Therapy For Esophageal Adenocarcinoma Research Articles

Paneth cell differentiation associated with neoadjuvant therapy in esophageal adenocarcinoma.

Paneth cells and Paneth cell metaplasia are well-known in pathology as foundational components in the gastrointestinal system. When within malignant cells (Paneth cell differentiation [PCD]), however, the function and significance of these cells is less well understood. Here, we present findings from the first study focused on PCD in postneoadjuvant esophageal adenocarcinoma (EAC) resection specimens. Patients with EAC treated with neoadjuvant chemoradioation and followed by esophagectomy between 2012 and 2018 in our institution were retrospectively evaluated. A tissue microarray was constructed, and special and immunohistochemical stains were performed. A total of 64 cases were collected, of which 8 had PCD, as highlighted by periodic acid-Schiff with diastase staining. Adenocarcinomas with PCD were more commonly seen in patients 60 to 70 years of age and typically had a poorly differentiated morphology, observationally fewer stromal mucinous changes, and less lymph node metastasis. β-catenin activation induced by neoadjuvant therapy was more frequent in the PCD-positive cases. Patients with PCD-positive disease had low programmed cell death 1 ligand 1 levels, no positive or equivocal ERBB2 (HER2) expression, and low CD8-positive T-cell infiltration; they were also mismatch repair proficient. Patients with PCD-positive disease showed a survival pattern inferior to that of patients with PCD-negative disease. When induced by neoadjuvant therapy in EAC, PCD is associated with high β-catenin activation, less expression of targetable biomarkers, and a potentially worse clinical prognosis.

ARID1A Deficiency Regulates Anti-Tumor Immune Response in Esophageal Adenocarcinoma.

ARID1A, a member of the chromatin remodeling SWI/SNF complex, is frequently lost in many cancer types, including esophageal adenocarcinoma (EAC). Here, we study the impact of ARID1A deficiency on the anti-tumor immune response in EAC. We find that EAC tumors with ARID1A mutations are associated with enhanced tumor-infiltrating CD8+ T cell levels. ARID1A-deficient EAC cells exhibit heightened IFN response signaling and promote CD8+ T cell recruitment and cytolytic activity. Moreover, we demonstrate that ARID1A regulates fatty acid metabolism genes in EAC, showing that fatty acid metabolism could also regulate CD8+ T cell recruitment and CD8+ T cell cytolytic activity in EAC cells. These results suggest that ARID1A deficiency shapes both tumor immunity and lipid metabolism in EAC, with significant implications for immune checkpoint blockade therapy in EAC.

Abstract 3806: Investigating the role of miRNA-34a in the resistance of esophageal adenocarcinoma to neoadjuvant chemoradiation therapy

Abstract Background: The current standard of care for locally advanced esophageal adenocarcinoma (EAC) involves neo-adjuvant chemoradiation therapy (neo-CRT) followed by surgery. However, response to neo-CRT is poor and resistance remains a significant barrier to effective treatment. There are currently no clinical biomarkers to predict treatment response in EAC. Evidence supports a role for microRNA-34a (miR-34a) as a tumor suppressor in cancer, however, the role of miR-34a in the tumor response to therapy in EAC is largely unknown. Methods: Irradiation of EAC cell lines was performed using an Xstrahl RS225 X-ray irradiator at a clinically-relevant dose of 2 Gy. Radiosensitivity of EAC cell lines (OE33 P, OE33 R, OE33, OE19, Flo-1Par and Flo-1LM) was assessed by the gold standard clonogenic assay. miR-34a expression was assessed by qPCR. EAC tumor biopsies were obtained from consenting patients undergoing diagnostic endoscopy. Pathological response of the resected tumor was assigned by a pathologist using the Mandard Tumor Regression scale. miRTarBase and KEGG pathway analysis were used to identify predicted target genes and pathways of miR-34a. Results: miR-34a was demonstrated to be expressed in a panel of EAC cell lines (OE33 P, OE33 R, OE19, Flo-1Par and Flo-1LM cells). Interestingly, miR-34a expression was significantly decreased in EAC cell line models of both acquired radioresistance (OE33 R) and inherent radioresistance (OE19). miR-34a was also significantly decreased in a model of radioresistant metastatic EAC (Flo-1LM). Supporting in vitro data, in pre-treatment tumor biopsies from EAC patients (n=18), miR-34a was significantly decreased in patients having a subsequent poor pathological response to neo-CRT, when compared to patients having a good pathological response to neo-CRT. Target and pathway analysis demonstrated miR-34a-mediated regulation of genes and pathways associated with treatment resistance, including the complement system, cellular metabolism and p53 signaling, among others. Conclusion: Decreased miR-34a expression is associated with radioresistance across a panel of in vitro EAC models and in pre-treatment tumor biopsies from EAC patients having a poor pathological response to neo-CRT. This highlights a potential role for miR-34a as a novel biomarker predicting response to neo-CRT in EAC. Analysis of validated and predicted gene targets of miR-34a identified a number of pathways associated with treatment resistance. We are currently investigating the functional role of miR-34a in modulating tumor response to radiation in vitro to determine its potential as a novel therapeutic target to boost treatment response in EAC. Citation Format: Christina Cahill, Stephen G. Maher, Rebecca O'Brien, Wei-Lin Winnie Wang, John V. Reynolds, Jacintha O'Sullivan, Niamh Lynam-Lennon. Investigating the role of miRNA-34a in the resistance of esophageal adenocarcinoma to neoadjuvant chemoradiation therapy. [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 3806.

