Esophageal Adenocarcinoma Patients Research Articles

Chemotherapy and chemoradiotherapy for adenocarcinoma of the esophagus and junction with oligometastases: Results of the TNT-OES-1 trial.

328 Background: Chemotherapy (FLOT) and chemoradiotherapy (CROSS) are effective as neoadjuvant regimens for esophageal and junction cancer. Total Neoadjuvant Therapy (TNT) aims to increase efficacy by combining chemotherapy with chemoradiotherapy. Although TNT is increasingly used in rectal cancer, there are no data on combining FLOT and CROSS in esophageal cancer. This study aimed to evaluate the feasibility and safety of the FLOT-CROSS combination in esophageal and junction adenocarcinoma patients with oligometastatic disease. Methods: This phase-II study included patients with oligometastatic (a maximum of four lesions in up to two organs, excluding lymph nodes) esophageal adenocarcinoma. Patients were treated with four biweekly cycles of FLOT. Response was evaluated by CT-scan 4-6 weeks after completion of FLOT. If patients showed regression or stable disease (SD) based on RECIST criteria (v1.1), they received CROSS. Four to six weeks after completion of CROSS, response was assessed by CT-scan, endoscopy with biopsies and endoscopic ultrasonography. The multidisciplinary tumor board discussed whether patients could proceed to four additional cycles of FLOT or local therapy of metastases and/or esophagectomy. Primary endpoint was tolerability of FLOT-CROSS, defined as the proportion completing the full regimens. Secondary endpoints included disease control rate (DCR), objective response rate, toxicity and the proportion proceeding to local therapy of metastases and/or esophagectomy. Results: Twenty patients were included, the majority was male (85%) with a median age of 62.5 years (interquartile range 58-66) Most patients (80%) had a single metastatic lesion. 14 of 20 patients (70%) successfully completed the FLOT regimen, four are still in therapy and two patients died. Eleven of 14 patients completed FLOT-CROSS and three patients showed disease progression following FLOT. Toxicity mainly consisted of grade 1-2 leukopenia/neutropenia during FLOT, leading to treatment delay in seven patients. One patient had malaise grade 2. No grade 3-4 toxicities or treatment delays/discontinuations occurred during CROSS. Following FLOT-CROSS, seven patients underwent four additional cycles of FLOT. Six patients underwent esophagectomy and two of those also underwent local treatment of metastases. A pathologically complete response was seen in two of these six patients (33%). Three of seven patients had a clinically complete response and opted for active surveillance after shared decision making. Three months after completion of FLOT-CROSS, the DCR was 82%. Conclusions: This study showed that sequencing FLOT-CROSS in patients with oligometastatic esophageal adenocarcinoma is feasible and comes with manageable toxicity. We saw promising efficacy, with 82% having disease control three months after FLOT-CROSS. Survival data are expected mid-2024. Clinical trial information: NL9269 .

TRIM31: A Protein With an Oncogenic Role in Esophageal Adenocarcinoma

Background: Esophageal adenocarcinoma (EAC) is a major cancer in the United States with increasing incidence. It is an aggressive cancer involving columnar-type cells different from the normal esophageal (NE) squamous cells. This metaplasia often involves an intermediary morphology called Barrett’s esophagus (BE), which occurs from repeated acid exposure of the esophagus from gastroesophageal reflux disease (GERD). GERD leading to BE is a common pre-occurrence in EAC patients, but the mechanism remains obscure. To explore the mechanism and its components, we compared gene expression in BE and EAC cells with normal cells and discovered the overexpression of TRIM31 in the pathogenic cells. Although previous studies have shown oncogenic potential of TRIM31 in some cancers, its role in EAC is yet to be understood.
 Methods: RNA sequencing and transcriptomic profiling were performed on human NE, BE, and EAC epithelial tissue samples. TRIM31 expression in NE cell line (Het-1A) and EAC cell lines (OE19, Flo-1, OE33, SK-GT-2, and OACM5.1C) were identified by Western blot. The Het-1A cell line, after exposure to acidic pH and bile acid, was assessed for variable TRIM31 expression. Cell viability analysis of NE and EAC cell lines after exposure to acidic pH and bile acids was observed by WST-1 assay.
 Results: RNA sequencing, transcriptomic profiling, and western blot revealed overexpression of TRIM31 in BE and EAC epithelium. Exposure of Het-1A cells to bile acids in acidic pH changed the cell morphology with enhanced expression of TRIM31. WST-1 revealed that EAC cells were more resistant to acidic pH and bile acid exposure.
 Conclusions and potential impact: Our data suggests that increased TRIM31 expression correlates with esophageal epithelium resistance when exposed to bile acids and acidic pH. Consequently, TRIM31 may be a key player in the metaplasia of GERD-induced EAC development and may be an innovative therapeutic target and marker for EAC.

