Recent Progress in Immunotherapy for Gastric Cancer

Comparison of immune checkpoint inhibitors in combination with chemotherapy versus chemotherapy alone in the first-line treatment of advanced gastric cancer patients with low PD-L1 expression: a systematic review and meta-analysis

Background

Immune checkpoint inhibitors (ICIs) + chemotherapy became standard her2-GC first line treatment.

Objectives

The aim of this study is to investigate whether ICIs + chemo provides benefit for patients with low programmed death-ligand 1 (PD-L1) expression.

Design

This study is a systematic review and meta-analysis.

Data sources

We searched PubMed, Embase, Web of Science, and Cochrane Library as well as the 2019 to 2024 Annual Meetings of the European Society for Medical Oncology, the American Association for Cancer Research, the American Society of Clinical Oncology (ASCO), and the ASCO Symposium on Gastrointestinal Oncology (ASCO-GI) and the ClinicalTrials.gov database.

Methods

This systematic review included phase III randomized controlled trials comparing first-line immunotherapy combined with chemotherapy versus chemotherapy alone in advanced gastric cancer. KMSubtraction was used to estimate survival data for those trials that did not report data for the PD-L1 low-expression population.

Results

We included a total of nine randomized clinical trials. In patients with combined positive score (CPS) < 1 and CPS < 5, monoclonal antibody + chemotherapy did not show an improvement in overall survival (OS) or progression-free survival (PFS) (CPS < 1 OS: hazard ratio (HR) = 0.91, 95% CI: 0.77-1.08; PFS: HR = 0.88, 95% CI: 0.73-1.07. CPS < 5 OS: HR = 0.92, 95% CI: 0.79-1.08; PFS: HR = 0.78, 95% CI: 0.53-1.14). However, in trials using dual antibodies, patients with PD-L1 CPS < 5 achieved improvements in PFS (HR = 0.64, 95% CI: 0.52-0.80). In trials using tumor area positivity (TAP) scoring, the subgroup with TAP < 5% did not achieve benefits in OS or PFS from immunotherapy plus chemotherapy (OS: HR = 0.92, 95% CI: 0.75-1.13; PFS: HR = 0.91, 95% CI: 0.74-1.13).

Conclusion

Our study results indicate that in the first-line treatment of advanced gastric cancer, monoclonal antibody combined with chemotherapy does not provide a survival benefit compared to chemotherapy alone for patients with low PD-L1 expression. However, it is noteworthy that in the COMPASSION-15 trial, patients with CPS < 5 achieve significant improvements in OS and PFS, which may be related to the bispecific antibodies and needs to be validated by further studies.

Trial registration

This study was registered in PROSPERO (CRD42024568972).

Efficacy and safety of camrelizumab in combination with S-1 plus oxaliplatin sequenced by camrelizumab-based maintenance therapy as a first-line treatment for advanced gastric or gastroesophageal junction adenocarcinoma: a retrospective cohort study

Background

S-1 plus oxaliplatin (SOX) is a first-line standard-of-care treatment for patients with advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma. Programmed cell death protein 1 (PD-1) inhibitors plus chemotherapy, including SOX have also shown promising outcomes in such patients. This study was performed to evaluate the efficacy and safety of camrelizumab plus SOX sequenced by camrelizumab-based maintenance therapy as a first-line treatment for advanced G/GEJ adenocarcinoma.

Methods

In total, 31 patients with an age of 18 years or older and newly diagnosed with human epidermal growth factor receptor 2 (HER2)-negative advanced G/GEJ adenocarcinoma who underwent camrelizumab in combination with SOX followed by camrelizumab plus S-1 from February 2020 to December 2023 were enrolled in the study. All patients were regularly followed up every 1-2 months. The primary endpoint of the study was progression-free survival (PFS). And the safety profiles were also assessed.

Results

As of December 31, 2023, 25 male and 6 female patients were enrolled. The median follow-up time was 14.6 months. The median PFS time of the patients treated with the combination regimen was 7.3 months [95% confidence interval (CI): 3.0-11.6]. In addition, the median overall survival (OS) time was 13.3 months (95% CI: 10.3-16.4), and the median duration of response (DoR) was 5.0 months (95% CI: 2.0-8.1). Moreover, the objective response rate (ORR) and disease control rate (DCR) were 71.0% and 87.1%, respectively. Further, the most commonly observed grade ≥3 adverse events (AEs) were increased gamma-glutamyltransferase (GGT) (9.7%) and a decreased neutrophil count (6.5%). No treatment-related deaths occurred.

Conclusions

First-line treatment with camrelizumab in combination with SOX sequenced by camrelizumab-based maintenance therapy demonstrated favorable outcomes for and was well tolerated by patients with advanced G/GEJ adenocarcinoma. Thus, it might serve as a first-line standard-of-care treatment for such patients. However, prospective randomized studies should be carried out to confirm the findings.

