Targeting interleukin-6 as a treatment approach for peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) is a complex manifestation of abdominal cancers, with a poor prognosis and limited treatment options. Recent work identifying high concentrations of the cytokine interleukin-6 (IL-6) and its soluble receptor (sIL-6-Rα) in the peritoneal cavity of patients with PC has highlighted this pathway as an emerging potential therapeutic target. This review article provides a comprehensive overview of the current understanding of the potential role of IL-6 in the development and progression of PC. We discuss mechansims by which the IL-6 pathway may contribute to peritoneal tumor dissemination, mesothelial adhesion and invasion, stromal invasion and proliferation, and immune response modulation. Finally, we review the prospects for targeting the IL-6 pathway in the treatment of PC, focusing on common sites of origin, including ovarian, gastric, pancreatic, colorectal and appendiceal cancer, and mesothelioma.

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 .

Elucidating the Heterogeneity of Immunotherapy Response and Immune-Related Toxicities by Longitudinal ctDNA and Immune Cell Compartment Tracking in Lung Cancer

PURPOSE

Although immunotherapy is the mainstay of therapy for advanced non-small cell lung cancer (NSCLC), robust biomarkers of clinical response are lacking. The heterogeneity of clinical responses together with the limited value of radiographic response assessments to timely and accurately predict therapeutic effect-especially in the setting of stable disease-calls for the development of molecularly informed real-time minimally invasive approaches. In addition to capturing tumor regression, liquid biopsies may be informative in capturing immune-related adverse events (irAE).

EXPERIMENTAL DESIGN

We investigated longitudinal changes in circulating tumor DNA (ctDNA) in patients with metastatic NSCLC who received immunotherapy-based regimens. Using ctDNA targeted error-correction sequencing together with matched sequencing of white blood cells and tumor tissue, we tracked serial changes in cell-free tumor load (cfTL) and determined molecular response. Peripheral T-cell repertoire dynamics were serially assessed and evaluated together with plasma protein expression profiles.

RESULTS

Molecular response, defined as complete clearance of cfTL, was significantly associated with progression-free (log-rank P = 0.0003) and overall survival (log-rank P = 0.01) and was particularly informative in capturing differential survival outcomes among patients with radiographically stable disease. For patients who developed irAEs, on-treatment peripheral blood T-cell repertoire reshaping, assessed by significant T-cell receptor (TCR) clonotypic expansions and regressions, was identified on average 5 months prior to clinical diagnosis of an irAE.

CONCLUSIONS

Molecular responses assist with the interpretation of heterogeneous clinical responses, especially for patients with stable disease. Our complementary assessment of the peripheral tumor and immune compartments provides an approach for monitoring of clinical benefits and irAEs during immunotherapy.

The Evolving Landscape of Neoadjuvant Immunotherapy in Gastroesophageal Cancer

Despite advances in treatment strategies and surgical approaches in recent years, improving survival outcomes in esophagogastric cancer (EGC) patients treated with curative intent remains a significant area of unmet need. The recent emergence of adjuvant immunotherapy as the standard of care for resected EGC demonstrates the impact of immunotherapy in improving recurrence-free survival. Neoadjuvant and perioperative immunotherapies represent another promising approach with potential advantages over adjuvant therapy. Despite the promising results of early neoadjuvant immunotherapy studies, there are several challenges and future research needs. The optimal timing, duration and number of doses in relation to surgery and the optimal combination of immunotherapies are still unclear. In addition, rigorous correlative studies need to be performed to identify biomarkers for patient selection and treatment response prediction to maximize the benefits of neoadjuvant immunotherapy. In this review, we provide a concise summary of the current standard of care for resectable EGC and discuss the rationale for the use of immune checkpoint inhibitors in this setting and the pre-clinical and early clinical data of these novel therapies. Finally, we will examine the potential role and future direction of immunotherapy in the treatment paradigm and the perceived challenges and opportunities that lay ahead.

The Utility of Symptom Association Probability (SAP) in Predicting Outcome After Laparoscopic Fundoplication in Patients with Abnormal Esophageal Acid Exposure

INTRODUCTION

Abnormal DeMeester score on pH monitoring is a well-established predictor of favorable outcome after antireflux surgery (ARS). Esophageal pH monitoring also facilitates analysis of the temporal association between symptoms and reflux episodes. This association can be expressed with several symptom-reflux association indices with symptom association probability (SAP) being the most reliable. SAP is often used as an adjunct to DeMeester score during preoperative assessment of patients seeking ARS. However, data on the utility of SAP in predicting ARS outcome is limited. The aim of this study was to determine the utility of SAP as an adjunct to DeMeester score in predicting outcomes after fundoplication.

METHODS

Records of patients who underwent primary fundoplication from 2015 to 2021 were reviewed. Patients with a preoperative DeMeester score >14.7 on Bravo pH monitoring were included. A SAP >95% was considered SAP-positive. Favorable outcome was defined as freedom from proton pump inhibitors (PPIs) and patient satisfaction at 1 year postoperatively. Outcomes were compared based on the presence and number of SAP-positive symptoms, individual typical and atypical SAP-positive symptoms, and within demographic, clinical, and reflux severity subgroups.

RESULTS

The final study population consisted of 597 patients (71.4% female) with a median (IQR) age of 59.0 (49-67). At a mean (SD) follow-up of 10.5 (8) months, 82.0% patients achieved favorable outcome (satisfaction and freedom from PPI), freedom from PPI was 91.7%, and satisfaction was 87.4%. SAP was positive in 430 (72.0%) patients, of which 221 (37.0%) had one SAP-positive symptom, 164 (27.5%) had two SAP-positive symptoms, and 45 (7.5%) had all three SAP-positive symptoms. There was no association between having at least one SAP-positive symptom and favorable outcome (p=0.767). There was no difference in favorable outcome between patients with one, two, or all SAP-positive symptoms (0.785). Outcomes were comparable for SAP-positive typical (p=0.873) and atypical symptoms (p=1.000) and all individual symptoms (p>0.05). Outcomes were also comparable within all subgroups (p>0.05).

CONCLUSION

Symptom association probability with an abnormal DeMeester score did not enhance the prediction of antireflux surgery outcome. These findings suggest that SAP should not be used in surgical decision-making in patients with objective evidence of reflux.

