Gas-Bloat Syndrome after Magnetic Sphincter Augmentation: Incidence, Natural History, Risk Factors, and Impact on Surgical Outcomes Over Time

BACKGROUND

The notion that gas-bloat syndrome (GBS) after magnetic sphincter augmentation (MSA) is less detrimental has not been substantiated by data. This study aimed to identify the incidence, natural history, risk factors, and impact on outcomes of GBS after MSA.

STUDY DESIGN

Records of patients who underwent MSA at our institution were reviewed. GBS was defined as a score of 4 or more on the gas bloat-specific item within the GERD health-related quality-of-life (GERD-HRQL) questionnaire. Preoperative clinical and objective testing data were compared between those with and without GBS at 1 year using univariate followed by multivariable analysis. GBS evolution over time and its impact on outcomes were assessed in those with 1- and 2-year follow-up.

RESULTS

A total of 489 patients underwent MSA. At a mean (SD) follow-up of 12.8 (2.1) months, patient satisfaction was 88.8%, 91.2% discontinued antisecretory medications, and 74.2% achieved DeMeester score normalization.At 1 year, 13.3% of patients developed GBS, and had worse GERD-HRQL scores and antisecretory medication use and satisfaction (p < 0.0001). DeMeester score normalization was comparable (p = 0.856). Independent predictors of GBS were bloating (odds ratio [OR] 1.8, p = 0.043), GERD-HRQL score greater than 30 (OR 3, p = 0.0010), and MSA size 14 or less beads (OR 2.5, p = 0.004). In a subgroup of 239 patients with 2-year follow-up, 70.4% of patients with GBS at 1 year had resolution by 2 years. The GERD-HRQL total score improved when GBS resolved from 11 (7 to 19) to 7 (4 to 10), p = 0.016. Patients with persistent GBS at 2 years had worse 2-year GERD-HRQL total scores (20 [5 to 31] vs 5 [3 to 12], p = 0.019).

CONCLUSIONS

GBS affects 13.3% of patients at 1 year after MSA and substantially diminishes outcomes. However, GBS resolves spontaneously with quality-of-life improvement. Patients with preoperative bloating, high GERD-HRQL scores, or small MSA devices are at greatest risk of this complication.

Magnetic Sphincter Augmentation for Laryngopharyngeal Reflux: An Assessment of Efficacy and Predictors of Outcome

INTRODUCTION

Magnetic sphincter augmentation (MSA) is an effective treatment for typical reflux symptoms, but data on its impact on laryngopharyngeal reflux (LPR) is limited. This study aimed to determine the efficacy of MSA for LPR and to identify predictors of outcome.

METHODS

This was a retrospective review of 775 patients who underwent MSA between 2013 and 2021. LPR was defined as presence of atypical reflux symptoms and a reflux symptom index (RSI) score >13. Favorable outcome was defined as primary symptom resolution, freedom from proton pump inhibitors, and five-point improvement or RSI score normalization. Preoperative clinical, high-resolution manometry, and impedance-pH data were analyzed for impact on favorable outcome using univariate followed by multivariable analysis.

RESULTS

There were 128 patients who underwent MSA for LPR. At a mean (SD) follow-up of 13 (5.4) months, favorable outcome was achieved by 80.4% of patients, with median (IQR) RSI score improving from 29 (22-35) to 9 (4-17), (P < 0.001). Independent predictors of favorable outcome on multivariable analysis included LPR with typical reflux symptoms [OR (95% CI): 8.9 (2.3-31.1), P = 0.001], >80% intact swallow on high-resolution manometry [OR (95% CI): 3.8 (1.0-13.3), P = 0.035], upper esophageal sphincter (UES) resting pressure >34 mmHg [OR (95% CI): 4.1 (1.1-14.1), P = 0.027] and short total proximal acid clearance time [OR (95% CI): 1.1 (1.0-1.1), P = 0.031]. Impedance parameters including number of LPR events, full column reflux and proximal acid exposure events were similar between outcome groups (P > 0.05).

CONCLUSION

MSA is an effective surgery for patients with LPR. Patients with concomitant typical reflux symptoms, normal esophageal body motility, and competent UES benefit the most from surgery. Individual impedance-pH parameters were not associated with outcome.

Sitravatinib combined with PD-1 blockade enhances cytotoxic T-cell infiltration by M2 to M1 tumor macrophage repolarization in esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is a leading cause of cancer-related mortality. Sitravatinib is a novel multi-gene tyrosine kinase inhibitor (TKI) that targets tumor-associated macrophage (TAM) receptors, VEGF, PDGF and c-Kit. Currently, sitravatinib is actively being studied in clinical trials across solid tumors and other TKIs have shown efficacy in combination with immune checkpoint inhibitors (ICI) in cancer models. In this study, we investigated the anti-tumor activity of sitravatinib alone and in combination with PD-1 blockade in an EAC rat model. Treatment response was evaluated by mortality, pre- and post-treatment MRI, gene expression, immunofluorescence and immunohistochemistry. Our results demonstrated adequate safety and significant tumor shrinkage in animals treated with sitravatinib, and more profoundly, sitravatinib and PD-1 inhibitor, AUNP-12 (P < 0.01). Suppression of TAM receptors resulted in increased gene expression of pro-inflammatory cytokines and decreased expression of anti-inflammatory cytokines, enhanced infiltration of CD8+ T cells, and M2 to M1 macrophage phenotype repolarization in the tumor microenvironment of treated animals (P < 0.01). Moreover, endpoint immunohistochemistry staining corroborated the anti-tumor activity by downregulation of Ki67 and upregulation of Caspase-3 in the treated animals. Additionally, pretreatment gene expression of TAM receptors and PD-L1 were significantly higher in major responders compared with the non-responders, in animals that received sitravatinib and AUNP-12 (P < 0.02), confirming that TAM suppression enhances the efficacy of PD-1 blockade. In conclusion, this study proposes a promising immunomodulatory strategy using a multi-gene TKI to overcome developed resistance to an ICI in EAC, establishing rationale for future clinical development.

