Impact of liver metastasis on immunotherapy in gastric carcinoma.

The programed death ligand-1 combined positive score (PD-L1 CPS), the only FDA-approved biomarker for immune checkpoint inhibitor therapy in gastric cancer (GC) patients, is an important but imperfect predictive biomarker. The molecular characteristics of tumors that influence the PD-L1 CPS are largely unknown and would be helpful for screening patients who would benefit from immunotherapy. PD-L1 immunohistochemistry (IHC) and targeted next-generation sequencing techniques were used to compare genomic alterations in 492 GC patients in two groups (PD-L1 CPS ⩾ 1, positive; CPS < 1, negative). Screened PD-L1 expression-related factors were analyzed for immunotherapy efficacy in three distinct GC cohorts from public databases. Positive PD-L1 expression occurred in 40% of GC patients and was associated with a higher proportion of phosphatidylinositol 3-kinase (PI3K), SWItch/Sucrose NonFermentable (SWI/SNF), lysine demethylase (KDM), and DNA (cytosine-5)-methyltransferase (DNMT) (all p < 0.01), pathway alterations. Compared to wild-type GC patients, those with PI3K pathway alterations had a higher response rate (p = 0.002) and durable clinical benefit rate with immunotherapy (p = 0.023, p = 0.038) as well as longer progression-free survival (p = 0.084, p = 0.0076) and overall survival (p = 0.2, p = 0.037) with immunotherapy. This study revealed PD-L1 expression-related factors in the tumor genome in a GC cohort. Alterations in the PI3K pathway associated with PD-L1 positivity were shown to be associated with better immunotherapy efficacy in three distinct GC cohorts from public databases. Our results provide a potential avenue for patient selection and rational immune combination development for GC patients.

Immune-related thyroid dysfunction (irTD) has been associated with clinical outcomes in non-endocrine tumors. However, the association between irTD and therapeutic efficacy or prognosis in gastric cancer remains unclear. The present study retrospectively investigated the occurrence of irTD during immunotherapy for gastric cancer and analyzed its association with clinical efficacy and patient prognosis. A total of 106 patients with advanced gastric cancer, treated with either first-line or second-line programmed cell death protein 1 (PD-1) monoclonal antibody (MAB) in combination with chemotherapy between January 2019 and December 2022 at the Department of Oncology of Changzhou Tumor Hospital (Changzhou, China), were included. Thyroid hormone levels, including thyroid-stimulating hormone, free thyroxine, free triiodothyronine and thyroid peroxidase (TPO), were determined before and after treatment using the electroluminescence method. The changes in the levels of thyroid hormones based on various clinical characteristics were evaluated in relation to the treatment outcomes, including progression-free survival (PFS) and overall survival (OS), in response to PD-1 MAB therapy. No significant associations were detected between the thyroid hormone levels and different clinical characteristics. Among the patients receiving first-line treatment, 40.6% developed irTD and 49.3% experienced TPO abnormalities. Patients with irTD demonstrated a significantly longer median PFS time than those without irTD (312.0±47.6 vs. 222.0±14.7 days; P=0.040), although no significant difference was noted in the median OS time. Similarly, patients with TPO abnormalities exhibited a longer median PFS time when compared to those without abnormalities (312.0±52.5 vs. 222.0±13.6 days; P=0.006), yet no significant difference was noted in the median OS time. In the second-line treatment, the incidence of irTD was 45.9, and 59.5% of the patients showed TPO abnormalities. Although there were no statistically significant differences in the median PFS or OS times between patients without or with irTD or TPO abnormalities, a trend toward longer PFS and OS was recorded in patients with TPO abnormalities. In conclusion, the occurrence of irTD and TPO abnormalities is associated with better efficacy and prolonged survival in patients with gastric cancer undergoing immunotherapy. These thyroid-related changes may serve as valuable biomarkers for predicting the response to PD-1 MAB therapy in this patient population.

