Individual Patient Data Meta-Analysis of the Value of Microsatellite Instability As a Biomarker in Gastric Cancer

Helicobacter pylori reversing the landscape of neoadjuvant immunotherapy for microsatellite stable gastric cancer: a multicenter cohort study

BACKGROUND

Microsatellite stable (MSS) gastric cancer (GC) is largely unresponsive to immunotherapy, presenting a persistent and formidable challenge in the field. Patients with advanced GC and Helicobacter pylori (H. pylori) infection have shown benefits from immunotherapy. However, it remains unreported whether neoadjuvant immunotherapy is beneficial for H. pylori-positive MSS GC patients.

METHODS

This retrospective cohort study analyzed data from GC patients treated at three medical centers in China between January 1, 2014, and July 1, 2024. Patients with gastric adenocarcinoma or adenocarcinoma of the gastroesophageal junction underwent testing for H. pylori infection prior to receiving neoadjuvant therapy.

RESULTS

In this retrospective analysis, those positive for H. pylori had a higher objective response rate of 63.77% (95% CI, 51.98-74.11%) compared to 47.73% (95% CI, 39.39-56.19%) in H. pylori-negative patients. Pathological complete remission was higher in H. pylori-positive patients at 17.39% (95% CI, 10.24-27.98%) versus 15.91% (95% CI, 10.65-23.10%). Logistic regression analysis revealed a strong correlation between H. pylori positivity and increased objective remission rate (P = 0.031, OR = 1.928, 95% CI 1.06-3.51). In H. pylori-positive MSS GC patients receiving neoadjuvant immunotherapy pCR rates can reach 27.27% (95% CI, 15.07-44.21%), much higher than the 8.33% (95% CI, 2.87-21.82%) in neoadjuvant chemotherapy patients. Survival analysis showed a 3-year OS rate of 74.2% (95% CI, 56.75-86.30%) in the H. pylori-positive group and 64.3% (95% CI, 51.20-75.55%) in the H. pylori-negative group, and the hazard ratio (HR) of these two groups was 0.50 (95% CI, 0.28-0.87; P <.001). Multivariable analysis for OS further showed the survival benefit of H. pylori, with HRs of 0.51 (95% CI, 0.29-0.91; P = 0.02).

CONCLUSIONS

H. pylori infection has emerged as a favorable factor for neoadjuvant immunotherapy in MSS GC, underscoring the importance of considering H. pylori status in preoperative treatment strategies.

Microsatellite-Stable Gastric Cancer Can be Classified into 2 Molecular Subtypes with Different Immunotherapy Response and Prognosis Based on Gene Sequencing and Computational Pathology

Most patients with gastric cancer (GC) exhibit microsatellite stability, yet comprehensive subtyping for prognostic prediction and clinical treatment decisions for microsatellite-stable GC is lacking. In this work, RNA-sequencing gene expression data and clinical information of patients with microsatellite-stable GC were obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. We employed several machine learning methods to develop and validate a signature based on immune-related genes (IRGs) for subtyping patients with microsatellite-stable GC. Moreover, 2 deep learning models based on the Vision Transformer (ViT) architecture were developed to predict GC tumor tiles and identify microsatellite-stable GC subtypes from digital pathology slides. Microsatellite status was evaluated by immunohistochemistry, and prognostic data as well as hematoxylin and eosin whole-slide images were collected from 105 patients with microsatellite-stable GC to serve as an independent validation cohort. A signature comprising 5 IRGs was established and validated, stratifying patients with microsatellite-stable GC into high-risk (microsatellite-stable-HR) and low-risk (microsatellite-stable-LR) groups. This signature demonstrated consistent performance, with areas under the receiver operating characteristic curve (AUC) of 0.65, 0.70, and 0.70 at 1, 3, and 5 years in the TCGA cohort, and 0.70, 0.60, and 0.62 in the GEO cohort, respectively. The microsatellite-stable-HR subtype exhibited higher levels of tumor immune dysfunction and exclusion, suggesting a greater potential for immune escape compared with the microsatellite-stable-LR subtype. Moreover, the microsatellite-stable-HR/LR subtypes showed differential sensitivities to various therapeutic drugs. Leveraging morphologic differences, the tumor recognition segmentation model achieved an impressive AUC of 0.97, whereas the microsatellite-stable-HR/LR identification model effectively classified microsatellite-stable-HR/LR subtypes with an AUC of 0.94. Both models demonstrated promising results in classifying patients with microsatellite-stable GC in the external validation cohort, highlighting the strong ability to accurately differentiate between microsatellite-stable GC subtypes. The IRG-related microsatellite-stable-HR/LR subtypes had the potential to enhance outcome prediction accuracy and guide treatment strategies. This research may optimize precision treatment and improve the prognosis for patients with microsatellite-stable GC.

Perioperative chemotherapy for gastric cancer patients with microsatellite instability or deficient mismatch repair: A systematic review and meta-analysis

BACKGROUND

The efficacy of perioperative chemotherapy for deficient mismatch repair or microsatellite instability-high (dMMR/MSI-H) gastric cancer (GC) remains controversial.

METHODS

This study was preregistered with the PROSPERO platform (CRD42023494276), and studies comparing perioperative chemotherapy with surgery alone in resectable dMMR/MSI-H GC were included. Hazard ratios (HRs) and their 95% confidence intervals (CIs) of survival outcomes were extracted. A random-effects model was used in the pooled analysis.

RESULTS

Twenty-two studies, which encompassed approximately 1600 patients with dMMR/MSI-H GC, were included. The results indicated that perioperative chemotherapy does not significantly improve overall survival (OS) (HR, 0.85; 95% CI, 0.58-1.26) and disease-free survival (DFS) (HR, 0.77; 95% CI, 0.53-1.12) in dMMR/MSI-H GC. In the subgroup analysis, adjuvant chemotherapy was not associated with improved OS (HR, 0.83; 95% CI, 0.50-1.37) but was associated with improved DFS (HR, 0.64; 95% CI, 0.43-0.96). However, the benefit of adjuvant chemotherapy for DFS was not significant in the pooled analysis of multivariable-adjusted results. Similar results were observed for neoadjuvant chemotherapy (OS: HR, 0.84; 95% CI, 0.44-1.57; DFS: HR, 1.13; 95% CI, 0.50-2.53). Additionally, stage stratification analysis demonstrated no significant survival benefit of adjuvant chemotherapy for stage II (OS: HR, 0.77; 95% CI, 0.31-1.90) or stage III (OS: HR, 0.72; 95% CI, 0.36-1.46) dMMR/MSI-H GC.