Neoadjuvant nivolumab or nivolumab plus LAG-3 inhibitor relatlimab in resectable esophageal/gastroesophageal junction cancer: a phase Ib trial and ctDNA analyses

Gastroesophageal cancer dynamics and drivers of clinical responses with immune checkpoint inhibitors (ICI) remain poorly understood. Potential synergistic activity of dual programmed cell death protein 1 (PD-1) and lymphocyte-activation gene 3 (LAG-3) inhibition may help improve immunotherapy responses for these tumors. We report a phase Ib trial that evaluated neoadjuvant nivolumab (Arm A, n = 16) or nivolumab-relatlimab (Arm B, n = 16) in combination with chemoradiotherapy in 32 patients with resectable stage II/stage III gastroesophageal cancer together with an in-depth evaluation of pathological, molecular and functional immune responses. Primary endpoint was safety; the secondary endpoint was feasibility; exploratory endpoints included pathological complete (pCR) and major pathological response (MPR), recurrence-free survival (RFS) and overall survival (OS). The study met its primary safety endpoint in Arm A, although Arm B required modification to mitigate toxicity. pCR and MPR rates were 40% and 53.5% for Arm A and 21.4% and 57.1% for Arm B. Most common adverse events were fatigue, nausea, thrombocytopenia and dermatitis. Overall, 2-year RFS and OS rates were 72.5% and 82.6%, respectively. Higher baseline programmed cell death ligand 1 (PD-L1) and LAG-3 expression were associated with deeper pathological responses. Exploratory analyses of circulating tumor DNA (ctDNA) showed that patients with undetectable ctDNA post-ICI induction, preoperatively and postoperatively had a significantly longer RFS and OS; ctDNA clearance was reflective of neoantigen-specific T cell responses. Our findings provide insights into the safety profile of combined PD-1 and LAG-3 blockade in gastroesophageal cancer and highlight the potential of ctDNA analysis to dynamically assess systemic tumor burden during neoadjuvant ICI that may open a therapeutic window for future intervention. ClinicalTrials.gov registration: NCT03044613 .

Esophageal body adaptation to Nissen fundoplication: Increased esophagogastric outflow resistance yields delayed and sustained peristaltic contractions without increased amplitude

BACKGROUND

Improvement in lower esophageal sphincter (LES) competency after laparoscopic Nissen fundoplication (LNF) is well established, yet esophageal body physiology data are limited. We aimed to describe the impact of LNF on whole esophagus physiology using standard and novel manometric characteristics.

METHODS

A cohort of patients with an intact fundoplication without herniation and no postoperative dysphagia were selected and underwent esophageal manometry at one-year after surgery. Pre- and post-operative manometry files were reanalyzed using standard and novel manometric characteristics and compared.

KEY RESULTS

A total of 95 patients were included in this study. At 16.1 (8.7) months LNF increased LES overall and abdominal length and resting pressure (p < 0.0001). Outflow resistance (IRP) increased [5.8 (3-11) to 11.1 (9-15), p < 0.0001] with a 95th percentile of 20 mmHg in this cohort of dysphagia-free patients. Distal contractile integral (DCI) also increased [1177.0 (667-2139) to 1321.1 (783-2895), p = 0.002], yet contractile amplitude was unchanged (p = 0.158). There were direct correlations between pre- and post-operative DCI [R: 0.727 (0.62-0.81), p < 0.0001] and postoperative DCI and postoperative IRP [R: 0.347 (0.16-0.51), p = 0.0006]. Contractile front velocity [3.5 (3-4) to 3.2 (3-4), p = 0.0013] was slower, while distal latency [6.7 (6-8) to 7.4 (7-9), p < 0.0001], the interval from swallow onset to proximal smooth muscle initiation [4.0 (4-5) to 4.4 (4-5), p = 0.0002], and the interval from swallow onset to point when the peristaltic wave meets the LES [9.4 (8-10) to 10.3 (9-12), p < 0.0001] were longer. Esophageal length [21.9 (19-24) to 23.2 (21-25), p < 0.0001] and transition zone (TZ) length [2.2 (1-3) to 2.5 (1-4), p = 0.004] were longer. Bolus clearance was inversely correlated with TZ length (p = 0.0002) and time from swallow onset to proximal smooth muscle initiation (p < 0.0001). Bolus clearance and UES characteristics were unchanged (p > 0.05).

CONCLUSIONS & INFERENCES

Increased outflow resistance after LNF required an increased DCI. However, this increased contractile vigor was achieved through sustained, not stronger, peristaltic contractions. Increased esophageal length was associated with increased TZ and delayed initiation of smooth muscle contractions.

The Dubai Definition and Diagnostic Criteria of Laryngopharyngeal Reflux: The IFOS Consensus

OBJECTIVE

The objective of this work was to gather an international consensus group to propose a global definition and diagnostic approach of laryngopharyngeal reflux (LPR) to guide primary care and specialist physicians in the management of LPR.

METHODS

Forty-eight international experts (otolaryngologists, gastroenterologists, surgeons, and physiologists) were included in a modified Delphi process to revise 48 statements about definition, clinical presentation, and diagnostic approaches to LPR. Three voting rounds determined a consensus statement to be acceptable when 80% of experts agreed with a rating of at least 8/10. Votes were anonymous and the analyses of voting rounds were performed by an independent statistician.

RESULTS

After the third round, 79.2% of statements (N = 38/48) were approved. LPR was defined as a disease of the upper aerodigestive tract resulting from the direct and/or indirect effects of gastroduodenal content reflux, inducing morphological and/or neurological changes in the upper aerodigestive tract. LPR is associated with recognized non-specific laryngeal and extra-laryngeal symptoms and signs that can be evaluated with validated patient-reported outcome questionnaires and clinical instruments. The hypopharyngeal-esophageal multichannel intraluminal impedance-pH testing can suggest the diagnosis of LPR when there is >1 acid, weakly acid or nonacid hypopharyngeal reflux event in 24 h.

CONCLUSION

A global consensus definition for LPR is presented to improve detection and diagnosis of the disease for otolaryngologists, pulmonologists, gastroenterologists, surgeons, and primary care practitioners. The approved statements are offered to improve collaborative research by adopting common and validated diagnostic approaches to LPR.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:1614-1624, 2024.

Impact of Change in Sizing Protocol on Outcome of Magnetic Sphincter Augmentation

OBJECTIVE

To evaluate and compare magnetic sphincter augmentation (MSA) device sizing protocols on postoperative outcomes and dysphagia.

SUMMARY BACKGROUND DATA

Among predictors of dysphagia after MSA, device size is the only factor that may be modified. Many centers have adopted protocols to increase device size. However, there is limited data on the impact of MSA device upsizing protocols on the surgical outcomes.

METHODS

Patients who underwent MSA were implanted with 2 or 3-beads above the sizing device's pop-off point (POP). Clinical and objective outcomes >1-year after surgery were compared between patients implanted with POP+2-vs-POP+3 sizing protocols. Multiple subgroups were analyzed for benefit from upsizing. Pre- and postoperative characteristics were compared between size patients received, regardless of protocol.