BackgroundIntegrin β5 (ITGB5) is a pivotal player in the pathogenesis of gastric cancer (GC). We aimed to explore the potential value of ITGB5 as a predictor of diagnosis and immunotherapy in gastric cancer.MethodsThe expression of ITGB5 in GC was assessed using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and verified through quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Kaplan-Meier curves were conducted to evaluate the prognostic significance. The immune cells infiltration, tumor mutational burden (TMB), and immunophenoscore (IPS) were examined using CIBERSORT, TIMER, and TISIDB. In addition, colony formation, scratch assays, and transwell assays were employed to determine the impact on tumor progression and metastasis. CD276 expression was detected by western blotting following the knockdown of ITGB5. ELISA was utilized to measure serum ITGB5 levels.ResultsThe expression of ITGB5 in GC tissue surpassed that in normal tissue, it might contribute to GC pathogenesis through pathways including PI3K-AKT, ECM-receptor interaction, and TGF-beta. The elevated ITGB5 expression is associated with poor prognosis in GC patients. In addition, a strong positive association between ITGB5 overexpression and the infiltration levels of macrophages and monocytes, and it significantly influenced immune response. Moreover, lower expression of ITGB5 was associated with better immunotherapy efficacy. Subsequent investigation demonstrated that silencing of ITGB5 suppressed the proliferation and migration of GC cell lines in vitro. ITGB5 expression was positively correlated with CD276 expression and the knockdown of ITGB5 resulted a notable decrease CD276 expression. Futhermore, a significantly high level of serum ITGB5 was observed in GC patients. The combined assessment of ITGB5, CEA, and CA19-9 improved the diagnostic accuracy.ConclusionsITGB5 potentially serve as both a diagnostic biomarker and therapeutic target in managing GC.

Gastric cancer (GC) is a potential dominant disease in tumor immunotherapy checkpoint inhibitors, and adoptive cell therapy have brought great hope to GC patients. However, only some patients with GC can benefit from immunotherapy, and some patients develop drug resistance. More and more studies have shown that long non-coding RNAs (lncRNAs) may be important in GC immunotherapy's prognosis and drug resistance. Here, we summarize the differential expression of lncRNAs in GC and their impact on the curative effect of GC immunotherapy, discuss potential mechanisms of activity in GC immunotherapy resistance regulated by lncRNAs. This paper reviews the differential expression of lncRNA in GC and its effect on immunotherapy efficacy in GC. In terms of genomic stability, inhibitory immune checkpoint molecular expression, the cross-talk between lncRNA and immune-related characteristics of GC was summarized, including tumor mutation burden (TMB), microsatellite instability (MSI), and Programmed death 1 (PD-1). At the same time, this paper reviewed the mechanism of tumor-induced antigen presentation and upregulation of immunosuppressive factors, as well as the association between Fas system and lncRNA, immune microenvironment (TIME) and lncRNA, and summarized the functional role of lncRNA in tumor immune evasion and immunotherapy resistance.

Gastric cancer (GC) ranks among the most prevalent forms of cancer and contributes significantly to cancer-related mortality. There exists a pressing need to investigate novel approaches for GC management to improve diagnostic methods, therapeutic interventions, and patient outcomes. Exosomes are nanoscale extracellular vesicles (EVs) derived from various cell types that carry a diverse range of biomolecular cargo, including DNA, RNA, proteins, lipids, and other bioactive constituents. They play significant roles in GC pathogenesis and tumor microenvironment (TME) modulation. Exosomes derived from cancer cells can enhance tumor progression, transform the TME, and modulate immune responses. Immune cell-derived exosomes can similarly modulate immune functions and the TME. Immunotherapy represents a GC treatment breakthrough and is expected to show efficacy when combined with exosome-targeted therapy. Abundant research has demonstrated that exosomes are crucial for tumor growth, immune evasion, immune microenvironment reconfiguration, and immunotherapy efficacy in GC. This review describes the role of exosomes in the GC microenvironment, focusing on the mechanisms by which exosomes regulate immune responses to GC, and summarizes the current status of and challenges in the development of exosome-based diagnostics and immunotherapy for GC.

