Immune Activation and Benefit From Avelumab in EBV-Positive Gastric Cancer

Comprehensive landscape of m6A regulator-related gene patterns and tumor microenvironment infiltration characterization in gastric cancer

The epigenetic regulation of N6-methyladenosine (m6A) has attracted considerable interest in tumor research, but the potential roles of m6A regulator-related genes, remain largely unknown within the context of gastric cancer (GC) and tumor microenvironment (TME). Here, a comprehensive strategy of data mining and computational biology utilizing multiple datasets based on 28 m6A regulators (including novel anti-readers) was employed to identify m6A regulator-related genes and patterns and elucidate their underlying mechanisms in GC. Subsequently, a scoring system was constructed to evaluate individual prognosis and immunotherapy response. Three distinct m6A regulator-related patterns were identified through the unsupervised clustering of 56 m6A regulator-related genes (all significantly associated with GC prognosis). TME characterization revealed that these patterns highly corresponded to immune-inflamed, immune-excluded, and immune-desert phenotypes, and their TME characteristics were highly consistent with different clinical outcomes and biological processes. Additionally, an m6A-related scoring system was developed to quantify the m6A modification pattern of individual samples. Low scores indicated high survival rates and high levels of immune activation, whereas high scores indicated stromal activation and tumor malignancy. Furthermore, the m6A-related scores were correlated with tumor mutation loads and various clinical traits, including molecular or histological subtypes and clinical stage or grade, and the score had predictive values across all digestive system tumors and even in all tumor types. Notably, a low score was linked to improved responses to anti-PD-1/L1 and anti-CTLA4 immunotherapy in three independent cohorts. This study has expanded the important role of m6A regulator-related genes in shaping TME diversity and clinical/biological traits of GC. The developed scoring system could help develop more effective immunotherapy strategies and personalized treatment guidance.

N6-methyladenosine methylation regulates the tumor microenvironment of Epstein-Barr virus-associated gastric cancer

BACKGROUND

N6-methyladenosine (m6A) methylation modification exists in Epstein-Barr virus (EBV) primary infection, latency, and lytic reactivation. It also modifies EBV latent genes and lytic genes. EBV-associated gastric cancer (EBVaGC) is a distinctive molecular subtype of GC. We hypothesized EBV and m6A methylation regulators interact with each other in EBVaGC to differentiate it from other types of GC.

AIM

To investigate the mechanisms of m6A methylation regulators in EBVaGC to determine the differentiating factors from other types of GC.

METHODS

First, The Cancer Gene Atlas and Gene Expression Omnibus databases were used to analyze the expression pattern of m6A methylation regulators between EBVaGC and EBV-negative GC (EBVnGC). Second, we identified Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment of m6A-related differentially expressed genes. We quantified the relative abundance of immune cells and inflammatory factors in the tumor microenvironment (TME). Finally, cell counting kit-8 cell proliferation test, transwell test, and flow cytometry were used to verify the effect of insulin-like growth factor binding protein 1 (IGFBP1) in EBVaGC cell lines.

RESULTS

m6A methylation regulators were involved in the occurrence and development of EBVaGC. Compared with EBVnGC, the expression levels of m6A methylation regulators Wilms tumor 1-associated protein, RNA binding motif protein 15B, CBL proto-oncogene like 1, leucine rich pentatricopeptide repeat containing, heterogeneous nuclear ribonucleoprotein A2B1, IGFBP1, and insulin-like growth factor 2 binding protein 1 were significantly downregulated in EBVaGC (P < 0.05). The overall survival rate of EBVaGC patients with a lower expression level of IGFBP1 was significantly higher (P = 0.046). GO and KEGG functional enrichment analyses showed that the immunity pathways were significantly activated and rich in immune cell infiltration in EBVaGC. Compared with EBVnGC, the infiltration of activated CD4+ T cells, activated CD8+ T cells, monocytes, activated dendritic cells, and plasmacytoid dendritic cells were significantly upregulated in EBVaGC (P < 0.001). In EBVaGC, the expression level of proinflammatory factors interleukin (IL)-17, IL-21, and interferon-γ and immunosuppressive factor IL-10 were significantly increased (P < 0.05). In vitro experiments demonstrated that the expression level of IGFBP1 was significantly lower in an EBVaGC cell line (SNU719) than in an EBVnGC cell line (AGS) (P < 0.05). IGFBP1 overexpression significantly attenuated proliferation and migration and promoted the apoptosis levels in SNU719. Interfering IGFBP1 significantly promoted proliferation and migration and attenuated the apoptosis levels in AGS.

CONCLUSION

m6A regulators could remodel the TME of EBVaGC, which is classified as an immune-inflamed phenotype and referred to as a “hot” tumor. Among these regulators, we demonstrated that IGFBP1 affected proliferation, migration, and apoptosis.

N6-methyladenosine methylation regulates the tumor microenvironment of Epstein-Barr virus-associated gastric cancer

BACKGROUND

N6-methyladenosine (m6A) methylation modification exists in Epstein-Barr virus (EBV) primary infection, latency, and lytic reactivation. It also modifies EBV latent genes and lytic genes. EBV-associated gastric cancer (EBVaGC) is a distinctive molecular subtype of GC. We hypothesized EBV and m6A methylation regulators interact with each other in EBVaGC to differentiate it from other types of GC.

AIM

To investigate the mechanisms of m6A methylation regulators in EBVaGC to determine the differentiating factors from other types of GC.

METHODS

First, The Cancer Gene Atlas and Gene Expression Omnibus databases were used to analyze the expression pattern of m6A methylation regulators between EBVaGC and EBV-negative GC (EBVnGC). Second, we identified Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment of m6A-related differentially expressed genes. We quantified the relative abundance of immune cells and inflammatory factors in the tumor microenvironment (TME). Finally, cell counting kit-8 cell proliferation test, transwell test, and flow cytometry were used to verify the effect of insulin-like growth factor binding protein 1 (IGFBP1) in EBVaGC cell lines.

RESULTS

m6A methylation regulators were involved in the occurrence and development of EBVaGC. Compared with EBVnGC, the expression levels of m6A methylation regulators Wilms tumor 1-associated protein, RNA binding motif protein 15B, CBL proto-oncogene like 1, leucine rich pentatricopeptide repeat containing, heterogeneous nuclear ribonucleoprotein A2B1, IGFBP1, and insulin-like growth factor 2 binding protein 1 were significantly downregulated in EBVaGC (P < 0.05). The overall survival rate of EBVaGC patients with a lower expression level of IGFBP1 was significantly higher (P = 0.046). GO and KEGG functional enrichment analyses showed that the immunity pathways were significantly activated and rich in immune cell infiltration in EBVaGC. Compared with EBVnGC, the infiltration of activated CD4+ T cells, activated CD8+ T cells, monocytes, activated dendritic cells, and plasmacytoid dendritic cells were significantly upregulated in EBVaGC (P < 0.001). In EBVaGC, the expression level of proinflammatory factors interleukin (IL)-17, IL-21, and interferon-γ and immunosuppressive factor IL-10 were significantly increased (P < 0.05). In vitro experiments demonstrated that the expression level of IGFBP1 was significantly lower in an EBVaGC cell line (SNU719) than in an EBVnGC cell line (AGS) (P < 0.05). IGFBP1 overexpression significantly attenuated proliferation and migration and promoted the apoptosis levels in SNU719. Interfering IGFBP1 significantly promoted proliferation and migration and attenuated the apoptosis levels in AGS.

CONCLUSION

m6A regulators could remodel the TME of EBVaGC, which is classified as an immune-inflamed phenotype and referred to as a "hot" tumor. Among these regulators, we demonstrated that IGFBP1 affected proliferation, migration, and apoptosis.

Progress and prospects of biomarker-based targeted therapy and immune checkpoint inhibitors in advanced gastric cancer

Gastric cancer and gastroesophageal junction cancer represent the leading cause of tumor-related death worldwide. Although advances in immunotherapy and molecular targeted therapy have expanded treatment options, they have not significantly altered the prognosis for patients with unresectable or metastatic gastric cancer. A minority of patients, particularly those with PD-L1-positive, HER-2-positive, or MSI-high tumors, may benefit more from immune checkpoint inhibitors and/or HER-2-directed therapies in advanced stages. However, for those lacking specific targets and unique molecular features, conventional chemotherapy remains the only recommended effective and durable regimen. In this review, we summarize the roles of various signaling pathways and further investigate the available targets. Then, the current results of phase II/III clinical trials in advanced gastric cancer, along with the superiorities and limitations of the existing biomarkers, are specifically discussed. Finally, we will offer our insights in precision treatment pattern when encountering the substantial challenges.

The tumor immune composition of mismatch repair deficient and Epstein-Barr virus-positive gastric cancer: A systematic review

BACKGROUND

Gastric cancer (GC), known for its unfavorable prognosis, has been classified in four distinct molecular subtypes. These subtypes not only exhibit differences in their genome and transcriptome but also in the composition of their tumor immune microenvironment. The microsatellite instable (MSI) and Epstein-Barr virus (EBV) positive GC subtypes show clear clinical benefits from immune checkpoint blockade, likely due to a neoantigen-driven and virus-driven antitumor immune response and high expression of immune checkpoint molecule PD-L1. However, even within these subtypes response to checkpoint inhibition is variable, which is potentially related to heterogeneity in the tumor immune microenvironment (TIME) and expression of co-inhibitory molecules. We conducted a systematic review to outline the current knowledge about the immunological features on the TIME of MSI and EBV + GCs.

METHODS

A systematic search was performed in PubMed, EMBASE and Cochrane Library. All articles from the year 1990 and onwards addressing immune features of gastric adenocarcinoma were reviewed and included based on predefined in- and exclusion criteria.