An antibody-dependent cellular phagocytosis-related gene signature predicts survival and response to immunotherapy in stomach adenocarcinoma

Antibody-dependent cellular phagocytosis (ADCP) is an immune biological process and plays a biological role in the clearance of tumor cells and the response to immune checkpoint inhibitors. However, the effects of ADCP on stomach adenocarcinoma (STAD) remain unclear. Clinical and genomic data were extracted from multiple datasets. The ADCP-related signature was established using Cox least absolute shrinkage and selection operator regression. Expression of the C5a receptor also known as complement component 5a receptor 1 in the tumor and adjacent-normal tissues was calculated using immunohistochemistry staining. Validation of the signature was conducted in the training and validation cohorts by Cox regression and log-rank tests. Furthermore, the immune infiltrates, the tumor immune dysfunction and exclusion score, and tumor mutation burden score were calculated using the corresponding algorithms, and Mann-Whitney U tests were used to evaluate the differences between groups. Seventy-three hub genes with predictive performance were identified to establish an ADCP-related signature. Accordingly, a 27-gene signature was established, C5a receptor also known as complement component 5a receptor 1, one of the signature genes, had higher expression in tumors than adjacent-normal samples, and its predictive performance was validated in the GSE84437 and The Cancer Genome Atlas cohorts. We found that the ADCP-related signature is an excellent prognostic predictor of STAD. Moreover, the molecular characteristics and some indices of response to immunotherapy differed between the high- and low-risk groups. We constructed a 27-gene signature that is associated with the prognosis and response to STAD-based immunotherapy and provide insights into the biological mechanisms underlying this predictive function.

Immune-mediated liver injury from checkpoint inhibitors: mechanisms, clinical characteristics and management

Immunotherapy has changed the treatment landscape for patients with cancer in the past decade. Immune checkpoint inhibitor (ICI)-based therapies have proven effective in a range of malignancies, including liver and gastrointestinal cancers, but they can cause diverse off-target organ toxicities. With the increasingly wider application of these drugs, immune-mediated liver injury from ICIs has become a commonly encountered challenge in clinical hepatology and gastroenterology. In this Review, we discuss the evidence from human and animal studies on the immunological mechanisms of immune-mediated liver injury from ICIs and summarize its clinical features and practical considerations for its management.

Downregulation of LncRNA CCAT1 Enhances Chemosensitivity in Cisplatin-Resistant Gastric Cancer Cells

Chemotherapy is an effective treatment for gastric cancer. However, many patients develop resistance to chemotherapeutic agents during clinical treatment. LncRNA CCAT1 has recently been shown to influence cellular resistance to specific chemotherapeutic drugs, but its role in gastric cancer remains underexplored. This study aims to investigate the role of LncRNA CCAT1 in cisplatin resistance in gastric cancer cells and its potential underlying mechanisms. Gastric cancer cell lines with acquired resistance were established. The expression of CCAT1 was assessed in both cisplatin-sensitive and cisplatin-resistant AGS cell lines. CCAT1 expression was knocked down in AGS/DDP cells, and the changes in IC50 values were measured using the Cell Counting Kit-8 (CCK-8) assay. Apoptosis in gastric cancer cells was evaluated by flow cytometry. Additionally, Western blotting was employed to measure the expression levels of PI3K/AKT/mTOR signaling pathway proteins and apoptosis-related proteins in both interference and control groups. RT-qPCR results indicated that CCAT1 expression was significantly elevated in cisplatin-resistant gastric cancer cells compared to non-resistant cells. Similarly, CCK-8 assay results demonstrated that knocking down CCAT1 in resistant cells increased their sensitivity to cisplatin treatment. Flow cytometry and Western blot results further confirmed that silencing CCAT1 promoted apoptosis in these cells. Additionally, the expression of PI3K/AKT/mTOR signaling pathway proteins was higher in resistant cells compared to their sensitive counterparts, and silencing CCAT1 in AGS/DDP cells resulted in reduced expression of these proteins. In conclusion, the above studies demonstrated that LncRNA CCAT1 induced cisplatin resistance in gastric cancer cells.

Gastric cancer liver metastases in China: a real-world, multicentre, prospective, observational cohort study protocol

INTRODUCTION

Gastric cancer liver metastases (GCLM) is a highly heterogeneous disease with a poor prognosis. The multidisciplinary diagnosis and treatment model is applied throughout the entire treatment process. In addition to the previous RECORD study, which was based on the C-GCLM classification system developed by our team, there is a lack of recent data on patient baseline characteristics, clinical treatment and efficacy evaluation. A large-scale prospective observational study is necessary to determine the current situation of GCLM treatment in China. The findings of this study may inform the development of relevant healthcare policies, clinical pathways and treatment guidelines.

