Esophageal Squamous Cell Carcinoma Research Articles

Perioperative toripalimab plus neoadjuvant chemotherapy might improve outcomes in resectable esophageal cancer: an interim analysis of a phase III randomized clinical trial.

In the era of immunotherapy, neoadjuvant immunochemotherapy (NAIC) for the treatment of locally advanced esophageal squamous cell carcinoma (ESCC) is used clinically but lacks of high-level clinical evidence. This study aimed to compare the safety and long-term efficacy of NAIC followed by minimally invasive esophagectomy (MIE) with those of neoadjuvant chemotherapy (NAC) followed by MIE. A prospective, single-center, open-label, randomized phase III clinical trial was conducted at Henan Cancer Hospital, Zhengzhou, China. Patients were randomly assigned to receive either neoadjuvant toripalimab (240 mg) plus paclitaxel (175 mg/m2) + cisplatin (75 mg/m2) (toripalimab group) or paclitaxel + cisplatin alone (chemotherapy group) every 3 weeks for 2 cycles. After surgery, the toripalimab group received toripalimab (240 mg every 3 weeks for up to 6 months). The primary endpoint was event-free survival (EFS). The pathological complete response (pCR) and overall survival (OS) were key secondary endpoints. Adverse events (AEs) and quality of life were also assessed. Between May 15, 2020 and August 13, 2021, 252 ESCC patients ranging from T1N1-3M0 to T2-3N0-3M0 were enrolled for interim analysis, with 127 in the toripalimab group and 125 in the chemotherapy group. The 1-year EFS rate was 77.9% in the toripalimab group compared to 64.3% in the chemotherapy group (hazard ratio [HR] = 0.62; 95% confidence interval [CI] = 0.39 to 1.00; P = 0.05). The 1-year OS rates were 94.1% and 83.0% in the toripalimab and chemotherapy groups, respectively (HR = 0.48; 95% CI = 0.24 to 0.97; P = 0.037). The patients in the toripalimab group had a higher pCR rate (18.6% vs. 4.6%; P = 0.001). The rates of postoperative Clavien-Dindo grade IIIb or higher morbidity were 9.8% in the toripalimab group and 6.8% in the chemotherapy group, with no significant difference observed (P = 0.460). The rates of grade 3 or 4 treatment-related AEs did not differ between the two groups (12.5% versus 12.4%). The interim results of this ongoing trial showed that in resectable ESCC, the addition of perioperative toripalimab to NAC is safe, may improve OS and might change the standard treatment in the future.

Impact of taxanes after PD-1 blockade exposure in advanced esophageal squamous cell carcinoma.

Programmed cell death-1 (PD-1) blockade improves survival in patients with advanced esophageal squamous cell carcinoma (ESCC). However, the efficacy of taxanes after exposure to PD-1 blockade remains unclear in patients with advanced ESCC. We retrospectively analyzed the clinical outcomes of advanced ESCC patients treated with taxanes (paclitaxel or docetaxel) with/without prior exposure to PD-1 blockade (Exposed /Naïve group) at National Cancer Center Hospital from June 2016 to December 2020. Ninety-nine patients (Exposed group, n = 32; Naïve group, n = 67) were included. The objective response rate (ORR) of the Exposed group was significantly higher than that of the Naïve group (37.5% vs. 13.4%, p = 0.009). The median progression-free survival was similar between the Exposed and Naïve groups (3.8 vs. 2.8months, HR 1.12, 95% CI 0.65-1.86, p = 0.66). PD-1 blockade exposure independently predicated higher ORR to taxanes in multivariate analysis. Grade ≥ 3 adverse events were comparable between the Exposed and Naïve groups (45.8% vs. 40.3%, p = 0.64). Taxanes following PD-1 blockade in advanced ESCC showed a higher ORR but similar PFS compared to taxanes without prior PD-1 exposure.

Evaluation of pembrolizumab plus cisplatin and fluorouracil in radical treatment for patients with T4b esophageal squamous cell carcinoma