Abstract 1066: BMS-754807, a small-molecule inhibitor of insulin-like growth factor-1 receptor/insulin receptor is cytotoxic to esophageal adenocarcinoma cells and enhances nab-paclitaxel response in experimental esophageal adenocarcinoma

Abstract Introduction: Esophageal adenocarcinoma (EAC) is one of the fastest growing cancers in the Western world and the overall 5-year survival rate of EAC is below 20 percent. Epidemiological studies have linked obesity with EAC. Insulin-like growth factor (IGF) signaling is an important mediator in obesity-associated EAC. Paclitaxel (PT) has been used in combination with carboplatin as a standard combination therapy for advanced EAC. PT required emulsification with solvents which have resulted in serious adverse effects in patients. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is an albumin-stabilized, cremophor-free and water-soluble nanoparticle formulation of PT. Nab-paclitaxel has recently shown greater efficacy over PT in EAC. In this study, we evaluated the potential of targeting IGF signaling and improvement in nab-paclitaxel response by the addition of BMS-754807 in experimental EAC. Methods: We first evaluated the phosphorylation status of IGF-1R/IR protein by Western blot in a panel of EAC cell lines. BMS-754807 and nab-paclitaxel, alone or in combination were tested for effects on cell growth, cell apoptosis, cell migration and cell cycle analyses of EAC cell lines detected respectively by WST-1 assay, Western blotting, would healing scratch assay and propidium iodide flow cytometry. We then explored the antitumor efficacy of BMS-754807 and nab-paclitaxel monotherapy and in combination in murine subcutaneous xenograft and peritoneal metastatic survival models of human EAC. Results: BMS-754807 dose-dependently inhibited in-vitro cell proliferation of EAC cell lines having phosphorylation of IGF-1R/IR protein. The co-administration of BMS-754807 and nab-paclitaxel effectively enhanced cell growth inhibition, cleavage of caspase-3 and PARP, in-vitro wound healing inhibition and cell cycle arrest at sub G0/G1 phase. BMS-754807 in combination with nab-paclitaxel treatment resulted in significantly higher antitumor efficacy by increasing intratumoral apoptosis and survival benefit compared with BMS-754807 or nab-paclitaxel treatment alone. In subcutaneous xenografts using OE19 cells, average net tumor growth after two weeks in different therapy groups was 558.67 mm3 in control, 208.47 mm3 after BMS-754807 (p=0.043), 104.60 mm3 after nab-paclitaxel (p=0.013), and 14.30 mm3 after BMS-754807 plus nab-paclitaxel (p=0.0005). There was a significant increase in median animal survival after BMS-754807 plus nab-paclitaxel treatment (85 days) compared to control (47 days, p=0.0034), BMS-754807 monotherapy (57 days, p=0.0021) or nab-paclitaxel (68 days, p=0.0339) monotherapy. Conclusion: These results support the potential of BMS-754807 in combination with nab-paclitaxel as an effective option for EAC therapy. Citation Format: Md Sazzad Hassan, Nicholas Cwidak, Chloe Johnson, Saisantosh Ponna, Niranjan Awasthi, Urs von Holzen. BMS-754807, a small-molecule inhibitor of insulin-like growth factor-1 receptor/insulin receptor is cytotoxic to esophageal adenocarcinoma cells and enhances nab-paclitaxel response in experimental esophageal adenocarcinoma [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 1066.