METHODS AND ANALYSIS

This is a prospective, non-interventional, observational, multicentre, real-world study designed to monitor the general condition, treatment pattern and prognosis of patients with GCLM. Patients with GCLM were classified into three distinct categories: type I (resectable type), type II (potentially resectable type) and type III (unresectable type). The patients' general information, medical history, imaging results, laboratory tests, surgical and systemic therapy details will be recorded and subjected to analysis. The 2-year overall survival (OS) will be recorded as the primary endpoint. The different therapeutic modalities employed in the treatment of GCLM, including surgery, chemotherapy and immunotherapy, will be recorded as secondary endpoints. Additionally, the effects of these therapies on prognosis, including OS of type I, II and III; R0 resection and disease-free survival of type I; and successful conversion rate and R0 resection rate and event-free survival of type II will be documented.

ETHICS AND DISSEMINATION

This study involving human participants was reviewed and approved by the Ethics Committee of Chinese PLA General Hospital (no. S2023-724-02) and will be conducted in accordance with the guidelines of the Declaration of Helsinki. Study findings will be disseminated through international peer-reviewed journal articles as well as public, academic presentations at national and international conferences.

TRIAL REGISTRATION NUMBERS

NCT06493448; ChiCTR2400083955.

PD-L1 as a Biomarker in Gastric Cancer Immunotherapy

Combining chemotherapy with immune checkpoint inhibitors (ICIs) that target the programmed death-1 (PD-1) protein has been shown to be a clinically effective first-line treatment for human epidermal growth factor receptor 2 (HER2)-negative and -positive advanced or metastatic gastric cancer (GC). Currently, PD-1 inhibitors combined with chemotherapy are the standard treatment for patients with HER2-negative/positive locally advanced or metastatic GC. Programmed death-ligand 1 (PD-L1) expression, as assessed using immunohistochemistry (IHC), is a crucial biomarker for predicting response to anti-PD-1/PD-L1 agents in various solid tumors, including GC. In GC, the PD-L1 IHC test serves as a companion or complementary diagnostic test for immunotherapy, and an accurate interpretation of PD-L1 status is essential for selecting patients who may benefit from immunotherapy. However, PD-L1 IHC testing presents several challenges that limit its reliability as a biomarker for immunotherapy. In this review, we provide an overview of the current practices of immunotherapy and PD-L1 testing in GC. In addition, we discuss the clinical challenges associated with PD-L1 testing and its future use as a biomarker for immunotherapy. Finally, we present prospective biomarkers currently under investigation as alternative predictors of immunotherapy response in GC.

Decorin as a key marker of desmoplastic cancer-associated fibroblasts mediating first-line immune checkpoint blockade resistance in metastatic gastric cancer

BACKGROUND

Gastric cancer (GC) remains a significant cause of cancer-related mortality worldwide. Despite the transformative impact of immune checkpoint blockade (ICB) therapies across various cancers, only a minority of patients with metastatic GC (mGC) benefit, emphasizing the urgent need for precise biomarkers to predict therapeutic responses and optimize patient selection.

METHODS

In this multi-omics study, we conducted whole exome and transcriptome sequencing on 12 tumors from mGC patients treated with nivolumab as first-line therapy. To validate our findings, we performed whole transcriptome sequencing on 17 additional tumors and analyzed 45 tumors from public dataset (PRJEB25780) of patients who received ICB therapy as second or third-line treatment. Comprehensive multi-omics analyses were conducted using single-cell RNA sequencing (n = 5, GSE167297) and spatial transcriptome sequencing (n = 2, independent internal dataset).

RESULTS

ICB-sensitive tumors exhibited robust activation of the interferon response pathway, while ICB-resistant tumors displayed epithelial-mesenchymal transition signatures. Intriguingly, at the single-cell level, genes associated with ICB sensitivity were predominantly expressed in immune cells, whereas genes associated with resistance were primarily found in cancer-associated fibroblasts (CAFs), particularly the desmoplastic CAF (dCAF) subtype. We identified DCN as a hallmark dCAF marker, and high DCN expression was inversely correlated with PD-L1 levels, ICB resistance, and poor prognosis in mGC (log-rank p = 0.027).

CONCLUSION

This study elucidates the critical influence of the tumor microenvironment, specifically dCAFs, in mediating ICB resistance in mGC. Our findings highlight DCN as a representative marker for dCAF and a promising negative predictive biomarker for ICB response. These findings highlight the complex stromal-immune interactions and open avenues for personalized treatment for mGC.