Impact of the number of lymph node dissections and a novel risk stratification on the prognosis in elderly locally advanced esophageal adenocarcinoma.

Background: Elderly patients with locally advanced esophageal adenocarcinoma (EAC) have a poor prognosis. The purpose of this study was to identify prognostic factors and construct a risk stratification for assessing the prognosis of elderly (≥ 70 years old) EAC patients who receiving neoadjuvant chemoradiotherapy (NCRT) and esophagectomy. Methods: A total of 688 patients with non-metastatic locally advanced EAC who underwent NCRT and esophagectomy were selected from the Surveillance Epidemiology and End Results (SEER) database. Multivariable Cox analysis was used to identify prognostic factors of overall survival (OS). Restricted Cubic Splines (RCS) was used to examine the linear relationship between the number of lymph node dissection (LND) and OS. Result: RCS showed a linear relationship between LND and OS (P = 0.690). As the number of LND increased, the risk of death decreased. Multivariable analysis demonstrated that LND > 23, grade III/IV, and regional node positive were independent prognostic factors. Subgroup analysis indicated that enlarged lymph node dissection (LND > 23) did not improve OS in patients with grade I/II or T1-2 stage, whereas enlarged lymph node dissection significantly improved OS in patients with grade III/IV or T3-4 stage. Furthermore, we constructed a novel risk score based on LND, grade, and regional node status, which stratified patients into low-, medium-, and high-risk groups. Patients in the high-risk group (risk score = 3) had a worse prognosis. Conclusions: Enlarged lymph node dissection (LND > 23) improved OS in patients with grade III/IV or T3-4 stage. Moreover, a novel risk score was constructed, which facilitated risk stratification and postoperative surveillance in elderly EAC patients.

Using saliva epigenetic data to develop and validate a multivariable predictor of esophageal cancer status.

Background: Salivary epigenetic biomarkers may detect esophageal cancer. Methods: A total of 256 saliva samples from esophageal adenocarcinoma patients and matched volunteers were analyzed with Illumina EPIC methylation arrays. Three datasets were created, using 64% for discovery, 16% for testing and 20% for validation. Modules of gene-based methylation probes were created using weighted gene coexpression network analysis. Module significance to disease and gene importance to module were determined and a random forest classifier generated using best-scoring gene-related epigenetic probes. A cost-sensitive wrapper algorithm maximized cancer diagnosis. Results: Using age, sex and seven probes, esophageal adenocarcinoma was detected with area under the curve of 0.72 in discovery, 0.73 in testing and 0.75 in validation datasets. Cancer sensitivity was 88% with specificity of 31%. Conclusion: We have demonstrated a potentially clinically viable classifier of esophageal cancer based on saliva methylation.

The Expression Patterns and Implications of MALAT1, MANCR, PSMA3-AS1 and miR-101 in Esophageal Adenocarcinoma.

Esophageal adenocarcinoma (EAC) is a malignant tumor with poorly understood molecular mechanisms. This study endeavors to elucidate how the long non-coding RNAs (lncRNAs) MALAT1, MANCR and PSMA3-AS1, as well as the microRNA miR-101, exhibit specific expression patterns in the pathogenesis and prognosis of EAC. A total of 50 EAC tissue samples (tumors and lymph nodes) and a control group comprising 26 healthy individuals were recruited. The samples underwent quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses. The relative expression levels of MALAT1, MANCR, PSMA3-AS1, and miR-101 were ascertained and correlated with various clinicopathological parameters including TNM staging, tumor characteristics (size and grade of the tumor) lymphatic invasion, disease-free (DFS) and overall survival (OS) of EAC patients. Quantitative analyses revealed that MALAT1 and MANCR were significantly upregulated in EAC tumors and positive lymph nodes when compared to control tissues (p < 0.05). Such dysregulations correlated positively with advanced lymphatic metastases and a higher N stage. DFS in the subgroup of patients with negative lymph nodes was higher in the setting of low-MANCR-expression patients compared to patients with high MANCR expression (p = 0.02). Conversely, miR-101 displayed a significant downregulation in EAC tumors and positive lymph nodes (p < 0.05), and correlated negatively with advanced tumor stage, lymphatic invasion and the grade of the tumor (p = 0.006). Also, patients with low miR-101 expression showed a tendency towards inferior overall survival. PSMA3-AS1 did not demonstrate statistically significant alterations (p > 0.05). This study reveals MALAT1, MANCR, and miR-101 as putative molecular markers for prognostic evaluation in EAC and suggests their involvement in EAC progression.