128: DECIPHERING THE IMMUNOLOGICAL DETERMINANTS OF RESPONSE TO NEOADJUVANT CHEMO-RADIATION IN ESOPHAGEAL ADENOCARCINOMA

Abstract Background and aim The standard therapy for esophageal adenocarcinoma (EAC) is pre-operative neoadjuvant chemo-radiation (NACR) and surgery. Less that 30% of patients achieve a pathological complete response (pCR) and increased 5-year survival after NACR. Understanding the mechanisms of response to NACR is pivotal to better stratify patients and inform the design of more efficacious therapies. Cancer progression partly depends on defective immune surveillance, and the presence of tumor infiltrating T lymphocytes (TILs) is associated with better prognosis of several malignancies. We hypothesize that NACR induces immunogenic cell death that stimulates immune responses against tumor neoantigens (TNAs), derived from cancer somatic mutations, in the responders. We thus compared responders and non-responders for tumor immune contexture, immune molecular pathways, circulating immune markers and TNAs-specific T cells responses. Methods Pre-NACR tumor biopsies prospectively collected from consecutive EAC patients were subjected to DNA whole exome and RNA sequencing, high dimensional (HD) multiparametric flow cytometry and immune contexture analysis by histology and by proteome digital spatial profiling (n = 53 targets), while their peripheral blood mononuclear cells and plasma collected pre- and post- NACR were analyzed by HD flow cytometry and cytokine multiplexing assay respectively. Results Treatment-naïve EACs of NACR responders showed higher TNA load and enriched immune signatures compared to non-responders. Moreover, pre-treatment EACs of responders demonstrate augmented effector T cell infiltration and reduced Treg cells and M2-like pro-tumoral macrophages. High M2-like macrophages score associated with lower overall survival. Increased frequencies of circulating myeloid suppressor populations were detected both at baseline and after NACR in non-responder patients. These observations were associated with circulating levels of n = 30 cytokines/chemokines and with spatial expression of immune markers in tumor biopsies. Conclusion Collectively, these results support pre-existing immune-mediated mechanisms of anti-tumor response stimulated by NACR in the fraction of responder EAC patients, suggesting possible ways to stratify patients and direct them to more tailored neoadjuvant and/or adjuvant treatments, possibly in combination with personalized immunotherapy approaches.

The Role of the TP53 Pathway in Predicting Response to Neoadjuvant Therapy in Esophageal Adenocarcinoma.

In patients with locally advanced esophageal adenocarcinoma, response to neoadjuvant therapy strongly predicts survival, but robust molecular predictors of response have been lacking. We therefore sought to discover meaningful predictors of response in these patients. We retrospectively identified all patients with adenocarcinoma of the lower esophagus or gastroesophageal junction who (i) were treated with multimodality therapy with curative intent at our institution from 2014 through 2020 and (ii) underwent prospective sequencing by Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets. Clinicopathologic and genomic data were analyzed to identify potential genomic features, somatic alterations, and oncogenic pathways associated with treatment response. In total, 237 patients were included. MDM2 amplification was independently associated with poor response to neoadjuvant therapy [OR, 0.10 (95% confidence interval, 0.01-0.55); P = 0.032], when accounting for significant clinicopathologic variables, including clinical stage, tumor grade, and chemotherapy regimen. Moreover, TP53 pathway alterations, grouped according to inferred severity of TP53 dysfunction, were significantly associated with response to neoadjuvant therapy (P = 0.004, q = 0.07). Patients with MDM2 amplifications or truncating biallelic TP53 mutations had similar outcomes in terms of poor responses to neoadjuvant therapy and, consequently, shorter progression-free survival, compared with patients with TP53 pathway wild-type tumors. Thus, worsening TP53 dysfunction was directly correlated with worse outcomes. MDM2 amplification and TP53 status are associated with response to therapy in patients with esophageal adenocarcinoma. Given the dearth of actionable targets in esophageal adenocarcinoma, MDM2 inhibition, in combination with cytotoxic chemotherapy, may represent an important therapeutic strategy to overcome treatment resistance and improve outcomes in these patients.

Human Microbiota in Esophageal Adenocarcinoma: Pathogenesis, Diagnosis, Prognosis and Therapeutic Implications.

Esophageal adenocarcinoma (EAC) is one of the main subtypes of esophageal cancer. The incidence rate of EAC increased progressively while the 5-year relative survival rates were poor in the past two decades. The mechanism of EAC has been studied extensively in relation to genetic factors, but less so with respect to human microbiota. Currently, researches about the relationship between EAC and the human microbiota is a newly emerging field of study. Herein, we present the current state of knowledge linking human microbiota to esophageal adenocarcinoma and its precursor lesion—gastroesophageal reflux disease and Barrett’s esophagus. There are specific human bacterial alternations in the process of esophageal carcinogenesis. And bacterial dysbiosis plays an important role in the process of esophageal carcinogenesis via inflammation, microbial metabolism and genotoxicity. Based on the human microbiota alternation in the EAC cascade, it provides potential microbiome-based clinical application. This review is focused on novel targets in prevention, diagnosis, prognosis, and therapy for esophageal adenocarcinoma.

Clinicopathologic correlations of superficial esophageal adenocarcinoma in endoscopic submucosal dissection specimens