Gastric cancer (GC) is the fifth most common type of cancer and has the fourth highest death rate among all cancers. There is a lack of studies examining the impact of liver metastases on the effectiveness of immunotherapy in individuals diagnosed with GC. To investigate the influence of liver metastases on the effectiveness and safety of immunotherapy in patients with advanced GC. This retrospective investigation collected clinical data of patients with advanced stomach cancer who had immunotherapy at our hospital from February 2021 to January 2023. The baseline attributes were compared using either the Chi-square test or the Fisher exact probability method. The chi-square test and Kaplan-Meier survival analysis were employed to assess the therapeutic efficacy and survival duration in GC patients with and without liver metastases. The analysis comprised 48 patients diagnosed with advanced GC, who were categorized into two groups: A liver metastasis cohort (n = 20) and a non-liver metastatic cohort (n = 28). Patients with liver metastasis exhibited a more deteriorated physical condition compared to those without liver metastasis. The objective response rates in the cohort with metastasis and the cohort without metastasis were 15.0% and 35.7% (P > 0.05), respectively. Similarly, the disease control rates in these two cohorts were 65.0% and 82.1% (P > 0.05), respectively. The median progression-free survival was 5.0 months in one group and 11.2 months in the other group, with a hazard ratio of 0.40 and a significance level (P) less than 0.05. The median overall survival was 12.0 months in one group and 19.0 months in the other group, with a significance level (P) greater than 0.05. Immunotherapy is less effective in GC patients with liver metastases compared to those without liver metastasis.

Background: The immunotherapy efficacy in gastric cancer (GC) is limited. Cancer-associated fibroblasts (CAFs) induce primary resistance to immunotherapy. However, CAF infiltration in tumors is difficult to evaluate due to the lack of validated and standardized quantified methods. This study aimed to investigate the impact of infiltrating CAFs alternatively using fibroblast-associated mutation scoring (FAMscore).Methods: In a GC cohort from Affiliated Hospital of Jiangsu University (AHJU), whole exon sequencing of genomic mutations, whole transcriptome sequencing of mRNA expression profiles, and immunofluorescence staining of tumor-infiltrating immune cells were performed. GC data from The Cancer Genome Atlas were used to identify genetic mutations which were associated with overall survival (OS) and impacted infiltrating CAF abundance determined by transcriptome-based estimation. FAMscore was then constructed through a least absolute shrinkage and selection operator Cox regression model and further validated in AHJU. The predictive role of FAMscore for immunotherapy outcomes was tested in 1 GC, one melanoma, and two non-small-cell lung cancer (NSCLC-1 and -2) cohorts wherein participants were treated by immune checkpoint inhibitors.Results: FAMscore was calculated based on a mutation signature consisting of 16 genes. In both TCGA and AHJU, a high FAMscore was an independent predictor for poor OS of GC patients. FAMscore was associated with immune-associated genome biomarkers, immune cell infiltration, and signaling pathways of abnormal immunity. Importantly, patients with high FAMscore presented inferiority in the objective response rate of immunotherapy compared to those with low FAMscore, with 14.6% vs. 66.7% (p<0.001) in GC, 19.6% vs. 68.2% (p<0.001) in NSCLC-1, 23.1% vs 75% (p = 0.007) in NSCLC-2, and 40.9% vs 75% (p = 0.037) in melanoma. For available survival data, a high FAMscore was also an independent predictor of poor progression-free survival in NSCLC-1 (HR = 2.55, 95% CI: 1.16–5.62, p = 0.02) and NSCLC-2 (HR = 5.0, 95% CI: 1.13–22.19, p = 0.034) and poor OS in melanoma (HR = 3.48, 95% CI: 1.27–9.55, p = 0.015).Conclusions: Alternative evaluation of CAF infiltration in GC by determining the FAMscore could independently predict prognosis and immunotherapy outcomes. The FAMscore may be used to optimize patient selection for immunotherapy.

BackgroundEpstein-Barr virus (EBV)-associated gastric cancer (GC) (EBVaGC) is a distinct molecular subtype of GC with a favorable prognosis. However, the exact effects and potential mechanisms of EBV infection on immune...