The impact of immune-related adverse events on the outcome of advanced gastric cancer patients with immune checkpoint inhibitor treatment

Background

The occurrence of immune-related adverse events (irAEs) seemed to be associated with better outcomes in advanced gastric cancer (AGC) patients. However, research focusing on the impact of the single-organ irAE (uni-irAE) or multi-organ irAEs (multi-irAEs) on the AGC outcome is relatively limited. In this study, we investigated individually the impact of the different irAEs on AGC survival as well as the co-occurrence patterns of multi-irAEs.

Methods

The uni-irAE, multi-irAEs, and non-irAE were identified based on National Comprehensive Cancer Network (NCCN) guidelines. ICI efficacy for the disease control rate (DCR) and the objective response rate (ORR) was assessed based on the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1. The association for the irAEs with progression-free survival (PFS) or overall survival (OS) was analyzed using the Kaplan-Meier method and Cox regression model. We also performed pairwise correlation analysis to identify co-occurrence patterns of multi-organ irAEs.

Results

A total of 288 patients including 175 non-irAE, 73 uni-irAE, and 40 multi-irAE patients were evaluated for their association with AGC outcome. The irAEs patients displayed higher DCR (78.8% vs. 67.4%, p=0.037) when compared with those of non-irAE patients, and both uni-irAE patients (82.2% vs. 67.4%, p=0.019) and multi-irAE patients (72.5% vs. 67.4%, p=0.534) showed higher DCR than that of non-irAE patients. The multivariate analyses revealed that multi-irAEs was an independent risk factor for PFS (hazard ratio [HR] of 0.63, 95% confidence interval [CI] 0.41~0.96, p=0.031) and OS (HR 0.47, 95% CI 0.29~0.76, p=0.002), whereas the survival association for uni-irAE was not obtained. The analysis of the co-occurrence patterns for multi-irAEs revealed that the thyroid, adrenal gland, heart, skin, and lung irAEs exhibited a high risk of co-occurrence of multi-irAEs. The multivariate Cox regression analysis for organ-specific irAEs revealed that patients experiencing thyroid, adrenal gland, and skin irAEs had favorable survival outcomes compared with those without these irAEs.

Conclusion

Multi-irAEs and some organ-specific irAEs can be used as predictive indicators for ICI treatment efficacy in AGC patients. The thyroid, adrenal gland, heart, skin, and lung irAEs are often accompanied by multi-irAE occurrence.

The oncogenic role and prognostic value of PXDN in human stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is known for its high prevalence and poor prognosis, which underscores the need for novel therapeutic targets. Peroxidasin (PXDN), an enzyme with peroxidase activity, has been linked to cancer development in previous studies. However, its specific role in STAD is not well understood. In our study, we used public databases and clinical specimens to determine that PXDN expression is significantly elevated in STAD tissues and serves as an independent prognostic marker for patient outcomes. Our in vitro assays demonstrated that silencing PXDN significantly reduced STAD cell proliferation, invasion, and migration. Mechanistically, we found that PXDN promotes epithelial‒mesenchymal transition and angiogenesis in STAD cells and may be regulated by the PI3K/AKT pathway. Further analysis revealed that PXDN levels affect the sensitivity of STAD cells to various chemotherapeutic and small molecule drugs. Additionally, we observed a significant association between PXDN levels and the abundances of various immune cell types in patients with STAD. Our study highlighted a strong link between PXDN levels and the tumor immune microenvironment (TIM), suggesting that PXDN is a useful metric for evaluating the response to immune checkpoint inhibitors. Moreover, we found that PXDN is significantly associated with multiple immune checkpoints. In summary, our findings indicate that PXDN plays a critical role in STAD and that its level could serve as a potential prognostic biomarker. Thus, targeting PXDN may represent an effective treatment strategy for STAD.

Immunotherapy plus chemotherapy versus chemotherapy alone in the first-line treatment for advanced gastric cancer/gastroesophageal junction cancer: a real-world retrospective study

Background

Immunotherapy offers new hope for improved survival in patients with advanced gastric cancer. Although large randomized controlled trials (RCTs) have been conducted to explore the efficacy and safety of first-line immunotherapy plus chemotherapy versus chemotherapy alone for advanced gastric cancer, the results are not completely consistent. And the strict inclusion criteria of RCTs lead to limited extrapolation. Therefore, it is of great significance to continue to conduct real-world studies comparing the clinical efficacy and safety of immunotherapy combined with chemotherapy versus chemotherapy alone in advanced gastric cancer.

Methods

This retrospective study included patients with HER-2 negative, unresectable advanced or recurrent gastric/gastroesophageal junction cancer (GC/GEJC) who received first-line immune checkpoint inhibitors (ICIs) in combination with chemotherapy or chemotherapy alone between January 1, 2018 to May 31, 2023. Progression-free survival (PFS), overall survival (OS), overall response rate (ORR), disease control rate (DCR) and adverse events (AEs) were compared between two groups.