BackgroundPembrolizumab plus cisplatin and 5-fluorouracil administered as first-line therapy for advanced esophageal cancer patients has shown a better objective response and survival than conventional chemotherapy with less severe hematological adverse events. The safety and efficacy of this regimen were evaluated in patients with T4b esophageal squamous cell carcinoma (ESCC).MethodsEight consecutive patients with T4b ESCC received this regimen according to KEYNOTE-590 as induction, and they were evaluated after 1–3 courses. The programmed death-ligand 1 (PD-L1) combined positive score (CPS) was also evaluated before chemotherapy. Efficacy for the primary lesion was evaluated by our original formula for the tumor reduction rate.ResultsThe numbers of patients with partial response (PR), stable disease, and progressive disease (PD) were 5, 1, and 2, respectively. The tumor reduction rate ranged from 69 to 87% in PR patients, and all PR patients had relief from T4b. Two patients underwent conversion surgery with R0 resection. PD-L1 CPS was over 90 in 2 PR patients, but under 10 in 2 other PR patients. PD-L1 CPS was under 10 in PD patients. One patient had hyperprogression, resulting in an esophago-pulmonary fistula. Greater than grade 3 adverse events were bleeding gastric ulcer in one patient (12.5%), neutropenia without G-CSF in 3 patients (37.5%), and hypopotassemia in 1 patient (12.5%). No patient had febrile neutropenia.ConclusionsMarked tumor reduction was confirmed in 62.5% of patients with pembrolizumab plus cisplatin and 5-fluorouracil with less adverse events. This regimen could be administered as induction chemotherapy for patients with T4b ESCC.

439. INTEGRATION OF SCRNA-SEQ AND BULK RNA-SEQ TO VALIDATE A PROGNOSTIC ASSOCIATED SIGNATURE IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Considerable evidence has identified important targets for esophageal squamous cell carcinoma (ESCC), but its efficacy and the heterogeneity of ESCC are the main causes of treatment failure. Single-cell RNA-sequencing (scRNA-seq) is a powerful tool for analyzing tumor heterogeneity at the single-cell level and helps to better identify potential therapeutic targets. Methods ESCC scRNA-seq data were extracted from the Gene Expression Omnibus (GEO) database. Single-sample gene set enrichment analysis (ssGSEA) was performed using the limma package to analyze ESCC-associated prognostic marker genes from ESCC transcriptome data downloaded from the TCGA database and the results were validated with transcriptomic data from 56 ESCC patients in our hospital. KEGG (Kyoto Encyclopedia of Genes and Genomes) and GO (Gene Ontology) analyses of prognostic marker genes were performed by GSEA. Then, univariate and multivariate Cox and lasso regressions were performed to further build signatures. Finally, qPCR was used to assess the expression of prognostic marker genes in 5 pairs ESCC samples. Results Integrate scRNA-seq (GSE53624) datasets to obtain 13 cell clusters. We characterized single-cell expression profiles of 24076 cell samples and identified 4 marker genes associated with prognosis. Four key prognostic marker genes were trained and validated on the TCGA-ESCA dataset and in 55 patients from our in-hospital cohort to evaluate predictive overall survival (OS) models. Correlation analysis showed that prognostic marker genes were independent of risk clinical characteristics. In addition, we performed Cox regression analysis, suggesting that the 4 prognostic marker genes screened were independent risk factors related to the prognosis of ESCC patients. In addition, qPCR showed that the expression of IER3 and SAA1 was decreased and the expression of CDKN3 was increased in ESCC tissues, while the expression of TINP3 was not significantly different. Conclusion We constructed prognostic marker genes by scRNA-seq and validated the model in a large patient population as well as in ESCC tissues, which provides reasonable evidence and valuable resources for prognostic stratification and the study of potential targets for ESCC.

242. BRD4 INHIBITION ENHANCES THE RADIOSENSITIVITY OF ESOPHAGEAL SQUAMOUS CELL CARCINOMA THROUGH REGULATING ATF3-MEDIATED SERINE AND NUCLEOTIDE SYNTHESIS

Abstract Background Radioresistance is a major culprit for radiotherapy failure in esophageal squamous cell carcinoma (ESCC). This study aimed to investigate the underlying mechanism of Brd4 in radiosensitivity of ESCC. Methods Brd2/3/4 proteins were assessed in radiosensitive and radioresistant ESCC tissues using IHC. A serial of functional experiments was performed to verify the significance of Brd4 in ESCC. RNA-seq and bioinformatics analyses were used to determine the potential downstream targets. The dual-luciferase reporter and ChIP assay were further examined the underlying regulatory mechanism among targets. Besides, we further verified the importance of ATF3-mediated serine and nucleotide metabolism in radiated ESCC cells. Results Brd4 is highly expressed in radio-resistant ESCC tissue. Knockdown of Brd4 led to increased DNA damage and cell apoptosis in irradiated ESCC cells. RNA-seq analyses exhibited that ATF3 was a potential downstream target of Brd4. The dual-luciferase reporter and ChIP assay demonstrated that Brd4 upregulated ATF3 expression via activation its promoter region. Besides, we found that ATF3 could facilitate the enzyme activities involved in serine and nucleotide biosynthesis pathway to promote radiation-induced DNA damage repair. Conclusion Brd4 facilitates ATF3 expression via binding to and activating ATF3 promoter region. Enhanced ATF3 further increases crucial enzymes activity in serine and nucleotide biosynthesis pathway to promote radiation-induced DNA damage repair. Targeting Brd4 is a promising treatment strategy to improve radiosensitivity in ESCC.