CONCLUSIONS

Despite indications that adjuvant chemotherapy may improve DFS in the subgroup analysis, this benefit was not sustained in multivariate assessments. Overall, the pooled results indicate that perioperative chemotherapy does not significantly improve OS or DFS in patients with resectable dMMR/MSI-H GC, and therefore such treatment may be spared in these patients.

How do I treat dMMR/MSI gastro-oesophageal adenocarcinoma in 2025? A position paper from the EORTC-GITCG gastro-esophageal task force

In less than a decade, immune checkpoint inhibitors (ICIs) have transformed the management of mismatch repair-deficient (dMMR) and microsatellite instability-high (MSI) cancers. However, beyond colorectal cancer (CRC), much of the evidence is mostly derived from non-randomized phase II studies or post-hoc analyses of broader clinical trials. dMMR/MSI tumours represent a specific subgroup of gastro-esophageal adenocarcinomas (GEA), accounting for approximately 9 % of cases, with a higher prevalence in early-stage compared to advanced-stage disease and older female patients. These tumours are predominantly sporadic, often linked to MLH1 promoter methylation, and rarely exhibit HER2 overexpression/ERBB2 amplification or other oncogenic drivers. The treatment landscape for early stage dMMR/MSI GEA is likely to change substantially soon, as ICIs have shown high pathological complete response (pCR) rates in small phase II trials, raising questions on optimisation of neoadjuvant therapy, and paving the way for organ preservation. The standard of treatment for untreated patients with advanced dMMR/MSI GEA is chemotherapy + ICI irrespectively of PDL-1 status. However, the role of chemotherapy-free regimen consisting of CTLA-4 plus PD-1 inhibitors remains undetermined. This review addresses these and other emerging questions, offering expert opinions and insights into the future therapeutic landscape for dMMR/MSI GEA.

Prevalence and clinicopathological features of microsatellite instability-high metastatic or recurrent gastric and esophagogastric junction cancer: WJOG13320GPS

BACKGROUND

Microsatellite instability (MSI)-high tumors represent a distinct, small-fraction subtype in esophagogastric junction cancer or gastric cancer (GC), yet their clinical significance remains poorly understood. This study aimed to investigate the prevalence and clinicopathological features of chemotherapy-naïve metastatic or recurrent MSI-high GC as a prescreening study for a phase II trial of nivolumab plus ipilimumab.

METHODS

Key inclusion criteria included metastatic or recurrent adenocarcinoma of GC, ECOG performance status of 0 or 1, and no prior systemic therapy for metastatic or recurrent disease. MSI status was tested using multiplex PCR fragment analysis (MSI Testing Kit, FALCO). The primary endpoint was the prevalence of MSI-high GC.

RESULTS

Between October 2020 and October 2022, 930 eligible patients from 75 centers in Japan were analyzed. The prevalence of MSI-high GC was 5.6% (95% CI 4.2-7.3). MSI-high GC was more frequently observed in females than males (9.6% vs 3.8%, p < 0.001), patients aged ≥ 70 years compared to those < 70 years (8.0% vs 2.8%, p < 0.001), in the lower stomach than other locations (10.5% vs 3.2%, p < 0.001), HER2-negative tumors than HER2-positive tumors (6.5% vs 1.8%, p = 0.02), and in patients without liver metastasis than those with liver metastasis (6.9% vs 2.2%, p = 0.004).

CONCLUSIONS

The prevalence of MSI-high tumors among chemotherapy-naïve patients with unresectable GC was 5.6%. These tumors were associated with female sex, older age, lower stomach, HER2-negative, and absence of liver metastasis. These findings would help assuming MSI-high tumors and may have significant implications for clinical practice and studies targeting this GC subtype.

Tremelimumab and durvalumab as neoadjuvant or non-operative management strategy of patients with microsatellite instability-high resectable gastric or gastroesophageal junction adenocarcinoma: the INFINITY study by GONO

BACKGROUND

In resectable gastric/gastroesophageal junction adenocarcinoma, microsatellite instability-high (MSI-H) confers improved survival, but limited benefit from chemotherapy. Immunotherapy may eliminate the need for chemotherapy or surgery.

PATIENTS AND METHODS

INFINITY is a multicenter, multicohort phase II trial (NCT04817826) investigating in cohort 1 the activity and safety of tremelimumab + durvalumab (T300/D) as neoadjuvant treatment of mismatch repair deficient/MSI-H, resectable gastric/gastroesophageal junction adenocarcinoma. Primary endpoint was pathologic complete response (pCR) rate; Secondary endpoints: progression-free survival (PFS), overall survival (OS), quality of life, and translational analyses. In cohort 2, the activity and safety of T300/D was explored as definitive treatment in patients achieving clinical complete response (cCR). Primary endpoint was 2-year cCR rate, and secondary endpoints were PFS, OS, quality of life, gastrectomy-free survival and translational analyses.

RESULTS

In cohort 1, 18 patients were recruited and 15 evaluable. pCR and major pathologic response-pCR were 60% and 80%, respectively. Since pCR rate in T4 tumors was 17%, this subgroup of patients was excluded from enrollment in cohort 2. At 28.1 months median follow-up, 24-month gastric cancer-specific PFS and OS rates were 85% and 92%, respectively. In cohort 2, 18 patients were enrolled and 17 assessable, and 13 had cCR and started non-operative management. At 11.5 months median follow-up, one patient had local regrowth and underwent salvage surgery; 12-month gastrectomy-free survival was 64.2%.

CONCLUSIONS

The INFINITY study provided promising activity results of a chemo-free T300/D combination regimen as preoperative treatment in mismatch repair deficient/MSI gastric/gastroesophageal junction adenocarcinoma and the first available feasibility results of a non-operative management strategy in this disease setting, worthy of further validation in larger cohorts.

Chemotherapy Options for Locally Advanced Gastric Cancer: A Review

Cancers represent a significant global health burden, affecting millions of individuals each year [...].