BackgroundEndoscopic submucosal dissection (ESD) is a novel endoscopic treatment for early esophageal adenocarcinoma (EAC). The western pathologists’ experience with ESD specimens remains limited. This study aimed to correlate histopathologic features of Barrett’s esophagus (BE)-associated adenocarcinoma in ESD resections with clinical outcomes to determine whether they aid future management decisions.MethodsWe retrospectively evaluated 49 consecutive ESD resection specimens from 42 patients with BE-associated adenocarcinoma (24 intramucosal and 18 submucosal EAC) at a single tertiary referral center. Pathologic evaluation included presence of dysplasia, invasive adenocarcinoma, peritumoral inflammation, desmoplasia, lymphovascular and perineural invasion; tumor differentiation, depth of invasion, morphology, and budding; and margin status for dysplasia or carcinoma. Follow up data included endoscopic biopsies in 35 patients and pathology reports of esophagectomies in 11 patients. Poor outcomes were defined as recurrence or residual invasive adenocarcinoma at esophagectomy, metastasis on imaging, or R1 resection in patients undergoing ESD for tumor debulking.ResultsTwo patients (8%) with intramucosal adenocarcinoma and 9 patients (50%) with submucosal adenocarcinoma had poor outcomes. Histopathologic features associated with poor outcomes included poor differentiation, lymphovascular invasion, submucosal invasion > 500 μm, tumor budding, and tubuloinfiltrative histologic pattern. Four patients had positive deep margin away from the deepest tumor invasion and did not show residual tumor on follow up.ConclusionsOur results validated European Society of Gastroenterology (ESGE) guidelines of high-risk pathologic features for additional therapy in esophageal adenocarcinoma and identified tumor budding frequently in association with other high-risk features. Positive deep margin distant from deepest tumor invasion could be procedural and warrants endoscopic correlation for management.

Towards Personalized Treatment Strategies for Esophageal Adenocarcinoma; A Review on the Molecular Characterization of Esophageal Adenocarcinoma and Current Research Efforts on Individualized Curative Treatment Regimens.

Simple SummaryEsophageal adenocarcinoma (EAC) is one of the two major subtypes of esophageal cancer. In early disease stage, many EAC patients are asymptomatic. Most patients will present with late-stage disease in case of dysphagia and/or weight loss. Patients who undergo treatment with curative intent, have 5-year survival rates rarely exceeding 30%. Currently, curative treatment consists of chemo- and radiotherapy combined with surgical resection. Despite differences between tumors at the molecular level, all patients receive similar treatment, which results in heterogeneous therapeutic response. The aim of this review is to discuss the current research on molecular characteristics in EAC, which may predict tumor response. Moreover, we also discuss the rationale and research on adjusted regimens for EAC with for instance chemoradiotherapy and surveillance instead of (immediate) surgical resection. In future, these findings will lead to more personalized treatment approaches for EAC.Esophageal cancers confer a major health challenge and are highly aggressive malignancies with poor prognosis. Esophageal adenocarcinoma (EAC) is one of the two major histopathological subtypes of esophageal cancer. Despite advances in treatment modalities, the prognosis of patients with EAC remains poor, with a 5-year survival rate that rarely exceeds 30% in patients treated with curative intent. Chemoradiotherapy followed by resection is the treatment of choice for EAC patients, which are deemed to be curable. Current patient stratification and treatments are based on outcomes from clinical trials. Unfortunately, the molecular heterogeneity of EAC which determines the chemo- and radiosensitivity of these cancers are not taken into account. A more personalized approach in the treatment of EAC could improve patient outcomes. This review aims at summarizing literature on translational and clinical research in the field of EAC which could be of importance to develop personalized approaches. As suggested by the TCGA, expression data features molecular classifications by different platforms, including miRNA, genomic mutations and reverse-phase protein arrays. Here, we summarize literature on transcriptomic, data-driven approaches to identify distinct subtypes of EAC associated with molecular features. These novel classifications may determine the responsiveness to chemo(radio)therapy and help to identify novel molecular targets within cell signaling pathways. Moreover, we discuss the current clinical research efforts on tailored treatment regimens for patients with EAC taking into account the heterogeneous response to chemoradiotherapy. We summarize the evidence regarding active surveillance instead of immediate surgical resection after application of neoadjuvant chemo(radio)therapy in EAC. We consider that in future patients with complete response to chemo(radio)therapy, predicted by (transcriptomic) biomarkers, might benefit most from this approach. Finally, challenges to overcome for current findings to be implemented in clinical practice and move the field forward are being discussed.

Immune determinants of Barrett's progression to esophageal adenocarcinoma.

Esophageal adenocarcinoma (EAC) develops from Barrett’s esophagus (BE), a chronic inflammatory state that can progress through a series of transformative dysplastic states before tumor development. While molecular and genetic changes of EAC tumors have been studied, immune microenvironment changes during Barrett’s progression to EAC remain poorly understood. In this study, we identify potential immunologic changes that can occur during BE-to-EAC progression. RNA sequencing (RNA-Seq) analysis on tissue samples from EAC patients undergoing surgical resection demonstrated that a subset of chemokines and cytokines, most notably IL6 and CXCL8, increased during BE progression to EAC. xCell deconvolution analysis investigating immune cell population changes demonstrated that the largest changes in expression during BE progression occurred in M2 macrophages, pro–B cells, and eosinophils. Multiplex immunohistochemical staining of tissue microarrays showed increased immune cell populations during Barrett’s progression to high-grade dysplasia. In contrast, EAC tumor sections were relatively immune poor, with a rise in PD-L1 expression and loss of CD8+ T cells. These data demonstrate that the EAC microenvironment is characterized by poor cytotoxic effector cell infiltration and increased immune inhibitory signaling. These findings suggest an immunosuppressive microenvironment, highlighting the need for further studies to explore immune modulatory therapy in EAC.