The TDP-43/TP63 Positive Feedback Circuit Promotes Esophageal Squamous Cell Carcinoma Progression.

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent malignancies with a 5-year survival rate of only 15% in patients with advanced diseases. Tumor protein 63 (TP63), a master transcription factor (TF) in ESCC, cooperates with other TFs to regulate enhancers and/or promoters of target oncogenes, which in turn promotes tumorigenesis. TAR-DNA-binding protein-43 (TDP-43) is an RNA/DNA binding protein with elevated expression in several neoplasms. However, it remains unclear how TDP-43 contributes to ESCC progression. In this study, TDP-43 is identified as a novel oncogene with markedly upregulated expression in ESCC tissues through profiling expression levels of one hundred and fifty canonical RNA binding protein (RBP) genes in multiple ESCC patient cohorts. Importantly, TDP-43 boosted TP63 expression via post-transcriptionally stabilizing TP63 mRNAs as a RBP and promoting TP63 transcription as a TF binding to the TP63 promoter in ESCC cells. In contrast, the master TF TP63 also bound to the TDP-43 promoter, accelerated TDP-43 transcription, and caused a noticeable increase in TDP-43 expression in ESCC cells. The findings highlight TDP-43 as a viable therapeutic target for ESCC and uncover a hitherto unrecognized TDP-43/TP63 circuit in cancer.

260. LOW BLOOD LEVEL OF TUMOR SUPPRESSOR MIR-3619 AS A TARGET OF NUCLEIC ACID THERAPY TO PIM-1 IN ESOPHAGEAL CANCER

Abstract Background Numerous studies have attempted to understand the molecular mechanisms of tumorigenesis and identify clinical biomarkers and molecular targets for esophageal squamous cell carcinoma (ESCC). However, there are still only a few biomarkers and targets. We focused on tumor suppressor micro-RNA (miR)s in the plasma of ESCC patients, and we investigated the usefulness of these tumor suppressor miRs as biomarkers and therapeutic agents for ESCC. Methods: Plasma samples of 94 ESCC patients and 86 healthy volunteers were analyzed in this study. Among the group of 2600 miRs candidates registered in miRbase, we selected 25 miRs candidates which are low expressed in ESCC tissues, have tumor suppressive functions, and unreported as a body fluid biomarker. We selected 5 miRs (miR-564/ 637/ 1182/ 3178/ 3619), whose signals were detectable in the blood of healthy volunteers by microarray analysis. By test-scale analysis using TaqMan assay and validation analysis, we identified miR-3619, which showed the most significant difference in ESCC patients compared to healthy volunteers (p < 0.001). Results: 1) Prognostic analysis revealed that a low miR-3619 plasma level was significantly associated with advanced stage and recurrence rate, and was an independent factor predicting poor prognosis in ESCC patients (p = 0.028, HR = 2.09). 2) Overexpression of miR-3619 mimic inhibited the proliferation of ESCC cells, induced the accumulation of apoptosis or G1/S phase cells, and reduced the cell migration and invasion abilities compared with negative control mimic. 3) We tested PIM-1xas candidate putative target genes for miR-3619 using microRNA database. PIM-1 protein expression levels were decreased in miR-3619-5p transfectants compared with NC. 4) In vivo, subcutaneous injection of miR-3619 could significantly inhibit tumor growth in mice. Administration of miR-3619 did not cause any clinical adverse events or side effects in blood-based parameters reflecting organ disorders. Conclusion: These results suggest that depleted tumor-suppressor miR-3619 in plasma could be one of blood-based biomarkers for predicting malignant potential of ESCC.

Identifying Survival Subtypes of Esophageal Squamous Cell Carcinoma Patients: An Application of Deep Learning in Gene Expression Data Analysis

Background: Esophageal squamous cell carcinoma (ESCC) is one of the most lethal types of cancer. Late diagnosis significantly decreases patient survival rates. Objectives: The study aimed to identify survival groups for patients with ESCC and find predictive biomarkers of time-to-death from ESCC using state-of-the-art deep learning (DL) and machine learning algorithms. Methods: Expression profiles of 60 ESCC patients, along with their demographic and clinical variables, were downloaded from the GEO dataset. A DL autoencoder model was employed to extract lncRNA features. The univariate Cox proportional hazard (Cox-PH) model was used to select significant extracted features related to patient survival. Hierarchical clustering (HC) identified risk groups, followed by a decision trees algorithm which was used to identify lncRNA profiles. We used Python.3.7 and R.4.0.1 software. Results: Inputs of the autoencoder were 8,900 long noncoding RNAs (lncRNAs), of which 1000 features were extracted. Out of the features, 42 lncRNAs were significantly related to time-to-death using the Cox-PH model and used as input for clustering of patients into high and low-risk groups (P-value of log-rank test = 0.022). These groups were then labeled for supervised HC. The C5.0 algorithm achieved an overall accuracy of 0.929 on the test set and identified four hub lncRNAs associated with time-to-death. Conclusions: Novel discovered lncRNAs lnc-FAM84A-1, LINC01866, lnc-KCNE4-2 and lnc-NUDT12-4 implicated in the pathogenesis of death from ESCC. Our findings represent a significant advancement in understanding the role of lncRNAs on ESCC prognosis. Further research is necessary to confirm the potential and clinical application of these lncRNAs.