RESULTS

A total of 388 patients were implanted under POP+2 and 216 under POP+3. At a mean of 14.2(7.9) months pH normalization was 73.6% and 34.1% required dilation, 15.9% developed persistent dysphagia, and 4.0% required removal. Sizing protocol had no impact on persistent dysphagia ( P =0.908), pH normalization ( P =0.822), or need for dilation ( P =0.210) or removal ( P =0.191). Subgroup analysis found that upsizing reduced dysphagia in patients with <80 percent peristalsis (10.3-vs-31%, P =0.048) or DCI >5000 (0-vs-30.4%, P =0.034). Regardless of sizing protocol, as device size increased there was a stepwise increase in percent male sex ( P <0.0001), BMI>30 ( P <0.0001), and preoperative hiatal hernia>3 cm ( P <0.0001), LA grade C/D esophagitis ( P <0.0001), and DeMeester score ( P <0.0001). Increased size was associated with decreased pH-normalization ( P <0.0001) and need for dilation ( P =0.043) or removal ( P =0.014).

CONCLUSIONS

Upsizing from POP+2 to POP+3 does not reduce dysphagia or affect other MSA outcomes; however, patients with poor peristalsis or hypercontractile esophagus do benefit. Regardless of sizing protocol, preoperative clinical characteristics varied among device sizes, suggesting size is not a modifiable factor, but a surrogate for esophageal circumference.

Need for frequent dilations after magnetic sphincter augmentation: an assessment of associated factors and outcomes

BACKGROUND

Dysphagia is the most common complaint after magnetic sphincter augmentation (MSA), with nearly one-third of patients requiring at least one dilation following MSA. A subset of patients require frequent dilations, but there is a paucity of data on the characteristics of this population. This study aimed to identify predictors of the need for frequent dilations within the first year after implant and to assess these patients' outcomes.

METHODS

This is a retrospective review of prospectively collected data of patients who underwent MSA over an 8-year period. Frequent dilations were defined as 2 or more dilations within 1 year of surgery. Patients completed baseline and 1-year postoperative GERD-HRQL questionnaires and objective physiology testing. Baseline demographic, clinical characteristics, and objective testing data were compared between patients who did and did not require frequent dilations.

RESULTS

A total of 697 (62.7% female) patients underwent MSA, with 62 (8.9%) patients requiring frequent dilation. At a mean (SD) of 12.3 (3.4) months follow-up, the frequent dilation group had higher median GERD-HRQL total scores (21.0 vs. 5.0, p < 0.001), PPI use (20.8% vs.10.1%, p = 0.023), dissatisfaction (46.7% vs. 11.6%, p < 0.001), and device removal (25.8% vs. 2.2%, p < 0.001) rates. Acid normalization was comparable (p = 0.997). Independent predictors of frequent dilation included preoperative odynophagia (OR 2.85; p = 0.001), IRP > 15 mmHg (OR 2.88; p = 0.006), and > 30% incomplete bolus clearance (OR 1.94; p = 0.004). At a mean (SD) of 15.7 (10.7) months, 28 (45.1%) patients underwent device removal after frequent dilation. Independent predictors of device removal after frequent dilation within 5 years of surgery were preoperative odynophagia (OR 7.18; p = 0.042), LES resting pressure > 45 mmHg (OR 28.5; p = 0.005), and ≥ 10% failed swallows (OR 23.5; p < 0.001).

CONCLUSIONS

The need for frequent dilations after MSA is a marker for poor symptom control, dissatisfaction, and device removal. Patients with preoperative odynophagia, high LES pressures, and poor esophageal motility should be counseled of their risk for these poor outcomes.

Ineffective esophageal motility: The impact of change of criteria in Chicago Classification version 4.0 on predicting outcome after magnetic sphincter augmentation

BACKGROUND

The most recent update of the Chicago Classification (CCv4.0) attempts to provide a more clinically relevant definition for ineffective esophageal motility (IEM). The impact of this new definition on predicting outcome after antireflux surgery is unknown. The aim of this study was to compare utility of IEM diagnosis based on CCv4.0 to CCv3.0 in predicting surgical outcome after magnetic sphincter augmentation (MSA) and to assess any additional parameters that hold value in future definitions.

METHODS

Records of 336 patients who underwent MSA at our institution between 2013 and 2020 were reviewed. Preoperative manometry files were re-analyzed using both Chicago Classification version 3.0 (CCv3.0) and CCv4.0 definitions of IEM. The utility of each IEM definition in predicting surgical outcome was then compared. Individual manometric components and impedance data were also assessed.

KEY RESULTS

Immediate dysphagia was reported by 186 (55.4%) and persistent dysphagia by 42 (12.5%) patients. CCv3.0 IEM criteria were met by 37 (11%) and CCv4.0 IEM by 18 (5.4%) patients (p = 0.011). CCv3.0 and CCv4.0 IEM were equally poor predictors of immediate (AUC = 0.503 vs. 0.512, p = 0.7482) and persistent (AUC = 0.519 vs. 0.510, p = 0.7544) dysphagia. The predicted dysphagia probability of less than 70% bolus clearance (BC) was 17.4%, higher than CCv4.0 IEM at 16.7%. When BC was incorporated into CCv4.0 IEM criteria, the probability increased significantly to 30.0% (p = 0.0042).

CONCLUSIONS & INFERENCES

The CCv3.0 and CCv4.0 of IEM are poor predictors of dysphagia after MSA. Adding BC to the new definition improves its predictive utility and should be considered in future definitions.

The impact of delayed gastric emptying as measured by gastric emptying scintigraphy on the outcome of magnetic sphincter augmentation

INTRODUCTION

The impact of delayed gastric emptying (DGE) on the outcome of anti-reflux surgery (ARS) is controversial. There is concern that poor gastric emptying diminishes outcomes. Magnetic sphincter augmentation (MSA) may have a comparatively mild impact on gastric physiology, but the relationship between DGE and MSA outcomes is unknown. This study aims to evaluate the relationship between objective DGE and MSA outcomes over time.

METHODS

Patients who completed gastric emptying scintigraphy (GES) prior to MSA between 2013 and 2021 were included. DGE was defined as a 4 h retention > 10% or half emptying time > 90 min on GES. Outcomes were compared between DGE and normal gastric emptying (NGE) groups at 6 months, 1 and 2 years. Sub-analysis of patients with severe (> 35%) DGE and correlation analysis between 4-h retention and symptom and acid-normalization were performed.