Mismatch repair (MMR) and microsatellite instability (MSI) phenotypes across solid tumors: A comprehensive cBioPortal study on prevalence and prognostic impact

Mismatch repair deficiency (MMR-d) and microsatellite instability (MSI) are prognostic and predictive biomarkers in oncology. Current testing for MMR/MSI relies on immunohistochemistry (IHC) for MMR proteins and molecular assays for MSI detection. This combined diagnostic strategy, however, lacks tumor specificity and does not account for gene variants. This study provides an in-depth analysis of MMR mutations frequency, spectrum, and distribution in solid tumors. Data from 23,893 patients across 11 tumor types, using 66 publicly available studies, were analyzed. MMR-mutated (MMR-m) status was defined by alterations in MLH1, PMS2, MSH2, and/or MSH6; MSI was assessed by MSIsensor. Cases with indeterminate labelling were excluded. Survival was analyzed using the Kaplan-Meier method. Among 19,353 tumors, 949 MMR variants were identified, comprising 432 pathogenic and 517 variants of unknown significance (VUS), as defined by OncoKB. MSH6 mutations were the most frequent (n = 279, 29.4 %), followed by MSH2 (n = 198, 20.9 %), MLH1 (n = 187, 19.7 %), and PMS2 (n = 161, 16.9 %). MMR-m cases were more frequent in endometrial (EC, 20.5 %), colorectal (CRC, 8.2 %), bladder (BLCA, 8.7 %), and gastroesophageal cancers (GEC, 5.4 %). Pathogenic mutations were more common than non-pathogenic in EC, CRC, and GEC (p < 0.001, p = 0.01, p = 0.32, respectively). MMR-m status was not associated with MSI in 247 (48.9 %) cases, including 67 (13.2 %) with pathogenic mutations. The highest concordance between MMR-m and MSI was observed in CRC (65.7 %), EC (91.2 %), and GEC (69.6 %), while the lowest in pancreatic (0.2 %) and lung cancers (0.1 %). MMR-m GECs showed improved overall survival compared to MMR-wt (p = 0.009), a relationship not observed in other tumor types. This study demonstrates that the MMR spectrum is extremely hetoerogeneous in solid tumors, highliting the need for comprehensive and tumor-specific testing strategies.

Combination of cadonilimab (PD-1/CTLA-4 bispecific antibody) and apatinib as salvage therapy achieves partial response in MSI-H advanced gastric cancer: a case report

Microsatellite instability-high (MSI-H) gastric cancer (GC) is recognized as a unique subtype of gastric cancer. While patients with advanced MSI-H gastric cancer may respond favorably to a combination of immune checkpoint inhibitors and chemotherapy in first-line treatment, no definitive recommendations exist regarding the optimal regimen for subsequent therapy. Cadonilimab, a PD-1 and CTLA-4 bispecific antibody, has shown encouraging efficacy and safety in the first-line treatment of advanced gastric cancer. However, its utility in the MSI-H gastric cancer subtype following multiple lines of therapy remains uncertain. This case report describes a patient with advanced MSI-H gastric adenocarcinoma that progressed after multiple treatments and achieved notable efficacy with a combination of cadonilimab and apatinib. By examining the current therapeutic landscape for MSI-H gastric cancer, this study explores the potential of combining PD-1/CTLA-4 dual-immunity with anti-vascular therapy as salvage treatment for this gastric cancer subtype. The findings provide valuable reference points for future clinical trials, offering a promising perspective on backline therapeutic strategies for MSI-H gastric cancer and highlighting the potential of integrating bispecific antibodies with anti-vascular therapies.

Towards the Prediction of Responses to Cancer Immunotherapy: A Multi-Omics Review

Tumor treatment has undergone revolutionary changes with the development of immunotherapy, especially immune checkpoint inhibitors. Because not all patients respond positively to immune therapeutic agents, and severe immune-related adverse events (irAEs) are frequently observed, the development of the biomarkers evaluating the response of a patient is key for the application of immunotherapy in a wider range. Recently, various multi-omics features measured by high-throughput technologies, such as tumor mutation burden (TMB), gene expression profiles, and DNA methylation profiles, have been proved to be sensitive and accurate predictors of the response to immunotherapy. A large number of predictive models based on these features, utilizing traditional machine learning or deep learning frameworks, have also been proposed. In this review, we aim to cover recent advances in predicting tumor immunotherapy response using multi-omics features. These include new measurements, research cohorts, data sources, and predictive models. Key findings emphasize the importance of TMB, neoantigens, MSI, and mutational signatures in predicting ICI responses. The integration of bulk and single-cell RNA sequencing has enhanced our understanding of the tumor immune microenvironment and enabled the identification of predictive biomarkers like PD-L1 and IFN-γ signatures. Public datasets and machine learning models have also improved predictive tools. However, challenges remain, such as the need for large and diverse clinical datasets, standardization of multi-omics data, and model interpretability. Future research will require collaboration among researchers, clinicians, and data scientists to address these issues and enhance cancer immunotherapy precision.

Confirmed Pathological Response to Nivolumab Combined with Chemotherapy for Advanced Gastric Cancer with Left Subclavicular Lymph Node Metastasis: A Case Report

We report the case of a 44-year-old male with advanced gastric cancer with distal lymph node metastasis who achieved a pathological complete response to chemotherapy combined with nivolumab. After five months of treatment, the patient underwent total gastrectomy with D2 lymph node dissection, and histological examination revealed the absence of malignant cells not only in the resected specimen but also in the harvested lymph nodes. At present, more than 1 year after the initial surgery, the patient is still alive without any recurrence. This case highlights the potential of chemotherapy combined with nivolumab to induce a complete response in advanced gastric cancer patients.

Integrative analysis of anoikis-related prognostic signature to evaluate the immune landscape and predict therapeutic response in stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is the most prevalent gastrointestinal malignancy and seriously threatens the life of the global population. Anoikis, a process of programmed cell death that occurs when cells detach from the extracellular matrix, is closely associated with tumor invasion and metastasis. In this study, we used the TCGA-STAD database to identify the expression patterns and prognostic relevance of anoikis-related genes (ARGs) in STAD. Functional enrichment analysis was used to explore the potential pathway. LASSO and Cox regression were used to construct anoikis-related prognostic signature. The anoikis risk score (ARS) incorporated 7 genes and stratified patients into highand low-risk subgroups by median value splitting. In addition, external validation was performed based on GSE66229, GSE15459, and GSE84437 cohorts. Nomograms were created based on risk characteristics in combination with clinical variants and the performance of the model was validated with time-dependent AUC, calibration curves, and decision curve analysis (DCA). The prognostic signature indicated that the low-risk subgroup had better outcomes and significant correlations with tumor microenvironment, immune landscape, immunotherapy response, and drug sensitivity. In addition, single-cell analysis displayed the cell types, the subcellular localization of prognostic genes, and the cellular interaction to reveal the potential molecular communication mechanism of anoikis resistance. Finally, in vitro experiments confirmed the critical role of CRABP2 in STAD. The results indicated that CRABP2 knockdown inhibited gastric cancer cell proliferation, migration and invasion, and promoted apoptosis. In summary, ARS can serve as a biomarker for predicting survival outcomes in STAD patients, providing new tools for personalized treatment decisions for STAD patients.