Results

A total of 210 patients were enrolled in the combination treatment group (n=100) and chemotherapy alone group (n=110). After 12 months of follow-up, median PFS (mPFS) was 270 days (95%CI 177.510-362.490) in the chemotherapy alone group and 357 days (95%CI 250.103-463.897) in the combination treatment group (P<0.05). The median OS (mOS) was 14.9 months (95%CI 9.831-17.769) in the chemotherapy alone group and 15 months (95%CI 12.386-17.614) in the combination treatment group (P>0.05). There was no statistically significant difference in ORR between two groups (P=0.050). The DCR was 14.5% in the chemotherapy alone group and 38% in the combination treatment group (P<0.05). Subgroup analyses showed that primary tumor location of GEJC, ECOG PS of 1, without liver metastasis, and chemotherapy plus ICIs were associated with PFS benefit. Cox multivariate analysis showed that only surgery or not was correlated with patients' prognosis (P<0.05). Most of AEs were grade 1-2 and manageable.

Conclusions

Compared with chemotherapy alone, first-line ICIs combined with chemotherapy in patients with advanced GC/GEJC could greatly prolong PFS, but OS was not significantly improved, and the AEs were manageable.

Large-scale analysis of CDH1 mutations defines a distinctive molecular subset with treatment implications in gastric cancer

Although histological and molecular classifications have been extensively studied for gastric cancer (GC), targeted therapies for GC remain limited. CDH1 mutations (MT) are characteristic of genomically stable GC and are associated with poor prognosis, but lack effective or targeted therapies. Here, we showed the overall mutation frequency of CDH1 was 9.7% (155 of 1596). CDH1-MT GC showed significantly lower rates of PD-L1 positivity (CPS score ≥1) than CDH1-wildtype (WT) GC (56.7% vs. 73.3%, p < 0.05). Compared to CDH1-WT GC, mutations of ARID1A, WRN, POT1, CDK12, and FANCC were significantly higher, while TP53 and APC were significantly lower in CDH1-MT GC (p < 0.05); The rates of KRAS and HER2 amplifications were significantly lower, while CRKL and IGF1R amplifications were significantly higher in CDH1-MT GC, compared to CDH1-WT GC (p < 0.05). Frequently altered genes in CDH1-MT GC were especially enriched in DNA damage repair and cell cycle checkpoint pathways. Inhibition of E-cadherin sensitized GC cell lines to PARP and Wee1 inhibitors by disrupting DNA damage repair pathway and cell cycle checkpoint. This is the largest study to investigate the distinct genomic landscape of CDH1-MT GC. Our data indicated GC patients with CDH1 mutations could potentially benefit from agents targeting PARP and Wee1.

Putative Dual Roles of Bone Morphogenetic Protein 8B (BMP8B) in Disease Progression of Gastric Cancer

Background/Aim

Increased expression of bone morphogenetic protein 8B (BMP8B) in bone marrow and primary tumors of patients with gastric cancer (GC) is associated with disease progression and poor prognosis. However, a reduced expression has also been seen in GCs due to histone acetylation. This study aimed to evaluate BMP8B transcript levels in a large GC cohort and its impact on cellular functions.

Materials and Methods

BMP8B transcripts were determined in 319 gastric tumors and compared with 182 adjacent normal tissues using real time PCR, with a further analysis conducted in the TCGA database. Kaplan-Meier plotter analysis was performed to evaluate the correlation between BMP8B and prognosis of the disease. BMP8B knockdown model was employed to determine the effect of BMP8B on the function of GC cells (HGC27).

Results

BMP8B mRNA levels were significantly up-regulated in the GC tissues compared with adjacent normal tissues in both TCGA database and our own database from Beijing Cancer Hospital, and high BMP8B expression was associated with poor prognosis. BMP8B is most likely to be involved in the differentiation of GC. Poorly differentiated GC samples presented a significantly reduced BMP8B expression in relation to well-differentiated and moderately differentiated GC. BMP8B knockdown inhibited proliferation of GC cells, while promoted invasion and migration of cancer cells.

Conclusion

BMP8B was reduced in GCs, whereas higher BMP8B expression was associated with poor prognosis. BMP8B knockdown inhibited proliferation of GC cells, and promoted invasion and migration. Our results suggest that BMP8B plays dual roles in GC.