436. IDENTIFICATION OF M6A-RELATED SIGNATURE GENES IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA BY MACHINE LEARNING METHOD

Abstract Background We aimed to construct and validate the esophageal squamous cell carcinoma (ESCC)-related m6A regulators by means of machine leaning. Methods We used ESCC RNA-seq data of 66 pairs of ESCC from West China Hospital of Sichuan University and the transcriptome data extracted from The Cancer Genome Atlas (TCGA)-ESCA database to find out the ESCC-related m6A regulators, during which, two machine learning approaches: RF (Random Forest) and SVM (Support Vector Machine) were employed to construct the model of ESCC-related m6A regulators. Calibration curves, clinical decision curves, and clinical impact curves (CIC) were used to evaluate the predictive ability and best-effort ability of the model. Finally, western blot and immunohistochemistry staining were used to assess the expression of prognostic ESCC-related m6A regulators. Results 2 m6A regulators (YTHDF1 and HNRNPC) were found to be significantly increased in ESCC tissues after screening out through RF machine learning methods from our RNA-seq data and TCGA-ESCA database, respectively, and overlapping the results of the two clusters. A prognostic signature, consisting of YTHDF1 and HNRNPC, was constructed based on our RNA-seq data and validated on TCGA-ESCA database, which can serve as an independent prognostic predictor. Experimental validation including the western and immunohistochemistry staining were further successfully confirmed the results of bioinformatics analysis. Conclusion We constructed prognostic ESCC-related m6A regulators and validated the model in clinical ESCC cohort as well as in ESCC tissues, which provides reasonable evidence and valuable resources for prognostic stratification and the study of potential targets for ESCC. Key words m6A, RNA methylation, esophageal squamous cell carcinoma, machine learning, experimental validation

Prognostic value of tumor-infiltrating lymphocytes and PD-L1 expression in esophageal squamous cell carcinoma.

Tumor cells (TC) participate in tumor progression by altering the immune responses in the tumor microenvironment. However, the clinical relevance and prognostic effect of PD-L1 expression and tumor-infiltrating lymphocytes (TILs) in esophageal squamous cell carcinoma (ESCC) are unknown. The purpose of this study was to investigate the interactions and clinical significance of PD-L1 expression and TILs in ESCC. Tissue specimens were collected from 126 patients with ESCC who underwent curative esophagectomy. Immunohistochemical analysis and multiplex immunofluorescence for CD4, CD8, CD25, FOXP3, and PD-L1 in the tumor were used to identify multiple tumor-infiltrating immune cells (TIIC), Tregs, and TC. PD-L1 was expressed in tumor cells (PD-L1 TC). PD-L1 TIIC and PD-L1 TC affected the biological behavior of TC. The positive expression rate of PD-L1 TC and CD8+ TILs was 27.8% (35/126) and 31.7% (40/126), respectively. Kaplan-Meier analysis showed that overall survival (OS) was significantly associated with decreased CD8+ TILs and PD-L1 TC-positive expression, which promote ESCC progression and metastasis. Tumor depth, CD8, and PD-L1 TC were independent prognostic factors in ESCC, and a predictive nomogram with these three risk factors improved the accuracy of predicting OS in patients with ESCC after surgical resection. The conjoint analysis of multiple immune-related factors is beneficial for stratifying patient survival risk.