Clinicopathological significance of deficient DNA mismatch repair and MLH1 promoter methylation in gastric adenosquamous carcinoma

Primary gastric adenosquamous carcinoma (GASC) is a rare tumor that exhibits aggressive behavior and currently lacks standardized therapeutic recommendations. Microsatellite instability (MSI)/mismatch repair deficiency (dMMR) and positive PD-L1 expression confer sensitivity to immune checkpoint inhibitors; however, their statuses in GASC remain uncertain. In this study, clinical features, MMR/MSI status, MLH1 methylation, two T-cell markers, and PD-L1 expression of 30 GASC cases were collected from three institutions. Additionally, 196 gastric adenocarcinomas (GACs) were collected for comparison. The median age of GASC patients was 62 years, with 76.7% being males, and 56.7% at stage III. dMMR/MSI-high with MLH1 hypermethylation was observed in 33.3% GASCs, and was significantly associated with older age, female, distal location, larger size, deeper tumor invasion, and higher CD3 and CD8 densities and PD-L1 expression. Both glandular and squamous components of all dMMR GASCs showed loss of MLH1 and PMS2 expression. No significant difference in overall survival was observed between dMMR and mismatch repair proficiency (pMMR) GASC patients, while inferior overall survival was observed in pMMR GASC treated with surgery alone compared to those receiving chemotherapy. When comparing to GAC, GASC exhibited clinicopathological features indicative of more aggressive behavior (larger size, poorly tumor differentiation, deeper tumor invasion and more lymph node metastases). A significantly higher frequency of dMMR was found in GASC (33.3%) than that in GAC (16.3%). This study offers a comprehensive perspective on the clinicopathological features of GASC, emphasizing a subset of GASC associated with dMMR and MLH1 hypermethylation. Immunotherapy might be a promising strategy for GASC.

Evolving Strategies in the Management of Microsatellite Instability-High/Mismatch Repair Deficient Esophagogastric Adenocarcinoma

PURPOSE OF REVIEW

This review addresses the current treatment paradigm and new advancements in the management of microsatellite instability-high/mismatch repair deficient (MSI-H/dMMR) esophagogastric cancer (EGC).

RECENT FINDINGS

While chemotherapy and surgery remain the cornerstone of EGC treatment, MSI-H/dMMR tumors harbor high tumor mutational burden and represent a subset of patients who benefit from immune checkpoint inhibitors (ICI). ICI has been incorporated in the front line setting with and without chemotherapy for advanced disease. Recently, ICI has been studied in the perioperative setting for resectable disease. Though perioperative ICI results in improved response rates, it is not yet clear whether this translates to a survival benefit. Despite high response rates with ICI in this patient population, many do not respond to therapy, representing a major challenge in treatment. Preclinical studies have highlighted potential mechanisms of resistance which will guide drug development and clinical trials.

FGL1 facilitates rather than suppresses anticancer immunity against microsatellite instable gastric cancer

Microsatellite instability (MSI) is a phenotype characterized by changes in the sequence length of microsatellites in tumor cells and is closely linked to tumorigenesis and prognosis. Immune checkpoint inhibitors have shown good therapeutic effects in gastric cancer (GC) with MSI-high (MSI-H). However, the role of the novel immune checkpoint fibrinogen-like protein 1 (FGL1) in GC treatment has not been fully investigated. FGL1 expression in GC tissues and the difference in FGL1 immune infiltration between MSI/ microsatellite stability (MSS) patients were analyzed by bioinformatics and were verified in clinical samples. Xenograft models of MSS and MSI GC were constructed in human immune reconstitution mice, and FGL1 expression in tumors was detected. Immunofluorescence and immunohistochemistry were used to assay the infiltration of immune cells in the two types of mice. Cytotoxicity and chemotaxis tests were used to detect the toxicity and chemotaxis of CD8+T cells to GC cells, respectively. The cytokine content was detected by enzyme-linked immunosorbent assay. The therapeutic effects of FGL1 antibody on different types of GC were analyzed by xenograft mouse models. FGL1 exhibited significantly higher expression in GC, and its expression and immune cell infiltration levels were significantly higher in MSI GC than in MSS GC. CD8+T cells were significantly more effective in killing and chemotaxis of MSI GC cells than MSS GC cells. The FGL1 antibody was more effective in treating MSI GC.The novel immunosuppressor FGL1 antibody exerts a good therapeutic influence on MSI GC. These findings provide a basis for the development of drugs targeting FGL1 for MSI GC treatment.

Treatment of Gastric Cancer Carcinomatosis

Patients with gastric cancer peritoneal metastases (GCPM) have Stage IV disease. Systemic therapy is a crucial aspect of their care. Patients with GCPM should have their tumors tested for HER2 and PD-L1 expression and microsatellite instability for potential targeted therapies. If patients with synchronous GCPM have stable disease following neoadjuvant therapy, surgical intervention can be considered. Patients with positive cytology or low-volume peritoneal disease (peritoneal carcinomatosis index [PCI] < 7) may "convert" to negative cytology or resolution of peritoneal metastases following intraperitoneal therapy and may be candidates for subsequent gastrectomy.

Multimodality Treatment for Locally Advanced Gastric Adenocarcinoma

Gastric cancer is prevalent worldwide and is a leading cause of cancer-related death. Patients with GC often present at advanced stages at diagnosis. Patients with locally advanced diseases experience poor survival rates with surgery alone. Multimodality therapy, including peri-operative therapy and adjuvant therapy, has improved outcomes. However, there is no consensus on the optimal treatment approach. Molecular characteristics of GC may help guide treatment choices and studies are currently underway to evaluate other treatment modalities including immunotherapy and targeted therapy.

Perioperative chemotherapy strategies in diffuse gastric cancer

This study reviews the findings of a recent study by Li et al, which demonstrated that perioperative chemotherapy benefits patients with diffuse-type gastric cancer compared to surgery alone. Despite potential biases, the study supports the inclusion of perioperative chemotherapy in treatment guidelines. Neoadjuvant and adjuvant chemotherapy may also provide similar survival outcomes, allowing for flexible treatment planning.