Single-molecule genome-wide mutation profiles of cell-free DNA for non-invasive detection of cancer

Somatic mutations are a hallmark of tumorigenesis and may be useful for non-invasive diagnosis of cancer. We analyzed whole-genome sequencing data from 2,511 individuals in the Pan-Cancer Analysis of Whole Genomes (PCAWG) study as well as 489 individuals from four prospective cohorts and found distinct regional mutation type-specific frequencies in tissue and cell-free DNA from patients with cancer that were associated with replication timing and other chromatin features. A machine-learning model using genome-wide mutational profiles combined with other features and followed by CT imaging detected >90% of patients with lung cancer, including those with stage I and II disease. The fixed model was validated in an independent cohort, detected patients with cancer earlier than standard approaches and could be used to monitor response to therapy. This approach lays the groundwork for non-invasive cancer detection using genome-wide mutation features that may facilitate cancer screening and monitoring.

Elucidating the heterogeneity of immunotherapy response and immune-related toxicities by longitudinal ctDNA and immune cell compartment tracking in lung cancer

Purpose

Although immunotherapy is the mainstay of therapy for advanced non-small cell lung cancer (NSCLC), robust biomarkers of clinical response are lacking. The heterogeneity of clinical responses together with the limited value of radiographic response assessments to timely and accurately predict therapeutic effect -especially in the setting of stable disease-call for the development of molecularly-informed real-time minimally invasive predictive biomarkers. In addition to capturing tumor regression, liquid biopsies may be informative in evaluating immune-related adverse events (irAEs).

Experimental design

We investigated longitudinal changes in circulating tumor DNA (ctDNA) in patients with metastatic NSCLC who received immunotherapy-based regimens. Using ctDNA targeted error-correction sequencing together with matched sequencing of white blood cells and tumor tissue, we tracked serial changes in cell-free tumor load (cfTL) and determined molecular response for each patient. Peripheral T-cell repertoire dynamics were serially assessed and evaluated together with plasma protein expression profiles.

Results

Molecular response, defined as complete clearance of cfTL, was significantly associated with progression-free (log-rank p=0.0003) and overall survival (log-rank p=0.01) and was particularly informative in capturing differential survival outcomes among patients with radiographically stable disease. For patients who developed irAEs, peripheral blood T-cell repertoire reshaping, assessed by significant TCR clonotypic expansions and regressions were noted on-treatment.

Conclusions

Molecular responses assist with interpretation of heterogeneous clinical responses especially for patients with stable disease. Our complementary assessment of the tumor and immune compartments by liquid biopsies provides an approach for monitoring of clinical benefit and immune-related toxicities for patients with NSCLC receiving immunotherapy.

Statement of translational relevance

Longitudinal dynamic changes in cell-free tumor load and reshaping of the peripheral T-cell repertoire capture clinical outcomes and immune-related toxicities during immunotherapy for patients with non-small cell lung cancer.

Abstract 3366: A machine learning approach to determine the cellular origin of variants in liquid biopsies

Introduction: Targeted next-generation sequencing (NGS) of cell-free DNA in plasma, referred to as liquid biopsy, has become a valuable diagnostic tool in clinical oncology. However, detection of variants related to clonal hematopoiesis (CH) is a major confounder that significantly impairs the clinical utility of liquid biopsies. Here we developed a machine-learning model to determine tumor versus CH origin of variants identified in plasma-only NGS.

Methods: We assembled a training cohort of 352 variants identified by targeted deep plasma sequencing from 199 patients with stage I-IV breast, colorectal, esophageal, lung, and ovarian cancer, coupled with matched white blood cell (WBC) and tumor tissue NGS to allow determination of the reference origin for each plasma variant. We employed Extreme Gradient Boosting (XGBoost) to integrate fragment, variant, gene, and patient level features to predict tumor versus CH plasma variant origin, evaluating the performance of this approach within the training cohort using 10-fold cross-validation. We applied the fixed model to two independent validation cohorts: a small cell lung cancer (SCLC) cohort comprising of 74 variants from targeted plasma NGS from 26 patients and a multi-cancer cohort of 409 variants detected using the MSK-Impact panel from 74 patients with breast, colorectal, and prostate cancer.

Results: Variant allele frequencies (VAF) did not differentiate tumor from CH variants, as the VAFs between tumor (median VAF 0.53%) and CH (median VAF 0.409%) variants in the training cohort were largely overlapping (area under the ROC curve-AUC 0.54, 95% confidence interval-CI 0.48-0.61). Similarly, individual fragmentomic features (mutant fragment length, cut points, and endpoint motifs) had limited ability to distinguish tumor from CH variants (AUC range 0.51-0.76). Using serial plasma samples, we identified stable statistical measures of differences in fragment feature distributions between mutant and wild type fragments; these were subsequently incorporated into an XGBoost machine-learning model along with variant, gene and patient features to predict tumor versus CH variant origin. Our model predicted variant origin with an AUC of 0.95 (95% CI 0.87-1) from 10-fold cross validation in the training cohort. The performance of the model was tested in independent SCLC and multi-cancer validation cohorts; the fixed model predicted plasma variant origin with an AUC of 0.87 (95% CI 0.73-1) and 0.89 (95% CI 0.86-0.92) respectively.

Conclusion: We developed a machine-learning model that integrates patient, gene, variant and fragment features to predict tumor versus CH origin of plasma variants across solid tumors and NGS sequencing platforms. The ability to identify bona fide tumor variants in plasma-only sequencing fills a critical need in the clinical implementation of liquid biopsy-guided cancer therapy by reducing misinterpretation due to CH contamination.

Citation Format: Jenna V. Canzoniero, Archana Balan, Jillian Phallen, Blair V. Landon, Lavanya Sivapalan, Benjamin Green, Zineb Belcaid, Susan C. Scott, Gavin Pereira, Vincent K. Lam, Ali H. Zaidi, Ronan J. Kelly, Christine L. Hann, Wade T. Iams, Christine M. Lovly, Patrick M. Forde, Gerrit A. Meijer, Geraldine R. Vink, Remond J. Fijneman, The MEDOCC Group, Victor E. Velculescu, Robert B. Scharpf, Valsamo Anagnostou. A machine learning approach to determine the cellular origin of variants in liquid biopsies [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 3366.

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.

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.

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.