569. PROGNOSTIC VALUE OF T CELL PHENOTYPES AND PD-L1 EXPRESSION IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Backgrounds The tumor microenvironment (TME) is a complex niche for tumor cells and immune cells to survive. Tumor-infiltrating lymphocytes (CD8+ T cells, FoxP3+ Tregs…etc), one of the main components of TME, are key factors in the host-tumor immune response, and the exact immune response in esophageal squamous cell carcinoma (ESCC) is still unclear. The purpose of this study was to investigate the expression of PD-L1 and TILs phenotypes in ESCC, their interactions and clinical significance. Methods Surgical specimens from 126 ESCC patients who underwent curative surgery between January 2001 and April 2017. We performed immunophenotyping of CD4, CD8, CD25, FOXP3 and PD-L1 within the tumor using immunohistochemistry and multiple immunofluorescence immunolabeling. PD-L1 was detected to expressed on tumor cells (PD-L1 TC) and tumor-infiltrating immune cells (PD-L1 TIIC), and PD-L1 TC affect biologic behavior. The calculation of overall survival (OS) and recurrence-free survival (RFS) were made using Kaplan-Meier analysis, and Cox regression model was used to analyze the correlation between survival and prognosis. Results CD8, FoxP3 and PD-L1 expression were positive in 40 (31.7%), 55 (43.7%) and 35 (27.8%) ESCC patient, respectively. CD8 and FoxP3 positive were associated with prolonged OS (p=0.0028, p=0.0324, respectively) and RFS (p=0.0019, p=0.0628, respectively). The overall survival rate in the PD-L1 positive group was statistically lower than that in the negative group (p=0.0402). Furthermore, the combination of CD8/PD-L1 and CD8/Foxp3 was able to more clearly classify and predict prognostic groups of ESCC. Considering the Treg phenotype, the presence of triple positive cell infiltration with Foxp3, CD4, and CD25 was strongly associated with poor prognosis of ESCC (p=0.0349). Cox proportional hazard model suggested that tumor depth, CD8+ infiltration and PD-L1 expression were significantly correlated with overall survival. CD8+ infiltration and PD-L1 expression were revealed to be independent prognostic factors. Conclusion CD8 and PD-L1 expression are independent prognostic and predictive factors for ESCC. And it is necessary to elucidate the immune mechanism comprehensively and thoroughly in the insight of multidimensional, multi-molecular and to provide therapeutic strategies for immunotherapy of ESCC.

203. THE NUMBER OF RESECTED LYMPH NODES FROM THE UPPER MEDIASTINAL AREA PREDICTS LONG-TERM OUTCOMES OF ESOPHAGEAL CANCER AFTER MIE

Abstract Background The total number of resected lymph nodes (LNs) is an important determinant of longer survival after esophagectomy for esophageal squamous cell carcinoma (ESCC). However, resected LN counts from which areas affect long-term outcomes remain unclear. Methods: This study comprised 406 patients who underwent minimally invasive esophagectomy (MIE) at Kobe University Hospital. Resected LN counts were evaluated in the following areas: upper mediastinal (UM), middle mediastinal (MM), lower mediastinal (LM), and abdominal (Abd). Cut-off values for LN counts from each area were determined using receiver operating characteristics analysis to the survival status. Cox proportional hazards regression analyses were performed to identify prognostic factors. Results: The cut-off values for large or small numbers of resected LN counts in the UM, MM, LM, and Abd areas were 4, 8, 5, and 18 in patients with upper and middle thoracic (Ut/Mt) ESCC, respectively, and 7, 6, 5, and 24 in patients with lower thoracic (Lt) ESCC, respectively. Multivariate analysis in patients with Ut/Mt ESCC revealed that tumor invasion depth, lymph node metastasis and the resected LN count from the UM area were independent risk factors for overall survival (hazard ratio = 7.04; 95% confidence interval = 4.47-11.1, hazard ratio = 4.01; 95% confidence interval = 1.96-8.21, hazard ratio = 2.18; 95% confidence interval = 1.24-3.82, respectively). In patients with Lt ESCC, tumor invasion depth, lymph node metastasis and pulmonary complication were independent risk factors for overall survival (hazard ratio = 4.23; 95% confidence interval = 2.14-8.35, hazard ratio = 3.83; 95% confidence interval = 1.75-8.38, hazard ratio = 2.80; 95% confidence interval = 1.38-5.65, respectively). Resected LN counts from no areas were prognostic factors. Conclusions: The number of resected LNs from the UM area influenced survival outcomes of patients with Ut/Mt ESCC after MIE.

199. YOUNGER AGE AS AN INDEPENDENT FACTOR FOR SUBSEQUENT HEAD AND NECK CANCER AFTER CURATIVE ESOPHAGECTOMY FOR ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Post-operative survival of esophageal cancer patients has improved with advances in technology and treatment modalities. However, squamous cell carcinoma often affects the esophagus together with the head and neck regions, with second primary head and neck cancer (SPHNC) adversely influencing the patients’ quality of life. Therefore, patients with esophageal squamous cell carcinoma (ESCC) should be carefully followed up post-operatively. This study evaluated the risk of developing SPHNCs after an esophagectomy for ESCC. Methods Patients with ESCC who underwent curative esophagectomy from January 2008 to December 2017 from two tertiary medical centers, Taipei Veteran General Hospital and Kaohsiung Veteran General Hospital, were retrospectively reviewed. SPHNC development was documented according to anatomic region and the cumulative incidence rate and risk factors were analyzed. Results The median observation time of the 435 patients included in our study was 48.5 months [interquartile range (IQR) 16.7–92.4 months]. Among the ESCC patients after curative esophagectomy, younger age <50 [hazard ratio (HR) 4.13, 95% CI: 2.53–6.75, p < 0.001) was the only independent factor for developing SPHNCs in the multivariable analysis. The cumulative incidence rate of SPHNCs of patients aged < 50 years old was 14.3%, 22.1%, and 34.2% after 3, 5, and 10 years, respectively. Conclusion There was a high risk of secondary cancer after ESCC in the upper aerodigestive tract, especially the head and neck regions, therefore active surveillance is strongly recommended, especially in younger patients.