RESULTS

The study population consisted of 26 (19.8%) patients with DGE and 105 with NGE. DGE was associated with more 90-days readmissions (18.5 vs 2.9%, p = 0.009). At 6 months patients with DGE had higher median (IQR) GERD-HRQL total [17.0(10-29) vs 5.5(3-16), p = 0.0013], heartburn [1(1-3) vs 0(0-1), p = 0.0010) and gas-bloat [4(2-5) vs 2(1-3), p = 0.033] scores. Outcomes at 1 and 2 years follow-up were comparable (p > 0.05). From 6 months to 1-year the gas-bloat score decreased from 4(2-5) to 3(1-3), p = 0.041. Total and heartburn scores decreased, but not significantly. Severe DGE (n = 4) patients had lower antiacid medication freedom at 6 months (75 vs 87%, p = 0.014) and 1-year (50 vs 92%, p = 0.046). There were non-significant trends for higher GERD-HRQL scores, dissatisfaction, and removal rates in severe DGE at 6 months and 1-year. There was a weak correlation between 4-h retention and 6-month GERD-HRQL total score [R = 0.253, 95%CI (0.09-0.41), p = 0.039], but not acid-normalization (p > 0.05).

CONCLUSION

Outcomes after MSA are diminished early on in patients with mild-to-moderate DGE, but comparable by 1 year and durable at 2 years. Severe DGE outcomes may be suboptimal.

Chevalier Jackson: father of endoscopic surgery, and champion of women in medicine, social justice, and public health

BACKGROUNDS

Chevalier Jackson (1865-1958) was a pioneering force in the medical world, whose extraordinary contributions to surgery and public health have left an indelible impact. He developed the endoscope and perfected the bronchoscope, and his mastery of these tools enabled him to transform the prognosis of foreign body aspiration from 98% mortality to 98% survival. He was also a passionate advocate of public health chairing the national committee on lye legislation, which culminated in the Caustic Poison Act, responsible for poison and antidote labels. Yet Jackson's accomplishments were not limited to these. The aim of this manuscript was to shed light on Chevalier Jackson's lesser-known contributions to surgical science and culture, and to celebrate and honor the life of this remarkable surgeon.

METHODS

Digital and physical historical records from the National Library of Medicine, Smithsonian Institution, Heinz History Center in Pittsburgh PA, and Sunrise Mill Museum, Montgomery County PA were reviewed for Chevalier Jackson's scientific, cultural, and social contributions to the field of surgery.

RESULTS

Among his lesser-known contributions, Chevalier Jackson was the first to describe erosive esophagitis. He developed the first standardized tracheotomy procedure, still in use today. He was ahead of his time in many ways, pioneering a multidisciplinary approach to medicine, advocating for patient-centered care, and advancing the inclusion of women in the medical profession.

CONCLUSION

Chevalier Jackson's legacy extends far beyond the tools and techniques he invented. He was a champion of social justice, a protector of patients, and an inspiration to medical professionals across the globe.

Magnetic sphincter augmentation and high-resolution manometry: impact of biomechanical properties on esophageal motility and clinical significance for selection and outcomes

Magnetic sphincter augmentation (MSA)was introduced as an alternative to laparoscopic Nissen fundoplication (LNF). This reproducible, outpatient procedure addresses the etiology of gastroesophageal reflux disease by implanting a ring of magnetic beads across the esophagogastric junction (EGJ). MSA is designed to resist effacement of the lower esophageal sphincter (LES) and, similar to LNF, results in restoration of anti-reflux barrier competency by increasing overall length, intraabdominal length and resting pressure of the sphincter. However, the novel use of magnets to augment the physiology of the LES poses unique challenges to the physiology of the EGJ and esophagus. These impacts are best revealed through manometry. The degree of restrictive forces at the EGJ, as measured by intrabolus pressure and integrated relaxation pressure, is higher after MSA compared with LNF. In addition, contrary to the LNF, which retains neurohormonal relaxation capability during deglutition, the magnetic forces remain constant until forcibly opened. Therefore, the burden of overcoming EJG resistance is placed solely on the esophageal body contractile force, as measured by distal contractile integral and distal esophageal amplitude. The main utility of preoperative manometry is in determining whether a patient's esophagus has sufficient contractility or peristaltic reserve to adapt to the challenge of an MSA. Manometric thresholds predictive of MSA outcomes deviate from those used to define named Chicago Classification motility disorders. Therefore, individual preoperative manometric characteristics should be analyzed to aid in risk stratification and patient selection prior to MSA.

Abstract 3374: Circulating cell-free tumor DNA dynamics capture minimal residual disease with neoadjuvant immune checkpoint blockade plus chemoradiotherapy for patients with operable esophageal/gastroesophageal junction cancer

Introduction: There is a critical need to incorporate molecular assessments of minimal residual disease (MRD) during neoadjuvant immunotherapy, in order to identify individuals at high risk for disease recurrence based on analyses of circulating cell-free tumor DNA (ctDNA) landscapes. Here we employed longitudinal liquid biopsies to dynamically assess clinical outcomes with neoadjuvant immuno-chemoradiotherapy in patients with esophageal/gastroesophageal junction (E/GEJ) cancer.

Methods: We utilized targeted error-correction sequencing to perform high-depth ctDNA next-generation sequencing for 141 serial plasma and 32 matched white blood cell (WBC) DNA samples from 32 patients with operable stage II/III E/GEJ cancer that received neoadjuvant immune checkpoint blockade (ICB) with chemoradiotherapy prior to surgery (NCT03044613). ctDNA analyses were performed at baseline, post-ICB induction, after completion of chemoradiotherapy (pre-op), and post-operatively (post-op). Using a tumor-agnostic WBC DNA-informed panel NGS approach we determined the cellular origin of plasma variants, filtering out germline and clonal hematopoiesis (CH) variants and evaluated ctDNA clonal dynamics over time. Molecular MRD was evaluated post-ICB, pre-op and post-op and correlated with recurrence-free (RFS) and overall survival (OS).