Clinical Risk Prediction Model for Neoadjuvant Therapy in Resectable Esophageal Adenocarcinoma.

Clinical staging with endoscopic ultrasound (EUS) and positron emission tomography (PET) is used to identify esophageal adenocarcinoma (EAC) patients with locally advanced disease and therefore, benefit from neoadjuvant therapy. However, EUS is operator dependent and subject to interobserver variability. Therefore, we aimed to identify clinical predictors of locally advanced EAC and build a predictive model that can be used as an adjunct to current staging methods. This was a cross-sectional study of patients with EAC who underwent preoperative staging with EUS and PET scan followed by definitive therapy at our institution from January 2011 to December 2017. Demographic data, symptoms, endoscopic findings, EUS, and PET scan findings were obtained. Four hundred and twenty-six patients met the study criteria, of which 86 (20.2%) patients had limited stage EAC and 340 (79.8%) had locally advanced disease. The mean age was 65.4±10.3 years of which 356 (83.6%) were men and 393 (92.3%) were White. On multivariable analysis, age (above 75 or below 65 y), dysphagia [odds ratio (OR): 2.84], weight loss (OR: 2.06), protruding tumor (OR: 2.99), and tumor size >2 cm (OR: 3.3) were predictive of locally advanced disease, while gastrointestinal bleeding (OR: 0.36) and presence of visible Barrett's esophagus (OR: 0.4) were more likely to be associated with limited stage. A nomogram for predicting the risk of locally advanced EAC was constructed and internally validated. We constructed a nomogram to facilitate an individualized prediction of the risk of locally advanced EAC. This model can aid in decision making for neoadjuvant therapy in EAC.

Response rate and diagnostic accuracy of early PET-CT during neo-adjuvant therapies in oesophageal adenocarcinoma: A systematic review and meta-analysis.

Only 25% of oesophageal adenocarcinoma (OAC) patients have a pathological response to neo-adjuvant therapy (NAT) before oesophagectomy. Early response assessment using PET imaging may help guide management of these patients. We performed a systematic review and meta-analysis to synthesise the evidence detailing response rate and diagnostic accuracy of early PET-CT assessment. We systematically searched several databases including MEDLINE and Embase. Studies with mixed cohorts of histology, tumour location and a repeat PET-CT assessment after more than one cycle of NAT were excluded. Reference standard was pathological response defined by Becker or Mandard classifications. Primary outcome was metabolic response rate after one cycle of NAT defined by a reduction in maximum standardised uptake value (SUVmax) of 35%. Secondary outcome was diagnostic accuracy of treatment response prediction, defined as the sensitivity and specificity of early PET-CT using this threshold. Quality of evidence was also assessed. Random-effects meta-analysis pooled response rates and diagnostic accuracy. This study was registered with PROSPERO (CRD42019147034). Overall, 1341 articles were screened, and 6 studies were eligible for analysis. These studies reported data for 518 patients (aged 27-78years; 452 [87.3%] were men) between 2005 and 2020. Pooled sensitivity of early metabolic response to predict pathological response was 77.2% (95% CI 53.2%-100%). Significant heterogeneity existed between studies (I2 =80.6% (95% CI 38.9%-93.8%), P=.006). Pooled specificity was 75.0% (95% CI 68.2%-82.5%), however, no significant heterogeneity between studies existed (I2 =0.0% (95% CI 0.0%-67.4%), P=.73). High-quality evidence is lacking, and few studies met the inclusion criteria of this systematic review. The sensitivity of PET using a SUVmax reduction threshold of 35% was suboptimal and varied widely. However, specificity was consistent across studies with a pooled value of 75.0%, suggesting early PET assessment is a better predictor of treatment resistance thanof pathologicalresponse. Further research is required to define optimal PET-guided treatment decisions in OAC.