RESULTS

In total 5962 records were screened, of which 139 were included that reported immunological data on molecular GC subtypes. MSI and EBV + GCs were reported to have a more inflamed TIME compared to non-MSI and EBV- GC subtypes. Compared to microsatellite stable (MSS) tumors, MSI tumors were characterized by higher numbers of CD8 + and FoxP3 + T cells, and tumor infiltrating pro- and anti-inflammatory macrophages. HLA-deficiency was most common in MSI tumors compared to other molecular GC subtypes and associated with lower T and B cell infiltrates compared to HLA-proficient tumors. EBV + was associated with a high number of CD8 + T cells, Tregs, NK cells and macrophages. Expression of PD-L1, CTLA-4, Granzyme A and B, Perforin and interferon-gamma was enriched in EBV + tumors. Overall, MSI tumors harbored a more heterogeneous TIME in terms of immune cell composition and immune checkpoints compared to the EBV + tumors.

DISCUSSION AND CONCLUSION

MSI and EBV + GCs are highly Handbook for Conducting a Literature-Based Health Assessment Using OHAT Approach for Systematic Review and Evidence Integration.; 2019pro-inflammatory immune cell populations. Although studies on the direct comparison of EBV + and MSI tumors are limited, EBV + tumors show less intra-subgroup heterogeneity compared to MSI tumors. More studies are needed to identify how Intra-subgroup heterogeneity impacts response to immunotherapy efficacy.

Comprehensive multi-omics analysis of pyroptosis for optimizing neoadjuvant immunotherapy in patients with gastric cancer

Background: Pyroptosis plays a crucial role in immune responses. However, the effects of pyroptosis on tumor microenvironment remodeling and immunotherapy in gastric cancer (GC) remain unclear. Patients and Methods: Large-sample GEO data (GSE15459, GSE54129, and GSE62254) were used to explore the immunoregulatory roles of pyroptosis. TCGA cohort was used to elucidate multiple molecular events associated with pyroptosis, and a pyroptosis risk score (PRS) was constructed. The prognostic performance of the PRS was validated using postoperative GC samples from three public databases (n=925) and four independent Chinese medical cohorts (n=978). Single-cell sequencing and multiplex immunofluorescence were used to elucidate the immune cell infiltration landscape associated with PRS. Patients with GC who received neoadjuvant immunotherapy (n=48) and those with GC who received neoadjuvant chemotherapy (n=49) were enrolled to explore the value of PRS in neoadjuvant immunotherapy. Results: GC pyroptosis participates in immune activation in the tumor microenvironment and plays a powerful role in immune regulation. PRS, composed of four pyroptosis-related differentially expressed genes (BATF2, PTPRJ, RGS1, and VCAN), is a reliable and independent biomarker for GC. PRSlow is associated with an activated pyroptosis pathway and greater infiltration of anti-tumor immune cells, including more effector and CD4+ T cells, and with the polarization of tumor-associated macrophages in the tumor center. Importantly, PRSlow marks the effectiveness of neoadjuvant immunotherapy and enables screening of GC patients with combined positive score ≥1 who benefit from neoadjuvant immunotherapy. Conclusion: Our study demonstrated that pyroptosis activates immune processes in the tumor microenvironment. A low PRS correlates with enhanced infiltration of anti-tumor immune cells at the tumor site, increased pyroptotic activity, and improved patient outcomes. The constructed PRS can be used as an effective quantitative tool for pyroptosis analysis to guide more effective immunotherapeutic strategies for patients with GC.

The viral etiology of EBV-associated gastric cancers contributes to their unique pathology, clinical outcomes, treatment responses and immune landscape

Epstein-Barr virus (EBV) is a pathogen known to cause a number of malignancies, often taking years for them to develop after primary infection. EBV-associated gastric cancer (EBVaGC) is one such malignancy, and is an immunologically, molecularly and pathologically distinct entity from EBV-negative gastric cancer (EBVnGC). In comparison with EBVnGCs, EBVaGCs overexpress a number of immune regulatory genes to help form an immunosuppressive tumor microenvironment (TME), have improved prognosis, and overall have an "immune-hot" phenotype. This review provides an overview of the histopathology, clinical features and clinical outcomes of EBVaGCs. We also summarize the differences between the TMEs of EBVaGCs and EBVnGCs, which includes significant differences in cell composition and immune infiltration. A list of available EBVaGC and EBVnGC gene expression datasets and computational tools are also provided within this review. Finally, an overview is provided of the various chemo- and immuno-therapeutics available in treating gastric cancers (GCs), with a focus on EBVaGCs.

Case report: A case of rare metastasis of gastric cancer to the axillary lymph node metastasis treated with combination immunotherapy

Lymph node (LN) metastasis is a common mode of metastasis in advanced gastric cancer (GC), while axillary LN metastasis infrequently occurs in GC. There are few reports on this rare type of metastasis - especially its clinicopathological features - and systemic treatment are unclear. We describe a case of GC with extensive metastasis, including the rare axillary LN metastasis. The patient achieved partial response of optimal efficacy, who was treated with combination immunotherapy as second-line treatment for nearly two years. The potential mechanisms were revealed by clinical and immune characteristics, such as high expression of PD-L1, high tumor mutational burden (TMB-H), Epstein-Barr virus (EBV) positive and CD8+ tumor-infiltrating lymphocyte positive.

Development and validation of a nomogram to predict pathological complete response in patients with locally advanced gastric adenocarcinoma treated with neoadjuvant chemotherapy in combination with PD-1 antibodies

Background

Currently, the survival benefits of combining neoadjuvant chemotherapy with programmed death 1 (PD-1) antibody immunotherapy in advanced gastric adenocarcinoma remain controversial. Emerging evidence suggests that the survival benefits of neoadjuvant therapy in advanced gastric adenocarcinoma hinge upon the attainment of pathological complete response (pCR). Therefore, the prediction of pCR in patients undergoing neoadjuvant chemotherapy combined with PD-1 antibody immunotherapy holds significant importance and is beneficial for the individualized treatment of gastric cancer (GC) patients.

Methods

Clinical and pathological characteristics of patients with GC who received neoadjuvant chemotherapy combined with PD-1 inhibitor (camrelizumab) therapy and radical gastrectomy between January 2019 and December 2020 at the Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital were retrospectively analyzed. A total of 52 patients were enrolled in the study, with all subjects assigned to the training set. The neoadjuvant regimen consisted of a combination of PD-1 inhibitor and fluorouracil analogues plus oxaliplatin, comprising two drugs. The patients were divided into a pCR group and a non-pCR group according to pCR occurrence. Multifactor logistic regression analysis was applied to determine the correlation between each factor and pCR. A prediction model was developed based on the results of the logistic regression analysis. The predictive performance of the model was evaluated using the receiver operating characteristic curves. Internal verification was completed via the bootstrapping method.

Results

The pCR was observed in 10 out of 52 patients (19.2%). The results of binary logistic regression multivariate analysis showed that cN stage [odds ratio (OR): 0.215; P=0.03], combined positive score (CPS) (OR: 6.364; P=0.026), and tumor diameter (OR: 0.112; P=0.026) were independent predictors of pCR. The nomogram prediction model for the pCR was plotted with a concordance index of 0.923 [95% confidence interval (CI): 0.8441-1].

Conclusions

Neoadjuvant chemotherapy combined with PD-1 antibodies may be the preferred option for patients with advanced gastric adenocarcinoma who have a small tumor diameter, no or few lymph node metastases, and high CPS. The presented nomogram model exhibits the potential to predict pCR in advanced gastric adenocarcinoma patients, showcasing satisfactory predictive performance and potentially facilitating the implementation of personalized treatment strategies.

Implementing an On-Slide Molecular Classification of Gastric Cancer: A Tissue Microarray Study

Background and Objectives: Gastric cancer (GC) is one of the most commonly diagnosed cancers and the fourth cause of cancer death worldwide. Personalised treatment improves GC outcomes. A molecular classification is needed to choose the appropriate therapy. A classification that uses on-slide biomarkers and formalin-fixed and paraffin-embedded (FFPE) tissue is preferable to comprehensive genomic analysis. In 2016, Setia and colleagues proposed an on-slide classification; however, this is not in widespread use. We propose a modification of this classification that has six subgroups: GC associated with Epstein-Barr virus (GC EBV+), GC with mismatch-repair deficiency (GC dMMR), GC with epithelial-mesenchymal transformation (GC EMT), GC with chromosomal instability (GC CIN), CG that is genomically stable (GC GS) and GC not otherwise specified (GC NOS). This classification also has a provision for biomarkers for current or emerging targeted therapies (Her2, PD-L1 and Claudin18.2). Here, we assess the implementation and feasibility of this inclusive working classification. Materials and Methods: We constructed a tissue microarray library from a cohort of 79 resection cases from FFPE tissue archives. We used a restricted panel of on-slide markers (EBER, MMR, E-cadherin, beta-catenin and p53), defined their interpretation algorithms and assigned each case to a specific molecular subtype. Results: GC EBV(+) cases were 6%, GC dMMR cases were 20%, GC EMT cases were 14%, GC CIN cases were 23%, GC GS cases were 29%, and GC NOS cases were 8%. Conclusions: This working classification uses markers that are widely available in histopathology and are easy to interpret. A diagnostic subgroup is obtained for 92% of the cases. The proportion of cases in each subgroup is in keeping with other published series. Widescale implementation appears feasible. A study using endoscopic biopsies is warranted.