Results: Twenty out of 32 patients had detectable ctDNA at any timepoint. Of the 12 patients with undetectable ctDNA, 9 had only CH- and/or germline-derived variants, while 3 patients had no detectable variants of any origin. ctDNA clearance post-ICB was correlated with tumor regression &gt;80% at the time of resection (Fischer’s exact p=0.04). The subset of patients that did not attain complete pathologic response was heterogeneous with respect to ctDNA dynamics; such that ctDNA clearance pre-op identified patients with longer OS despite residual tumor of &gt;0% at the time of resection (log rank p=0.06). Patients with undetectable ctDNA or ctDNA clearance pre-op had a longer RFS (log rank p=0.007) and OS (log rank p=0.03). Molecular MRD was associated with RFS and OS such that patients with ctDNA clearance post-op had longer RFS (log-rank p=0.007) and OS (log-rank p=0.017).

Conclusion: ctDNA clearance post-ICB, pre-op and post-op reflects differential clinical outcomes for patients with E/GEJ cancer receiving neoadjuvant immuno-chemoradiotherapy. Understanding ctDNA dynamics and their relationship with pathological response and long-term outcomes can help identify patients at higher risk for recurrence and open a therapeutic window for future intervention.

Citation Format: Blair V. Landon, Ronan J. Kelly, Ali H. Zaidi, Archana Balan, Jenna V. Canzoniero, Gavin Pereira, Zineb Belcaid, Russell K. Hales, K Ranh Voong, Richard J. Battafarano, Blair A. Jobe, Stephen C. Yang, Stephen Broderick, Jinny Ha, Kellie N. Smith, Elizabeth Thompson, Fyza Y. Shaikh, James R. White, Cynthia L. Sears, Eun J. Shin, Ali I. Amjad, Benny Weksler, Josephine L. Feliciano, Chen Hu, Vincent K. Lam, Valsamo Anagnostou. Circulating cell-free tumor DNA dynamics capture minimal residual disease with neoadjuvant immune checkpoint blockade plus chemoradiotherapy for patients with operable esophageal/gastroesophageal junction cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3374.

The Impact of Ineffective Esophageal Motility on Patients Undergoing Magnetic Sphincter Augmentation

OBJECTIVE

To evaluate and characterize outcomes of MSA in patients with IEM.

SUMMARY BACKGROUND DATA

MSA improves patients with gastroesophageal reflux and normal motility. However, many patients have IEM, which could impact the outcomes of MSA and discourage use.

METHODS

An international, multi-institutional case control study of IEM patients undergoing MSA matched to normal patients was performed. Primary outcomes were new onset dysphagia and need for postoperative interventions.

RESULTS

A total of 105 IEM patients underwent MSA with matching controls. At 1 year after MSA: GERD-Health Related Quality of Life was similar; DeMeester scores in IEM patients improved to 15.7 and 8.5 in controls ( P = 0.021); and normalization of the DeMeester score for IEM = 61.7% and controls = 73.1% ( P = 0.079).In IEM patients, 10/12 (83%) with preop dysphagia had resolution; 11/66 (17%) had new onset dysphagia and 55/66 (83%) never had dysphagia. Comparatively, in non-IEM patients, 22/24 (92%) had dysphagia resolve; 2/24 (8%) had persistent dysphagia; 7/69 (10%) had new onset dysphagia, and 62/69 (90%) never had dysphagia.Overall, 19 (18%) IEM patients were dilated after MSA, whereas 12 (11%) non-IEM patients underwent dilation ( P = 0.151). Nine (9%) patients in both groups had their device explanted.

CONCLUSIONS

Patients with IEM undergoing MSA demonstrate improved quality of life and reduction in acid exposure. Key differences in IEM patients include lower rates of objective GERD resolution, lower resolution of existing dysphagia, higher rates of new onset dysphagia and need for dilation. GERD patients with IEM should be counselled about these possibilities.

Predictors of favorable outcome after pyloroplasty for gastroparesis: should response to pyloric dilation or Botox injection be used as a marker of surgical outcome?

INTRODUCTION

Pyloroplasty and gastric peroral endoscopic myotomy (G-POEM) are effective surgeries for gastroparesis. The primary aim of this study was to evaluate outcomes of pyloroplasty and G-POEM in patients with gastroparesis and determine factors associated with favorable outcome. The secondary aim was to assess the utility of clinical response to preoperative pyloric dilation or botulinum toxin injection (Botox) on surgical outcome, a factor conventionally used as a favorable marker.

METHODS

There were 204 patients who underwent pyloroplasty (n = 177) or G-POEM (n = 27) for gastroparesis at our institution from 2014 to 2021. Demographic and clinical parameters were analyzed to assess their impact on surgical outcome. A subgroup of patients who had pyloric dilation or Botox injection were assessed separately. Favorable outcome was defined as patient reported complete resolution of the predominant gastroparesis symptom.

RESULTS

Favorable outcome was achieved in 78.4% of patients (pyloroplasty: 79.7% and G-POEM: 70.4%, p = 0.274). Among 61 patients where pre- and postoperative gastric emptying studies (GES) were available, mean 4-hour retention significantly improved from 33.5 to 15.0% (p < 0.001) and 77.0% of patients achieved normalization. Favorable outcome was not significantly impacted by etiology of gastroparesis (p = 0.120), GERD (p = 0.518), or primary gastroparesis symptom (p = 0.244). Age ≥ 40 was a significant predictor of favorable surgical outcome on multivariate analysis [OR: 2.476 (1.224-5.008), p = 0.012]. Among the patients who had preoperative dilation (n = 82) or Botox injection (n = 46), response to these interventions was not a predictor of favorable surgical outcome (p = 0.192 and 0.979, respectively). However, preoperative Botox injection, regardless of response to injection, was associated with favorable surgical outcome [OR: 3.205 (CI 1.105-9.299), p = 0.032].

CONCLUSION

Symptomatic improvement after pyloroplasty or G-POEM is independent of etiology of gastroparesis, GERD, and primary symptom. Response to dilation or Botox are not markers of response to surgery. However, patients who receive Botox are 3.2 times more likely to improve postoperatively.

Impact of Objective Colonic and Whole Gut Motility Data as Measured by Wireless Motility Capsule on Outcomes of Antireflux Surgery

BACKGROUND

Studies show higher rates of dissatisfaction with antireflux surgery (ARS) outcomes in patients with chronic constipation. This suggests a relationship between colonic dysmotility and suboptimal surgical outcome. However, due to limitations in technology, there is no objective data available examining this relationship. The wireless motility capsule (WMC) is a novel technology consisting of an ingestible capsule equipped with pH, temperature, and pressure sensors, which provide information regarding regional and whole gut transit times, pH and motility. The aim of this study was to assess the impact of objective regional and whole gut motility data on the outcomes of ARS.