Cranberry Proanthocyanidins Mitigate Reflux-Induced Transporter Dysregulation in an Esophageal Adenocarcinoma Model.

We recently reported that cranberry proanthocyanidins (C-PACs) inhibit esophageal adenocarcinoma (EAC) by 83% through reversing reflux-induced bacterial, inflammatory and immune-implicated proteins and genes as well as reducing esophageal bile acids, which drive EAC progression. This study investigated whether C-PACs' mitigation of bile reflux-induced transporter dysregulation mechanistically contributes to EAC prevention. RNA was isolated from water-, C-PAC- and reflux-exposed rat esophagi with and without C-PAC treatment. Differential gene expression was determined by means of RNA sequencing and RT-PCR, followed by protein assessments. The literature, coupled with the publicly available Gene Expression Omnibus dataset GSE26886, was used to assess transporter expression levels in normal and EAC patient biopsies for translational relevance. Significant changes in ATP-binding cassette (ABC) transporters implicated in therapeutic resistance in humans (i.e., Abcb1, Abcb4, Abcc1, Abcc3, Abcc4, Abcc6 and Abcc10) and the transport of drugs, xenobiotics, lipids, and bile were altered in the reflux model with C-PACs' mitigating changes. Additionally, C-PACs restored reflux-induced changes in solute carrier (SLC), aquaporin, proton and cation transporters (i.e., Slc2a1, Slc7a11, Slc9a1, Slco2a1 and Atp6v0c). This research supports the suggestion that transporters merit investigation not only for their roles in metabolism and therapeutic resistance, but as targets for cancer prevention and targeting preventive agents in combination with chemotherapeutics.

Abstract C157: Targeting PIK3CA and CDKN2A alterations in Esophageal Adenocarcinoma with Alpelisib and Palbociclib

Abstract Our study investigates the efficacy of targeted therapies for Esophageal Adenocarcinoma (EAC) tumors harboring an activating PIK3CA mutation and inactivating CDKN2A mutation. We tested the small molecule inhibitors alpelisib, which targets the Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit (PIK3CA), and palbociclib, which targets Cyclin D kinase 4/6 (CDK4/6), in EAC in vitro organoid and in vivo mouse models. EAC and Gastric cancer (GC) organoid models were treated with single agent alpelisib or palbociclib on a log scale to determine their IC50 values. An EAC organoid harboring activating PIK3CA E545K and inactivating CDKN2A D74A mutations demonstrated more significant growth inhibition when treated with each agent alone versus standard of care chemotherapy. Subsequent experiments involved combination treatment of our EAC-mutant organoid with alpelisib and palbociclib as well as a representative GC organoid and EAC organoids lacking these specific mutations as controls. We confirmed PIK3CA downstream target engagement after alpelisib treatment by qPCR, western blot analysis and immunofluorescence analysis. Once in vitro efficacy was confirmed, EAC-mutant organoids were transplanted into mice by either subcutaneous or orthotopic injections and treated with chemotherapy, alpelisib and palbociclib alone or in combination. Our data demonstrate that a PIK3CA/CDKN2A mutated patient-derived EAC organoid is sensitive to alpelisib and palbociclib in a dose dependent manner, and analysis of PIK3CA downstream targets by western and qPCR was consistent with growth inhibition of treated organoids. These findings offer support for the use of alpelisib and palbociclib in the treatment of EAC patients with PIK3CA/CDKN2A mutations. Citation Format: Naryan Rustgi, Thomas Ryan, Jin Cho, Ryan Moy, Sam Yoon, Sandra Ryeom, Changhwan Yoon. Targeting PIK3CA and CDKN2A alterations in Esophageal Adenocarcinoma with Alpelisib and Palbociclib [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C157.

Predicting outcomes in esophageal adenocarcinoma following neoadjuvant chemoradiation: Interactions between tumor response and survival