Dissecting the role of the gut microbiome and fecal microbiota transplantation in radio- and immunotherapy treatment of colorectal cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and poses a major burden on the human health worldwide. At the moment, treatment of CRC consists of surgery in combination with (neo)adjuvant chemotherapy and/or radiotherapy. More recently, immune checkpoint blockers (ICBs) have also been approved for CRC treatment. In addition, recent studies have shown that radiotherapy and ICBs act synergistically, with radiotherapy stimulating the immune system that is activated by ICBs. However, both treatments are also associated with severe toxicity and efficacy issues, which can lead to temporary or permanent discontinuation of these treatment programs. There's growing evidence pointing to the gut microbiome playing a role in these issues. Some microorganisms seem to contribute to radiotherapy-associated toxicity and hinder ICB efficacy, while others seem to reduce radiotherapy-associated toxicity or enhance ICB efficacy. Consequently, fecal microbiota transplantation (FMT) has been applied to reduce radio- and immunotherapy-related toxicity and enhance their efficacies. Here, we have reviewed the currently available preclinical and clinical data in CRC treatment, with a focus on how the gut microbiome influences radio- and immunotherapy toxicity and efficacy and if these treatments could benefit from FMT.

SOX combined with sintilimab versus SOX alone in the perioperative management of locally advanced gastric cancer: a propensity score-matched analysis

OBJECTIVES

To evaluate the efficacy of SOX combined with a programmed cell death protein-1 (PD-1) inhibitor compared with SOX alone in the perioperative management of locally advanced gastric cancer and to explore biomarkers that may predict response to anti-PD-1 therapy.

METHODS

Data of patients with clinical stage T3-4aN0-3M0 (IIb-III) gastric cancer were reviewed to create a primary database. Patients treated with perioperative SOX combined with sintilimab were included in Group A, while those treated with SOX alone were included in Group B. After one-to-one propensity score matching, pathological response and short-term survival outcomes were compared between the two groups. In addition, potential efficacy-related biomarkers were analyzed.

RESULTS

Between January 2018 and December 2022, a total of 150 patients were included in the analysis, with 75 patients in each group. The rates of pathological complete response (21.3% vs. 4.0%; P = 0.001) and major pathological response (45.3% vs. 22.7%; P = 0.003) in Group A were statistically higher than those in Group B. There was no significant difference in 1-year overall survival (92.8% vs. 92.0%; P = 0.392) and disease-free survival (88.9% vs. 88.0%; P = 0.357) between the two groups. Subgroup analysis of Group A showed that the pathological complete response (40.6% vs. 8.6%; P = 0.002) and major pathological response (65.6% vs. 28.6%; P = 0.002) rates were significantly higher in programmed death ligand-1-positive patients with a combined positive score of ≥ 5. A pathological complete response was achieved in 42.9% patients (3/7) with mismatch repair deficiency. For the two patients confirmed as Epstein-Barr virus-positive, one patient achieved a pathological complete response and the other achieved a major pathological response.

CONCLUSIONS

The adoption of SOX combined with a PD-1 inhibitor may improve the pathological response rate of patients with locally advanced gastric cancer, especially those with programmed death ligand-1 combined positive score ≥ 5, Epstein-Barr virus-positivity and mismatch repair deficiency. However, further prospective studies are still warranted to confirm the long-term survival benefit.

Dynamic single-cell mapping unveils Epstein‒Barr virus-imprinted T-cell exhaustion and on-treatment response

Epstein‒Barr virus (EBV)-associated gastric cancer (GC) manifests an intriguing immunotherapy response. However, the cellular basis for EBV-imprinted tumour immunity and on-treatment response remains undefined. This study aimed to finely characterize the dynamic tumour immune contexture of human EBV (+) GC treated with immunochemotherapy by longitudinal scRNA-seq and paired scTCR/BCR-seq. EBV (+) GC exhibits an inflamed-immune phenotype with increased T-cell and B-cell infiltration. Immunochemotherapy triggers clonal revival and reinvigoration of effector T cells which step to determine treatment response. Typically, an antigen-specific ISG-15+CD8+ T-cell population is highly enriched in EBV (+) GC patients, which represents a transitory exhaustion state. Importantly, baseline intratumoural ISG-15+CD8+ T cells predict immunotherapy responsiveness among GC patients. Re-emerged clonotypes of pre-existing ISG-15+CD8+ T cells could be found after treatment, which gives rise to a CXCL13-expressing effector population in responsive EBV (+) tumours. However, LAG-3 retention may render the ISG-15+CD8+ T cells into a terminal exhaustion state in non-responsive EBV (+) tumours. In accordance, anti-LAG-3 therapy could effectively reduce tumour burden in refractory EBV (+) GC patients. Our results delineate a distinct implication of EBV-imprinted on-treatment T-cell immunity in GC, which could be leveraged to optimize the rational design of precision immunotherapy.

Efficacy and safety of preoperative immunotherapy alone followed by surgery in the treatment of advanced gastric cancer with MSI-H/dMMR or EBV-positive

BACKGROUND

At present, there is no consensus on whether preoperative immunotherapy (PIT) without chemotherapy followed by surgery could benefit patients with advanced gastric cancer (AGC). Here, we report a six-case series study to describe the safety and efficacy of PIT plus gastrectomy in patients with AGC.

METHODS

This study involved six patients with AGC who received PIT and surgery at our center between January 2019 and July 2021. Demographic characteristics, preoperative gastroscope biopsy pathology, surgical tissue pathology, radicalness of tumor resection, surgical safety, and recovery parameters were reported.

RESULTS

Six patients, including four patients with Epstein-Barr virus (EBV)-positive gastric cancer (GC) and two patients with microsatellite instability-high (MSI-H)/expression deficiency of mismatch repair (dMMR) protein GC, were enrolled in this study. Four patients experienced immunotherapy-related adverse events (irAEs), without severe adverse events (SAEs). Five patients underwent R0 resection, and one patient underwent palliative gastrectomy due to liver and hilar lymph node metastasis. Pathologic responses from the surgical tissue were observed in all patients, including two pathological complete response (pCR). No operative complications or postoperative deaths occurred. Three patients (50%) experienced mild or moderate postoperative complications without severe postoperative complications. All six patients eventually recovered and were discharged.

CONCLUSION

This study indicated that PIT was effective and tolerant in some patients with MSI-H/dMMR and/or EBV-positive AGC. PIT followed by gastrectomy might be an alternative treatment option for these selected patients.

Phase I study of MSB2311, a novel pH-dependent anti-PD-L1 monoclonal antibody, treating patients with advanced solid tumors and lymphoma

MSB2311 is a novel pH-dependent humanized anti-programmed death-ligand 1 (PD-L1) monoclonal antibody. This phase I study primarily aimed to determine the maximum tolerated dose (MTD)/recommended phase 2 dose level (RP2D) of MSB2311 in patients with advanced solid tumors or lymphoma. MSB2311 was intravenously administered at 3, 10, and 20 mg/kg every 3 weeks (Q3W) and 10 mg/kg every 2 weeks (Q2W) using 3 + 3 design. During expansion phase, eligible patients with either PD-L1 overexpression, Epstein-Barr Virus positive, microsatellite instability high/mismatch repair deficient, or high tumor mutation burden tumors were treated at RP2D. A total of 37 Chinese patients were treated, including 31 with solid tumors and 6 lymphoma. No dose limiting toxicity was reported and MTD was not reached. The trial was expanded at 20 mg/kg Q3W or 10 mg/kg Q2W, both of which were determined as RP2D. Most common drug-related treatment-emergent adverse events were anemia (43.2%), aspartate aminotransferase increase (27.0%), proteinuria (21.6%), alanine aminotransferase increase and hypothyroidism (18.9% each), thyroid stimulating hormone increased and hyperglycemia (16.2% each). Out of 20 efficacy evaluable patients with biomarker positive solid tumors, 6 achieved confirmed partial response with the median duration of response of 11.0 months (95% CI 7.0-11.4) and 4 had stable disease, resulting an objective response rate of 30.0% (95% CI 11.9, 54.3) and disease control rate of 50.0% (95% CI 27.2, 72.8). One partial response was also observed among 6 patients with lymphoma. MSB2311 demonstrated a manageable safety profile and promising antitumor activity in patients with advanced solid tumors and lymphomas.

Mutational Signatures in Gastric Cancer and Their Clinical Implications

Gastric cancer is characterised by high inter- and intratumour heterogeneity. The majority of patients are older than 65 years and the global burden of this disease is increasing due to the aging of the population. The disease is usually diagnosed at advanced stages, which is a consequence of nonspecific symptoms. Few improvements have been made at the level of noninvasive molecular diagnosis of sporadic gastric cancer, and therefore the mortality rate remains high. A new field of mutational signatures has emerged in the past decade with advances in the genome sequencing technology. These distinct mutational patterns in the genome, caused by exogenous and endogenous mutational processes, can be associated with tumour aetiology and disease progression, and could provide novel perception on the treatment possibilities. This review assesses the mutational signatures found in gastric cancer and summarises their potential for use in clinical setting as diagnostic or prognostic biomarkers. Associated treatment options and biomarkers already implemented in clinical use are discussed, together with those that are still being explored or are in clinical studies.

Clinical and pathologic characteristics of gastric adenocarcinoma associated with Epstein-Barr virus in a region with a high incidence of gastric cancer in Colombia

INTRODUCTION AND AIMS

Epstein-Barr virus (EBV) infection is an etiologic factor in EBV-associated gastric carcinoma (EBVaGC). The aim of our study was to describe the clinical and histopathologic characteristics of EBV infection in intestinal-type gastric adenocarcinoma samples.

MATERIAL AND METHODS

Of 180 paraffin-embedded gastrectomy samples, 28 were studied. Chromogenic in situ hybridization was performed to detect EBV. Sociodemographic and histopathologic data were obtained from the patients' clinical histories.

RESULTS

A total of 21.4% of the samples were positive for EBV. The predominant morphologic characteristic was the lace pattern, with dense inflammatory infiltration. Fifty percent of the EBVaGC+ patients were men, and the median age of the positive patients was 59 years (range: 50-75); 77.2% of the EBVaGC- patients were men, and the median age of the negative patients was 66 years (range: 34-89). Helicobacter pylori infection was associated with 10.7% of the EBVaGC+ patients and 53.6% of the EBVaGC- patients. In the EBVaGC+ patients, the cardia was the most frequent tumor location (17.9%), 7.1% had histologic grades 2 and 3, and 17.9% presented with Borrmann classification type III. In the EBVaGC- patients, the cardia and fundus were the most frequent tumor locations (71.4%), 35.7% had histologic grade 2, and 39.3% and 21.4% presented with Borrmann classification type III and IV, respectively.