Expression of Interleukin-8, Interleukin-12 and Interleukin-13 in Esophageal Squamous Cell Carcinoma: Biomarker Potentiality and Prognostic Significance.

Interleukin-8 (IL8), Interleukin-12 (IL12) and Interleukin-13 (IL13) are cytokines that play regulatory role in cancer pathogenesis. We analysed their expression profile to evaluate as molecular biomarkers of esophageal squamous cell carcinoma (ESCC) and their association with different parameters and patient survival. Expression analysis was performed by Real time quantitative polymerase chain reaction and receiver operating characteristic (ROC) curve analysis was done. The expression profiles were associated with different clinicopathological and dietary factors. Survival and hazard analysis were also performed. IL8 expression showed upregulation in tissue (p = 0.000) and blood samples (p = 0.481), IL12 expression showed downregulation in tissue samples (p = 0.064) and upregulation in blood samples (p = 0.689) and IL13 expression showed upregulation in tissue (p = 0.000) and blood samples (p = 0.006). IL13 expression in tissue showed the highest area under the curve (AUC) value (0.773) for ESCC diagnosis, followed by IL8 expression in tissue (0.704) and IL13 expression in blood (0.643). This study also reveals the correlation of studied cytokines in tissue and blood level. Different clinicopathological and dietary factors showed significant association (p < 0.05) with IL8, IL12 and IL13 expression and with survival of ESCC patients. IL8 expression in blood and IL12 expression in tissue and blood showed significant association (p < 0.05) with patient survival. Altered expression of IL8, IL12 and IL13 may be associated with ESCC progression. Overexpression of IL8 and IL13 in tissue samples may be potential biomarkers for ESCC screening. Additionally, both survival and hazard analysis data indicate the effects of different parameters on the prognosis of ESCC patients.

240. CACHEXIA INDEX AS A POTENTIAL BIOMARKER FOR SENSITIVITY OF NEOADJUVANT THERAPY AND PROGNOSIS IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Cancer cachexia has a negative impact on the clinical outcome of patients with esophageal squamous cell carcinoma (ESCC). The cachexia index (CXI) is a potential biomarker for cancer cachexia, whereas its implications for ESCC prognosis and treatment outcomes have not been investigated. Methods In our study, 454 ESCC patients who had neoadjuvant therapy followed by surgery were included. Based on the exclusion criteria, a total of 224 patients were finally enrolled in this study. The CXI was determined as the serum albumin/neutrophil-lymphocyte ratio × the skeletal muscle index (based on CT image), which was classified as L3-CXI or pectoralis muscles-CXI depending upon the type of muscle involved. The patients were divided into high- and low-CXI groups using sex-specific medians as cutoff values for CXI. Results Tumor regression grade = 0,1 (sensitive to treatment) to neoadjuvant therapy was obtained in 61.6% and 46.4% of patients in the high-pretreatment L3-CXI and low-pretreatment L3-CXI groups, respectively (P = 0.023). ESCC patients with △L3-CXI &amp;lt;0 (L3-CXI decreased during treatment) had significantly shorter overall survival (P = 0.006) and disease-free survival (P = 0.002) than those with △L3-CXI ≥0. Multivariable analysis showed that △L3-CXI &amp;lt;0 was an independent negative prognostic factor for overall survival and disease-free survival. Conclusions In patients with ESCC, pretreatment CXI is a biomarker for treatment response, and △CXI can predict postoperative complications and survival outcomes. Patients could be clearly stratified by pretreatment CXI and △CXI categories, which provides a new nutritional assessment tool for clinical decision-making for patients with ESCC.