Transcriptome-Based Survival Analysis Identifies MAP4K4 as a Prognostic Marker in Gastric Cancer with Microsatellite Instability

Background/Objectives: Gastric cancer (GC) is a highly aggressive malignancy with diverse molecular subtypes. While microsatellite instability (MSI) GC generally carries a favorable prognosis, a subset of patients experiences poor outcomes, highlighting the need for refined prognostic markers. Methods: This study utilized transcriptomic and clinical data from two independent cohorts, The Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG), to identify novel prognostic genes in MSI-GC. Results: Through rigorous survival analysis, we identified high MAP4K4 expression (MAP4K4high) as an independent and robust predictor of poor overall survival (OS) and disease-free survival (DFS) specifically within the MSI-GC subtype. MAP4K4high was associated with increased hazard ratios for both OS and DFS in both cohorts, even after adjusting for clinicopathological factors. Further analysis revealed that MAP4K4high MSI-GC tumors exhibit a distinct molecular profile characterized by increased extracellular matrix remodeling, epithelial-mesenchymal transition, and a microenvironment enriched in monocytes and cancer-associated fibroblasts (CAFs). Notably, a subgroup of MSI-GC patients with a CIN-like phenotype and high MAP4K4 expression exhibited particularly dismal outcomes. Conclusions: Our findings establish MAP4K4 as a promising prognostic biomarker for risk stratification in MSI-GC and suggest its potential role in driving aggressive tumor behavior through modulation of the tumor microenvironment.

Harnessing Machine Learning and Nomogram Models to Aid in Predicting Progression-Free Survival for Gastric Cancer Patients Post-Gastrectomy with Deficient Mismatch Repair(dMMR)

OBJECTIVE

To assess the effectiveness of a machine learning framework and nomogram in predicting progression-free survival (PFS) post-radical gastrectomy in patients with dMMR.

METHOD

Machine learning models and nomograms to forecast PFS in patients undergoing radical gastrectomy for nonmetastatic gastric cancer with dMMR. Independent risk factors were identified using Cox regression analysis to develop the nomogram. The performance of the models was assessed through C-index, time receiver operating characteristic (T-ROC) curves, calibration curves, and decision curve analysis (DCA) curves. Subsequently, patients were categorized into high-risk and low-risk groups based on the nomogram's risk scores.

RESULTS

Among the 582 patients studied, machine learning models exhibited higher c-index values than the nomogram. Random Survival Forests (RSF) demonstrated the highest c-index (0.968), followed by Extreme Gradient Boosting (XG boosting, 0.945), Decision Survival Tree (DST, 0.924), the nomogram (0.808), and 8th TNM staging (0.757). All models showed good calibration with low integrated Brier scores (< 0.1), although there was calibration drift over time, particularly in the traditional nomogram model. DCA showed an incremental net benefit from all machine learning models compared with conventional models currently used in practice. Age, positive lymph nodes, neural invasion, and Ki67 were identified as key factors and integrated into the prognostic nomogram.

CONCLUSION

Our research has demonstrated the effectiveness of the RSF algorithm in accurately predicting progression-free survival (PFS) in dMMR gastric cancer patients after gastrectomy. The nomogram created from this algorithm has proven to be a valuable tool in identifying high-risk patients, providing clinicians with important information for postoperative monitoring and personalized treatment strategies.

Is it time to retire preoperative radiation for localized esophageal and gastro-esophageal adenocarcinoma?

Whether preoperative chemoradiotherapy (CRT) or perioperative chemotherapy is superior for localized esophageal or gastro-esophageal junction (GEJ) cancers has been a topic of long-standing debate. For years, standard of care in the United States for localized esophageal or GEJ adenocarcinoma (EAC) has been physician's choice between the 2 strategies. More recently, adjuvant immunotherapy has also been introduced into the treatment approach for those who received neoadjuvant CRT. While preoperative radiation remains an important option for patients with esophageal squamous cell carcinomas, the ESOPEC trial presented in 2024 suggested that perioperative chemotherapy is superior to preoperative CRT in EAC. In addition, the results of the TOPGEAR trial presented in 2024 showed that adding CRT to perioperative chemotherapy did not lead to improved outcomes. This has led to a shift in practice among oncologists. However, there are various complexities and factors to consider when interpreting these studies. In this review, we outline both trials and what their findings may mean for the future of preoperative CRT in EAC. Ultimately, until more data are available that incorporate novel agents such as immunotherapy, these studies indicate that we should defer the routine inclusion of radiation in preoperative treatment for EAC.

Digestive cancers: mechanisms, therapeutics and management

Cancers of the digestive system are major contributors to global cancer-associated morbidity and mortality, accounting for 35% of annual cases of cancer deaths. The etiologies, molecular features, and therapeutic management of these cancer entities are highly heterogeneous and complex. Over the last decade, genomic and functional studies have provided unprecedented insights into the biology of digestive cancers, identifying genetic drivers of tumor progression and key interaction points of tumor cells with the immune system. This knowledge is continuously translated into novel treatment concepts and targets, which are dynamically reshaping the therapeutic landscape of these tumors. In this review, we provide a concise overview of the etiology and molecular pathology of the six most common cancers of the digestive system, including esophageal, gastric, biliary tract, pancreatic, hepatocellular, and colorectal cancers. We comprehensively describe the current stage-dependent pharmacological management of these malignancies, including chemo-, targeted, and immunotherapy. For each cancer entity, we provide an overview of recent therapeutic advancements and research progress. Finally, we describe how novel insights into tumor heterogeneity and immune evasion deepen our understanding of therapy resistance and provide an outlook on innovative therapeutic strategies that will shape the future management of digestive cancers, including CAR-T cell therapy, novel antibody-drug conjugates and targeted therapies.

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.

The Prognostic Nutritional Index in patients with microsatellite instability-high metastatic gastric or gastroesophageal cancers receiving immune checkpoint inhibitors

BACKGROUND

Microsatellite instability high (MSI-H) and/or mismatch repair deficient (dMMR) status is the strongest predictive factor for immune checkpoint inhibitors (ICIs) benefit in patients with metastatic gastroesophageal cancer (mGC). Primary resistance to ICIs is a relevant issue, but prognostic and predictive factors are lacking.

MATERIALS AND METHODS

In this multinational, retrospective cohort of patients with MSI-H/dMMR mGC treated with ICIs without chemotherapy we collected baseline laboratory values to establish the prognostic nutritional index (PNI). We evaluated the association between baseline PNI with the activity and efficacy of ICIs.

RESULTS

At a median follow-up of 31.6 months, median progression-free survival (PFS) and 2-year PFS rate were not reached and 73.6 % in the PNI-high subgroup versus 6.3 months and 38.3 % in the PNI-low one (HR 0.32, 95 % CI: 0.16-0.61, p < .001). Median overall survival (OS) and 2-year OS rate were not reached and 81.9 % in the PNI-high subgroup versus 24.4 months and 50.5 % in the PNI-low one (HR 0.26, 95 % CI: 0.12-0.56, p < .001). In multivariable models, high PNI was associated with longer PFS and OS (HR 0.30, 95 % CI: 0.15-0.61, p <0.001 and 0.37, 95 % CI: 0.15-0.91, p = .031).