ObjectivesThe prognostic value of tumor regression scores (TRS) in patients with esophageal adenocarcinoma (EAC) who underwent neoadjuvant chemoradiation remains unclear. We sought to investigate the prognostic value of pathologic and metabolic treatment response among EAC patients undergoing neoadjuvant chemoradiation. MethodsPatients who underwent esophagectomy for EAC after neoadjuvant CROSS protocol between 2016 and 2020 were evaluated. TRS was grouped according to the modified Ryan score; metabolic response, according to the PERCIST criteria. Variables from endoscopic ultrasound, endoscopic biopsies, and positron emission tomography (primary and regional lymph node standardized uptake values [SUVs]) were collected. ResultsThe study population comprised 277 patients. A TRS of 0 (complete response) was identified in 66 patients (23.8%). Seventy-eight patients (28.1%) had TRS 1 (partial response), 97 (35%) had TRS 2 (poor response), and 36 (13%) had TRS 3 (no response). On survival analysis for overall survival (OS), patients with TRS 0 had longer survival compared to those with TRS 1, 2, or 3 (P = .010, P < .001, and P = .005, respectively). On multivariable logistic regression, the presence of signet ring cell features on endoscopic biopsy (odds ratio [OR], 7.54; P = .012) and greater SUV uptake at regional lymph nodes (OR, 1.42; P = .007) were significantly associated with residual tumor at pathology (TRS 1, 2, or 3). On multivariate Cox regression for predictors of OS, higher SUVmax at the most metabolically active nodal station (hazard ratio [HR], 1.08; P = .005) was independently associated with decreased OS, whereas pathologic complete response (HR, 0.61; P = .021) was independently associated with higher OS. ConclusionsPatients with pathologic complete response had prolonged OS, whereas no difference in survival was detected among other TRS categories. At initial staging, the presence of signet ring cells and greater SUV uptake at regional lymph nodes predicted residual disease at pathology and shorter OS, suggesting the need for new treatment strategies for these patients.

Developing sarcopenia during neoadjuvant therapy is associated with worse survival in esophageal adenocarcinoma patients

BackgroundSarcopenia in cancer patients has been associated with mixed postoperative outcomes. The aim of this study was to evaluate whether the development of sarcopenia during the neoadjuvant period is predictive of postoperative mortality in esophageal adenocarcinoma patients. MethodsWe queried a prospective database to retrieve the sarcopenic status of patients with esophageal adenocarcinoma who underwent cross-sectional imaging of the third lumbar vertebra at diagnosis and within 2 months of undergoing an esophagogastrectomy between 2014 and 2022. ResultsOf the 71 patients included in the study, 36 (50.7%) presented with sarcopenia at diagnosis. Of the 35 non-sarcopenic patients, 14 (40%) developed sarcopenia during the neo-adjuvant period. Patients who were not sarcopenic at diagnosis but developed sarcopenia preoperatively had significantly worse overall survival than patients sarcopenic at diagnosis and not sarcopenic preoperatively and patients experiencing no change in sarcopenic status (median 18 vs 47 vs 31 months; P = .02). Diagnostic and preoperative sarcopenic status alone were not significantly associated with overall survival (P = .48 and P = .56, respectively). Although 37 (52.1%) patients died, the cause of death was often not cancer-related (54.1%) and included acute respiratory failure, pneumonia, and cardiac arrest. No significant survival difference was observed when stratified by >10% weight loss (P = .9) or large loss in body mass index (P = .8). ConclusionDeveloping sarcopenia during the neo-adjuvant period may be associated with worse overall survival in patients requiring esophagogastrectomy.

Risk of second cancer in esophageal squamous cell carcinoma and adenocarcinoma survivors: a population-based analysis in SEER dataset.

Previous studies have reported increased risk of second cancer in both esophageal squamous cell cancer (ESCC) and esophageal adenocarcinoma (EAC) survivors. This study aimed to examine the risk and influential factors of second cancer in ESCC and EAC patients. This population-based cohort study included 7,297 ESCC patients and 11,812 EAC patients who were in 1992-2019 from the Surveillance, Epidemiology, and End Results (SEER) program in the United States. These patients were followed up until diagnosis of second cancer, death, or end of the study (December 31, 2019). We calculated standard incidence ratio (SIR) and 95% confidence interval (CI) of second cancer and performed competing-risk regression to estimate the subdistribution hazard ratios (sHR) comparing categories of patients' characteristics. After a total of 49,509.38 person-years of follow-up, 431 (5.9%) ESCC patients and 636 (5.9%) EAC patients developed a second cancer. An overall increased risk of second cancer was observed in both ESCC patients (SIR: 1.66, 95% CI: 1.51-1.83) and EAC patients (SIR: 1.11, 95% CI: 1.02-1.20). ESCC patients were at increased risk of second malignancy in oral cavity and pharynx (SIR: 12.57, 95% CI: 9.87-15.79), stomach (SIR: 3.03, 95% CI: 1.77-4.85), nose and larynx (SIR: 4.79, 95% CI: 2.47-8.37), and lung and bronchus (SIR: 2.44, 95% CI: 1.96-2.99), but decreased risk of prostate cancer (SIR: 0.73, 95% CI: 0.52-0.99). EAC patients had increased risk of second malignancies in stomach (SIR: 4.41, 95% CI: 3.23-5.89), lung and bronchus (SIR: 1.26, 95% CI: 1.02-1.54), and kidney (SIR: 1.57, 95% CI: 1.05-2.25). The risk of second cancer was higher in female ESCC patients than in males (sHR: 1.34, 95% CI: 1.11-1.63) and decreased with more advanced tumor stage in both ESCC patients (sHR: 0.62, 95% CI: 0.50-0.76 for regional stage; sHR: 0.27, 95% CI: 0.20-0.36 for distant stage) and EAC patients (sHR: 0.47, 95% CI: 0.40-0.56 for regional stage; sHR: 0.10, 95% CI: 0.07-0.13 for distant stage). Both ESCC and EAC patients are at considerable risk of certain types of second cancer.