CONCLUSIONS

The present study describes the clinical and histopathologic characteristics associated with EBVaGC positivity. Those data may aid in the selection of cases that are candidates for analysis through molecular methods aimed at identifying EBV infection in intestinal-type gastric adenocarcinoma.

A novel scoring model based on RNA modification "writers" can predict the prognosis and guide immunotherapy in gastric cancer

Although extensive research has been carried out on the epigenetic regulation of single RNA modifications in gastric cancer, little is known regarding the crosstalk of four major RNA adenosine modifications, namely, m6A, m1A, alternative polyadenylation and adenosine-to-inosine RNA editing. By analyzing 26 RNA modification "writers" in 1750 gastric cancer samples, we creatively constructed a scoring model called the "Writers" of the RNA Modification Score (WRM_Score), which was able to quantify the RNA modification subtypes of individual patients. In addition, we explored the relationship between WRM_Score and transcriptional and posttranscriptional regulation, tumor microenvironment, clinical features and molecular subtypes. We constructed an RNA modification scoring model including two different subgroups: WRM_Score_low and WRM_Score_high. The former was associated with survival benefit and good efficacy of immune checkpoint inhibitors (ICIs) due to gene repair and immune activation, while the latter was related to poor prognosis and bad efficacy of ICIs because of stromal activation and immunosuppression. The WRM score based on immune and molecular characteristics of the RNA modification pattern is a reliable predictor of the prognosis of gastric cancer and the therapeutic efficacy of immune checkpoint inhibitors in gastric cancer.

Tumor Immunophenotyping-Derived Signature Identifies Prognosis and Neoadjuvant Immunotherapeutic Responsiveness in Gastric Cancer

The effectiveness of neoadjuvant immune checkpoint inhibitor (ICI) therapy is confirmed in clinical trials; however, the patients suitable for receiving this therapy remain unspecified. Previous studies have demonstrated that the tumor microenvironment (TME) dominates immunotherapy; therefore, an effective TME classification strategy is required. In this study, five crucial immunophenotype-related molecules (WARS, UBE2L6, GZMB, BATF2, and LAG-3) in the TME are determined in five public gastric cancer (GC) datasets (n = 1426) and an in-house sequencing dataset (n = 79). Based on this, a GC immunophenotypic score (IPS) is constructed using the least absolute shrinkage and selection operator (LASSO) Cox, and randomSurvivalForest. IPS^Low is characterized as immune-activated, and IPS^High is immune-silenced. Data from seven centers (n = 1144) indicate that the IPS is a robust and independent biomarker for GC and superior to the AJCC stage. Furthermore, patients with an IPS^Low and a combined positive score of ≥5 are likely to benefit from neoadjuvant anti-PD-1 therapy. In summary, the IPS can be a useful quantitative tool for immunophenotyping to improve clinical outcomes and provide a practical reference for implementing neoadjuvant ICI therapy for patients with GC.

Current Progress on Predictive Biomarkers for Response to Immune Checkpoint Inhibitors in Gastric Cancer: How to Maximize the Immunotherapeutic Benefit?

Gastric cancer is the fifth most prevalent cancer and the fourth leading cause of cancer death globally. Delayed diagnosis and pronounced histological and molecular variations increase the complexity and challenge of treatment. Pharmacotherapy, which for a long time was systemic chemotherapy based on 5-fluorouracil, is the mainstay of management for advanced gastric cancer. Trastuzumab and programmed cell death 1 (PD-1) inhibitors have altered the therapeutic landscape, contributing to noticeably prolonged survivorship in patients with metastatic gastric cancer. However, research has revealed that immunotherapy is only beneficial to some individuals. Biomarkers, such as programmed cell death ligand 1 (PD-L1), microsatellite instability (MSI), and tumor mutational load (TMB), have been shown to correlate with immune efficacy in numerous studies and are increasingly employed for the selection of patients most likely to respond to immunotherapy. Gut microorganisms, genetic mutations like POLE/POLD1 and NOTCH4, tumor lymphoid infiltrating cells (TILs), and other novel biomarkers have the potential to develop into new predictors. Prospective immunotherapy for gastric cancer should be guided by a biomarker-driven precision management paradigm, and multidimensional or dynamic marker testing could be the way to go.

Combining of immunotherapeutic approaches with chemotherapy for treatment of gastric cancer: Achievements and limitations

Evidence reveals that gastric cancer (GC) is the fifth most common malignancy in humans, and about 770,000 people die from this cancer yearly. It has been reported that new cases and deaths from GC are more common in men than women. Therapeutic approaches, such as surgery, chemotherapy, and radiotherapy, have been common for treating GC. Nevertheless, due to the complications and limitations of these methods, researchers use novel approaches, such as immunotherapeutic or target therapies, to evaluate the effectiveness of treatment in patients with metastatic GC. Studies have shown that monotherapy is usually associated with unpromising outcomes, and combination therapy can be a more practical option for treating metastatic GC. Therefore, to clarify different aspects of chemotherapy and immunotherapy in patients with metastatic GC, this review discussed the achievements and challenges of combining immunotherapeutic methods with chemotherapeutic agents.

Recent advances in immunotherapy and molecular targeted therapy for gastric cancer

Our increasing understanding of the molecular biological characteristics of cancer and of cancer genomics is facilitating the development of immunotherapy and molecular targeted drugs for gastric cancer. After the approval of immune checkpoint inhibitors (ICIs) for melanoma in 2010, many different cancers have been shown to respond to such treatments. Thus, the anti-PD-1 antibody nivolumab was reported to prolong survival in 2017, and ICIs have become the mainstay of treatment development. Many clinical trials of combination therapies with cytotoxic agents and molecular-targeted agents, as well as combinations of immunotherapeutic agents acting via different mechanisms, are currently underway for each treatment line. As a result, further improvements in therapeutic outcomes for gastric cancer are anticipated in the near future.

Role of PD-1 Inhibitors in the Treatment of Esophagogastric Adenocarcinoma: Patient Selection and Reported Outcomes

Esophagogastric cancers are aggressive malignancies, with poor prognosis despite current standard-of-care therapies. PD-1 inhibitors are a newer class of antitumor agents with the potential to improve outcomes among appropriately selected patients. This review provides an overview of the key trials that have guided the use of PD-1 and PD-L1 inhibitors in the refractory and first-line settings. We highlight recent studies investigating the role of genomic classification in predicting therapeutic activity of PD-1 inhibitors. In addition, there is a discussion of the use of different scoring systems and criteria to determine PD-L1 positivity, the impact on the therapeutic use of immune checkpoint inhibition with anti-PD-1 agents, and the controversies in current methods of PD-L1 testing and their implications in patient selection for anti-PD-1 therapy.

Genomic Profiling Reveals Differences in Primary Central Nervous System Lymphoma and Large B-Cell Lymphoma, With Subtyping Suggesting Sensitivity to BTK Inhibition

BACKGROUND

B-cell primary central nervous system (CNS) lymphoma (PCL) is diffuse large B-cell lymphoma (DLBCL) confined to the CNS. Less than 50% of patients with PCL achieve complete remission with current therapies. We describe the findings from comprehensive genomic profiling (CGP) of a cohort of 69 patients with PCL, 36 cases of secondary CNS lymphoma (SCL), and 969 cases of DLBCL to highlight their differences and characterize the PCL cohort. In addition, we highlight the differences in frequency of germinal center B-cell like (GCB) and non-GCB subtypes and molecular subtypes, particularly MCD and EZH subtypes, between PCL and DLBCL.

MATERIALS AND METHODS

Sixty-nine cases of B-cell PCL, 36 cases of secondary CNS lymphoma (SCL), and 969 cases of DLBCL were evaluated by CGP of 405 genes via DNAseq and 265 genes via RNAseq for fusions (FoundationOne Heme). Tumor mutational burden (TMB) was calculated from 1.23 Mb of sequenced DNA.

RESULTS

Genomic alterations with significant differences between PCL and DLBCL included MYD88, ETV6, PIM1, PRDM1, CXCR4, TP53, and CREBBP, while only MYD88 was significantly different between SCL and DLBCL. PCL cases were significantly enriched for the MCD molecular subtypes, which have an excellent response to BTKi. We report a patient with a durable complete response to BTKi consistent with their genomic profile. EBV status, CD274 amplification, and TMB status suggest that 38% of PCL patients may benefit from ICPI; however further study is warranted.

CONCLUSION

CGP of PCLs reveals biomarkers, genomic alterations, and molecular classifications predictive of BTKi efficacy and potential ICPI efficacy. Given the limitations of standard of care for PCL, CGP is critical to identify potential therapeutic approaches for patients in this rare form of lymphoma.

Current understanding of the intratumoral microbiome in various tumors

It is estimated that in the future, the number of new cancer cases worldwide will exceed the 19.3 million recorded in 2020, and the number of deaths will exceed 10 million. Cancer remains the leading cause of human mortality and lagging socioeconomic development. Intratumoral microbes have been revealed to exist in many cancer types, including pancreatic, colorectal, liver, esophageal, breast, and lung cancers. Intratumoral microorganisms affect not only the host immune system, but also the effectiveness of tumor chemotherapy. This review concentrates on the characteristics and roles of intratumoral microbes in various tumors. In addition, the potential of therapies targeting intratumoral microbes, as well as the main challenges currently delaying these therapies, are explored. Furthermore, we briefly summarize existing technical methods used to characterize intratumoral microbes. We hope to provide ideas for exploring intratumoral microbes as potential biomarkers and targets for tumor diagnosis, treatment, and prognostication.