4050 Background: Liver metastases contribute to immunotherapeutic resistance and unfavorable outcomes. Transarterial chemoembolization (TACE) may alter the immune microenvironment and enhance immunotherapy efficacy. In this trial, we assessed the efficacy and safety of TACE followed by sintilimab (anti-PD-1), oxaliplatin and S-1 combined with either trastuzumab (HER-2 positive) or apatinib (HER-2 negative) in the treatment of gastric cancer with liver metastases (GCLM). Additionally, we explored gene mutations and the immune microenvironment between gastric cancer and its paired liver metastases. Methods: This single-center, single-arm, phase II trial enrolled 31 treatment-naive patients with GCLM. Patients received TACE for liver metastases, followed by sintilimab (200mg), oxaliplatin (130mg/m 2 ) and S-1 (40-60 mg bid for 14 days) every 3weeks combined with either trastuzumab (HER-2 positive, 8 mg/kg then 6 mg/kg, q3w) or apatinib (HER-2 negative, 250mg qd) until disease progression or intolerable toxicities. Tissue samples from gastric cancer and liver metastases were collected before treatment for DNA and RNA detection. The primary endpoints were PFS and ORR. The secondary endpoints were DCR, OS, and safety. Results: A total of 31 patients were enrolled, median 63 (41-76) years old, 27 male, 26 multiple liver metastases and all adenocarcinoma. Of them, 10 (32.3%) were HER2 IHC 3+, 7 (22.6%) HER2 IHC 2+/FISH+. Patients with PD-L1 CPS≥5, &lt; 1 accounted for 19.4%, 51.6% respectively. With the median follow-up time of 396 days, the patients received a median of 6 treatment cycles. As of January 25, 2025, 27 patients were included in the efficacy and safety analyses. The ORR was 74.1%, with 5 CR, 15 PR, 3 SD, and 4 PD. DCR was 85.2%. The median PFS was 12 months, and the median OS was not reached. One- and two-year PFS rates were 51.6 and 27.1 %, respectively. One- and two-year OS rates were 89.1 and 74.0 %, respectively. Grade 3/4 treatment-related adverse events occurred in 18.5% of the patients, notably neutropenia, neurotoxicity and thyroid and liver dysfunctions. Forty-four unique mutated genes were identified in gastric cancer, which were involved in PI3K-Akt and drug resistance pathways. In its paired liver metastases, 59 specific mutated genes associated with MMR and cell cycle were identified. Liver metastases had more macrophages and CD8+ T cells, whereas NK and CD4+ memory resting cells were fewer than those in paired gastric cancer. Conclusions: TACE followed by sintilimab, oxaliplatin and S-1 combined with either trastuzumab or apatinib demonstrated promising efficacy and manageable safety as first-line therapy for GCLM. Gastric cancer and its paired liver metastases exhibited distinct gene mutations and immune microenvironment. Clinical trial information: ChiCTR2200057726 .

Reprogramming of glutamine metabolism in Gastric Cancer (GC) can significantly affect the tumor immune microenvironment and immunotherapy. This study examines the role of glutamine metabolism in the microenvironment and prognosis of gastric cancer. We obtained gene expression data and clinical information of patients from the TCGA database. The patients were divided into two metabolic subtypes based on consistent clustering. A prognostic risk model containing three glutamine metabolism-related genes (GMRGs) was developed using Lasso-Cox. It was validated by the GEO validation cohort. Additionally, the immune microenvironment composition of the highand low-risk groups was assessed using ESTIMATE, CIBERSORT, and ssGSEA. Drug sensitivity analysis was conducted using the "oncoPredict" R package. We outlined the distinct clinical characteristics of two subtypes and developed a prognostic risk model. The high-risk group has a poorer prognosis due to an increased expression of immune checkpoints and immunosuppressive cellular infiltration. Our analysis, which included Cox risk regression, ROC curves, and nomogram, demonstrated that this risk model is an independent prognostic factor. The TIDE score was higher in the high-risk group than in the low-risk group. Additionally, the high-risk group did not respond well to chemotherapeutic drug treatment. This study shows that modelling glutamine metabolism is a good predictor of prognosis and immunotherapy efficacy in gastric cancer. Thus, we can better understand the role of glutamine metabolism in the development of cancer and use these insights to develop more targeted and effective treatments.