Esophageal Cancer-Derived Organoids to Predict Patients' Treatment Response

The absolute 10-year overall survival of esophageal adenocarcinoma (EAC) has significantly increased from 26% to 36% due to neoadjuvant chemoradiotherapy (nCRT) with consecutive radical resection. However, 20-25% of EAC patients don't respond to nCRT and need alternative treatment, and 20-30% have a complete pathological response and may not need resection. Therefore, there is an urgent need for better models to accurately predict response of EAC to nCRT. Accumulating evidence indicates that patient-derived organoids (PDOs) may predict treatment responses, but the ability of PDOs to predict responses to chemoradiation in EAC patients remains unknown. Hence, we generated patient derived EAC cancer organoids (ec-PDOs) to examine their response to nCRT. The biopsies from treatment-naïve EAC patients after informed consent were used to establish ec-PDOs. Next, we investigated the response of ec-PDOs to the components of standard-of-care neoadjuvant treatment, including irradiation, carboplatin, and paclitaxel. Finally, the potential of ec-PDOs to reflect patients' response to nCRT before esophageal resection was evaluated. Mechanically and enzymatically dispersed patient derived EAC biopsies were cultured as ec-PDOs for up to 10 passages, indicating the self-renewal and expansion potential. These ec-PDOs expressed the EAC marker MUC5AC, indicating the EAC origin. Differences in growth kinetics and response to irradiation, carboplatin, and paclitaxel were observed between patients specific ec-PDOs. However, similar dose-response curves were seen within ec-PDOs from the same patient after different passages. This indicates that ec-PDOs exhibit interpatient response heterogeneity but have good reproducible responses within the same patient. Moreover, after combined treatment with irradiation (IR), carboplatin (Car), and paclitaxel (Pac) to mimic nCRT in EAC patients, the stem cell survival of ec-PDOs from patients with complete response (CR) and partial response (PR) are lower than that from those with progressive disease (PD). The preliminary findings in this study suggest a great potential of ec-PDOs to predict patient-specific responses to neoadjuvant treatment in EAC patients.

25. THE ROLE OF ADJUVANT THERAPY FOR PATIENTS WITH ESOPHAGEAL ADENOCARCINOMA UNDERGOING NEOADJUVANT THERAPY AND ESOPHAGECTOMY

Abstract Background The use of adjuvant therapy after neoadjuvant therapy followed by esophagectomy is controversial due to limited studies. The aim of this study was to investigate the role of adjuvant therapy for patients with esophageal adenocarcinoma (EAC) after neoadjuvant therapy and esophagectomy and to provide a basis for clinical decision-making. Methods Patients who were diagnosed as EAC and underwent neoadjuvant therapy followed by surgery were included in this study. The data of the patients in training group are derived from Surveillance, Epidemiology, and End Results (SEER) database. Patients from two institutions (West China Hospital and Nanjing Jinling Hospital) were used to validate the results. Results A total of 3445 EAC patients were identified from the SEER database according to the eligibility criteria. No significant difference was found between adjuvnat therapy and non-adjuvant therapy group (5-year overall survival (OS): 35.7 and 37.2%, p = 0.920; 5-year cancer-specific survival (CSS): 39.5 and 43.2%, p = 0.520). Meanwhile, 130 patients were identified from West China Hospital (n = 84) and Jinling Hospital (n = 46). The results showed that patients undergoing adjuvant therapy group had a better OS than non-adjuvant therapy group (p = 0.031). Conclusion On the basis of the SEER database, this study revealed no survival benefit of adjuvant therapy for patients with EAC after neoadjuvant therapy and surgery. However, the analysis results of patients from two institutions in China show that patients with EAC may benefit from adjuvant therapy after neoadjuvant therapy and esophagectomy.