Real-World Efficacy and Safety of First-Line Nivolumab Plus Chemotherapy in Patients with Advanced Gastric, Gastroesophageal Junction, and Esophageal Adenocarcinoma: A Nationwide Observational Turkish Oncology Group (TOG) Study

Based on the CheckMate 649 trial, nivolumab plus chemotherapy is the recommended first-line treatment for HER2-negative unresectable advanced or metastatic gastric, gastroesophageal junction (GEJ), or esophageal adenocarcinoma. This nationwide, multicenter, retrospective study evaluated the real-world effectiveness of this regimen in Turkish patients and identified subgroups that may experience superior outcomes. Conducted across 16 oncology centers in Turkey, this study retrospectively reviewed the clinical charts of adult patients diagnosed with HER2-negative unresectable advanced or metastatic gastric, GEJ, or esophageal adenocarcinoma from 2016 to 2023. This study included 111 patients (54 women, 57 men) with a median age of 58 years. The median progression-free survival (PFS) and overall survival (OS) were 11.7 months and 18.2 months, respectively, whereas the objective response rate (ORR) was 70.3%. Multivariable analyses revealed that previous curative surgery was a favorable independent prognostic factor for both PFS and OS. Conversely, an Eastern Cooperative Oncology Group performance status of 2 emerged as an adverse independent prognostic factor for OS. The safety profile of nivolumab plus chemotherapy was found to be manageable. Our findings support the use of nivolumab plus chemotherapy for the first-line treatment of Turkish patients with HER2-negative unresectable advanced or metastatic gastric, GEJ, or esophageal adenocarcinoma. Patient selection based on clinical characteristics is crucial for optimizing treatment outcomes.

Cost-effectiveness of tislelizumab plus chemotherapy vs chemotherapy as first-line treatment of PD-L1 positive advanced gastric or gastroesophageal junction adenocarcinoma from a Chinese perspective

BACKGROUND

This work was designed to assess the cost-effectiveness of front-line tislelizumab plus chemotherapy (TIS+Chemo) in advanced gastric cancer (GC) or gastroesophageal junction cancer (GEJC) with positive expression of programmed cell death ligand 1 (PD-L1) from the perspective of Chinese healthcare system.

RESEARCH DESIGN AND METHODS

A 10-year partitioned survival model was undertaken utilizing clinical data from RATIONALE 305. Costs and utilities were both discounted at an annual rate of 5%. The primary outcome was incremental cost-effectiveness ratios (ICERs) and calculated as the cost per quality-adjusted life years (QALYs). The willingness-to-pay (WTP) threshold was set as $18,625/QALY. Only direct medical costs were considered. Sensitivity analyses and subgroup analyses were performed to evaluate the robustness of the model.

RESULTS

In the base-case analysis, the incremental cost and effectiveness associated with TIS+Chemo vs Chemo was 7,361 and 0.38 QALYs, respectively, leading to an ICER of 19,371/QALY. At the WTP threshold of $18,625/QALY, the TIS+Chemo was not a cost-effective first-line treatment option. The model outcomes were robust.

CONCLUSIONS

TIS+Chemo did not provide a cost-effective approach for PD-L1 positive advanced GC/GEJC in China setting. However, TIS+Chemo might be cost-effective in provinces with higher WTP threshold.

CLINICAL TRIAL REGISTRATION

RATIONALE 305, www.clinicaltrials.gov, identifier is NCT03777657.

Interpretable machine learning for predicting the response duration to Sintilimab plus chemotherapy in patients with advanced gastric or gastroesophageal junction cancer

Background

Sintilimab plus chemotherapy has proven effective as a combination immunotherapy for patients with advanced gastric and gastroesophageal junction adenocarcinoma (GC/GEJC). A multi-center study conducted in China revealed a median progression-free survival (PFS) of 7.1 months. However, the prediction of response duration to this immunotherapy has not been thoroughly investigated. Additionally, the potential of baseline laboratory features in predicting PFS remains largely unexplored. Therefore, we developed an interpretable machine learning (ML) framework, iPFS-SC, aimed at predicting PFS using baseline (pre-treatment) laboratory features and providing interpretations of the predictions.

Materials and methods

A cohort of 146 patients with advanced GC/GEJC, along with their baseline laboratory features, was included in the iPFS-SC framework. Through a forward feature selection process, predictive baseline features were identified, and four ML algorithms were developed to categorize PFS duration based on a threshold of 7.1 months. Furthermore, we employed explainable artificial intelligence (XAI) methodologies to elucidate the relationship between features and model predictions.

Results

The findings demonstrated that LightGBM achieved an accuracy of 0.70 in predicting PFS for advanced GC/GEJC patients. Furthermore, an F1-score of 0.77 was attained for identifying patients with PFS durations shorter than 7.1 months. Through the feature selection process, we identified 11 predictive features. Additionally, our framework facilitated the discovery of relationships between laboratory features and PFS.

Conclusion

A ML-based framework was developed to predict Sintilimab plus chemotherapy response duration with high accuracy. The suggested predictive features are easily accessible through routine laboratory tests. Furthermore, XAI techniques offer comprehensive explanations, both at the global and individual level, regarding PFS predictions. This framework enables patients to better understand their treatment plans, while clinicians can customize therapeutic approaches based on the explanations provided by the model.