EpCAM is highly expressed in various cancer types of the gastrointestinal system and at metastatic sites. It serves as a promising prognostic marker and therapeutic target. We conducted a first-in-human, open-label, single-arm, multicenter, phase 1 clinical trial following the classical "3+3" dose escalation design. The endpoints of this clinical trial are to assess the safety, efficacy, and pharmacokinetic (PK)/pharmacodynamic (PD) profile of EpCAM CAR-T. The trial is still ongoing, and our interim analysis results revealed a favorable safety profile of EpCAM CAR-T. No treatment-related deaths were observed within the 4-week follow-up period after infusion. 2 (12.5%) patients in high dose group (3*106) experienced dose-limiting toxicity (DLT) and 8 (50%) patients experienced grade 1-3 CRS. EpCAM CAR-T showed promising efficacy in gastric cancer. In gastric cancer group, the overall response rate (ORR) and disease control rate (DCR) reached 20.0% and 90.0%, respectively. However, the efficacy of EpCAM CAR-T in treating colorectal cancer was suboptimal, with an objective response rate (ORR) of 0% and disease control rate (DCR) of 50%. In our study, we observed that patients in gastric cancer (GC) group who developed cytokine release syndrome (CRS) had a weak response to CAR-T cell therapy, which is consistent with previous observations in animal models. We employed single-cell RNA sequencing (scRNA-seq) to analyze peripheral blood mononuclear cells (PBMCs) from GC group patients receiving EpCAM CAR-T treatment to explore the potential antagonism between CRS and treatment efficacy. Our findings underscore the significant role of monocytes in the regulation of CRS and treatment response. Specifically, we identified an increased abundance of Toll-like receptor (TLR)-dependent CD36+ monocytes in non-responders experiencing CRS. In a mouse model, we demonstrated that blocking TLR signaling in monocytes attenuated CRS induced by EpCAM CAR-T cells. Conversely, CD16+ monocytes were enriched in responders, displaying upregulated antigen presentation pathways and enhanced tumor infiltration capacity. In vivo, experiments revealed that blocking the antigen presentation pathway or inhibiting tumor infiltration of CD16+ monocytes resulted in reduced anti-tumor response of EpCAM CAR-T cells. Our findings highlight the critical role of intrinsic monocyte subpopulations as determinants of CAR-T efficacy and CRS. These insights may provide valuable strategies for predicting and enhancing the safety and efficacy of CAR-T cell therapy for solid tumors. Citation Format: TIanhang Luo, Zhengmao Lu, Zhongen Wu, Yuxuan Dong, Yuanyuan Zhu, Mei Feng, Shenglin Mei, Weijia Fang, Di Zhu. Targeting EpCAM via CAR T-cells is an effective treatment for gastric cancer patients and subsequent toll-like receptor signaling activation in CD36+ monocyte underlies the resulting cytokine release syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT069.

P-167 Identification of peptides inhibitor clade A member 1 as a novel serum biomarker for gastric cancer and promotes liver metastasis

The majority of gastric cancer (GC) patients are in a progressive stage at the initial stage of treatment, and the overall response rate to immunotherapy remains unsatisfactory largely due to the lack of effective prognostic biomarkers. Immunogenic cell death (ICD) was identified as a new form of regulated cell death that can activate adaptive immune responses and further promote immunotherapy efficacy. Therefore, we attempted to characterize the ICD-associated signature to stratify patients who could benefit from immunotherapy. In our study, two subgroups of patients were identified based on the data of 34 ICD-related genes extracted from The Cancer Genome Atlas database via consensus clustering. The estimated scores, stromal scores, immune scores, tumor purity, and survival rate showed significant differences between the low and high ICD groups. Then, we constructed an ICD-related risk signature, including IFNB1, IL6, LY96, and NT5E, using least absolute shrinkage and selection operator Cox regression analysis; then, high- and low-risk groups could be clearly distinguished. Notably, the risk score is a reliable predictor of the prognosis and immunotherapy outcome in GC, which was further validated in an immunohistochemistry assay. These results suggest that ICD is closely associated with the prognosis and tumor immune microenvironment in GC. Taken together, this study first constructed and validated a prognostic ICD-related signature to predict the survival and effect of immunotherapy in GC, which provided new insight for potent individualized immunotherapy strategies.