268. DEVELOPMENT OF A NOVEL ESOPHAGUS-ON-A-CHIP MODEL: A HIGH-FIDELITY PLATFORM FOR DIRECTING PERSONALIZED THERAPY IN ESOPHAGEAL ADENOCARCINOMA

Abstract Background 80% of patients diagnosed with esophageal adenocarcinoma (EAC) die of disease. Current standard of care for EAC is systemic cytotoxic, platinum-based neoadjuvant chemotherapy followed by resection and additional rounds of chemotherapy. Locally advanced, resectable patients often fail to respond due to intrinsic and/or acquired chemoresistance. Traditional preclinical models fail to offer alternative salvage options. To our knowledge, this is the first high-fidelity dynamic 3D platform implemented to study esophageal function, pathophysiology, and drug effects. Methods Primary tissues obtained from EAC patients at diagnostic biopsy were propagated into patient-derived organoids (PDOs). The upper (mucosal) channel of the esophagus-chip was designated for PDO-derived epithelial cells, while the lower stromal channel was designated for matched fibroblasts. Autologous cell types were exposed to a physiologically relevant flow of nutrient media and microtissues were formed. Epithelial permeability was determined by cascade blue assay. Using this model, a clinically relevant chemotherapy protocol was administered to study patient-specific tumor response. To determine microtissue development and cellular fate in response to chemotherapy, level of several epithelial/mesenchymal biomarkers were evaluated. Results Study cohort consisted of both chemo-sensitive and -resistant EAC patients. Esophagus-chip models were developed with samples from patient-matched tumor and normal tissue. Chips recapitulated morphological and histological features of their parental tissues. Epithelial barrier integrity was established within 5 days on-chip. Scanning electron microscopy revealed the presence of pleomorphic cells and mature microvilli in EAC-chips. In vitro administration of docetaxel triplet chemotherapy demonstrated efficacy similar to that observed in the clinical setting when assessed directly or indirectly. Confocal imaging revealed treatment-associated differential expression of epithelial (CK7, CK19), and mesenchymal (vimentin) markers. Conclusion 3D-organoids conserve cellular heterogeneity of source patients, whereas esophagus-on-chip expand on this diversity by adding microphysiological relevance, stromal influence &amp; flexible complexity. This high-fidelity biomimetic platform enables clinical mimicry and can predict patient-specific chemosensitivity within a clinically relevant timeframe. This esophagus-chip system is a promising potential replacement for both inefficient preclinical animal models and existing tumor-only avatars lacking stromal and microphysiological context.

383. DEVELOPMENT OF PERSONALIZED ‘LIQUID BIOPSY’ FOR ESOPHAGEAL ADENOCARCINOMA FROM MATCHED ORGANOID CULTURE

Abstract Background Recurrent mutations are not a hallmark of esophageal adenocarcinoma (EAC). This challenges the identification of circulating tumor DNA in the plasma and can limit the development of liquid biopsy strategies. We have cultured patient-derived EAC organoids and hypothesize that these can be used as a roadmap for the identification of circulating tumor DNA in the corresponding patient’s blood. Methods EAC tumor tissue from patients was processed to generate patient-derived organoids (PDOs) in Matrigel domes. Established PDOs were then scaled-up in suspension culture. To isolate mononucleosomes (147 bp), chromatin from these cells was extracted and digested with micrococcal nuclease (MNase). Right size selection was used to remove DNA larger than the targeted 147 bp. Next Generation Sequencing will be performed for nucleosome mapping and to generate a personlized SNV map. Using the SNV map, a personalized PCR panel will be developed to detect circulating tumor somatic variants in patient plasma cfDNA. Results DNA from three different PDOs were collected and MNase digested. MNase concentration and digestion time were optimized for each sample to avoid over digestion. MNase digestion resulted in mononucleosomes at approximately 147 bp for all three samples, as well as large DNA segments between 300 to 8000 bp. Right size selection resulted in isolation of 34 to 48 ng of the mononucleosome peak. These results indicate that MNase digestion was successful in generating nucleosomes of the desired size range and the selected nucleosomes were of high quality, as confirmed by the Bioanalyzer. Samples will be subjected to next-generation sequencing. Conclusion This study will determine nucleosome SNVs maps in circulating cell-free DNA from EAC patients to allow for generation of optimized targeted PCR panels, prediction of recurrence based on specific variants unique to each patient, and development of more precise drug screening. These advantages have the potential to fill a void in early cancer detection and the prediction of cancer recurrence, leading to improved prognoses for individuals diagnosed with EAC.