Immune Landscape of Epstein-Barr Virus-Associated Gastric Cancer: Analysis From a Western Academic Institution

INTRODUCTION

Epstein-Barr virus-associated gastric cancer (EBVaGC) may be a meaningful biomarker for potential benefit from immunotherapy. Further investigation is needed to characterize the immune landscape of EBVaGC. We assessed our institutional frequency of surgically treated EBVaGC and analyzed the immunologic biomarker profile and tumor-infiltrating lymphocyte (TIL) phenotypes of a series of EBVaGC compared to non-EBVaGC cases.

METHODS

Available tissue samples from all patients with biopsy-confirmed gastric adenocarcinoma who underwent resection with curative intent from 2012 to 2020 at our institution were collected. In situ hybridization was used to assess EBV status; multiplex immunohistochemistry was performed to assess mismatch repair status, Programmed Death-Ligand 1 (PD-L1) expression, and phenotypic characterization of TILs.

RESULTS

Sixty-eight samples were included in this study. EBVaGC was present in 3/68 (4%) patients. Among all patients, 27/68 (40%) had positive PD-L1 expression; two of three (67%) EBVaGC patients exhibited positive PD-L1 expression. Compared to non-EBVaGC, EBV-positive tumors showed 5-fold to 10-fold higher density of TILs in both tumor and stroma and substantially elevated CD8+ T cell to Tregulatory cell ratio. The memory subtypes of CD8+ and CD4+ T cells were upregulated in EBVaGC tumors and stromal tissue compared to non-EBVaGC.

CONCLUSIONS

The incidence of surgically resected EBVaGC at our center was 4%. EBVaGC tumors harbor elevated levels of TILs, including memory subtypes, within both tumor and tumor-related stroma. Robust TIL presence and upregulated PD-L1 positivity in EBVaGC may portend promising responses to immunotherapy agents. Further investigation into routine EBV testing and TIL phenotype of patients with gastric cancer to predict response to immunotherapy may be warranted.

Exploring the therapeutic efficacy of crocetin in oncology: an evidence-based review

With cancer being a leading cause of death globally, there is an urgent need to improve therapeutic strategies and identify effective chemotherapeutics. This study aims to highlight the potential of crocetin, a natural product derived from certain plants, as an anticancer agent. It was  conducted an extensive review of the existing literature to gather and analyze the most recent data on the chemical properties of crocetin and its observed effects in various in vitro and in vivo studies. The study  particularly focused on studies that examined crocetin's impact on cell cycle dynamics, apoptosis, caspases and antioxidant enzyme levels, tumor angiogenesis, inflammation, and overall tumor growth. Crocetin exhibited diverse anti-tumorigenic activities including inhibition of tumor cell proliferation, apoptosis induction, angiogenesis suppression, and potentiation of chemotherapy. Multiple cellular and molecular pathways such as the PI3K/Akt, MAPK and NF-κB were modulated by it. Crocetin demonstrates promising anti-cancer properties and offers potential as an adjunctive or alternative therapy in oncology. More large-scale, rigorously designed clinical trials are needed to establish therapeutic protocols and ascertain the comprehensive benefits and safety profile of crocetin in diverse cancer types.

Immunotherapy of gastric cancer: Present status and future perspectives

In this editorial, we comment on the article entitled "Advances and key focus areas in gastric cancer immunotherapy: A comprehensive scientometric and clinical trial review (1999-2023)," which was published in the recent issue of the World Journal of Gastroenterology. We focused on the results of the authors' bibliometric analysis concerning gastric cancer immunotherapy, which they analyzed in depth by compiling the relevant publications of the last 20 years. Before that, we briefly describe the most recent data concerning the epidemiological parameters of gastric cancer (GC) in different countries, attempting to give an interpretation based on the etiological factors involved in the etiopathogenesis of the neoplasm. We then briefly discuss the conservative treatment (chemotherapy) of the various forms of this malignant neoplasm. We describe the treatment of resectable tumors, locally advanced neoplasms, and unresectable (advanced) cases. Special attention is given to modern therapeutic approaches with emphasis on immunotherapy, which seems to be the future of GC treatment, especially in combination with chemotherapy. There is also a thorough analysis of the results of the study under review in terms of the number of scientific publications, the countries in which the studies were conducted, the authors, and the scientific centers of origin, as well as the clinical studies in progress. Finally, an attempt is made to draw some con-clusions and to point out possible future directions.