A microRNA-based liquid biopsy signature for the early detection of esophageal squamous cell carcinoma: a retrospective, prospective and multicenter study

BACKGROUND

Currently, there is no clinically relevant non-invasive biomarker for early detection of esophageal squamous cell carcinoma (ESCC). Herein, we established and evaluated a circulating microRNA (miRNA)-based signature for the early detection of ESCC using a systematic genome-wide miRNA expression profiling analysis.

METHODS

We performed miRNA candidate discovery using three ESCC tissue miRNA datasets (n = 108, 238, and 216) and the candidate miRNAs were confirmed in tissue specimens (n = 64) by qRT-PCR. Using a serum training cohort (n = 408), we conducted multivariate logistic regression analysis to develop an ESCC circulating miRNA signature and the signature was subsequently validated in two independent retrospective and two prospective cohorts.

RESULTS

We identified eighteen initial miRNA candidates from three miRNA expression datasets (n = 108, 238, and 216) and subsequently validated their expression in ESCC tissues. We thereafter confirmed the overexpression of 8 miRNAs (miR-103, miR-106b, miR-151, miR-17, miR-181a, miR-21, miR-25, and miR-93) in serum specimens. Using a serum training cohort, we developed a circulating miRNA signature (AUC:0.83 [95%CI:0.79-0.87]) and the diagnostic performance of the miRNA signature was confirmed in two independent validation cohorts (n = 126, AUC:0.80 [95%CI:0.69-0.91]; and n = 165, AUC:0.89 [95%CI:0.83-0.94]). Finally, we demonstrated the diagnostic performance of the 8-miRNA signature in two prospective cohorts (n = 185, AUC:0.92, [95%CI:0.87-0.96]); and (n = 188, AUC:0.93, [95%CI:0.88-0.97]). Importantly, the 8-miRNA signature was superior to current clinical serological markers in discriminating early stage ESCC patients from healthy controls (p < 0.001).

CONCLUSIONS

We have developed a novel and robust circulating miRNA-based signature for early detection of ESCC, which was successfully validated in multiple retrospective and prospective multinational, multicenter cohorts.

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.

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

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

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.

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.

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.

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.

Serial Endoscopic Evaluation of Esophageal Disease in a Cancer Model: A Paradigm Shift for Esophageal Adenocarcinoma (EAC) Drug Discovery and Development

A rat model of surgically induced reflux recapitulates the development and progression of human esophageal adenocarcinoma (EAC). In this study, reflux was induced in rats followed by postoperative endoscopy with biopsy, to diagnose and monitor disease progression. Overall, percentage agreement between visual endoscopy and gold standard histology was 95%, with disease-specific classification accuracies of 100% and 75% for Barrett's with dysplasia and EAC, respectively. Additionally, the percentage agreement for biopsy in tumors >4 mm was 75%. Thereby, establishing endoscopic evaluation as a reliable tool to assess disease progression and provide biopsies for downstream correlates in a de novo EAC model.

Phase II Study of Irinotecan Plus Panitumumab as Second-Line Therapy for Patients with Advanced Esophageal Adenocarcinoma

Lesson Learned.

Panitumumab plus irinotecan is not active for the treatment of esophageal adenocarcinoma.

Background.

Esophageal adenocarcinoma (EAC) is a lethal cancer with increasing incidence. Panitumumab (Pa) is a fully humanized IgG2 monoclonal antibody against human EGFR. Cetuximab (Cx) combined with irinotecan (Ir) is active for second‐line treatment of colorectal cancer. This phase II study was designed to evaluate Pa plus Ir as second‐line therapy for advanced EAC.

Methods.

The primary endpoint was response rate (RR). Patients with one prior treatment were given Pa 9 mg/m² on day 1 and Ir 125 mg/m² on days 1 and 8 of each 21‐day cycle. Inclusion criteria were confirmed EAC, measurable disease, no prior Ir or Pa, performance status <2, and normal organ function.

Results.

Twenty‐four patients were enrolled; 18 were eligible and evaluable. These patients were all white, with a median age of 62.5 years (range, 33–79 years), and included 15 men and 3 women. The median number of cycles was 3.5. The most common grade 1–2 adverse events were fatigue, diarrhea, anemia, leukopenia, and hypoalbuminemia. Grade 3–4 adverse events included hematologic, gastrointestinal, electrolyte, rash, fatigue, and weight loss. The median follow‐up was 7.2 months (range, 2.3–14 months). There were no complete remissions. The partial response rate was 6% (1/18; 95% confidence interval [CI], 0.01–0.26). The clinical benefit (partial response [PR] plus stable disease [SD]) rate was 50%. The median overall survival was 7.2 months (95% CI, 4.1–8.9) with an 11.1% 1‐year survival rate. The median progression‐free survival was 2.9 months (95% CI, 1.6–5.3).

Conclusion.

Irinotecan and panitumumab as second‐line treatment for advanced EAC are not active.

Primary tumor microRNA signature predicts recurrence and survival in patients with locally advanced esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is an aggressive cancer necessitating the development of improved risk stratification tools for personalized care. Previously, microRNAs have been shown to correlate with the progression and prognosis of various cancer types; however, the value in EAC remains largely unexplored. We performed global microRNA profiling on 32 formalin-fixed, paraffin-embedded EAC specimens to identify microRNAs associated with progression. Literature search and pathway analysis further refined output to five significantly deregulated candidate biomarkers. Four of the five microRNAs (miR-652-5p, miR-7-2-3p, miR-3925-3p, and miR-219-3p) were validated by qRT-PCR. Survival outcomes were evaluated in testing set of 26 stage II/III EAC patients to determine the prognostic relevance of the selected microRNAs. In the testing set, miR-652-5p and miR-7-2-3p expressions were significantly associated with progression-free survival (p-value = .00771 and p-value = .00293). The highest area under receiver operating characteristic (ROC) curve was 0.8212 for the combination of miR-652-5p and miR-7-2-3p. Collectively, our findings demonstrated that the miR-652-5p/miR-7-2-3p signature may serve as a promising prognostic marker in patients with locally advanced EAC.

Sep70/Pepsin expression in hypopharynx combined with hypopharyngeal multichannel intraluminal impedance increases diagnostic sensitivity of laryngopharyngeal reflux

BACKGROUND

Improved methods of diagnosis of laryngopharyngeal reflux (LPR) would enable surgeons to better identify patients who may benefit from antireflux surgery (ARS). The objective of the present study was to assess if hypopharyngeal Pepsin and Sep70 expression combined with hypopharyngeal multichannel intraluminal impedance (HMII) has the potential to increase diagnostic sensitivity of LPR.