Background: Gastric cancer (GC) remains one of the most malignant tumors around the world, and an accurate model that reliably predicts survival and therapeutic efficacy is urgently needed. As a novel predictor for prognosis in a variety of cancers, immune-related long noncoding RNA pairs (IRlncRNAPs) have been reported to predict tumor prognosis. Herein, we integrated an IRlncRNAPs model to predict the clinical outcome, immune features, and chemotherapeutic efficacy of GC.Methods: Based on the GC data obtained from The Cancer Genome Atlas (TCGA) database and the Immunology Database and Analysis Portal (ImmPort), differentially expressed immune-related long noncoding RNAs (DEIRlncRNAs) were identified. Least absolute shrinkage and selection operator (LASSO) regression and Cox regression analysis were used to select the most appropriate overall survival (OS)-related IRlncRNAPs to develop a prognostic signature. The riskScore of each sample was calculated by comparing the long noncoding RNA expression level in each IRlncRNAP. Based on the riskScore for each patient, GC patients were divided into high- and low-risk groups. Then, the correlation of the signature and riskScore with OS, clinical features, immune cell infiltration, immune-related gene (IRG) expression and chemotherapeutic efficacy in GC was analyzed.Results: A total of 107 DEIRlncRNAs were identified which formed 4297 IRlncRNAPs. Fifteen OS-related IRlncRNAPs were selected to develop a prognostic model. GC patients could be accurately classified into high- and low-risk groups according to the riskScore of the prognostic model. The 1-, 2-, 3-, and 5-year receiver operating characteristic (ROC) curves for the riskScore were drawn and the area under the curve (AUC) values were found to be 0.788, 0.810, 0.825, and 0.868, respectively, demonstrating a high sensitivity and accuracy of this prognostic signature. Moreover, the immune-related riskScore was an independent risk factor. Patients showed a poorer outcome within the high-risk group. In addition, the riskScore was found to be significantly correlated with the clinical features, immune infiltration status, IRG expression, and chemotherapeutic efficacy in GC.Conclusion: The prognostic model of IRlncRNAPs offers great promise in predicting the prognosis, immune infiltration status, and chemotherapeutic efficacy in GC, which might be helpful for the selection of chemo- and immuno-therapy of GC.

BackgroundM2-like tumor-associated macrophages (M2-like TAMs) play key roles in tumor progression and the immune response. However, the clinical significance and prognostic value of M2-like TAMs-associated regulatory genes in gastric cancer (GC) have not been clarified.MethodsHerein, we identified M2-like TAM-related genes by weighted gene coexpression network analysis of TCGA-STAD and GSE84437 cohort. Lasso-Cox regression analyses were then performed to screen for signature genes, and a novel signature was constructed to quantify the risk score for each patient. Tumor mutation burden (TMB), survival outcomes, immune cells, and immune function were analyzed in the risk groups to further reveal the immune status of GC patients. A gene-drug correlation analysis and sensitivity analysis of anticancer drugs were used to identify potential therapeutic agents. Finally, we verified the mRNA expression of signature genes in patient tissues by qRT-PCR, and analyzed the expression distribution of these genes by IHC.ResultsA 4-gene (SERPINE1, MATN3, CD36, and CNTN1) signature was developed and validated, and the risk score was shown to be an independent prognostic factor for GC patients. Further analyses revealed that GC patients in the high-risk group had a worse prognosis than those in the low-risk group, with significant differences in TMB, clinical features, enriched pathways, TIDE score, and tumor microenvironment features. Finally, we used qRT-PCR and IHC analysis to verify mRNA and protein level expression of signature genes.ConclusionThese findings highlight the importance of M2-like TAMs, provide a new perspective on individualized immunotherapy for GC patients.