Current therapies and progress in the treatment of advanced gastric cancer

Gastric cancer (GC) remains one of the most life-threatening disease worldwide with poor prognosis because of the absence of effective treatment and the delay in diagnosis. Due to the delay of diagnosis, a large proportion of GC patients are diagnosed as advanced GC, with extreme short lifespan. In the past few years, some pivotal progress and novel therapies was proposed, and conducted into clinical researches and practice. In this study, we summarized the development of several novel immunotherapy or targeted treatment modalities for advanced GC, including immune checkpoint inhibitors, anti-angiogenic therapy and cancer vaccines. Additionally, the advantage and potential weakness in each of these therapeutic methods are also listed. Finally, we discussed the promising research direction of advanced GC treatment, and the limitation in basic and clinical research of advanced GC, including the combination of immunotherapy and targeted therapy.

Association of PD-L1 Expression with Clinicopathologic Characters in Gastric Cancer: A Comprehensive Meta-analysis

PURPOSE

The expression level of programmed death ligand-1(PD-L1) in patients with gastric cancer is the key to determining the use of immune drugs. The relationship between PD-L1 expression level and clinical characteristics is worth exploring.

METHODS

By setting the search terms correlated to PD-L1 and gastric cancer, a nearly comprehensive search was carried out in four major databases, and the deadline for searching was September 1, 2022. The retrieved documents were further screened by strict inclusion and exclusion criteria after removing the duplication. Next, the quality of the included studies was evaluated with the Newcastle-Ottawa Scale (NOS) scale. Finally, the STATA15.1 software was used to process data and draw plots, and the odds ratios (ORs) were adopted to assess the pooled effect size.

RESULTS

A total of 85 works of literature were included in this study through screening strictly, and detailed data were extracted after evaluating the quality of the literature. The process of analysis was conducted in the whole population, Asia-Africa population, European and American population, and Asian population with CPS≥1, amd all found that the expression of PD-L1 in gastric cancer was correlated with age, tumor size, EBV infection, Her-2 expression and microsatellite status. However, the subgroup of the region also found some differences in Asian and Western regions, which was interesting and worth studying further. The included research of this study did not have significant publish bias.

CONCLUSION

After careful analysis, this study found that age (>60 years), tumor size (>5cm), EBV infection (+), Her-2 expression (+), microsatellite status (MSI), and mismatch repair status (dMMR) were risk factors for positive expression of PD-L1 in gastric cancer.

Anti-tumor activity of all-trans retinoic acid in gastric-cancer: gene-networks and molecular mechanisms

BACKGROUND

Gastric-cancer is a heterogeneous type of neoplastic disease and it lacks appropriate therapeutic options. There is an urgent need for the development of innovative pharmacological strategies, particularly in consideration of the potential stratified/personalized treatment of this tumor. All-Trans Retinoic-acid (ATRA) is one of the active metabolites of vitamin-A. This natural compound is the first example of clinically approved cyto-differentiating agent, being used in the treatment of acute promyelocytic leukemia. ATRA may have significant therapeutic potential also in the context of solid tumors, including gastric-cancer. The present study provides pre-clinical evidence supporting the use of ATRA in the treatment of gastric-cancer using high-throughput approaches.

METHODS

We evaluated the anti-proliferative action of ATRA in 27 gastric-cancer cell-lines and tissue-slice cultures from 13 gastric-cancer patients. We performed RNA-sequencing studies in 13 cell-lines exposed to ATRA. We used these and the gastric-cancer RNA-sequencing data of the TCGA/CCLE datasets to conduct multiple computational analyses.

RESULTS

Profiling of our large panel of gastric-cancer cell-lines for their quantitative response to the anti-proliferative effects of ATRA indicate that approximately half of the cell-lines are characterized by sensitivity to the retinoid. The constitutive transcriptomic profiles of these cell-lines permitted the construction of a model consisting of 42 genes, whose expression correlates with ATRA-sensitivity.  The model predicts that 45% of the TCGA gastric-cancers are sensitive to ATRA. RNA-sequencing studies performed in retinoid-treated gastric-cancer cell-lines provide insights into the gene-networks underlying ATRA anti-tumor activity. In addition, our data demonstrate that ATRA exerts significant immune-modulatory effects, which seem to be largely controlled by IRF1 up-regulation. Finally, we provide evidence of a feed-back loop between IRF1 and DHRS3, another gene which is up-regulated by ATRA.

CONCLUSIONS

ATRA is endowed with significant therapeutic potential in the stratified/personalized treatment gastric-cancer. Our data represent the fundaments for the design of clinical trials focusing on the use of ATRA in the personalized treatment of this heterogeneous tumor. Our gene-expression model will permit the development of a predictive tool for the selection of ATRA-sensitive gastric-cancer patients. The immune-regulatory responses activated by ATRA suggest that the retinoid and immune-checkpoint inhibitors constitute rational combinations for the management of gastric-cancer.