Inclusion was predicated by patients having continuous coverage during study period. The total procedural reimbursement and the disease-related and overall medical claims submitted up to 12 months prior to surgery and up to 12 months following surgery were obtained. The payer reimbursement data are presented as allowed cost per member per month (PMPM). These values were then compared between groups.

Results

There were 195 patients who underwent MSA and 1131 that had LNF. MSA results in comparable symptom control, PPI elimination rate, and quality of life measures compared to values reported for LNF in the literature. The median (IQR) reimbursement of surgery was $13,522 (13,195–14,439) for those who underwent MSA and $13,388 (9951–16,261) for patients with LNF, p = 0.02. In patients who underwent MSA, the median reimbursement related to the upper gastrointestinal disease was $ 305 PMPM, at 12 months prior to surgery and $ 104 at 12 months after surgery, representing 66% decrease in cost. These values were $ 233 PMPM and $126 PMPM for patients who underwent LNF, representing a 46% decrease (p = 0.0001). At 12 months following surgery, the reimbursement for overall medical expenses had decreased by 10.7% in the MSA group and 1.4% in the LNF group when compared to the preoperative baseline reimbursement. The reimbursement for PPI use after surgery showed a 95% decrease in the MSA group and 90% among LNF group when compared to the preoperative baseline (p = 0.10).

Conclusion

When compared with LNF, MSA results in a reduction of disease-related expenses for the payer in the year following surgery. While MSA is associated with a higher procedural payer cost compared to LNF, payer costs may offset due to reduction in the expenses after surgery.

Prognostic immune markers for recurrence and survival in locally advanced esophageal adenocarcinoma

Treatment options and risk stratification for esophageal adenocarcinomas (EAC) currently rely on pathological criteria such as tumor staging. However, with advancement in immune modulated treatments, there is a need for accurate predictive biomarkers that will help identify high-risk patients and provide novel therapeutic targets. Hence, we analyzed as prognostic classifiers a host of histopathological parameters in conjunction with novel immune biomarkers. Specifically, gene expression levels for CXCL9, IDO1, LAG3, and TIM3 were established in treatment naïve samples. Additionally, PD-L1 and CD8 positivity was determined by immunohistochemical staining. Based on our finding, a Cox model consisting of pathological complete response (CR), LAG3, and CXCL9 provided improved predictability for disease-free survival (DFS) compared to CR alone, and it demonstrated statistical significance for predictability of recurrence (p=0.0001). Likewise, for overall survival (OS), a Cox model constituted of TIM3, CR, and IDO1 performed better than CR alone, and it demonstrated statistical significance for predictability of survival (p = 0.0004). TIM3 was identified as the best predictor for OS (HR=4.43, p=0.0023). In conclusion, given the paucity of treatment options for EAC, evaluation of these biomarkers early in the disease course will lead to better risk stratification of patients and much needed alternatives for improved therapy.

Enhancing the Detection of Barrett Esophagus

In Western countries, the incidence of esophageal adenocarcinoma has increased rapidly in parallel with its premalignant condition, Barrett esophagus (BE). Unlike colonoscopy, endoscopic screening for BE is not currently recommended for all patients; however, surveillance endoscopy is advocated for patients with established BE. Novel imaging and sampling techniques have been developed and investigated for the purpose of improving the detection of Barrett esophagus, dysplasia, and neoplasia. This article discusses several screening and surveillance techniques, including Seattle protocol, chromoendoscopy, electronic chromoendoscopy, wide area transepithelial sampling with 3-dimensional analysis, nonendoscopic sampling devices, and transnasal endoscopy.

The Potential Clinical Utility of Circulating Tumor DNA in Esophageal Adenocarcinoma: From Early Detection to Therapy

Esophageal adenocarcinoma (EAC) is a lethal cancer requiring improved screening strategies and treatment options due to poor detection methods, aggressive progression, and therapeutic resistance. Emerging circulating tumor DNA (ctDNA) technologies may offer a unique non-invasive strategy to better characterize the highly heterogeneous cancer and more clearly establish the genetic modulations leading to disease progression. The presented review describes the potential advantages of ctDNA methodologies as compared to current clinical strategies to improve clinical detection, enhance disease surveillance, evaluate prognosis, and personalize treatment. Specifically, we describe the ctDNA-targetable genetic markers of prognostic significance to stratify patients into risk of progression from benign to malignant disease and potentially offer cost-effective screening of established cancer. We also describe the application of ctDNA to more effectively characterize the heterogeneity and particular mutagenic resistance mechanisms in real-time to improve prognosis and therapeutic monitoring strategies. Lastly, we discuss the inconsistent clinical responses to currently approved therapies for EAC and the role of ctDNA to explore the dynamic regulation of novel targeted and immunotherapies to personalize therapy and improve patient outcomes. Although there are clear limitations of ctDNA technologies for immediate clinical deployment, this review presents the prospective role of such applications to potentially overcome many of the notable hurdles to treating EAC patients. A deeper understanding of complex EAC tumor biology may result in the progress toward improved clinical outcomes.