A novel RNA modification prognostic signature for predicting the characteristics of the tumor microenvironment in gastric cancer

Gastric cancer (GC) is one of the most common neoplastic malignancies, which permutes a fourth of cancer-related mortality globally. RNA modification plays a significant role in tumorigenesis, the underlying molecular mechanism of how different RNA modifications directly affect the tumor microenvironment (TME) in GC is unclear. Here, we profiled the genetic and transcriptional alterations of RNA modification genes (RMGs) in GC samples from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohorts. Through the unsupervised clustering algorithm, we identified three distinct RNA modification clusters and found that they participate in different biological pathways and starkly correlate with the clinicopathological characteristics, immune cell infiltration, and prognosis of GC patients. Subsequently, univariate Cox regression analysis unveiled 298 of 684 subtype-related differentially expressed genes (DEGs) are tightly interwoven to prognosis. In addition, we conducted the principal component analysis to develop the RM_Score system, which was used to quantify and predict the prognostic value of RNA modification in GC. Our analysis indicated that patients with high RM_Score were characterized by higher tumor mutational burden, mutation frequency, and microsatellite instability which were more susceptible to immunotherapy and had a favorable prognosis. Altogether, our study uncovered RNA modification signatures that may have a potential role in the TME and prediction of clinicopathological characteristics. Identification of these RNA modifications may provide a new understanding of immunotherapy strategies for gastric cancer.

Impact of mature tertiary lymphoid structures on prognosis and therapeutic response of Epstein-Barr virus-associated gastric cancer patients

Background

Epstein-Barr virus-associated gastric cancer (EBVaGC) exhibits unique histological characteristics within the immune-cell-rich microenvironment, but the role of tertiary lymphoid structure (TLS) in EBVaGC is not yet fully understood.

Methods

We retrospectively identified EBVaGC from 8517 consecutive GC cases from the two top cancer centers in China. Furthermore, we evaluated the prognostic value of TLS in 148 EBVaGC patients from our institute and then validated it in an external cohort (76 patients). TLS was quantified and its relationships with overall survival (OS) and therapeutic response were further analyzed. Multiplex immunofluorescence staining and targeted sequencing were used to characterize the composition of TLS and the genomic landscape, respectively.

Results

In our study, EBVaGC was observed in 4.3% (190/4436) and 2.6% (109/4081) of GCs in the training and validation cohorts, respectively. TLS was identified in the intratumor (94.6%) and peritumor (77.0%) tissues with lymphoid aggregates, primary and secondary (i.e., mature TLSs) follicles in EBVaGC. Kaplan-Meier analysis showed that mature TLS in intratumoral tissues was associated with a favorable OS in the training and validation cohorts (p < 0.0001; p = 0.0108). Multivariate analyses demonstrated that intratumoral TLS maturation, pTNM, and PD-L1 expression were independent prognostic factors for OS (p < 0.05). Furthermore, the mature TLS was significantly associated with a good response to treatment in EBVaGC patients. Interestingly, the mutation frequency of SMARCA4 was significantly lower in the mature TLS groups.

Conclusions

Intratumoral mature TLS was associated with a favorable prognosis and good therapeutic response, suggesting that it is a potential prognostic biomarker and predicts a good therapeutic response in EBVaGC patients.

Deep learning model to predict Epstein-Barr virus associated gastric cancer in histology

The detection of Epstein-Barr virus (EBV) in gastric cancer patients is crucial for clinical decision making, as it is related with specific treatment responses and prognoses. Despite its importance, the limited medical resources preclude universal EBV testing. Herein, we propose a deep learning-based EBV prediction method from H&E-stained whole-slide images (WSI). Our model was developed using 319 H&E stained WSI (26 EBV positive; TCGA dataset) from the Cancer Genome Atlas, and 108 WSI (8 EBV positive; ISH dataset) from an independent institution. Our deep learning model, EBVNet consists of two sequential components: a tumor classifier and an EBV classifier. We visualized the learned representation by the classifiers using UMAP. We externally validated the model using 60 additional WSI (7 being EBV positive; HGH dataset). We compared the model's performance with those of four pathologists. EBVNet achieved an AUPRC of 0.65, whereas the four pathologists yielded a mean AUPRC of 0.41. Moreover, EBVNet achieved an negative predictive value, sensitivity, specificity, precision, and F1-score of 0.98, 0.86, 0.92, 0.60, and 0.71, respectively. Our proposed model is expected to contribute to prescreen patients for confirmatory testing, potentially to save test-related cost and labor.

Recent progress and current challenges of immunotherapy in advanced/metastatic esophagogastric adenocarcinoma

The new era of immunotherapy is successfully implemented in the treatment of metastatic/locally advanced esophagogastric adenocarcinoma (EGAC), as it has been investigated in combinations with/without chemotherapy in human epidermal growth factor receptor 2 (Her2)-positive and Her2-negative tumors. Recent approvals of immune checkpoint inhibitors (ICI) enrich the therapeutic landscape in nearly every therapeutic line. Based on CHECKMATE-649, the combination of nivolumab and chemotherapy in first-line therapy of programmed cell death protein 1 (PD-L1)-positive patients with advanced gastroesophageal junction cancer (GEJC), esophageal cancer (EC), and gastric cancer (GC) was approved in Europe for PD-L1 combined positivity score (CPS) ≥ 5 patients and independently from PD-L1 score in the USA and Asia. Based on KEYNOTE-590, patients with advanced GEJC and EC qualify for the combination of pembrolizumab plus chemotherapy in Europe (CPS ≥ 10) and the USA. For Her2-positive patients, trastuzumab with first-line chemotherapy plus pembrolizumab has beneficial response rates and resulted in approval in the USA (KEYNOTE-811). In third-line therapy, superior overall survival (OS) was achieved by the administration of nivolumab (approval in Japan, ATTRACTION-02), and pembrolizumab shows a positive effect on the duration of response (KEYNOTE-059). Questions of resistance to immunotherapy or the role of gender in response to ICI need to be clarified. This review provides an overview of the current approvals of ICI in advanced EGAC and reflects results of relevant phase II/III trials with focus on possible biomarkers, including PD-L1 CPS and microsatellite-instability (MSI) status.

Therapeutic approaches to Epstein-Barr virus cancers

Epstein-Barr virus (EBV) establishes a lifelong latent infection that can be a causal agent for a diverse spectrum of cancers and autoimmune disease. A complex and dynamic viral lifecycle evades eradication by the host immune system and confounds antiviral therapeutic strategies. To date, there are no clinically approved vaccines or therapies that selectively target EBV as the underlying cause of EBV-associated disease. Here, we review the challenges and recent advances in the development of EBV-specific therapeutics for treatment of EBV-associated cancers.

Current Immune Checkpoint Inhibitor Genetic Biomarker Exploration in Gastrointestinal Tumors

Simple Summary

Immune checkpoint inhibitors (ICIs) are now incorporated into the management of GI tumors. The heterogenous nature of these tumors, however, reveals a lack of ICI consistency in effectiveness. Certain biomarkers have emerged as being potentially predictive for ICI effectiveness. Our review focuses on these biomarkers while discussing the current limitations with these markers.

Abstract

Immune checkpoint inhibitors have revolutionized cancer management. Some patients with gastrointestinal (GI) tract malignancy have experienced remarkable results. Here, in our review, we discuss predictive/prognostic GI tumor biomarkers that appear to correlate with benefits with this strategy. Remarkable progress has been made in certain subsets of patients including the potential for solid tumor patients to avoid local therapies such as radiation and/or surgery (organ preservation), which come with acute and chronic risks that have historically been the only curable strategies for these GI tumors. These results provide new and exciting strategies for solid tumor management. Unfortunately, immune checkpoint inhibitors can correlate with biomarkers, but benefits occur in a small subset of patients with GI malignancies. Most frequently, immune checkpoint inhibitors fail to induce response in GI malignancies due to the “cold” tumor microenvironment that protects cancer. Translational strategies are needed to develop effective combination strategies and novel biomarkers to overcome the intrinsic resistance.

Versican enrichment predicts poor prognosis and response to adjuvant therapy and immunotherapy in gastric cancer

Background

Increasing evidence has revealed an important role of versican (VCAN) on various aspects of cancer progression. Here, we assessed the impact of VCAN expression on prognosis and the response to adjuvant therapy and immunotherapy in patients with gastric cancer (GC).

Methods

Four independent cohorts containing 1353 patients with GC, were utilized to investigate the effect of VCAN expression on prognosis and response to adjuvant therapy in GC. Two cohorts treated with immune checkpoint blockades were included to assess the predict value of VCAN expression on response to immunotherapy. Moreover, the bulk RNA-seq and single-cell RNA-seq data were analyzed to illustrate the role of VCAN in tumor microenvironment. Clinical outcomes of patient subgroups were compared by Kaplan-Meier curves with the log-rank test.

Result

High VCAN expression was associated with poor prognosis for patients with GC. Compared with patients with high VCAN expression, patients with low VCAN expression benefited more from adjuvant chemotherapy and adjuvant chemoradiotherapy. Moreover, patients with high VCAN expression tended to be resistant to immunotherapy, and VCAN could serve as a promising indicator for predicting the response to immunotherapy. VCANhigh tumors showed a specific microenvironment with more cancer associated fibroblasts infiltration and significant enrichment of stromal relevant signaling pathways.

Conclusion

VCAN could predict the response to adjuvant chemotherapy, adjuvant chemoradiotherapy and immunotherapy in GC, and designing new medicine target to VCAN might be an effective way to improve the efficacy of several treatment options for GC.