Smoking induces WEE1 expression to promote docetaxel resistance in esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) patients have poor clinical outcomes, with an overall 5-year survival rate of 20%. Smoking is a significant risk factor for EAC. The role of WEE1, a nuclear kinase that negatively regulates the cell cycle in normal conditions, in EAC tumorigenesis and drug resistance is not fully understood. Immunohistochemistry staining shows significant WEE1 overexpression in human EAC tissues. Nicotine, nicotine-derived nitrosamine ketone, or 2% cigarette smoke extract treatment induces WEE1 protein expression in EAC, detected by western blot and immunofluorescence staining. qRT-PCR and reporter assay indicates that smoking induces WEE1 expression through miR-195-5p downregulation in EAC. ATP-Glo cell viability and clonogenic assay confirmed that WEE1 inhibition sensitizes EAC cells to docetaxel treatment invitro. A TE-10 smoking machine with EAC patient-derived xenograft mouse model demonstrated that smoking induces WEE1 protein expression and resistance to docetaxel invivo. MK-1775 and docetaxel combined treatment improves EAC patient-derived xenograft mouse survival invivo. Our findings demonstrate, for the first time, that smoking-induced WEE1 overexpression through miRNA dysregulation in EAC plays an essential role in EAC drug resistance. WEE1 inhibition is a promising therapeutic method to overcome drug resistance and target treatment refractory cancer cells.

Genome-wide and panel-based cell-free DNA characterization of patients with resectable esophageal adenocarcinoma.

Circulating tumor DNA (ctDNA) holds promise in resectable esophageal adenocarcinoma (EAC) to predict patient outcome but is not yet sensitive enough to be clinically applicable. Our aim was to combine ctDNA mutation data with shallow whole-genome sequencing (sWGS)-derived copy number tumor fraction estimates (ichorCNA) to improve pathological response and survival prediction in EAC. In total, 111 stage II/III EAC patients with baseline (n = 111), post-neoadjuvant chemoradiotherapy (nCRT) (n = 68), and pre-surgery (n = 92) plasma samples were used for ctDNA characterization. sWGS (<5× coverage) was performed on all time-point samples, and copy number aberrations were estimated using ichorCNA. Baseline and pre-surgery samples were sequenced using a custom amplicon panel for mutation detection. Detection of baseline ctDNA was successful in 44.3% of patients by amplicon sequencing and 10.5% by ichorCNA. Combining both, ctDNA could be detected in 50.5% of patients. Baseline ctDNA positivity was related to higher T stage (cT3, 4) (p = 0.017). There was no relationship between pathological response and baseline ctDNA positivity. However, baseline ctDNA metrics (variant allele frequency > 1% or ichorCNA > 3%) were associated with a high risk of disease progression [HR = 2.23 (95% CI 1.22-4.07), p = 0.007]. The non-clearance of a baseline variant or ichorCNA > 3% in pre-surgery samples was related to early progression [HR = 4.58 (95% CI 2.22-9.46), p < 0.001]. Multi-signal analysis improves detection of ctDNA and can be used for prognostication of resectable EAC patients. Future studies should explore the potential of multi-modality sequencing for risk stratification and treatment adaptation based on ctDNA results. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Potential of damage associated molecular patterns in synergising radiation and the immune response in oesophageal cancer.

There is an intimate crosstalk between cancer formation, dissemination, treatment response and the host immune system, with inducing tumour cell death the ultimate therapeutic goal for most anti-cancer treatments. However, inducing a purposeful synergistic response between conventional therapies and the immune system remains evasive. The release of damage associated molecular patterns (DAMPs) is indicative of immunogenic cell death and propagation of established immune responses. However, there is a gap in the literature regarding the importance of DAMP expression in oesophageal adenocarcinoma (OAC) or by immune cells themselves. To investigate the effects of conventional therapies on DAMP expression and to determine whether OAC is an immunogenic cancer. We investigated the levels of immunogenic cell death-associated DAMPs, calreticulin (CRT) and HMGB1 using an OAC isogenic model of radioresistance. DAMP expression was also assessed directly using ex vivo cancer patient T cells (n = 10) and within tumour biopsies (n = 9) both pre and post-treatment with clinically relevant chemo(radio)therapeutics. Hypoxia in combination with nutrient deprivation significantly reduces DAMP expression by OAC cells in vitro. Significantly increased frequencies of T cell DAMP expression in OAC patients were observed following chemo(radio)therapy, which was significantly higher in tumour tissue compared with peripheral blood. Patients with high expression of HMGB1 had a significantly better tumour regression grade (TRG 1-2) compared to low expressors. In conclusion, OAC expresses an immunogenic phenotype with two distinct subgroups of high and low DAMP expressors, which correlated with tumour regression grade and lymphatic invasion. It also identifies DAMPs namely CRT and HMGB1 as potential promising biomarkers in predicting good pathological responses to conventional chemo(radio)therapies currently used in the multimodal management of locally advanced disease.