STUDY DESIGN

This was a retrospective review of patients who underwent WMC testing before ARS. Transit times, motility, and pH data obtained from different gastrointestinal tract regions were used in analysis to determine factors that impact surgical outcome. A favorable outcome was defined as complete resolution of the predominant reflux symptom and freedom from antisecretory medications.

RESULTS

The final study population consisted of 48 patients (fundoplication [n = 29] and magnetic sphincter augmentation [n = 19]). Of those patients, 87.5% were females and the mean age ± SD was 51.8 ± 14.5 years. At follow-up (mean ± SD, 16.8 ± 13.2 months), 87.5% of all patients achieved favorable outcomes. Patients with unfavorable outcomes had longer mean whole gut transit times (92.0 hours vs 55.7 hours; p = 0.024) and colonic transit times (78.6 hours vs 47.3 hours; p = 0.028), higher mean peak colonic pH (8.8 vs 8.15; p = 0.009), and higher mean antral motility indexes (310 vs 90.1; p = 0.050).

CONCLUSIONS

This is the first study to demonstrate that objective colonic dysmotility leads to suboptimal outcomes after ARS. WMC testing can assist with preoperative risk assessment and counseling for patients seeking ARS.

Long-term clinical and functional results of magnetic sphincter augmentation

Magnetic sphincter augmentation (MSA) was introduced in 2007 as an alternative surgical procedure for patients with gastroesophageal reflux disease (GERD). The majority of data since MSA's introduction has focused on short and intermediate-term results, demonstrating safety and high efficacy in terms of reflux symptom control, freedom from proton pump inhibitor use and normalization of distal esophageal acid exposure. However, GERD is a chronic condition that demands a long-term solution. Limited available data from studies reporting outcomes at 5 years or later following MSA demonstrate that the promising short- and mid-term efficacy and safety profile of MSA remains relatively constant in the long term. Compared with Nissen fundoplication, MSA has a much lower rate of gas-bloat and inability to belch at a short-term follow-up, a difference that persists in the long-term. The most common complaint after MSA at a short-term follow-up is dysphagia. However, limited data suggest dysphagia rates largely decrease by 5 years. Dysphagia is the most common indication for dilation and device removal in both early- and long-term studies. However, the overall rates of dilation and removal are similar in short- and long-term reports, suggesting the majority of these procedures are performed in the short-term period after device implantation. The indications and standard practices of MSA have evolved over time. Long-term outcome data currently available are all from patient cohorts who were selected for MSA under early restricted indications and outdated regimens. Therefore, further long-term studies are needed to corroborate the preliminary, yet encouraging long-term results.

Abstract B60: Sitravatanib enhances immune checkpoint blockade in a de novo esophageal adenocarcinoma model

Background: Esophageal adenocarcinoma (EAC) is a leading cause of cancer-related mortality. Sitravatinib is a small molecule spectrum-selective tyrosine kinase inhibitor (TKI) that targets TAM receptors (AXL, MERTK and TYRO3), VEGF, PDGF, and c-Kit. Previously, dual inhibition of TAM and VEGF receptors has shown to successfully modulate the tumor immune microenvironment towards a less immunosuppressive state, by depletion of MDSCs and repolarization of TAMs towards a proinflammatory M1 phenotype. In clinical trials, TKIs have shown to improve patient outcomes, alone or in combination with immune checkpoint inhibitors, in multiple solid tumors. In the present study, the antitumor activity of sitravatinib alone and in combination with PD-1 blockade was investigated in a de novo EAC rat model. Methods: Ninety-six rats underwent an end-to-side esophagojejunostomy to induce gastroesophageal reflux, resulting in EAC carcinogenesis. At 32 weeks post-operatively, tumor bearing animals were randomized to a dose of 10mg/kg of sitravatanib (S) or vehicle control (VC), for a total of three 14 day cycles. A PD-1 inhibitor, AUNP-12 (IO), was administered at a dose of 3mg/kg or placebo, on day 12 of each cycle. At 38 weeks post-operatively animals were euthanized. Safety and efficacy was evaluated by on-treatment mortality, MRI, immunofluorescence and qRT PCR. Results: The S+/-IO groups demonstrated a higher mortality when compared to the control groups (p&lt;0.001). Pre- to post-treatment, mean MRI tumor volume decreased by 32% and 73% in the S-IO and S+IO and increased by 90% and 160% in the VC+IO and VC-IO, respectively (p&lt;0.001). Enhanced CD3+CD8+ T-cell densities were observed in the treatment groups when compared to the control groups (p&lt;0.001). Additionally, a higher CD86/CD206 ratio was observed in the S-IO and S+IO groups than in the control groups (p&lt;0.001), indicating a repolarization from M2 to M1 macrophage phenotype. Gene expression analysis of post treatment samples demonstrated upregulation of pro-inflammatory cytokines TNF-α, IFN-γ, IL-1β, IL-6, IL-12 and downregulation of anti-inflammatory cytokines including TGF-β, IL-4, IL-10, and IL-13 in the treated versus control animals (p&lt;0.05). Pre- to post-treatment qRT-PCR levels demonstrated significant inhibition of pathway genes, AXL, AKT, MERTK and PI3K, in the treated animals (p=&lt;0.001). Moreover, pre-treatment AXL levels were significantly higher in major responders (&gt;80% tumor reduction n=8) compared to the non-responders (&lt;25% tumor reduction/progression n=6), in the merged S +/- IO group (p=0.009). Lastly, increased apoptosis and decreased proliferation were confirmed through Cas-3 and Ki-67, respectively, in both treatment groups (p&lt;0.001). Conclusion: This study establishes a promising combination strategy using the multi-gene TKI sitravatinib to overcome PD-1/PD-L1 resistance and potentiate immune checkpoint inhibition in an EAC model.

Citation Format: Ryan W. Sweeney, John T. Fitzpatrick, Ashten N. Omstead, Ping Zheng, Anastasia Gorbunova, Patrick L. Wagner, Juliann E. Kosovec, Blair A. Jobe, Ronan J. Kelly, Ali H. Zaidi. Sitravatanib enhances immune checkpoint blockade in a de novo esophageal adenocarcinoma model [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr B60.

Prognostic and predictive biomarkers for response to neoadjuvant chemoradiation in esophageal adenocarcinoma

Background

Esophageal adenocarcinoma is a lethal disease. For locally advanced patients, neoadjuvant chemoradiotherapy followed by surgery is the standard of care. Risk stratification relies heavily on clinicopathologic features, particularly pathologic response, which is inadequate, therefore establishing the need for new and reliable biomarkers for risk stratification.