Association of peripheral basophils with tumor M2 macrophage infiltration and outcomes of the anti-PD-1 inhibitor plus chemotherapy combination in advanced gastric cancer

BACKGROUND

Although the anti-programmed death-1 (PD-1) inhibitor plus chemotherapy combination has been approved as the standard first-line treatment for advanced gastric cancer, a proportion of patients do not significantly benefit from this therapy. Who would respond poorly to this treatment and the underlying mechanisms of treatment failure are far from clear.

METHODS

We retrospectively analyzed the associations between the peripheral basophils at baseline and clinical outcomes in 63 advanced gastric cancer patients treated with anti-PD-1 plus chemotherapy and 54 patients treated with chemotherapy alone. Immunohistochemistry and immunofluorescence staining in gastric cancer samples were utilized to investigate the basophil-related immunophenotype.

RESULTS

The optimal cutoff of basophil count to distinguish responders to anti-PD-1 plus chemotherapy from non-responders was 20.0/μL. Compared with the low basophil group (≤ 20.0/μL, n = 40), the high basophil group (> 20.0/μL, n = 23) had a significantly lower objective response rate (ORR 17.4% vs. 67.5%, p = 0.0001), worse progression-free survival (median PFS 4.0 vs. 15.0 months, p = 0.0003), and worse overall survival (median OS not reached, p = 0.027). Multivariate analyses identified a basophil count of > 20.0/μL as an independent risk factor for a worse ORR (OR 0.040, 95% CI 0.007-0.241, p = 0.0004), worse PFS (HR 3.720, 95% CI 1.823-7.594, p = 0.0003) and worse OS (HR 3.427, 95% CI 1.698-6.917, p = 0.001). In contrast, there was no significant association between peripheral basophil counts and tumor response or survival in the chemotherapy-alone group (p > 0.05). In primary gastric cancer samples, we observed a correlation between higher peripheral basophil counts and the accumulation of tumor-infiltrating basophils (r = 0.6833, p = 0.005). Tumor-infiltrating basophils were found to be spatially proximate to M2 macrophages within TME and positively correlated with tumor M2 macrophage infiltration (r = 0.7234, p = 0.0023). The peripheral basophil counts also had a significant positive correlation with tumor-infiltrating M2 macrophage counts (r = 0.6584, p = 0.003). Further validation in tumor samples treated with the neoadjuvant anti-PD-1 inhibitor plus chemotherapy combination suggests that the peripheral basophils, tumor infiltration of basophils, and M2 macrophages were significantly more abundant in non-responders than in responders (p = 0.0333, p = 0.0007, and p = 0.0066, respectively).

CONCLUSIONS

The peripheral basophil count was observed to be a potential biomarker of anti-PD-1 efficacy for advanced gastric cancer. Moreover, basophils may induce an immune-evasive tumor microenvironment by increasing M2 macrophage infiltration, which could be a potential immunotherapeutic target for advanced gastric cancer.

Tumor immune contexture is a determinant of anti-CD19 CAR T cell efficacy in large B cell lymphoma

Axicabtagene ciloleucel (axi-cel) is an anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved for relapsed/refractory large B cell lymphoma (LBCL) and has treatment with similar efficacy across conventional LBCL subtypes. Toward patient stratification, we assessed whether tumor immune contexture influenced clinical outcomes after axi-cel. We evaluated the tumor microenvironment (TME) of 135 pre-treatment and post-treatment tumor biopsies taken from 51 patients in the ZUMA-1 phase 2 trial. We uncovered dynamic patterns that occurred within 2 weeks after axi-cel. The biological associations among Immunoscore (quantification of tumor-infiltrating T cell density), Immunosign 21 (expression of pre-defined immune gene panel) and cell subsets were validated in three independent LBCL datasets. In the ZUMA-1 trial samples, clinical response and overall survival were associated with pre-treatment immune contexture as characterized by Immunoscore and Immunosign 21. Circulating CAR T cell levels were associated with post-treatment TME T cell exhaustion. TME enriched for chemokines (CCL5 and CCL22), γ-chain receptor cytokines (IL-15, IL-7 and IL-21) and interferon-regulated molecules were associated with T cell infiltration and markers of activity. Finally, high density of regulatory T cells in pre-treatment TME associated with reduced axi-cel–related neurologic toxicity. These findings advance the understanding of LBCL TME characteristics associated with clinical responses to anti-CD19 CAR T cell therapy and could foster biomarker development and treatment optimization for patients with LBCL.

Analysis of tumor biopsies from the pivotal phase 1/2 ZUMA-1 trial identifies pre-treatment T cell–related characteristics that are associated with clinical response and neurologic toxicity after anti-CD19 CAR T cell therapy in patients with large B cell lymphoma.

Efficacy and Safety of Camrelizumab in Combination with Docetaxel + S-1 Sequenced by Camrelizumab + S-1 for Stage III (PD-1+/MSI-H/EBV+/dMMR) Gastric Cancer: Study Protocol for a Single-Center, Prospective, Open-Label, Single-Arm Trial

Background

Gastric cancer occupies the fourth highest morbidity rate of cancers worldwide. A higher incidence of gastric cancer had been found in East Asia compared to the other regions. Gastrectomy with radical lymph node dissection is the cornerstone of curative treatment for Stage III gastric cancer, and postoperative systemic chemotherapy with docetaxel, S-1 improved patients’ disease-free survival rates. However, advances in immunotherapy bring innovations in the management of patients with gastric cancer. The objective of this study was to explore the efficacy and safety of camrelizumab in combination with docetaxel + S-1, sequenced by camrelizumab + S-1 in stage III gastric cancer patients who are EBV positive, with defective mismatch repair and CPS ≥5.

Methods and analysis

This prospective, open-label, single-arm trial was performed at Renji Hospital. In this study, a total of 70 adult patients aged 18–80 years with Stage III (PD-1+/MSI-H/EBV+/dMMR) gastric cancer confirmed by post-operative pathology will be enrolled after screening. Participants will receive the specific chemotherapy regimen until 1 year after the operation or until tumor recurrence or metastasis. The primary outcome is the 3-year disease-free survival rate measured by the Clopper-Pearson method and 95% confidence intervals. The secondary outcomes include overall survival, incidence and severity of adverse effects, and laboratory abnormalities. The data will be analyzed by the Kaplan-Meier method and log-rank test. The patients will be followed up every 3 months with imaging investigation until clinical remission.

Ethics and dissemination

All participants will provide informed consent. The protocol has been approved by the Shanghai Jiaotong University School of Medicine, Renji Hospital Ethics Committee (KY2019-191). The results will be disseminated through peer-reviewed manuscripts, reports and presentations.

Clinical Trial Registration

ClinicalTrials.gov, identifier: ChiCTR1900027123. Registration date November 2019; first enrolment December 2019; expected end date December 2021; trial status: Ongoing.

Brief Abstract

A clinical trial for Stage III (PD-1+/MSI-H/EBV+/dMMR) gastric cancer patients who accepted anti-PD-1 therapy combined with docetaxel + S-1 as the first-line treatment and explored improvements in three-year disease-free survival rate.

The immune microenvironment in gastric adenocarcinoma

Like most solid tumours, the microenvironment of epithelial-derived gastric adenocarcinoma (GAC) consists of a variety of stromal cell types, including fibroblasts, and neuronal, endothelial and immune cells. In this article, we review the role of the immune microenvironment in the progression of chronic inflammation to GAC, primarily the immune microenvironment driven by the gram-negative bacterial species Helicobacter pylori. The infection-driven nature of most GACs has renewed awareness of the immune microenvironment and its effect on tumour development and progression. About 75-90% of GACs are associated with prior H. pylori infection and 5-10% with Epstein-Barr virus infection. Although 50% of the world's population is infected with H. pylori, only 1-3% will progress to GAC, with progression the result of a combination of the H. pylori strain, host susceptibility and composition of the chronic inflammatory response. Other environmental risk factors include exposure to a high-salt diet and nitrates. Genetically, chromosome instability occurs in ~50% of GACs and 21% of GACs are microsatellite instability-high tumours. Here, we review the timeline and pathogenesis of the events triggered by H. pylori that can create an immunosuppressive microenvironment by modulating the host's innate and adaptive immune responses, and subsequently favour GAC development.

Prevalence of Epstein-Barr Virus Infection and Mismatch Repair Protein Deficiency and the Correlation of Immune Markers in Tibetan Patients with Gastric Cancer

Background

Gastric cancer (GC) is a major cause of cancer-related death in China. Immunotherapies based on PD-1/PD-L1 inhibitors have improved the survival of some patients with GC. Epstein–Barr virus (EBV) infection, mismatch repair (MMR) deficiency, and tumor immune microenvironment (TIME) markers (such as CD3, CD8, and PD-L1) may help to identify specific patients who will respond to PD-1/PD-L1 inhibitors. Considering racial heterogeneity, the pattern of TIME markers in Tibetan patients with GC is still unclear. We aimed to identify the prevalence of EBV infection and the MMR status and their association with immune markers in Tibetan GC to aid in patient selection for immunotherapy.

Materials and Methods

From 2001 to 2015, we retrospectively collected 120 tissue samples from consecutive Tibetan GC patients and constructed tissue microarrays. EBV infection was assessed by Epstein–Barr-encoded RNA (EBER) in situ hybridization, and MMR protein levels were measured. Immune markers (including CD3 and CD8) in intraepithelial, stromal, and total areas were detected by immunohistochemistry (IHC). PD-L1 expression was assessed by the combined positive score (CPS). We also analyzed the relationships of EBV infection and MMR status with immune markers.

Results

Of the 120 samples, 11 (9.17%) were EBV positive (+), and 6 (5%) were MMR deficient (dMMR). PD-L1 CPS ≥1% was found in 32.5% (39/120) of Tibetan GC patients. EBV infection was associated with higher numbers of CD3+ T cells (P < 0.05) and CD8+ T cells (P < 0.05) and higher PD-L1 expression (P < 0.05). For the limited number of dMMR patients, no significant relationship was observed between dMMR and TIME markers (P > 0.05).