786. ANATOMICAL DISTRIBUTION OF HUMAN PAPILLOMAVIRUS INFECTION IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Human Papillomavirus (HPV) infection is a high-risk factor for many types of cancer development. The reported infectious rate in esophageal squamous cell carcinoma (ESCC) varies widely, ranging from 0% to 88.9%. It may be caused due to geographical location, sample size, and detection methods. In general, p16 expression is considered as a biomarker for HPV infection. However, the correlation between the p16 expression and HPV infectious status has been controversial. Methods Patients with ESCC underwent esophagectomy without neoadjuvant chemotherapy (NAC) from 2007 to 2021 were included. Three formalin-fixed paraffin-embedded blocks (oral side, tumor, and esophagogastric junction (EGJ)) from each surgical resected specimen were collected. p16 expression was examined by immunohistochemistry (labeling index ≥ 10% is defined as positive expression). The presence of HPV DNA was investigated by polymerase chain reaction. In addition, the anatomical distribution of HPV infection was investigated. Results A total of 158 patients with 417 samples were included. The positive expression rate of p16 was 3.6% (5/137), 19.2% (30/156) and 2.1% (3/146) in oral side, tumor, and EGJ, respectively. The HPV infectious rate was 7% (11/158), and six cases were detected in tumor site and the other 5 cases were detected in oral side or EGJ. In tumor tissue, HPV positive cases showed p16 positive, and the sensitivity and specificity for detecting HPV DNA by IHC of p16 were 100% and 84%, respectively. The HPV infection in ESCC specimens appears to be irregular. Conclusion This study is the largest sample size in Japan, demonstrating the p16 positive rate of 19.2% and HPV infectious rate of 7% in ESCC patients without NAC. IHC of p16 can be used as a screening examination for predicting HPV infection in ESCC because the false negative rate was 0%. In addition, we firstly reported the HPV infectious mapping in ESCC specimens, and it appears irregular and random.

424. EFFECT OF GUT MICROBIOTA ON THE RESPONSE TO NEOADJUVANT IMMUNOTHERAPY COMBINED WITH CHEMOTHERAPY IN PATIENTS WITH ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background To explore the impact of gut microbiota diversity on the efficacy of immunotherapy combined with chemotherapy in esophageal squamous cell carcinoma (ESCC) patients, aiming to identify microbial markers for predicting treatment outcomes. Methods In this study, we prospectively enrolled patients diagnosed with locally advanced esophageal squamous cell carcinoma who were scheduled to undergo neoadjuvant immunotherapy combined with chemotherapy; stool specimens were collected before the first cycle, the second cycle of immunotherapy, and at the time of preoperative disease evaluation. To examine the gut microbiota's composition and abundance, we employed the 16S rDNA sequencing technique. The sequencing data were preprocessed with FLASH and Uparse software, and species annotation was performed using the SSUrRNA database. Microbiota analysis was conducted using the R language, and group differences were assessed using appropriate statistical methods. Results In this study, 43 patients (totally 122 stool samples) with neoadjuvant immunotherapy combined with chemotherapy for esophageal squamous cell carcinoma were enrolled from December 2020 to January 2022. 16S rDNA sequencing results suggested that patients in the sensitive group had higher total fecal microbiota diversity than those in the drug-resistant group, and a notable variation in the structure of the microbiota was detected between the two groups. During treatment, the results did not show any significant statistical difference in the number of species (alpha diversity) in the sensitive group compared to the resistant group, although there was a trend towards a higher number of species in the pre-treatment sensitive group. As the treatment progressed, starting from the second cycle of treatment, the sensitive group had a higher alpha diversity than the resistant group. And we found that Bray-Curtis distance assessment of beta diversity showed that the difference between the sensitive and resistant groups also became more pronounced as treatment progressed. At the phylum level, the gut flora composition of the sensitive group remained relatively stable as treatment progressed, while the microbial diversity of the resistant group appeared to decrease. At the genus level, Bifidobacterium, Faecalibacterium, Akkermansia and Ruminococcus were more abundant in the immunotherapy-sensitive group; whereas Ligilactobacillus and Escherichia-Shigella was more rich in the immunotherapy-resistant group. The prediction model based on the baseline differences of gut microbiota in the two groups using a random forest method can be applied to predict the efficacy of immunotherapy for esophageal squamous cell carcinoma. Conclusion There are differences in species diversity and microbiota structure between the sensitive and resistant groups of esophageal squamous cell carcinoma patients receiving immunotherapy combined with chemotherapy, and the predictive model, which is based on the microbiota differences between the two groups before treatment, could be clinically relevant in predicting the efficacy of immunotherapy combined with chemotherapy for esophageal squamous cell carcinoma.