CONCLUSIONS

High PNI is associated with longer PFS and OS, in patients with MSI-H mGC receiving ICIs. Patients with low baseline PNI may benefit from intensive therapeutic approaches.

Pathological complete response achieved with FLOT chemotherapy in two patients with MSI-H esophagogastric junction and gastric adenocarcinoma

Globally, more than 1 million new cases of gastric cancer were estimated in 2020, ranking fourth in cancer mortality. Currently although in resectable gastric cancer and esophagogastric junction (EGJ) adenocarcinoma a perioperative triplet chemotherapy regimen including a fluoropyrimidine, a platinum compound and docetaxel (FLOT) demonstrated a better overall survival, the survival rate is still very low, and a massive effort is still required to improve clinical prognosis. High microsatellite instability (MSI-H) status in gastric cancer is a favorable prognostic factor but poor data are available on its predictive role for perioperative FLOT chemotherapy in resectable gastric cancer. Here, we presented the case of two patients with advanced MSI-H gastric cancer/EGJ adenocarcinoma who had no residual tumor following neoadjuvant FLOT chemotherapy maintaining a complete response for more than 30 months, suggesting MSI-H status to be a positive prognostic marker also in patients treated with a taxane-containing triplet in this setting. We also discuss the future perspectives including the opportunity to achieve excellent clinical outcomes with immune checkpoint inhibitor (ICI)-based regimens.

Korean Practice Guidelines for Gastric Cancer 2024: An Evidence-based, Multidisciplinary Approach (Update of 2022 Guideline)

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area. Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version. Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Efficacy, safety, and biomarker analysis of first-line immune checkpoint inhibitors with chemotherapy versus chemotherapy for advanced gastric cancer: a multicenter, retrospective cohort study

BACKGROUND

Recent phase III randomized controlled trials have demonstrated that first-line immune checkpoint inhibitors (ICIs) improve prognosis in advanced HER-2-negative gastric cancer patients with programmed death ligand 1 (PD-L1) combined positive score (CPS) higher than 5. However, these findings are not confirmed in real-world settings, and the benefits in PD-L1 CPS < 5 patients remain controversial.

METHODS

In this multicenter, retrospective cohort study, data from across thirteen medical centers were analyzed by inverse probability of treatment weighting for matching, alongside univariate and multivariate COX proportional hazard regression models. Genomic and transcriptomic analyses were conducted to identify efficacy prognostic models and resistance mechanisms.

RESULTS

This study included 573 patients with advanced gastric cancer, 265 treated with chemotherapy and 308 with ICIs plus chemotherapy. In the overall cohort and HER-2-negative patients, the combination therapy significantly improved progression-free survival and overall survival, without marked increases in severe adverse events. Notably, patients with PD-L1 CPS 1-4 showed significant overall survival prolongation and a trend towards improved progression-free survival with combination therapy. Patients with unknown PD-L1 status also benefitted from ICIs. SMARCA4 and BRCA2 mutations were more frequent in patients with responses, while CCNE1 and ZFHX3 alternation, alongside high "ABC transporters" signatures, were more common in non-responsive patients. A novel risk model, PGFIC, outperformed traditional biomarkers in predicting treatment outcomes.

CONCLUSIONS

Adding ICIs to first-line treatment significantly prolongs survival in overall patients and in those with PD-L1 CPS 1-4 or unknown. This study also provides valuable insights into prognostic markers and resistance mechanisms, potentially guiding immunotherapy strategies.

Three biomarkers (HER2, PD-L1, and microsatellite status) in a large cohort of metastatic gastroesophageal adenocarcinomas: The MD Anderson Cancer Center experience

Human epidermal growth factor receptor-2 (HER2), programmed death-ligand 1 (PD-L1), and microsatellite (MS) status are well-established biomarkers in gastroesophageal adenocarcinomas (GEAs). However, it is unclear how the combination of these biomarkers is associated with clinicopathological factors and prognosis. This retrospective study included baseline metastatic GEA patients who were tested for all three biomarkers (HER2, PD-L1, and MS status) at the MD Anderson Cancer Center between 2012 and 2022. Stratification was performed according to the combination of biomarker profiles: triple negative (TN), single positive (SP), and multiple positive (MP). Comparative analyses of clinicopathological factors and survival using combinations of biomarkers were performed. Among the 698 GEA patients analyzed, 251 (36.0%) were classified as TN, 334 (47.9%) as SP, and 113 (16.1%) as MP. The MP group showed a significant association with tumors located in the esophagus (p < .001), well to moderate differentiation (p < .001), and the absence of signet ring cells (p < .001). In the survival analysis, MP group had a significantly longer overall survival (OS) compared to the other groups (MP vs. TN, p < .001 and MP vs. SP, p < .001). Multivariate Cox regression analysis revealed that MP serves as an independent positive prognostic indicator for OS (hazard ratio = 0.63, p < .01). Our findings indicate that MP biomarkers are associated with a favorable prognosis in metastatic GEA. These results are reflective of clinical practice and offer valuable insights into how therapeutics and future biomarkers could influence therapy/prognosis.

Perioperative Treatment in Gastric Cancer: A Fast-Changing Field

Gastric cancer is the fifth most common cancer worldwide and its incidence is rising. Surgery is the only curative strategy and its association with perioperative chemotherapy is now standard treatment for most resectable tumors. Despite treatment advances, disease relapse is high, even in early stages, and continued improvement in curative treatment is imperative. With deeper knowledge of gastric cancer heterogeneity, molecular subtypes, and the tumor immune microenvironment, new standard treatment strategies may emerge in the near future. This paper provides a comprehensive review of the current treatment landscape in resectable gastric cancer and future perspectives for the next decade regarding new agents such as targeted therapies, immunotherapy, antibody-drug conjugates, and the combination of multiple treatment modalities.

Novel immunotherapeutic approaches in gastric cancer

Gastric cancer is a malignant tumor that ranks third in cancer-related deaths worldwide. Early-stage gastric cancer can often be effectively managed through surgical resection. However, the majority of cases are diagnosed in advanced stages, where outcomes with conventional radiotherapy and chemotherapy remain unsatisfactory. Immunotherapy offers a novel approach to treating molecularly heterogeneous gastric cancer by modifying the immunosuppressive tumor microenvironment. Immune checkpoint inhibitors and adoptive cell therapy are regarded as promising modalities in cancer immunotherapy. Food and Drug Administration-approved programmed death-receptor inhibitors, such as pembrolizumab, in combination with chemotherapy, have significantly extended overall survival in gastric cancer patients and is recommended as a first-line treatment. Despite challenges in solid tumor applications, adoptive cell therapy has demonstrated efficacy against various targets in gastric cancer treatment. Among these approaches, chimeric antigen receptor-T cell therapy research is the most widely explored and chimeric antigen receptor-T cell therapy targeting claudin18.2 has shown acceptable safety and robust anti-tumor capabilities. However, these advancements primarily remain in preclinical stages and further investigation should be made to promote their clinical application. This review summarizes the latest research on immune checkpoint inhibitors and adoptive cell therapy and their limitations, as well as the role of nanoparticles in enhancing immunotherapy.