Conclusions

In Tibetan GC patients, the rates of EBV infection, dMMR, and positive PD-L1 expression were 9.17%, 5%, and 32.5%, respectively. EBV infection was associated with the numbers of CD3+ T cells and CD8+ T cells and PD-L1 expression within the tumor. These markers may guide the selection of Tibetan GC patients for immunotherapy.

Metastasis Related Epithelial-Mesenchymal Transition Signature Predicts Prognosis and Response to Immunotherapy in Gastric Cancer

Background

Increasing evidence has revealed the effect of epithelial-mesenchymal transition (EMT) on tumor microenvironment and cancer treatment. However, an EMT-based signature to predict the prognosis and therapeutic effect in gastric cancer (GC) has rarely been established.

Methods

Differentially expressed genes (DEGs) between paired primary gastric and ovarian metastatic tumors were identified through comparative RNA-seq analysis, followed by the construction of metastasis-related EMT signature (MEMTS) based on DEGs and EMT gene set. Then, both The Cancer Genome Atlas (TCGA) cohort and the Asian Cancer Research Group (ACRG) cohort were analyzed to explore the potential association between MEMTS and prognosis in GC. Samsung Medical Center (SMC) cohort and two individual immunotherapy treatment cohorts, including Kim cohort and Hugo cohort, were utilized to evaluate the predictive value of MEMTS on the response to adjuvant therapy and immunotherapy, respectively. Finally, the potential association of MEMTS with tumor environment and immune escape mechanisms was investigated.

Results

High MEMTS predicted a poor prognosis in patients with GC. Patients with low MEMTS potentially gained more benefits from adjuvant chemoradiotherapy than those with high MEMTS. MEMTS reliably predicted the response to immunotherapy in GC (area under the curve = 0.896). MEMTS was significantly associated with cancer-associated fibroblasts and stromal score in the aspect of the tumor microenvironment.

Conclusion

MEMTS serves as a potential biomarker to predict the prognosis and response to adjuvant therapy and immunotherapy in GC. MEMTS-based evaluation of individual tumors enables personalized treatment for GC patients in the future.

A deep learning model and human-machine fusion for prediction of EBV-associated gastric cancer from histopathology

Epstein–Barr virus-associated gastric cancer (EBVaGC) shows a robust response to immune checkpoint inhibitors. Therefore, a cost-efficient and accessible tool is needed for discriminating EBV status in patients with gastric cancer. Here we introduce a deep convolutional neural network called EBVNet and its fusion with pathologists for predicting EBVaGC from histopathology. The EBVNet yields an averaged area under the receiver operating curve (AUROC) of 0.969 from the internal cross validation, an AUROC of 0.941 on an external dataset from multiple institutes and an AUROC of 0.895 on The Cancer Genome Atlas dataset. The human-machine fusion significantly improves the diagnostic performance of both the EBVNet and the pathologist. This finding suggests that our EBVNet could provide an innovative approach for the identification of EBVaGC and may help effectively select patients with gastric cancer for immunotherapy.

Epstein–Barr virus-associated gastric cancer shows a robust response to immune checkpoint inhibitors. Here the authors introduce a deep convolutional neural network and its fusion with pathologists for predicting it from histopathology.

TGFβ-Associated Signature Predicts Prognosis and Tumor Microenvironment Infiltration Characterization in Gastric Carcinoma

Background: Gastric carcinoma (GC) is a carcinoma with a high incidence rate, and it is a deadly carcinoma globally. An effective tool, that is, able to predict different survival outcomes for GC patients receiving individualized treatments is deeply needed.

Methods: In total, data from 975 GC patients were collected from TCGA-STAD, GSE15459, and GSE84437. Then, we performed a comprehensive unsupervised clustering analysis based on 54 TGFβ-pathway-related genes and correlated these patterns with tumor microenvironment (TME) cell-infiltrating characteristics. WGCNA was then applied to find the module that had the closest relation with these patterns. The least absolute shrinkage and selection operator (LASSO) algorithm was combined with cross validation to narrow down variables and random survival forest (RSF) was used to create a risk score.

Results: We identified two different TGFβ regulation patterns and named them as TGFβ Cluster 1 and Cluster 2. TGFβ Cluster 1 was linked to significantly poorer survival outcomes and represented an inflamed TME subtype of GC. Using WGCNA, a module (magenta) with the closest association with the TGFβ clusters was identified. After narrowing down the gene list by univariate Cox regression analysis, the LASSO algorithm and cross validation, four of the 243 genes in the magenta module were applied to build a risk score. The group with a higher risk score exhibited a considerably poorer survival outcome with high predictive accuracy. The risk score remained an independent risk factor in multivariate Cox analysis. Moreover, we validated this risk score using GSE15459 and GSE84437. Furthermore, we found that the group with a higher risk score represented an inflamed TME according to the evidence that the risk score was remarkably correlated with several steps of cancer immunity cycles and a majority of the infiltrating immune cells. Consistently, the risk score was significantly related to immune checkpoint genes and T cell–inflamed gene expression profiles (GEPs), indicating the value of predicting immunotherapy.

Conclusions: We have developed and validated a TGFβ-associated signature, that is, capable of predicting the survival outcome as well as depicting the TME immune characteristics of GC. In summary, this signature may contribute to precision medicine for GC.

Tumor Microenvironment Evaluation for Gastrointestinal Cancer in the Era of Immunotherapy and Machine Learning

A dynamic and mutualistic interplay between tumor cells and the surrounding tumor microenvironment (TME) triggered the initiation, progression, metastasis, and therapy response of solid tumors. Recent clinical breakthroughs in immunotherapy for gastrointestinal cancer conferred considerable attention to the estimation of TME, and the maturity of next-generation sequencing (NGS)-based technology contributed to the availability of increasing datasets and computational toolbox for deciphering TME compartments. In the current review, we demonstrated the components of TME, multiple methodologies involved in TME detection, and prognostic and predictive TME signatures derived from corresponding methods for gastrointestinal cancer. The TME evaluation comprises traditional, radiomics, and NGS-based high-throughput methodologies, and the computational algorithms are comprehensively discussed. Moreover, we systemically elucidated the existing TME-relevant signatures in the prognostic, chemotherapeutic, and immunotherapeutic settings. Collectively, we highlighted the clinical and technological advances in TME estimation for clinical translation and anticipated that TME-associated biomarkers may be promising in optimizing the future precision treatment for gastrointestinal cancer.

Research Progress of Biomarkers for Immune Checkpoint Inhibitors on Digestive System Cancers

Immunotherapy represented by immune checkpoint inhibitors has gradually entered a new era of precision medicine. In view of the limited clinical benefits of immunotherapy in patients with digestive system cancers, as well as the side-effects and high treatment costs, development of biomarkers to predict the efficacy of immune therapy is a key imperative. In this article, we review the available evidence of the value of microsatellite mismatch repair, tumor mutation burden, specific mutated genes or pathways, PD-L1 expression, immune-related adverse reactions, blood biomarkers, and patient-related biomarkers in predicting the efficacy of immunotherapy against digestive system cancers. Establishment of dynamic personalized prediction models based on multiple biomarkers is a promising area for future research.

Inflammation-Related Genes Serve as Prognostic Biomarkers and Involve in Immunosuppressive Microenvironment to Promote Gastric Cancer Progression

Gastric cancer (GC) is a typical inflammatory-related malignant tumor which is closely related to helicobacter pylori infection. Tumor inflammatory microenvironment plays a crucial role in tumor progression and affect the clinical benefit from immunotherapy. In recent years, immunotherapy for gastric cancer has achieved promising outcomes, but not all patients can benefit from immunotherapy due to tumor heterogeneity. In our study, we identified 29 differentially expressed and prognostic inflammation-related genes in GC and normal samples. Based on those genes, we constructed a prognostic model using a least absolute shrinkage and selection operator (LASSO) algorithm, which categorized patients with GC into two groups. The high-risk group have the characteristics of "cold tumor" and have a poorer prognosis. In contrast, low-risk group was "hot tumor" and had better prognosis. Targeting inflammatory-related genes and remodeling tumor microenvironment to turn "cold tumor" into "hot tumor" may be a promising solution to improve the efficacy of immunotherapy for patients with GC.

PD-L1 expression in EBV associated gastric cancer: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to the summarize the evidence on programmed cell death protein ligand 1 (PD-L1) in Epstein-Barr virus associated gastric cancer (EBVaGC) and to estimate the expression rate of PD-L1 among this subtype of Gastric Cancer (GC).

MATERIALS AND METHODS

For this study, PubMed^®, EMBASE^® and Web of Science^® databases were searched for articles published until 1st November 2021. A total of 43 eligible publications with a total of 11,327 patients were included analysis based on inclusion and exclusion criteria. A total of 41 publications present data for proportion estimation and 33 for comparison of PD-L1 between EBV positive and negative GC. DerSimonian-Laird random-effects model was used for meta-analysis.

RESULTS

The analysis showed that in EBVaGC the pooled positivity rate for PD-L1 was 54.6% (p < 0.001), with a high heterogeneity between the included studies, which was associated with variation on positivity criteria for PD-L1 expression. Overall, the study reveals an increased association between PD-L1 and EBVaGC (OR = 6.36, 95% CI 3.91-10.3, p < 0.001). Furthermore, the study revealed that GC with lymphoid stroma (GCLS) is highly associated with EBV (OR = 17.4, 95% CI 6.83-44.1, p < 0.001), with a pooled EBV positivity rate of 52.9% (p < 0.001).

CONCLUSIONS

Patients with EBVaGC tend to show higher PD-L1 expression, which enhances EBV positivity as a promising marker for patient selection for immunotherapy targeted agents. A uniform criteria for PD-L1 positivity in tumor cells is needed, as well as further prospective studies to validate our findings and their prognostic significance.