METHODS

This study was performed on patients who underwent unsedated transnasal endoscopy with hypopharyngeal biopsy and 24-h HMII to determine abnormal proximal exposure (APE) and DeMeester score (DMS) from 2013 to 2016. Pepsin and Sep70 protein expression was assessed by Western blots of biopsy specimens. The outcomes of ARS were assessed using reflux symptom index (RSI). HMII APE classification, Sep 70, and Pepsin protein levels were compared in normative and symptomatic LPR patients and further analyzed alongside quality of life changes following ARS.

RESULTS

Of 30 subjects enrolled, 23 were excluded for abnormal HMII results or endoscopic evidence of esophagitis. Seven subjects and 105 patients were included in the normative and symptomatic groups, respectively. Compared to the normative group, only Pepsin expression was significantly higher in the symptomatic group [APE+/LPR+ (p = 0.000), APE+/LPR- (p = 0.001), and APE- (p = 0.047)]. Further, the ratio of Sep70/Pepsin was significantly lower in the symptomatic group [APE+/LPR+ (p = 0.008), APE+/LPR- (p = 0.000), and APE- (p = 0.050)], and a cutoff ratio for a diagnosis of LPR was established as < 158. Of 105 symptomatic patients, 48 patients underwent ARS. Of these, 17 patients had complete pre- and post-RSI questionnaires. LPR symptoms improved in 15 (88%), of whom 2 were APE- but met criteria for a diagnosis of LPR based on the Sep70/Pepsin cutoff.

CONCLUSIONS

The identified Sep70/Pepsin ratio may serve as a reliable biomarker for the diagnosis of LPR. As a result, this may help identify additional patients who have a false-negative HMII result due to the 24-h testing window.

CDK4/6 dual inhibitor abemaciclib demonstrates compelling preclinical activity against esophageal adenocarcinoma: a novel therapeutic option for a deadly disease

Esophageal adenocarcinoma (EAC) is a deadly disease with limited therapeutic options. In the present study, we determined the preclinical efficacy of CDK4/6 inhibitor abemaciclib for treatment of EAC. In vitro, apoptosis, proliferation, and pathway regulation were evaluated in OE19, OE33, and FLO1 EAC cell lines. In vivo, esophagojejunostomy was performed on rats to induce EAC. At 36 weeks post-surgery, MRI and endoscopic biopsy established baseline tumor volume and molecular correlates, respectively. Next, the study animals were randomized to 26mg/kg intraperitoneal abemaciclib treatment or vehicle control for 28 days. Pre and post treatment MRIs, histopathology, and qRT-PCR were utilized to determine response. Our results demonstrated treatment with abemaciclib lead to increased apoptosis, and decreased proliferation in OE19 (p=0.185), OE33 (p=0.048), and FLO1 (p=0.043) with anticipated downstream molecular inhibition. In vivo, 78.9% of treatment animals demonstrated >20% tumor volume decrease (placebo 0%). Mean tumor volume changed in the treatment arm by -65.5% (placebo +133.5%) (p<0.01), and prevalence changed by -37.5% (placebo +16.7%) (p<0.01). Pre vs post treatment qRT-PCR demonstrated significant inhibition of all downstream molecular correlates. Overall our findings suggest potent antitumor efficacy of abemaciclib against EAC with evident molecular pathway inhibition and reasonable safety, establishing the rationale for future clinical development.

High yield reproducible rat model recapitulating human Barrett’s carcinogenesis

AIM

To efficiently replicate the biology and pathogenesis of human esophageal adenocarcinoma (EAC) using the modified Levrat model of end-to-side esophagojejunostomy.

METHODS

End-to-side esophagojejunostomy was performed on rats to induce gastroduodenoesophageal reflux to develop EAC. Animals were randomly selected and serially euthanized at 10 (n = 6), 17 (n = 8), 24 (n = 9), 31 (n = 6), 38 (n = 6), and 40 (n = 6) wk postoperatively. The esophagi were harvested for downstream histopathology and gene expression. Histological evaluation was completed to determine respective rates of carcinogenic development. Quantitative reverse transcription-polymerase chain reaction was performed to determine gene expression levels of MUC2, CK19, and CK20, and results were compared to determine significant differences throughout disease progression stages.

RESULTS

The overall study mortality was 15%. Causes of mortality included anastomotic leak, gastrointestinal hemorrhage, stomach ulcer perforation, respiratory infection secondary to aspiration, and obstruction due to tumor or late anastomotic stricture. 10 wk following surgery, 100% of animals presented with esophagitis. Barrett’s esophagus (BE) was first observed at 10 wk, and was present in 100% of animals by 17 wk. Dysplasia was confirmed in 87.5% of animals at 17 wk, and increased to 100% by 31 wk. EAC was first observed in 44.4% of animals at 24 wk and increased to 100% by 40 wk. In addition, two animals at 38-40 wk post-surgery had confirmed macro-metastases in the lung/liver and small intestine, respectively. MUC2 gene expression was progressively down-regulated from BE to dysplasia to EAC. Both CK19 and CK20 gene expression significantly increased in a stepwise manner from esophagitis to EAC.

CONCLUSION

Esophagojejunostomy was successfully replicated in rats with low mortality and a high tumor burden, which may facilitate broader adoption to study EAC development, progression, and therapeutics.

A Tissue Systems Pathology Test Detects Abnormalities Associated with Prevalent High-Grade Dysplasia and Esophageal Cancer in Barrett's Esophagus

BACKGROUND

There is a need for improved tools to detect high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) in patients with Barrett's esophagus. In previous work, we demonstrated that a 3-tier classifier predicted risk of incident progression in Barrett's esophagus. Our aim was to determine whether this risk classifier could detect a field effect in nondysplastic (ND), indefinite for dysplasia (IND), or low-grade dysplasia (LGD) biopsies from Barrett's esophagus patients with prevalent HGD/EAC.

METHODS

We performed a multi-institutional case-control study to evaluate a previously developed risk classifier that is based upon quantitative image features derived from 9 biomarkers and morphology, and predicts risk for HGD/EAC in Barrett's esophagus patients. The risk classifier was evaluated in ND, IND, and LGD biopsies from Barrett's esophagus patients diagnosed with HGD/EAC on repeat endoscopy (prevalent cases, n = 30, median time to HGD/EAC diagnosis 140.5 days) and nonprogressors (controls, n = 145, median HGD/EAC-free surveillance time 2,015 days).