Uncovering the potential of APOD as a biomarker in gastric cancer: A retrospective and multi-center study

Gastric cancer (GC) poses a significant health challenge worldwide, necessitating the identification of predictive biomarkers to improve prognosis. Dysregulated lipid metabolism is a well-recognized hallmark of tumorigenesis, prompting investigation into apolipoproteins (APOs). In this study, we focused on apolipoprotein D (APOD) following comprehensive analyses of APOs in pan-cancer. Utilizing data from the TCGA-STAD and GSE62254 cohorts, we elucidated associations between APOD expression and multiple facets of GC, including prognosis, tumor microenvironment (TME), cancer biomarkers, mutations, and immunotherapy response, and identified potential anti-GC drugs. Single-cell analyses and immunohistochemical staining confirmed APOD expression in fibroblasts within the GC microenvironment. Additionally, we independently validated the prognostic significance of APOD in the ZN-GC cohort. Our comprehensive analyses revealed that high APOD expression in GC patients was notably associated with unfavorable clinical outcomes, reduced microsatellite instability and tumor mutation burden, alterations in the TME, and diminished response to immunotherapy. These findings provide valuable insights into the potential prognostic and therapeutic implications of APOD in GC.

Chemotherapy combined with immunotherapy in a patient with multiple primary gastric and rectal cancers with good prognosis: A case report

RATIONALE

Multiple primary cancer is common in clinical practice, but its diagnosis process is complicated, and relevant genetic testing is required to assist in diagnosis when necessary. The formulation of treatment strategies for multiple primary cancer is a highly personalized process. In this article, we introduce a case of a patient with rectal cancer and gastric cancer who was diagnosed with multiple primary cancers, to investigate and explore the clinical application value of next-generation sequencing (NGS) testing in patients with multiple primary gastric and colorectal cancers.

PATIENT CONCERNS

A 74-year-old male patient had a mass at the anal verge.

DIAGNOSES

Endoscopy, imaging studies, and pathological examinations showed adenocarcinoma in both the rectal and gastric antral regions. Genetic testing confirmed the diagnosis of multiple primary cancer.

INTERVENTIONS

The patient received 8 cycles of neoadjuvant chemotherapy combined with immunotherapy and underwent laparoscopic radical resection for rectal cancer. Postoperative adjuvant chemotherapy (XELOX) supplemented with PD-1 immunotherapy, and Camrelizumab was continued.

OUTCOMES

Gastric lesions continued to regress and eventually disappeared completely at the end of adjuvant therapy.

LESSONS

According to the results of NGS testing, the multiple primary cancers' patient received personalized treatment and ultimately achieved clinical complete remission. This case highlights the critical role of genetic testing in accurately identifying multiple primary cancer and the value of personalized guidance for patient treatment using NGS in clinical practice.

Neoadjuvant PD-(L)1 blockade with or without chemotherapy versus chemotherapy alone in mismatch repair-deficient, potentially resectable stage III-IVA gastric cancer patients: a single-center retrospective study

BACKGROUND

Currently, PD-(L)1 blockade-based neoadjuvant treatment has shown promising outcomes in patients with potentially resectable gastric cancer. In this real-world study, we aimed to retrospectively observe the efficacy including tumor response and event-free survival (EFS), and safety of PD-(L)1 blockade-based neoadjuvant treatment versus chemotherapy alone in potentially resectable gastric cancer patients with microsatellite instability-high (MSI-H) or mismatch-repair deficient (dMMR) status.

METHODS

We retrospectively collected the clinical data of patients with potentially resectable gastric cancer and MSI-H/dMMR status who received neoadjuvant treatment followed by D2 gastrectomy at the Affiliated Hospital of Qingdao University from January 2019 to June 2023. The outcomes of interest mainly included overall complete response (CR) rates, radiographical and pathological tumor response, treatment-related adverse events (TRAEs), and EFS.

RESULTS

In total, 30 patients were included in the analysis; 23 patients received neoadjuvant PD-(L)1 blockade plus chemotherapy or PD-(L)1 blockade monotherapy, and seven patients received neoadjuvant chemotherapy. In the PD-(L)1 blockade-based treatment group, 7 of 23 patients (30.4%, 95% CI 0.141-0.530) achieved pathological CR (pCR), while three patients with radiographical CR did not undergo surgery. In contrast, 1 of 7 (14.3%) patients in the neoadjuvant chemotherapy group achieved pCR. The overall CR rate was 43.5% (10 of 23, 95% CI 0.239-0.651) in the PD-(L)1 blockade-based treatment group and 14.3% (1 of 7, 95% CI 0.026-0.513) in the chemotherapy group. The neoadjuvant PD-(L)1 blockade-based treatment regimen was mild and well tolerated. By the latest follow-up, median EFS time was not reached in both cohorts.

CONCLUSION

In potentially resectable gastric cancer patients with MSI-H/dMMR status, PD-(L)1 blockade-based neoadjuvant treatment regimen provided promising clinical benefits and was well tolerated.

Prognostic significance of CD8 and TCF1 double positive T cell subset in microsatellite unstable gastric cancer

Microsatellite instability-high (MSI-H) gastric cancer (GC) exhibits high tumor-infiltrating lymphocyte (TIL) density. Despite the recognized significance of the immune microenvironment in MSI-H GC, our understanding of TIL remains limited. This study aimed to investigate the clinicopathologic and prognostic implications of T cell subsets in MSI-H GC. Single immunohistochemistry (IHC) for CD8, TCF1, and CD103, and double IHC for CD8/TCF1 and CD8/CD103 were performed in 382 surgically resected MSI-H GC samples. Densities of single or double positive immune cells were quantified and correlated with clinicopathologic features and overall survival (OS). TCF1 + cell densities showed weak correlations with CD8 + and CD103 + cell densities, while CD8+/TCF1 + cell density moderately correlated with CD8+/CD103 + cell density (R2 = 0.539, p < 0.001). Single IHC analyses showed no significant associations between CD8+, TCF1+, or CD103 + cell densities and OS (p > 0.05). Notably, elevated CD8+/TCF1 + cell density and a high CD8+/TCF1 + to CD8 + ratio correlated with less aggressive clinicopathologic features and improved OS (p = 0.017 and 0.001, respectively). Multivariable Cox-regression identified CD8+/TCF1 + to CD8 + ratio as an independent prognostic factor (p = 0.028). We demonstrated the prognostic significance of CD8+/TCF1 + to CD8 + ratio using double IHC in a large cohort of MSI-H GC.