Methods

Thirty four patients with locally advanced esophageal adenocarcinoma were analyzed, of which 21 received a CROSS regimen with carboplatin, paclitaxel, and radiation. Capture-based targeted sequencing was performed on the paired baseline and post-treatment samples. Differentially mutated gene analysis between responders and non-responders of treatment was performed to determine predictors of response. A univariate Cox proportional hazard regression was used to examine associations between gene mutation status and overall survival.

Results

A 3-gene signature, based on mutations in EPHA5, BCL6, and ERBB2, was identified that robustly predicts response to the CROSS regimen. For this model, sensitivity was 84.6% and specificity was 100%. Independently, a 9 gene signature was created using APC, MAP3K6, ETS1, CSF3R, PDGFRB, GATA2, ARID1A, PML, and FGF6, which significantly stratifies patients into risk categories, prognosticating for improved relapse-free (p = 4.73E-03) and overall survival (p = 3.325E-06). The sensitivity for this model was 73.33% and the specificity was 94.74%.

Conclusion

We have identified a 3-gene signature (EPHA5, BCL6, and ERBB2) that is predictive of response to neoadjuvant chemoradiotherapy and a separate prognostic 9-gene classifier that predicts survival outcomes. These panels provide significant potential for personalized management of locally advanced esophageal cancer.

A blood-based circulating microbial metagenomic panel for early diagnosis and prognosis of oesophageal adenocarcinoma

BACKGROUND

Emerging evidence indicates the potential clinical significance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in oesophageal adenocarcinoma (EAC) patients, particularly as novel non-invasive, early detection, surveillance and prognostic classifiers.

METHODS

Metagenome sequencing was performed on 81 serum specimens collected across EAC spectrum, with sequencing reads classified using Bracken and MetaPhlAn3. Followed by the Linear Discriminant Analysis effect size (LEfSe) method to identify microbial profiles between groups. Logistic regression and Kaplan-Meier analyses were used to build classifiers.

RESULTS

A significant loss of alpha and beta diversity was identified in serum specimens from EAC patients. We observed a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 (95% CI: 0.78-0.95; P < 0.001) and this panel in conjunction with the TNM stage was a robust predictor of overall survival (≥24 months; AUC = 0.84 (95% CI: 0.66-0.92; P = 0.006)).

CONCLUSION

This study firstly describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

TRANSLATIONAL RELEVANCE

Accumulating data indicates the clinical relevance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in patients with oesophageal adenocarcinoma (EAC). Herein, we performed metagenome sequencing in serum specimens from EAC patients 81 collected across EAC spectrum and observed a significant loss of alpha and beta diversity, with a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 and this panel, in conjunction with the TNM stage, was a robust predictor of overall survival. This study for the first time describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

Abstract 1973: Patients with operable esophageal cancer and improved responses to combined chemoradiotherapy and immunotherapy display distinct microbiome profiles enriched in multiple Bacteroides species

Background: Preclinical and clinical data indicate that neoadjuvant chemoradiotherapy (CRT) may prime an anti-tumor immunological response in esophageal cancer driven by intratumoral CD8+ T cells and PD-L1 expression. LAG-3 is also highly expressed in esophagogastric cancers. The microbiome, a novel and potentially modifiable, biomarker of IO response, has not yet been examined in the neoadjuvant setting in esophageal cancer and is the goal of our study.

Methods: Fecal samples were collected from patients with stage II/III esophageal or gastroesophageal junction carcinoma eligible for curative resection treated with the standard of care regimen of carboplatin paclitaxel (50mg/m2), radiation 50.4 Gy in 28 fractions and an Ivor-Lewis esophagectomy 6-10 weeks after last CRT and immunotherapy (IO) dose. Patients on arm A (n=11) received 2 cycles of induction with nivolumab plus 3 additional cycles on week 1, 3 and 5 of CRT. Patients on arm B (n=8) received nivolumab plus relatlimab on the same schedule (Clinical trial: NCT03044613). We examined longitudinal fecal samples from n=19 patients across both arms (n=90 samples) using 16S rRNA amplicon sequencing. Patients were classified based on pathological response: complete response (CR) and grades 1, 2, and 3 (G1, G2, G3) with increasing residual tumor visible in the resected specimen. Sequencing data was trimmed and filtered for contaminants, followed by high-resolution taxonomic assignment and normalization of reads across all samples. Analysis was performed using multiple metrics for alpha diversity and beta-diversity, with principal coordinates analysis/PERMANOVA, and pathway analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt).

Results: Patients with improved response in the neoadjuvant setting (CR/G1 vs G2/G3) grouped in distinct clusters using Bray-Curtis (p &lt; 0.001). Patients with CR had higher alpha diversity, using both measures of richness and evenness, compared to patients with a G3 responses (p &lt; 0.03). Specifically, family Bacteroidaceae and genus Bacteroides were enriched in patients with CR vs G3 (p &lt; 0.02). At the species level, B. finegoldii, B. ovatus, and B. uniformis were enriched in patients with CR vs G3 (p &lt; 0.02). In contrast, genus Klebsiella and Clostridium termitidis were enriched in patients with a poor response, G3 (p &lt;0.001, both). Pathway analysis found two metabolic pathways enriched in patients with CR: secondary bile acid biosynthesis (p=0.005) and lysine biosynthesis (p=0.02).

Conclusions: Patients with operable esophageal cancer and improved responses to combined CRT and IO had distinct microbiome profiles enriched in multiple Bacteroides species. Further analyses and validation efforts are underway to confirm metabolomic pathways.

Citation Format: Fyza Y. Shaikh, James R. White, Ronan J. Kelly, Ali H. Zaidi, Jenna V. Canzoniero, Josephine L. Feliciano, Russell K. Hales, K Ranh Voong, Richard J. Battafarano, Blair A. Jobe, Stephen C. Yang, Stephen Broderick, Jinny Ha, Kellie N. Smith, Elizabeth Thompson, Eun J. Shin, Ali I. Amjad, Patrizia Guerrieri, Benny Weksler, Chen Hu, Valsamo Anagnostou, Vincent K. Lam, Cynthia L. Sears. Patients with operable esophageal cancer and improved responses to combined chemoradiotherapy and immunotherapy display distinct microbiome profiles enriched in multiple Bacteroides species [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1973.