RESULTS

The risk classifier stratified prevalent cases and non-progressor patients into low-, intermediate-, and high-risk classes [OR, 46.0; 95% confidence interval, 14.86-169 (high-risk vs. low-risk); P < 0.0001]. The classifier also provided independent prognostic information that outperformed the subspecialist and generalist diagnosis.

CONCLUSIONS

A tissue systems pathology test better predicts prevalent HGD/EAC in Barrett's esophagus patients than pathologic variables. The results indicate that molecular and cellular changes associated with malignant transformation in Barrett's esophagus may be detectable as a field effect using the test.

IMPACT

A tissue systems pathology test may provide an objective method to facilitate earlier identification of Barrett's esophagus patients requiring therapeutic intervention. Cancer Epidemiol Biomarkers Prev; 26(2); 240-8. ©2016 AACR.

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

BACKGROUND

Better methods are needed to predict risk of progression for Barrett's esophagus. We aimed to determine whether a tissue systems pathology approach could predict progression in patients with nondysplastic Barrett's esophagus, indefinite for dysplasia, or low-grade dysplasia.

METHODS

We performed a nested case-control study to develop and validate a test that predicts progression of Barrett's esophagus to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC), based upon quantification of epithelial and stromal variables in baseline biopsies. Data were collected from Barrett's esophagus patients at four institutions. Patients who progressed to HGD or EAC in ≥1 year (n = 79) were matched with patients who did not progress (n = 287). Biopsies were assigned randomly to training or validation sets. Immunofluorescence analyses were performed for 14 biomarkers and quantitative biomarker and morphometric features were analyzed. Prognostic features were selected in the training set and combined into classifiers. The top-performing classifier was assessed in the validation set.

RESULTS

A 3-tier, 15-feature classifier was selected in the training set and tested in the validation set. The classifier stratified patients into low-, intermediate-, and high-risk classes [HR, 9.42; 95% confidence interval, 4.6-19.24 (high-risk vs. low-risk); P < 0.0001]. It also provided independent prognostic information that outperformed predictions based on pathology analysis, segment length, age, sex, or p53 overexpression.

CONCLUSION

We developed a tissue systems pathology test that better predicts risk of progression in Barrett's esophagus than clinicopathologic variables.

IMPACT

The test has the potential to improve upon histologic analysis as an objective method to risk stratify Barrett's esophagus patients. Cancer Epidemiol Biomarkers Prev; 25(6); 958-68. ©2016 AACR.

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

Background

Toll-like receptors (TLRs) recognize known molecules from microbes and have an established role in tumorigenesis. Using a rat model of esophageal adenocarcinoma, and human clinical samples, we investigated genes central to TLR-mediated signal transduction and characterized the esophageal microbiome across the spectrum of esophageal adenocarcinoma carcinogenesis.

Methods

We surgically induced bile/acid reflux in rats and their esophagi were harvested at 40 weeks post-surgery. Tissue samples from the model were selected for gene expression profiling. Additionally, for rat and human samples microbiome analysis was performed using PCR-ESI-MS-TOF technology with validation by fluorescence in situ hybridization.

Results

Gene expression results in the rat model indicated a significant upregulation of TLRs 1-3, 6, 7 and 9 in EAC compared to normal epithelium. PCR-ESI-MS-TOF analysis revealed a prevalence of Escherichia coli in Barrett’s esophagus (60 %) and esophageal adenocarcinoma (100 %), which was validated by fluorescence in situ hybridization. In the human clinical samples, Streptococcus pneumonia was detected in high abundance in gastroesophageal reflux disease and Barrett’s esophagus (50–70 %) in comparison to tumor adjacent normal epithelium, dysplasia, and esophageal adenocarcinoma (20–30 %). E. coli was detected in the Barrett’s esophagus and esophageal adenocarcinoma groups but was absent in the tumor adjacent normal epithelium, dysplasia, and the gastroesophageal reflux disease groups.

Conclusions

We demonstrated an association between the TLR signaling pathway and E. coli hinting towards possible early molecular changes being mediated by microbes in the rat model of esophageal adenocarcinoma carcinogenesis. Studies on human clinical samples also corroborate results to some extent; however, a study with larger sample size is needed to further explore this association.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2093-8) contains supplementary material, which is available to authorized users.

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

Objective

To establish a miRNA signature for metastasis in an animal model of esophageal adenocarcinoma (EAC).

Background

The incidence of esophageal adenocarcinoma (EAC) has dramatically increased and esophageal cancer is now the sixth leading cause of cancer deaths worldwide. Mortality rates remain high among patients with advanced stage disease and esophagectomy is associated with high complication rates. Hence, early identification of potentially metastatic disease would better guide treatment strategies.

Methods

The modified Levrat’s surgery was performed to induce EAC in Sprague-Dawley rats. Primary EAC and distant metastatic sites were confirmed via histology and immunofluorescence. miRNA profiling was performed on primary tumors with or without metastasis. A unique subset of miRNAs expressed in primary tumors and metastases was identified with Ingenuity Pathway Analysis (IPA) along with upstream and downstream targets. miRNA-linked gene expression analysis was performed on a secondary cohort of metastasis positive (n=5) and metastasis negative (n=28) primary tumors.

Results

The epithelial origin of distant metastasis was established by IF using villin (VIL1) and mucin 5AC (MUC5AC) antibodies. miRNome analysis identified four down-regulated miRNAs in metastasis positive primary tumors compared to metastasis negative tumors: miR-92a-3p (p=0.0001), miR-141-3p (p=0.0022), miR-451-1a (p=0.0181) and miR133a-3p (p=0.0304). Six target genes identified in the top scoring networks by IPA were validated as significantly, differentially expressed in metastasis positive primary tumors: Ago2, Akt1, Kras, Bcl2L11, CDKN1B and Zeb2.

Conclusion

In vivo metastasis was confirmed in the modified Levrat’s model. Analysis of the primary tumor identified a distinctive miRNA signature for primary tumors that metastasized.