P118 LOSS OF SMAD4 EXPRESSION IN ESOPHAGEAL ADENOCARCINOMA (EAC) IS CORRELATED TO POOR SURVIVAL

Abstract Aim Our study is aimed to evaluate the impact of SMAD4 expression on the clinical outcome of therapy for esophageal adenocarcinoma (EAC). Background & Methods Esophageal adenocarcinoma is characterized by a high genetic heterogeneity and a low survival rate, despite the adoption of aggressive therapies. We evaluated the expression of SMAD4, a tumor suppressor gene frequently mutated in cancer. by immunohistochemistry in 67 formalin-embedded (FFPE) EAC surgical specimens (patients were primarily treated with surgical resection-naïve cases), 34 of which were analyzed for SMAD4 gene by Next Generation Sequencing (NGS) with a dedicated target panel. Loss of SMAD4 protein was defined by a complete loss of expression in least 30% of cancer cells. Survival curves were determined using Kaplan–Meier methods. Results Loss of SMAD4 immunoreactivity was found in 33 out of 67 EAC cases (49.3%). Among a subset of 34 cases assessed in NGS, SMAD4 mutations were found in 3 cases (8.8%), all associated with protein loss. Loss of SMAD4 expression was also found in several cases with no mutations in SMAD4 gene (17/34, 50%). Loss of SMAD4 immunoreactivity was associated with poor overall survival (p=0.013) and higher risk of recurrence (p=0.001). Conclusion Loss of SMAD4 expression was a recurrent event in EAC, linked with genetic mutations in few cases, whereas in the majority of cases it might be related to epigenetic mechanisms, such as promoter hypermethylation. SMAD4 loss was strongly associated with recurrence and poor survival in patients, suggesting SMAD4 expression as potential prognostic biomarker in EAC. Further studies are required to develop strategic therapeutic options directly targeting SMAD4 and/or its regulators.

Abstract 4958: Alterations in the immune microenvironment during progression from Barrett's esophagus to esophageal adenocarcinoma

Abstract The incidence of esophageal adenocarcinoma (EAC) has increased 500 fold over the past 30 years and is now a top ten leading cause of cancer death. Systemic chemotherapy and targeted radiation have led to modest increases in survival, however 5-year survival is still less than 20%. Immunotherapy has emerged as a promising approach for the treatment of various solid tumors, however very little is known about the EAC tumor immune microenvironment and how it changes during the progression from Barrett’s metaplasia to carcinoma. The goal of the current study was to identify key changes in the immune microenvironment during progression from Barrett’s Esophagus (BE) metaplasia to the formation of EAC. Tissue samples from 52 patients with various levels of dysplasia (BE, BE w/ low grade dysplasia, BE w/ high grade dysplasia, and EAC) were subject to RNA-Seq analysis and investigated for changes in gene expression of a variety of cytokines and chemokines. Gene expression analysis revealed more than 5-fold increases in expression of multiple cytokines, such as IL8, IL6, CXCR1, and CXCR2, which have been implicated in both immunosuppression and tumor survival. Increases in the expression of immune checkpoint markers, such as PD-L1, TIGIT and CTLA4, were also seen suggesting a worsening immunosuppressive microenvironment during progression from BE to EAC. To further investigate specific changes in the infiltration of CD8 T-cell and T-regulatory cell populations during EAC progression, we performed standard immunohistochemical staining on tissue microarrays from 122 direct-to-surgery EAC patients. Staining for T-cell markers CD3, CD4, CD8, and FoxP3 revealed that only CD8 positive T-cells were increased around tumor cells during progression. Further characterization of individual immune cells was performed through multiplex immunohistochemistry, allowing for the evaluation of multiple immune cell markers within the same tissue section. Multiplex staining for surface expressed markers (CD3, CD8, FoxP3, PD-L1, PanCK, CD163, DAPI), allowed for the quantification and localization of a variety of immune cell types within the EAC microenvironment. In general, the immune cell populations (T-regs, CD8 T cells, and macrophages) increase during progression from BE to BE w/ High Grade Dysplasia. In contrast, EAC tumor sections were relatively immune poor, indicating that the immune microenvironment may often be compromised in cancer. These data collectively demonstrate the EAC microenvironment is characterized by poor infiltration of cytotoxic effector cells, increased expression of immune inhibitory signals from T-regs, inhibitory immune checkpoints and cytokines such as IL-8 and IL-6. These findings suggest an immune suppressive microenvironment which highlights the need for further studies to explore the potential of immune modulating therapy in EAC. Citation Format: Dyke P. McEwen, Derek J. Nancarrow, Jules Lin, Rishindra M. Reddy, Andrew C. Chang, David G. Beer, Kiran H. Lagisetty. Alterations in the immune microenvironment during progression from Barrett's esophagus to esophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4958.

Elevated doublecortin-like kinase 1 serum levels revert to baseline after therapy in early stage esophageal adenocarcinoma