Esophageal retention cyst: Esophagogastric junction outflow obstruction (EGJOO) as a potential etiology and management with endoscopic mucosal resection (EMR)

INTRODUCTION AND IMPORTANCE

Esophageal retention cysts are acquired cysts with no known etiology. They are characterized by dilation of the submucosal glands. Symptomatic cysts are traditionally managed by surgical resection.

CASE PRESENTATION

We present a case of progressive dysphagia and chest pain secondary to esophageal retention cysts in the mid and distal esophagus with associated esophagogastric junction outflow obstruction (EGJOO) and jackhammer esophagus on high resolution manometry (HRM). The patient underwent staged endoscopic mucosal resection (EMR) with subsequent improvement in her symptoms. However, EGJOO persisted after resection, suggesting it was the primary pathology and not a consequence of the obstruction from the cysts.

CLINICAL DISCUSSION

Esophageal retention cysts are rarely reported in the literature with most descriptions coming from incidental post-mortems. The presented case suggests EGJOO as a potential etiology of retention cysts. The proposed mechanism is that a significant rise in esophageal intraluminal pressure creates a state of stasis in the esophagus, ideal for the development of these cysts. Symptomatic or malignant retention cysts should be resected. We demonstrate the feasibility of EMR as an alternative to surgical resection.

CONCLUSION

Esophageal retention cyst is a rare entity, which may arise as a result of EGJOO. The natural history and malignant potential of these cysts are unknown, and no formal guidelines have been established for follow-up for patients with asymptomatic retention cysts. Endoscopic mucosal resection can be used to successfully manage these cysts.

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

Esophageal adenocarcinoma (EAC) is a leading cause of cancer deaths. Pexidartinib, a multi-gene tyrosine kinase inhibitor, through targeting CSF-1R, down modulates macrophage mediated pro-survival tumor signaling. Previously, CSF-1R inhibitors have successfully shown to enhance antitumor activity of PD-1/PD-L1 inhibitors by suppressing tumor immune evasion, in solid tumors. In this study, we investigated the antitumor activity of pexidartinib alone or in combination with blockade of PD-1 in a de novo EAC rat model. Here, we showed limited toxicity with significant tumor shrinkage in pexidartinib treated animals compared to controls, single agent and in combination with a PD-1 inhibitor, AUNP-12. Suppression of CSF-1/CSF-1R axis resulted in enhanced infiltration of CD3+CD8+ T cells with reduced M2 macrophage polarization, in the tumor microenvironment (TME). Endpoint tissue gene expression in pexidartinib treated animals demonstrated upregulation of BAX, Cas3, TNFα, IFNγ and IL6 and downregulation of Ki67, IL13, IL10, TGFβ and Arg1 (p<0.05). Additionally, among the pexidartinib treated animals responders compared to non-responders demonstrated a significant upregulation of pre-treatment CSF-1 gene, confirming that tumor associated macrophage suppression directly translates to clinical benefit. Moreover, a post-treatment serum cytokine assay exhibited similar systemic trends as the gene expression in the TME, depicting increases in pro-inflammatory cytokines and decreases in anti-inflammatory cytokines. In conclusion, our study established a promising combinatorial strategy using a CSF-1R inhibitor to overcome resistance to PD-1/PD-L1 axis blockade in an EAC model, providing the rationale for future clinical strategies.

Acquired Morgagni hernia following coronary artery bypass graft (CABG) with successful robotic repair of hernia

INTRODUCTION AND IMPORTANCE

Morgagni hernia is an uncommon type of diaphragmatic hernia and commonly presents as a congenital disease. Acquired Morgagni hernias following open cardiac surgery are exceedingly rare and only reported in the pediatric population.

CASE PRESENTATION

The patient is a 70-year-old female who presented with complaints of shortness of breath and cough one year following a coronary artery bypass graft (CABG). A chest CT scan showed a large Morgagni type diaphragmatic hernia with herniated transverse colon occupying the anterior mediastinum as well as the right hemi-thorax. This hernia was successfully repaired using transabdominal robotic approach with complete resolution of patient's symptoms.

CLINICAL DISCUSSION

This is the first reported case of acquired Morgagni type diaphragmatic hernia in an adult following open cardiac surgery. The potential etiologies for this hernia include distal extension of the median sternotomy and involvement of the anterior diaphragm, iatrogenic injury to the attenuated anterior diaphragm during pericardial window creation, or pericardial drain placement. Operative repair is the mainstay of treatment and is usually performed with a transabdominal approach since it is thought to be less challenging and allows for evaluation of the entire abdominal cavity. If primary repair cannot be achieved, then synthetic mesh may be needed to obtain a tension free and durable repair.

CONCLUSION

We present a case of acquired Morgagni type diaphragmatic hernia in an adult following open cardiac surgery that was successfully repaired using a transabdominal robotic approach.

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

333

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

335

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.

•

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

•

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

•

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

•

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

•

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

4042

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

•

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.

•

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

•

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

•

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

•

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

4571

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

445

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.

The 2018 ISDE achalasia guidelines

Achalasia is a relatively rare primary motor esophageal disorder, characterized by absence of relaxations of the lower esophageal sphincter and of peristalsis along the esophageal body. As a result, patients typically present with dysphagia, regurgitation and occasionally chest pain, pulmonary complication and malnutrition. New diagnostic methodologies and therapeutic techniques have been recently added to the armamentarium for treating achalasia. With the aim to offer clinicians and patients an up-to-date framework for making informed decisions on the management of this disease, the International Society for Diseases of the Esophagus Guidelines proposed and endorsed the Esophageal Achalasia Guidelines (I-GOAL). The guidelines were prepared according the Appraisal of Guidelines for Research and Evaluation (AGREE-REX) tool, accredited for guideline production by NICE UK. A systematic literature search was performed and the quality of evidence and the strength of recommendations were graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Given the relative rarity of this disease and the paucity of high-level evidence in the literature, this process was integrated with a three-step process of anonymous voting on each statement (DELPHI). Only statements with an approval rate >80% were accepted in the guidelines. Fifty-one experts from 11 countries and 3 representatives from patient support associations participated to the preparations of the guidelines. These guidelines deal specifically with the following achalasia issues: Diagnostic workup, Definition of the disease, Severity of presentation, Medical treatment, Botulinum Toxin injection, Pneumatic dilatation, POEM, Other endoscopic treatments, Laparoscopic myotomy, Definition of recurrence, Follow up and risk of cancer, Management of end stage achalasia, Treatment options for failure, Achalasia in children, Achalasia secondary to Chagas' disease.