Role of microbiota and Toll-like receptors in progression of esophageal adenocarcinoma (EAC) in a rat reflux model

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Background: The discovery of the link between H. pylori and gastric cancer may be the most direct proof that bacterial signaling and host response can result in carcinogenesis. Accumulating evidence supports that activation of the Toll-like receptor (TLR) signaling pathway by microbes is associated with the development of GI malignancies. Using the modified Levrat model of gastroduodenojejunal reflux which mimics the physiological and molecular sequence of human EAC in the rat, this study profiles the expression of genes central to TLR-mediated signal transduction as well as characterizes the esophageal microbiome across the spectrum of EAC development. Methods: Modified Levrat’s surgery induced chronic acid reflux in Sprague-Dawley’s with harvest of esophagus 40 weeks post-surgery. Macordissection of normal adjacent epithelium, Barrett’s esophagus (BE), dysplasia and EAC tumor was performed followed by RNA/DNA isolation. Five samples per group were selected for gene expression profiling on the Qiagen TLR Signaling Pathway PCR Array as well as microbiome analysis by IBIS technology. Validation of IBIS was performed by fluorescence in situ hybridization (FISH). Results: Gene expression analysis identified TLRs 1-3 and 6, 7, 9 as significantly upregulated in EAC compared to normal esophagus. TLR 1 and 5 were significantly upregulated in dysplasia. TLR 1 was significantly upregulated in BE and normal adjacent epithelium. Thirty seven genes involved in the TLR signaling pathway were dysregulated in EAC, 30 in dysplasia, 21 in BE and 23 in normal adjacent. IBIS analysis revealed a prevalence of E. coli in BE and EAC which was validated by FISH. Conclusions: Toll-like receptor (TLR) signaling pathway responses to E. coli may participate in the development of EAC. E. coli may be a potential risk factor for EAC requiring further clinical validation.

Abstract B05: MRI provides a more reliable method of esophageal tumor detection than endoscopy in a rat model

Background: The surgical rat model of end-to-side esophagojejunal anastomosis has proven utility in terms of its ability to replicate Barrett's carcinogenesis by inducing gastroduodenoesophageal reflux (GDER). Previously, visual endoscopic analysis has been shown as a valuable tool for monitoring natural history of disease, with biopsy allowing for analysis of molecular markers while avoiding animal sacrifice. However, due to the inherent model limitation of the extraluminal presentation of the majority of tumors, as well as the small size of endoscopic biopsies, adenocarcinoma histology has only been validated post-mortem, and therefore treatment efficacy studies have been limited to chemoprevention. The current study aims to test and establish MRI and / or endoscopic visualization for diagnosis and monitoring of esophageal cancer in the rat model, in order to enhance utilization of this promising de novo model to study treatment response of novel agents in established esophageal cancer.

Methods: Chronic bile and acid reflux was induced in 24 Sprague-Dawley rats through a modified Levrat's model. At 40 weeks post-surgery, all animals underwent an endoscopy, T2-weighted turbo spin-echo (TSE) MRI scan and post-mortem histological analysis. A total of five esophageal surgeons and gastroenterologists participated in a blinded study and watched endoscopy videos to determine if esophageal tumor was present. Additionally, three radiology experts participated in a blinded study designed to assess correlated coronal and axial MRI scans and determine whether tumor was present. All videos and scans were studied in triplicate, and histology was used as the gold standard to assess accuracy of each participant's analysis.

Results: The accuracy of MRI and endoscopic analysis to correctly identify histology was 69.6% and 57.4%, respectively. The ROC curve analysis showed average MRI rating (AUC = 0.77, p-value = 0.032) was a better discriminator of tumor status in rats than average endoscopy rating (AUC = 0.595, p-value = 0.450). Additionally, false positive rates of MRI and endoscopy were 10.1% and 16.5%, respectively. Inter-observer variability was in substantial agreement for MRI participants (average Kappa = 0.768); whereas endoscopic analysis did not show greater agreement than that what would be expected by chance. All cases where MRI participants agreed on the presence of tumor, histology confirmed the positive findings.

Conclusions: MRI is a more reliable diagnostic method than endoscopy for esophageal tumor in rats. Endoscopic examination remains a valuable tool in terms of its ability to biopsy specimens for analysis of biomarker correlates for therapeutic efficacy; however, MRI is a more dependable technique in terms of confirming tumor presence and disease progression for utilization in a treatment model.

Citation Format: Juliann E. Kosovec, Yoshihiro Komatsu, Christina L. Rotoloni, Diane V. Thompson, Ali H. Zaidi, Blair A. Jobe. MRI provides a more reliable method of esophageal tumor detection than endoscopy in a rat model. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr B05.

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

INTRODUCTION

The management of laryngopharyngeal reflux (LPR) has been challenging. Hypopharyngeal multichannel intraluminal impedance (HMII) has shown to increase the sensitivity in diagnosing LPR. The objective of this study is to investigate the potential use of pepsin and Sep70 as diagnostic tools for detection of LPR in combination with HMII.

MATERIALS AND METHODS

Tissue samples of hypopharynx, distal esophagus, and gastric cardia were collected from patients with LPR symptoms regardless of gastroesophageal reflux (GERD) diagnosis and underwent HMII to detect LPR and high esophageal reflux (HER: reflux 2 cm distal to upper esophageal sphincter) events. Patients were classified into two groups based on the presence of abnormal proximal exposure (APE), which was defined as LPR ≥1/day and/or HER ≥5/day: (1) positive-APE and (2) negative-APE. Patients with typical GERD symptoms without LPR symptoms who did not undergo HMII were used as a "control" GERD group. Protein was isolated from tissue samples and Western blot analysis of pepsin and Sep70 was performed. Pepsinogen was used as a control to differentiate pepsin from pepsinogen. Relative quantitation was performed using Image Studio Lite Software with normalization against the internal actin of each blot.

RESULTS

From October 2012 to September 2013, 55 patients underwent HMII. Of 55, 20 patients underwent biopsies from hypopharynx (17 positive-APE and 3 negative-APE). Ten patients with typical GERD symptoms were identified from tissue bank as a "control" GERD group. Pepsin was detected in distal esophagus and hypopharynx in all groups without significant difference among groups. However, Sep70 in distal esophagus and hypopharynx was significantly depleted in the positive-APE group compared to the other groups (p = 0.032 and 0.002, respectively).