An Immune-Related Gene Signature for Predicting Survival and Immunotherapy Efficacy in Esophageal Adenocarcinoma.

BACKGROUND Immune checkpoint inhibitor (ICI) therapy has attracted wide attention in the treatment of malignant tumors. This study was designed to build a prognostic model based on immune-related genes for esophageal adenocarcinoma (EAC). MATERIAL AND METHODS The expression of immune-related differentially-expressed genes (IRDEGs) between EAC and normal samples from The Cancer Genome Atlas database was analyzed. Univariate and multivariate Cox regressions were used to identify the prognostic IRDEGs and construct an immune-related gene signature (IRGS) to predict the overall survival (OS) of EAC patients. Then, the molecular mechanisms and immune characteristics were comprehensively analyzed. RESULTS A total of 111 IRDEGs were obtained from the weighted gene co-expression network analysis. Univariate Cox regression analysis showed that 12 IRDEGs (P<0.05 for all) were linked with OS in the EAC patients. Four genes were used to construct the IRGS based on the multivariate Cox regression analysis. Patients in the high-risk group showed worse OS than those in the low-risk group (P<0.001). A high-risk score was related to DNA replication relevant pathways, an increase in mutation rate, and an increase in activated mast cell infiltration. Patients with high-risk scores had lower tumor immune dysfunction and exclusion scores (P<0.001). CONCLUSIONS IRDEGs may be involved in the progression of EAC. The high-risk group is more suitable for immunotherapy, which may provide a reference value for the treatment of clinical EAC patients. Therefore, it is possible to identify the patients who are better suited for ICI therapy.

Longitudinal immune monitoring of patients with resectable esophageal adenocarcinoma treated with Neoadjuvant PD-L1 checkpoint inhibition

ABSTRACT The analysis of peripheral blood mononuclear cells (PBMCs) by flow cytometry holds promise as a platform for immune checkpoint inhibition (ICI) biomarker identification. Our aim was to characterize the systemic immune compartment in resectable esophageal adenocarcinoma patients treated with neoadjuvant ICI therapy. In total, 24 patients treated with neoadjuvant chemoradiotherapy (nCRT) and anti-PD-L1 (atezolizumab) from the PERFECT study (NCT03087864) were included and 26 patients from a previously published nCRT cohort. Blood samples were collected at baseline, on-treatment, before and after surgery. Response groups for comparison were defined as pathological complete responders (pCR) or patients with pathological residual disease (non-pCR). Based on multicolor flow cytometry of PBMCs, an immunosuppressive phenotype was observed in the non-pCR group of the PERFECT cohort, characterized by a higher percentage of regulatory T cells (Tregs), intermediate monocytes, and a lower percentage of type-2 conventional dendritic cells. A further increase in activated Tregs was observed in non-pCR patients on-treatment. These findings were not associated with a poor response in the nCRT cohort. At baseline, immunosuppressive cytokines were elevated in the non-pCR group of the PERFECT study. The suppressive subsets correlated at baseline with a Wnt/β-Catenin gene expression signature and on-treatment with epithelial–mesenchymal transition and angiogenesis signatures from tumor biopsies. After surgery monocyte activation (CD40), low CD8+Ki67+ T cell rates, and the enrichment of CD206+ monocytes were related to early recurrence. These findings highlight systemic barriers to effective ICI and the need for optimized treatment regimens.

Tumor monocyte content predicts immunochemotherapy outcomes in esophageal adenocarcinoma.

For inoperable esophageal adenocarcinoma (EAC), identifying patients likely to benefit from recently approved immunochemotherapy (ICI+CTX) treatments remains a key challenge. We address this using a uniquely designed window-of-opportunity trial (LUD2015-005), in which 35 inoperable EAC patients received first-line immune checkpoint inhibitors for four weeks (ICI-4W), followed by ICI+CTX. Comprehensive biomarker profiling, including generation of a 65,000-cell single-cell RNA-sequencing atlas of esophageal cancer, as well as multi-timepoint transcriptomic profiling of EAC during ICI-4W, reveals a novel Tcell inflammation signature (INCITE) whose upregulation correlates with ICI-induced tumor shrinkage. Deconvolution of pre-treatment gastro-esophageal cancer transcriptomes using our single-cell atlas identifies high tumor monocyte content (TMC) as an unexpected ICI+CTX-specific predictor of greater overall survival (OS) in LUD2015-005 patients and of ICI response in prevalent gastric cancer subtypes from independent cohorts. Tumor mutational burden is an additional independent and additive predictor of LUD2015-005 OS. TMC can improve patient selection for emerging ICI+CTX therapies in gastro-esophageal cancer.