BackgroundBarrett’s esophagus (BE) and esophageal adenocarcinoma (EAC) incidence has been increasing in the United States for greater than 30 years. For the majority of EAC patients, treatment is limited and prognosis poor. Doublecortin like kinase-1 (DCLK1) is a cancer stem cell marker with elevated expression in BE patients with high grade dysplasia and/or EAC. This prospective cohort study was designed to compare serum DCLK1 levels before and after EAC treatment with endoscopic mucosal resection (EMR) and/or radio-frequency ablation (RFA).MethodsBarrett’s esophagus patients with low or high-grade dysplasia (n = 9) and EAC patients (Stage I/II) eligible for treatment were enrolled (n = 14). Serum was obtained at enrollment and at end of treatment (EoT) where possible (n = 6). Normal control samples (n = 5) were obtained from patients with normal upper endoscopies. Serum was analyzed for DCLK1 protein content by ELISA. Kruskal-Wallis, Mann Whitney U, Pearson correlation, and Receiver Operating Characteristic tests were used to analyze the data.ResultsSerum DCLK1 levels were increased by > 50% in Barrett’s Esophagus (n = 9) and EAC patients (n = 14) vs controls (n = 5, p = 0.0007). These levels were reduced > 50% at EoT compared to EAC (p = 0.033). Although age was significantly lower in controls, this factor was not statistically related to DCLK1 serum levels (p = 0.66).ConclusionsEAC treatment results in significantly decreased serum DCLK1 levels, suggesting that DCLK1 may be useful as a non-invasive disease regression biomarker following treatment.ImpactBiomarkers for EAC therapeutic response have been poorly studied and no reliable marker has been discovered thus far. These results demonstrate that DCLK1 may have potential as a circulating biomarker of the response to therapy in EAC, which could be used to improve patient outcomes.

Endoscopic therapy and surveillance versus esophagectomy for early esophageal adenocarcinoma: A review of early outcomes and cost analysis

BackgroundEndoscopic therapy is considered to be comparable to esophagectomy with respect to oncologic outcomes in early (cT1) esophageal adenocarcinoma (EC). The current study aims to compare early outcomes and financial costs, associated with endoscopic versus surgical therapy for early esophageal adenocarcinoma. MethodsRetrospective review of patients undergoing either endoscopic or surgical therapy for cT1 EC between 2010 and 2015. ResultsAge, BMI, and Charlson Comorbidity Scores were similar in patients undergoing endoscopic therapy (N = 20) and esophagectomy (N = 23). For patients undergoing endoscopic therapy a median of 6 endoscopic interventions, were performed per patient (range 2–18). Esophagectomy was associated with a median hospital stay of 9 (8–13) days and greater procedure specific morbidity compared to endoscopic therapy. Costs related to endoscopic therapy were significantly lower compared to esophagectomy ($22,640 vs. $53,849, P < 0.001). ConclusionsEndoscopic treatment is associated with decreased morbidity and financial costs when compared to esophagectomy.

Her2-Targeted Therapy Induces Autophagy in Esophageal Adenocarcinoma Cells.

Esophageal adenocarcinoma (EAC) is a highly lethal cancer type with an overall poor survival rate. Twenty to thirty percent of EAC overexpress the human epidermal growth factor receptor 2 (Her2), a transmembrane receptor tyrosine kinase promoting cell growth and proliferation. Patients with Her2 overexpressing breast and gastroesophageal cancer may benefit from Her2 inhibitors. Therapy resistance, however, is well documented. Since autophagy, a lysosome-dependent catabolic process, is implicated in cancer resistance mechanisms, we tested whether autophagy modulation influences Her2 inhibitor sensitivity in EAC. Her2-positive OE19 EAC cells showed an induction in autophagic flux upon treatment with the small molecule Her2 inhibitor Lapatinib. Newly generated Lapatinib-resistant OE19 (OE19 LR) cells showed increased basal autophagic flux compared to parental OE19 (OE19 P) cells. Based on these results, we tested if combining Lapatinib with autophagy inhibitors might be beneficial. OE19 P showed significantly reduced cell viability upon double treatment, while OE19 LR were already sensitive to autophagy inhibition alone. Additionally, Her2 status and autophagy marker expression (LC3B and p62) were investigated in a treatment-naïve EAC patient cohort (n = 112) using immunohistochemistry. Here, no significant correlation between Her2 status and expression of LC3B and p62 was found. Our data show that resistance to Her2-directed therapy is associated with a higher basal autophagy level, which is not per se associated with Her2 status. Therefore, we propose that autophagy may contribute to acquired resistance to Her2-targeted therapy in EAC, and that combining Her2 and autophagy inhibition might be beneficial for EAC patients.

RA08.05: ENDOSCOPIC THERAPY AND SURVEILLANCE VERSUS ESOPHAGECTOMY FOR EARLY ESOPHAGEAL ADENOCARCINOMA: A REVIEW OF EARLY OUTCOMES AND COST ANALYSIS