CONCLUSION

Depletion of Sep70 with the presence of pepsin in the hypopharynx may indicate cellular injury in laryngopharynx due to constant proximal reflux. However, the normative data for these markers have to be validated.

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

BACKGROUND

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

METHODS

A vertically integrated, proteomics-based biomarker discovery approach was used to identify candidate serum biomarkers for the detection of EAC. Liquid chromatography-tandem mass spectrometry analysis was performed on formalin-fixed, paraffin-embedded tissue samples that were collected from across the Barrett esophagus (BE)-EAC disease spectrum. The mass spectrometry-based spectral count data were used to guide the selection of candidate serum biomarkers. Then, the serum enzyme-linked immunosorbent assay data were validated in an independent cohort and were used to develop a multiparametric risk-assessment model to predict the presence of disease.

RESULTS

With a minimum threshold of 10 spectral counts, 351 proteins were identified as differentially abundant along the spectrum of Barrett esophagus, high-grade dysplasia, and EAC (P<.05). Eleven proteins from this data set were then tested using enzyme-linked immunosorbent assays in serum samples, of which 5 proteins were significantly elevated in abundance among patients who had EAC compared with normal controls, which mirrored trends across the disease spectrum present in the tissue data. By using serum data, a Bayesian rule-learning predictive model with 4 biomarkers was developed to accurately classify disease class; the cross-validation results for the merged data set yielded accuracy of 87% and an area under the receiver operating characteristic curve of 93%.

CONCLUSIONS

Serum biomarkers hold significant promise for the early, noninvasive detection of EAC.

Establishing magnetic resonance imaging as an accurate and reliable tool to diagnose and monitor esophageal cancer in a rat model

OBJECTIVE

To assess the reliability of magnetic resonance imaging (MRI) for detection of esophageal cancer in the Levrat model of end-to-side esophagojejunostomy.

BACKGROUND

The Levrat model has proven utility in terms of its ability to replicate Barrett's carcinogenesis by inducing gastroduodenoesophageal reflux (GDER). Due to lack of data on the utility of non-invasive methods for detection of esophageal cancer, treatment efficacy studies have been limited, as adenocarcinoma histology has only been validated post-mortem. It would therefore be of great value if the validity and reliability of MRI could be established in this setting.

METHODS

Chronic GDER reflux was induced in 19 male Sprague-Dawley rats using the modified Levrat model. At 40 weeks post-surgery, all animals underwent endoscopy, MRI scanning, and post-mortem histological analysis of the esophagus and anastomosis. With post-mortem histology serving as the gold standard, assessment of presence of esophageal cancer was made by five esophageal specialists and five radiologists on endoscopy and MRI, respectively.

RESULTS

The accuracy of MRI and endoscopic analysis to correctly identify cancer vs. no cancer was 85.3% and 50.5%, respectively. ROC curves demonstrated that MRI rating had an AUC of 0.966 (p<0.001) and endoscopy rating had an AUC of 0.534 (p = 0.804). The sensitivity and specificity of MRI for identifying cancer vs. no-cancer was 89.1% and 80% respectively, as compared to 45.5% and 57.5% for endoscopy. False positive rates of MRI and endoscopy were 20% and 42.5%, respectively.

CONCLUSIONS

MRI is a more reliable diagnostic method than endoscopy in the Levrat model. The non-invasiveness of the tool and its potential to volumetrically quantify the size and number of tumors likely makes it even more useful in evaluating novel agents and their efficacy in treatment studies of esophageal cancer.

Abstract A48: Enhanced efficacy of cisplatin and 5-fluorouracil combination with AUY-922 in esophageal adenocarcinoma cells

Background: Esophageal Adenocarcinoma (EAC) continues to rise in incidence, with prognosis remaining poor despite advances in multimodality therapy. Several novel target agents are now being explored as an option for treating EAC. One potential target is heat shock protein 90 (Hsp90), a chaperone protein that is involved in many diverse biological processes including cell signaling, proliferation, and survival. Many of the client proteins are known oncoproteins that allow Hsp90 to stabilize cancer cell growth by supporting proliferation and preventing apoptosis. The isoform, Hsp90β, is constituently expressed, while Hsp90α is inducible during times of stress, with expression increased 2-10 fold in cancers. Our hypothesis is that Hsp90 inhibition, in combination with standard chemotherapeutic drugs, will cause EAC cancer cells to be more susceptible to apoptosis and reduce the rate of proliferation.

Methods: EAC cell lines, OE19 and OE33, were used to evaluate the effects of Hsp90 inhibitor, AUY-922, in cancer cell growth and apoptosis. ELISA of WST-1 and BrdU were used to determine the effective dosage and assess proliferation. Pathway inhibition was evaluated by Western Blot of Hsp90α and Hsp70. OE19, OE33, and patient samples of EAC tumor and gastroesophageal reflux tissue were used to assess the gene expression of Hsp90 and several client protein pathways by reverse transcription polymerase chain reaction (RT-PCR).

Results: The ED50 of AUY-922 was determined to be 30ηM. A combination of chemotherapeutic drugs, cisplatin and 5-fluorouracil (5-Fu), along with AUY-922 showed significantly decreased proliferation compared to untreated and single agent treated cell lines. Western blot demonstrated that Hsp90 was inhibited by AUY-922 treatment, by a decrease in expression of Hsp90α, and an increase in the expression of Hsp70. RT-PCR in the cell line treatment groups showed an impact on many client oncoproteins involved in cancer cell survival and Hsp90 was shown to be upregulated in tumor samples when compared to normal GERD samples.

Conclusion: The use of Hsp90 inhibitor, AUY-922, leads to reduced Hsp90 pathway expression, resulting in a degradation of many Hsp90 client proteins involved in cancer genesis. Cell proliferation was decreased with AUY-922 treatment, with the greatest demonstrated effect when used in combination with cisplatin and 5-Fu. Therefore, Hsp90 inhibition may have an application in multimodal EAC chemotherapy.

Citation Format: Christina L. Rotoloni, Jaclyn M. LaRosa, Michael J. Porter, Lori A. Kelly, Katherine Nega, Emily Wolfson, Yoshihiro Komastu, Juliann E. Kosovec, Pashtoon M. Kasi, Toshitaka Hoppo, Ali H. Zaidi, Blair A. Jobe. Enhanced efficacy of cisplatin and 5-fluorouracil combination with AUY-922 in esophageal adenocarcinoma cells. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A48.