582. LOW EXPRESSION OF FRG1 PROMOTES MIGRATION AND INVASION IN ESOPHAGEAL CANCER

Abstract Purpose Distant metastasis is the primary cause of mortality among patients with esophageal cancer. Although FRG1 is known to play a role in the metastasis of various cancers, its specific function in esophageal squamous cell carcinoma (ESCC) has yet to be elucidated. In this study, we aimed to explore the role and potential molecular mechanism of FRG1 in the metastasis of ESCC. Methods Whole-exome sequencing was performed in ESCC patients who experienced distant metastasis (DM group) and those without metastasis within two years (non-DM group). Bioinformatics analysis and Immunohistochemistry (IHC) validation were conducted. In vitro, FRG1-overexpressed ESCC cell lines were established with lentivirus and validated by western blots. The wound-healing assay, transwell migration and invasion assay were performed in esophageal cancer cell lines. Additionally, RNA sequencing was conducted in ESCC cells to identify potential pathways involved. Results Mutations in FRG1 were more frequently observed in DM group compared to those in non-DM group. IHC revealed that the expression of FRG1 in DM group was significantly lower than non-DM group. In vitro, our results showed that ESCC cells with low FRG1 expression exhibited enhanced migration and invasion capabilities. Conversely, overexpression of FRG1 inhibited migration and invasion in ESCC cells. Mechanistically, RNA sequencing analysis showed a total of 93 differential expression genes between FRG1-overexpressed cells and the negative control. Notably, most differential genes were mainly enriched in the PPAR pathway and tyrosine metabolism pathway. Conclusion Our findings suggest that low FRG1 expression in patients may be indicative of rapid distant metastasis. The significant impact of FRG1's abnormal expression on the migration and invasion of ESCC cells highlights its potential as a therapeutic target for treating esophageal squamous cell carcinoma.

Expression and functional analyses of TERF2 in esophageal carcinoma

BackgroundEsophageal cancer (ESCA) is a prevalent malignancy with a high incidence of morbidity and mortality, particularly in Asia. Telomeric Repeat-binding Factor 2 (TERF2) is a crucial component of the telomere-binding protein complex that maintains telomere stability. Aberrant TERF2 expression has been implicated in tumorigenesis, however, its specific role in ESCA remains largely unexplored. MethodsThe expression levels of TERF2 were assessed in esophageal squamous cell carcinoma (ESCC) samples using RT-PCR, IHC, and Western blotting (WB). Serum tumor marker concentrations were determined via electrochemiluminescence immunoassay (ECLIA) and chemiluminescent microparticle immunoassay (CMIA). Bioinformatics analyses were employed to elucidate TERF2's function in EC. The impact of TERF2 on ESCC cell proliferation was evaluated through cell counting kit-8 (CCK8) assays and flow cytometry. ResultsTERF2 protein and mRNA expression were elevated in ESCC tissues and correlated with age, sex, cancer stage, tumor grade, lymph node metastasis (LNM), and tumor histology. Univariate Cox regression analysis indicated TERF2 was an independent prognostic factor for overall survival (OS). TERF2 mRNA levels were associated with serum levels of carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), and tissue polypeptide antigen (TPA) in patients with ESCC. Immune infiltration and chemokine profiles were linked to TERF2 expression in ESCA. TERF2 is involved in regulating ESCC cell proliferation may through the DDR/P53 signaling way. ConclusionsTERF2 is overexpressed in ESCA and contributes to ESCC cell proliferation may via DDR/TP53 signaling pathway. These results suggest that TERF2 may serve as a potential target for developing treatments and diagnostic biomarker for ESCA.

236. THE ROLE OF ADJUVANT THERAPY FOLLOWING NEOADJUVANT CHEMORADIOTHERAPY AND ESOPHAGECTOMY IN ESOPHAGEAL CANCER

Abstract Background The objective of this study was to assess the role of adjuvant therapy following neoadjuvant chemoradiotherapy and esophagectomy in esophageal squamous cell carcinoma (ESCC). Methods We conducted a retrospective analysis involving 506 ESCC patients who underwent trimodal therapy. The clinical significance of adjuvant therapy on overall survival and disease-free survival was evaluated using Kaplan–Meier curves with log-rank tests, the Cox regression model, and a forest plot displaying hazard ratios (HR) with 95% confidence intervals. Results Among the 506 patients who had clinically positive lymph nodes and no metastasis after neoadjuvant chemoradiotherapy and esophagectomy, those who received adjuvant therapy exhibited shorter post-resection overall survival (OS) and disease-free survival (DFS), with a statistically significant difference between the two groups (Log-Rank, OS: P = 0.002; DFS: P &amp;lt; 0.001). Adjuvant therapy was not identified as an independent prognostic factor for OS (HR: 1.249; 95% CI: 0.869-1.796; P = 0.230), but it was a significantly unfavorable independent prognostic factor for DFS (HR: 1.868; 95% CI: 0.349-2.586; P &amp;lt; 0.001). Conclusion Adjuvant therapy is associated with poorer overall survival (OS) and disease-free survival (DFS) outcomes in ESCC patients with ypTNM stage I and II on final pathology following neoadjuvant chemoradiotherapy and esophagectomy. However, there was no significant difference observed in patients with ypTNM stage III or IV. Therefore, it is not recommended to undergo postoperative adjuvant therapy for patients with ypTNM stage I and II ESCC. However, for patients with ypTNM stage III and IV ESCC, further research is needed to explore adjuvant treatment strategies.