Fibroblast Activation Protein-Alpha is a Prognostic Biomarker Associated With Ferroptosis in Stomach Adenocarcinoma

Background: The potential role of fibroblast activation protein-alpha (FAP) in modulating the progression and invasion of stomach adenocarcinoma (STAD) has not yet been comprehensively investigated. This study aimed to explore the role of FAP in STAD and the underlying association between FAP and the tumor microenvironment (TME) and ferroptosis.

Methods: Overall survival was analyzed to evaluate the prognostic value of FAP based on gene expression data and clinical information on STAD. Associations between FAP expression, clinical parameters, and immune characteristics were comprehensively analyzed. The ferroptosis-related patterns of STAD samples were investigated based on 43 ferroptosis-related genes, and the correlations between these clusters and clinical characteristics were evaluated. The possible biological functions and pathways were explored using gene set enrichment analysis (GSEA).

Results: FAP was identified as a novel biomarker that significantly contributed to the poor prognosis of STAD (hazard ratio = 1.270, P = 0.013). The elevated level of FAP expression was related to a more advanced tumor stage in STAD. The close relationship between FAP and the TME was validated. Four distinct ferroptosis-related clusters (A–D) were evident. Evaluating ferroptosis-related clusters could illustrate the stages of STAD and patient prognosis. Cluster C displayed the lowest FAP expression and a better prognosis than the other clusters. The different clusters were linked to different biological mechanisms, including epithelial-mesenchymal transition and immune-relevant pathways.

Conclusion: FAP is a promising biomarker to distinguish prognosis and is associated with the TME and ferroptosis in STAD.

Efficacy and predictive biomarkers of immunotherapy in Epstein-Barr virus-associated gastric cancer

Background

Epstein-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 checkpoint blockade (ICB) efficacy in GC remain to be clarified. Additionally, EBV-encoded RNA (EBER) in situ hybridization (ISH), the traditional method to detect EBV, could cause false-positive/false-negative results and not allow for characterizing other molecular biomarkers recommended by standard treatment guidelines for GC. Herein, we sought to investigate the efficacy and potential biomarkers of ICB in EBVaGC identified by next-generation sequencing (NGS).

Design

An NGS-based algorithm for detecting EBV was established and validated using two independent GC cohorts (124 in the training cohort and 76 in the validation cohort). The value of EBV infection for predicting ICB efficacy was evaluated among 95 patients with advanced or metastatic GC receiving ICB. The molecular predictive biomarkers for ICB efficacy were identified to improve the prediction accuracy of ICB efficacy in 22 patients with EBVaGC.

Results

Compared with orthogonal assay (EBER-ISH) results, the NGS-based algorithm achieved high performance with a sensitivity of 95.7% (22/23) and a specificity of 100% (53/53). EBV status was identified as an independent predictive factor for overall survival and progression-free survival in patients with DNA mismatch repair proficient (pMMR) GC following ICB. Moreover, the patients with EBV+/pMMR and EBV−/MMR deficient (dMMR) had comparable and favorable survival following ICB. Twenty-two patients with EBV+/pMMR achieved an objective response rate of 54.5% (12/22) on immunotherapy. Patients with EBVaGC with a high cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) level were less responsive to anti-programmed death-1/ligand 1 (PD-1/L1) monotherapy, and the combination of anti-CTLA-4 plus anti-PD-1/L1 checkpoint blockade benefited patients with EBVaGC more than anti-PD-1/L1 monotherapy with a trend close to significance (p=0.074). There were nearly significant differences in tumor mutational burden (TMB) level and SMARCA4 mutation frequency between the ICB response and non-response group.

Conclusions

We developed an efficient NGS-based EBV detection strategy, and this strategy-identified EBV infection was as effective as dMMR in predicting ICB efficacy in GC. Additionally, we identified CTLA-4, TMB, and SMARCA4 mutation as potential predictive biomarkers of ICB efficacy in EBVaGC, which might better inform ICB treatment for EBVaGC.

A Gene Panel for Early Identification of Future Responders to Immune Checkpoint Blockade

Immune checkpoint blockade (ICB), therapies that target the PD-1 pathway, CTLA-4 pathway, and other checkpoint pathways, lead to durable responses in many cancer types. Since only a minority of patients respond to ICB, it may be useful to identify the future responders early in the course of treatment. In this study we evaluated a small (15 genes) biologically motivated panel, consisting of genes involved in immune activation and checkpoint pathways, for early identification of future responders to ICB. The panel passed consistency check, pathological and in-silico validations, and was an excellent predictor (area under ROC curve >0.95) of eventual response to ICB, both CTLA-4 and PD-1 blockade, when applied to metastatic melanoma patients undergoing ICB (i.e., “on-treatment”) in a publicly available dataset. These results suggest that this small biologically motivated panel may be useful for early identification of future responders to ICB.

Immunotherapy in Gastric Cancer

Immune checkpoint inhibition is a new standard of targeted therapy in the treatment of advanced or metastatic gastric cancer (GC) and is represented in various combinations with and without chemotherapy in every therapy line within clinical trials. In advanced adenocarcinoma of GC, gastroesophageal junction cancer (GEJC) and esophageal cancer (EC), the combination of nivolumab and chemotherapy in first-line therapy improves overall survival (OS) in PD-L1 (programmed cell death protein 1)-positive patients with approval in Europe (PD-L1 CPS (combined positivity score) ≥ 5), USA and Taiwan (CHECKMATE-649) and pembrolizumab plus chemotherapy for GEJC and EC in Europe (CPS ≥ 10) and the USA (KEYNOTE-590). Furthermore, pembrolizumab plus trastuzumab and chemotherapy show clear benefits in OS and are approved as first-line treatment of Her2 (human epidermal growth factor receptor-2)-positive tumors in the USA (KEYNOTE-811). Nivolumab demonstrates superior OS regardless of PD-L1 expression in third-line therapy with approval in Japan (ATTRACTION-02) and pembrolizumab prolonged the duration of response in PD-L1 positive patients with approval in the USA in PD-L1 CPS ≥ 1 patients (KEYNOTE-059). This review reflects the rationale and current results of phase II and III clinical trials investigating various immune checkpoint inhibitors targeting PD-L1/1 and CTLA (anticytotoxic T-lymphocyte-associated antigen)-4 in combination with and without chemotherapy and Her2-targeted therapy in GC.

Recent insights into the use of immune checkpoint inhibitors in gastric cancer

Gastric cancer (GC) is the fifth most incident and the fourth deadliest cancer worldwide. GC is a heterogeneous disease from the histological and molecular standpoints. This malignancy is mostly diagnosed at advanced stages of the disease, where the available therapeutic interventions are not effective. The emergence of immunotherapy has transformed the landscape of cancer treatment, including GC, and currently immune checkpoint inhibitors have been approved for the treatment of patients with recurrent/metastatic GC. This review summarizes the main clinical trials evaluating the use of immune checkpoint inhibitors in GC. It also highlights the potential of biomarkers for patient selection for GC immune checkpoint inhibition therapy, including programmed cell death ligand 1 expression and tumor mutational burden, and characteristics of the GC molecular classification, such as microsatellite instability status and Epstein-Barr virus infection, as predictors of response to blockade of the programmed cell death 1/programmed cell death ligand 1 axis.

The Effect of Inflammatory Markers on the Survival of Advanced Gastric Cancer Patients Who Underwent Anti-Programmed Death 1 Therapy

Purpose

This clinical study sought to determine whether the levels of inflammatory markers predicted the survival of advanced gastric cancer (AGC) patients who underwent anti-programmed death 1 (PD-1) therapy.

Methods

Using AGC patient plasma samples and baseline characteristics, we investigated the specific value of inflammatory markers in AGC from a clinical perspective in immunotherapy.

Results

One hundred and six patients with AGC who underwent anti-PD-1 therapy were enrolled in this study between 20 July 2019 and 16 March 2021. A significant decrease in NLR, dNLR, and SII was noticed among the PR (P=0.023; P=0.036; P=0.001), SD (P=0.048; P=0.022; P=0.023), ORR (P=0.021; P=0.032; P=0.001), and DCR (P=0.003; P=0.001; P<0.001) groups after anti-PD-1 therapy. Additionally, a significant decline of PLR was also observed in PR (P=0.010), ORR (P=0.007), and DCR (P=0.005) after anti-PD-1 therapy. Only MLR levels increased significantly at the time of anti-PD-1 immunotherapy the failure compared to baseline (P=0.039). And statistically significant elevations in NLR (P=0.001), MLR (P=0.020), dNLR (P=0.002), and SII (P=0.019) were found in failure of anti-PD-1 treatment compared to optimal efficacy in AGC patients. In first-line treatment, the number of metastatic sites (P=0.001) was an independent prognostic factor for PFS, and peritoneal metastases (P=0.004) and platelet-to-lymphocyte ratio (PLR) level (P=0.014) were independent prognostic predictors of OS according to Cox regression analysis. In second-line or posterior treatment, the number of metastatic sites (P=0.007), ECOG (P=0.011), and PLR level (P=0.033) were independent prognostic factors for PFS in AGC patients, and the number of metastatic sites (P=0.003), differentiation (P=0.030), and NLR level (P<0.001) were independent prognostic factors for OS according to Cox regression analysis.

Conclusions

NLR, PLR, MLR, dNLR, and SII can reflect the short-term efficacy of immunotherapy in patients who underwent anti-PD-1 therapy with AGC. PLR is an independent prognostic factor for OS in AGC patients receiving first-line immunotherapy and PFS in those receiving second-line or posterior immunotherapy. And NLR was an independent prognostic factor for OS in AGC patients receiving second-line or posterior immunotherapy. The number of metastatic sites was significantly associated with the prognosis of AGC patients who received immunotherapy.