Smoothened inhibition leads to decreased proliferation and induces apoptosis in esophageal adenocarcinoma cells

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

Prevention of Barrett esophagus and esophageal adenocarcinoma by smoothened inhibitor in a rat model of gastroesophageal reflux disease

BACKGROUND

Activated hedgehog (Hh) pathway is associated with development of both Barrett esophagus (BE) and esophageal adenocarcinoma (EAC). We hypothesize that blockade of the Hh pathway with smoothened (Smo) inhibitor can prevent the development of BE/EAC in the Levrat model, in which induced gastroduodenoesophageal reflux (GDER) leads to esophageal carcinogenesis.

METHODS

GDER was induced in 6- to 8-week-old male Sprague-Dawley rats. The Smo inhibitor (10 mg/kg/d) was given orally on postoperative weeks 10 to 16, 18 to 22, and 24 to 28, and rats were killed on week 28. The primary outcome measure was the incidence of BE and EAC. To examine potential therapeutic effects of Smo inhibition on tumor tissue, semiquantitative immunohistochemistry for Ki-67 and caspase 3 was performed. In treated animals that developed cancer, gene expression was analyzed.

RESULTS

Thirty-eight of 48 controls and 32 of 46 treated animals survived to 28 weeks. messenger ribonucleic acid (mRNA) expression of Indian Hh, a ligand of transmembrane receptor patched 1, was 184× higher in BE and 99× higher in EAC compared with normal esophageal tissue (P = 0.0239 and P = 0.0004, respectively). Compared with controls, the incidence of BE and EAC was decreased in treated animals by 35.7% (relative risk reduction, 36%; P = 0.0015) and 36% (relative risk reduction, 62%; P = 0.0033), respectively. Compared with untreated EAC, Ki-67 was downregulated (P = 0.04) and cleaved caspase 3 was no different in treated EAC (P = 0.398). Of the 84 well-known genes involved in cancer drug resistance, 50 were dysregulated in treated EAC (P < 0.05 for each gene).

CONCLUSIONS

Smo inhibitor prevents the development of BE and EAC in an in vivo model of GDER.

Improving risk stratification in superficial (T1) gastroesophageal adenocarcinoma: Association of the intestinal phenotype (MUC2 positive) with prognosis

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Background: An increasing proportion of esophageal and gastroesophageal junction adenocarcinomas (EAC) are limited to the superficial mucosal layer (stage classification T1) at the time of diagnosis. Intramucosal lesions (stage classification T1a) are increasingly managed with endoscopic resection due to their relatively low risk of nodal metastasis and favorable prognosis compared to those with submucosal invasion (stage classification T1b). At esophagectomy, however, the majority of T1b EAC are node-negative; conversely, a small proportion of T1a EAC will have nodal metastasis at esophagectomy and/or develop recurrent disease. Additional prognostication tools, such as tumor biomarker panels, are needed to optimize treatment algorithms. Known to carry prognostic significance in other tumors, we evaluated mucin protein expression to determine whether the mucin phenotype in early EAC was associated with survival outcomes. Methods: We classified 141 induction naive, resected, T1 EAC as intestinal-, gastric- or ductal-type depending on the expression pattern of gastrointestinal mucins (MUC2, MUC5AC, MUC6 and MUC1) determined by immunohistochemistry (IHC) on tissue microarrays. CDX2 expression was assessed by IHC and EGFR amplification was assessed by in situ hybridization. The association between survival and mucin subtypes was determined in univariate and multivariate analyses. Results: The intestinal phenotype (MUC2+) is associated with poor prognosis in T1b (HR 2.1, 95%CI 1.1-4.0) and node negative T1 EAC (HR 2.5, 95%CI 1.1-5.7) after adjusting for other significant prognostic factors. Intestinal type EAC also showed accelerated time to first recurrence in these subgroups. The colloid histologic subtype and CDX2 expression were positively associated with MUC2 expression, but EGFR amplification was not. Conclusions: The mucin phenotype may serve as a useful adjunct to conventional risk assessment for optimizing therapy for potentially resectable, superficial EAC.

Evaluation of proteomic profiles of normal mucosa, Barrett’s esophagus (BE), and esophageal adenocarcinoma (EAC) obtained from humans and the Levrat’s rat model of BE/EAC

e14689

Background: EAC from BE is increasing, and prognosis is poor. Representative models are critical to understanding BE/EAC and developing therapies. We refined the Levrat’s model of BE/EAC and showed that a SMO inhibitor prevented BE/EAC (Proc ASCO 2012). To validate the rat model as representative of human and explore differentially expressed proteins/pathways, we evaluated the proteomic profiles of nl/BE/EAC from humans and rats. Methods: GE reflux was induced in 6-8 wk old male Sprague–Dawley rats by the Levrat’s procedure--approved by the IACUC. Incidence of BE/EAC at 28 wks was 90%/70%. Human nl/BE/EAC samples were obtained from the PENG database--IRB approved. Histology confirmed by a single pathologist (JD). Following LCM from paraffin, digests were analyzed in triplicate by nanoflow LC-MS/MS with a hybrid linear ion trap-Orbitrap Velos mass spectrometer followed by online nanoflow LC. Mass spectral data representing ~ 20-30,000 CID spectra were searched, and a quantitative estimate of relative abundance was obtained. Kruskal-Wallis non-parametric ANOVA was employed, and clusters were compared within and between humans and rats. Results: Data is available for rat tissues, 10 samples each for nl/BE/EAC. Heirarchical clustering of 410 features yielded 3 statistically significantly distinct groups corresponding to normal, BE and EAC (ANOVA p < 0.001). Pair-wise comparison between groups yielded statistically significant (p < 0.05) differential protein expression as follows: nl vs BE~550; nl vs EAC~450; BE vs EAC~150. For EAC, proteins were differentially expressed in pathways including: protein degradation/synthesis, cell death, growth and proliferation (NF-kB, EIF4A, Akt, b-tubulin). Analysis of human tissues and comparison to rat will be presented at the meeting. Conclusions: Proteomic evaluation of normal/BE/EAC tissues from the Levrat’s model of BE/EAC yielded distinct protein patterns for nl/BE/EAC. Proteins differentially expressed in EAC vs normal/EAC are involved in cancer related pathways. Differentially expressed proteins may provide targets for therapy, which could be tested in the Levrat’s model.