Abstract Background Endoscopic therapy is considered to be comparable to esophagectomy with respect to oncologic outcomes in early (clinical stage T1) esophageal adenocarcinoma (EC). The current study aims to compare early outcomes and financial costs, associated with endoscopic versus surgical therapy for early EC. Methods Retrospective review of patients undergoing either endoscopic or surgical therapy for cT1 EC between 2010 and 2015 at a single high-volume center. To ensure comparability between treatment groups only those patients who were deemed medically fit to undergo esophagectomy, regardless of ultimate management, were included. Cost analysis was performed for each patient group and was compared to procedural outcomes. Results Forty-three patients met the inclusion criteria for this study (endoscopic therapy n = 20; esophagectomy n = 23). All patients who underwent endoscopic therapy had clinical stage T1A, whilst 15 patients in the esophagectomy group had T1B disease (P &lt; 0.001). Patient groups were well matched for all other baseline characteristics (P &gt; 0.05). For patients undergoing endoscopic therapy a median of six interventions were performed per patient (range 2–18). Same day discharge was achieved after 98% of all endoscopic procedures with 72% of cases performed under general anesthesia. Endoscopic dilations due to stricture formation were required in five (25%) patients after endoscopic therapy. Esophagectomy was associated with a median hospital stay of 9 (8–13) days and greater procedure specific morbidity compared to endoscopic therapy. Median treatment costs for patients undergoing esophagectomy were significantly greater than that incurred for patients receiving endoscopic therapy only ($53,849, 95%-confidence interval: 50,541–88,784 vs. $22,640, 95%CI: 18,754–46,705, P &lt; 0.001). The minimum cost associated with esophagectomy in the current study was approximately four times greater than for endoscopic therapy ($40,410 vs. $9236). In comparison the maximum cost incurred for surgical and endoscopic therapy were $247,808 and $127,508 respectively. Overall costs were significantly correlated to either number and severity or postoperative complications or number of endoscopic procedures performed (P &lt; 0.002). Conclusion In patients with early EC endoscopic therapy was associated with lower rates of procedure specific morbidity compared to esophagectomy. Despite an increased number of interventions and longer duration of therapy, overall costs were significantly lower in patients undergoing endoscopic therapy when compared to esophagectomy. Disclosure All authors have declared no conflicts of interest.

Abstract 4813: Enhancement of nab-paclitaxel response by inhibition of insulin-like growth factor (IGF) signaling in experimental esophageal adenocarcinoma

Abstract Introduction: Esophageal adenocarcinoma (EAC) is the fastest growing cancer in the western world and the overall 5 year survival rate of EAC is below 20 percent. Most patients with EAC present with locally advanced or widespread metastatic disease, where current treatment is largely ineffective. Therefore, new therapeutic approaches are urgently needed. Epidemiological studies have linked obesity with EAC. IGF signaling is an important mediator in obesity-associated EAC. Paclitaxel (PT) has been used in combination with carboplatin as a standard combination therapy for advanced EAC. PT required emulsification with solvents which has resulted in serious adverse effects in patients. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is an albumin-stabilized, cremophor-free and water soluble nanoparticle formulation of PT. Nab-paclitaxel has recently shown greater efficacy over PT in EAC. Here we evaluated the improvement in nab-paclitaxel response by addition of BMS-754807, a small molecule inhibitor of IGF-1R/IR signaling, in experimental EAC. Methods: We first evaluated the phosphorylation status of IGF-1R/IR protein by western blot in a panel of EAC cell lines. BMS-754807 and nab-paclitaxel, alone or in combination were tested for effects on cell growth detected by WST-1 assay and on cell apoptosis detected by western blot of cleavage of caspase 3 and PARP. We then explored the antitumor efficacy with survival advantage following BMS-754807 and nab-paclitaxel mono and combination therapies in murine subcutaneous xenograft and peritoneal metastatic survival models of human EAC. Results: BMS-754807 dose dependently inhibited in-vitro cell proliferation of OE19 and FLO-1 EAC cell lines having strong tyrosine phosphorylation of IGF-1R/IR protein and interestingly the addition of IC25 dose of BMS-754807 significantly decreased the nab-paclitaxel IC50 in these EAC cells. In addition, co-administration of BMS-754807 and nab-paclitaxel effectively enhanced cleavage of caspase-3 and PARP in these EAC cells. In subcutaneous xenografts using OE19 cells, average net tumor growth after two weeks in different therapy groups was 558.67 mm3 in control, 208.47 mm3 after BMS-754807 (p=0.043), 104.60 mm3 after nab-paclitaxel (p=0.013), and 14.30 mm3 after BMS-754807 plus nab-paclitaxel (p=0.0005). In OE19 EAC survival model there was a significant increase in median animal survival after two weeks BMS-754807 plus nab-paclitaxel treatment (85 days) compared to control (47 days, p=0.0034), to BMS-754807 therapy (57 days, p=0.0021) or to nab-paclitaxel (68 days, p=0.0339) therapy. Conclusion: Thus BMS-754807 with nab-paclitaxel treatment resulted in significantly higher antitumor efficacy and survival benefit. These results support the potential of BMS-754807 in combination with nab-paclitaxel as an effective option for EAC therapy. Citation Format: Md Sazzad Hassan, Fiona Williams, Niranjan Awasthi, Margaret A. Schwarz, Roderich E. Schwarz, Urs von Holzen. Enhancement of nab-paclitaxel response by inhibition of insulin-like growth factor (IGF) signaling in experimental esophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4813.

PV-0098: Preoperative Nomogram for Early recurrence after Trimodality Therapy in Esophageal Adenocarcinoma

PV-0098: Preoperative Nomogram for Early recurrence after Trimodality Therapy in Esophageal Adenocarcinoma