SEOM-GEMCAD-TTD clinical guideline for the diagnosis and treatment of gastric cancer (2023)

Gastric cancer (GC) is the fifth most common cancer worldwide with a varied geographic distribution and an aggressive behavior. In Spain, the incidence is lower and GC represents the tenth most frequent tumor and the seventh cause of cancer mortality. Molecular biology knowledge allowed to better profile patients for a personalized therapeutic approach. In the localized setting, the multidisciplinary team discussion is fundamental for planning the therapeutic approach. Endoscopic resection in very early stage, perioperative chemotherapy in locally advanced tumors, and chemoradiation + surgery + adjuvant immunotherapy for the GEJ are current standards. For the metastatic setting, biomarker profiling including Her2, PD-L1, MSS status is needed. Chemotherapy in combination with checkpoint inhibitors had improved the outcomes for patients with PD-L1 expression. Her2 positive patients should receive antiHer2 therapy added to chemotherapy. We describe the different evidences and recommendations based on the literature.

Identifying the signature of NAD+ metabolism-related genes for immunotherapy of gastric cancer

NAD (Nicotinamide Adenine Dinucleotide) -related metabolic reprogramming in tumor cells involves multiple vital cellular processes. However, the role of NAD metabolism in immunity and the prognosis of gastric cancer (GC) remains not elucidated. Here we identified and clustered 33 NAD + metabolism-related genes (NMRGs) based on 808 GC samples from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Survival analysis between different groups found a poor prognosis in the GC patients with high NMRGs expression. Gene SGCE, APOD, and PPP1R14A were identified and performed high expression in GC samples, while the qRT-PCR results further confirmed that their expression levels in GC cell lines were significantly higher than those from normal human gastric mucosa epithelial cells. Based on the single-cell analysis, Gene SGCE, APOD, and PPP1R14A can potentially be novel biomarkers of tumor-associated fibroblasts (CAFs). In parallel, the proliferation and migration of GC cells were significantly hampered following the knockdown of SGCE, APOD, and PPP1R14A, particularly APOD, we confirmed that APOD knockdown can inhibit β-catenin and N-cadherin expression, while promote E-cadherin expression. This study unveils a novel NMRGs-related gene signature, highlighting APOD as a prognostic biomarker linked to the tumor microenvironment. APOD drives GC cell proliferation and metastasis through the Wnt/β-catenin/EMT signaling pathway, establishing it as a promising therapeutic target for GC patients.

Effector Function Characteristics of Exhausted CD8+ T-Cell in Microsatellite Stable and Unstable Gastric Cancer

PURPOSE

Gastric cancer exhibits molecular heterogeneity, with the microsatellite instability-high (MSI-H) subtype drawing attention for its distinct features. Despite a higher survival rate, MSI-H gastric cancer lack significant benefits from conventional chemotherapy. The immune checkpoint inhibitors, presents a potential avenue, but a deeper understanding of the tumor immune microenvironment of MSI-H gastric cancer is essential.

MATERIALS AND METHODS

We explored the molecular characteristics of CD8+ T-cell subtypes in three MSI-H and three microsatellite stable (MSS) gastric cancer samples using single-cell RNA sequencing and spatial transcriptome analysis.

RESULTS

In MSI-H gastric cancer, significantly higher proportions of effector memory T cell (Tem), exhausted T cell (Tex), proliferative exhausted T cell (pTex), and proliferative T cell were observed, while MSS gastric cancer exhibited significantly higher proportions of mucosal-associated invariant T cell and natural killer T cell. In MSI-H gastric cancer, Tex and pTex exhibited a significant upregulation of the exhaustion marker LAG3, as well as elevated expression of effector function markers such as IFNG, GZMB, GZMH, and GZMK, compared to those in MSS gastric cancer. The interferon γ (IFN-γ) signaling pathway of Tex and pTex was retained compared to those of MSS gastric cancer. The spatial transcriptome analysis demonstrates the IFN-γ signaling pathway between neighboring Tex and malignant cell, showcasing a significantly elevated interaction in MSI-H gastric cancer.

CONCLUSION

Our study reveals novel finding indicating that IFN-γ signaling pathway is retained in Tex and pTex of MSI-H gastric cancer, offering a comprehensive perspective for future investigations into immunotherapy for gastric cancer.

Prognostic significance of microsatellite instability in patients with resectable gastric cancer

BACKGROUND

Microsatellite instability (MSI) gastric cancer (GC) generally has a better prognosis than microsatellite-stable (MSS) GC and has been associated with nonsurvival benefit with the addition of chemotherapy (CMT) compared with surgery alone. However, patients with MSI have distinct clinicopathological characteristics. This study aimed to compare the survival outcomes between patients with MSI GC and those with MSS GC. In addition, this study analyzed the survival outcomes of patients with MSI GC who received CMT.

METHODS

This study reviewed all patients with GC who underwent curative gastrectomy. Patients were divided into MSI group and the MSS group. Propensity score matching (PSM) was used to match clinicopathological factors.

RESULTS

Among the 378 patients enrolled, 78 (20.6%) had MSI. Older age (P < .001), subtotal gastrectomy (P = .008), pN0 (P = .020), and earlier pTNM stage (P = .012) were associated with MSI GC. Survival analysis showed better disease-free survival (DFS) and overall survival (OS) of patients in the MSI group (P = .012 and P = .019, respectively). After PSM, 78 patients were matched to each group. All variables assigned to the scores were well matched, and both groups became equivalent. After the matching, the differences in DFS and OS according to MSI/MSS status were estimated to be larger than before (DFS: 63.3% vs 41.4%; P = .002; OS: 65.8% vs 42.5%; P = .002). Regarding patients referred for CMT, there was no difference in DFS and OS between patients with MSI GC who underwent CMT and those who underwent surgery alone (P = .255 and P = .178, respectively).

CONCLUSION

Even after controlling for clinicopathological characteristics, MSI was identified as a prognostic factor for patient survival. MSI GC showed no significant survival benefit with the addition of CMT.

Systemic Therapy of Gastric Cancer-State of the Art and Future Perspectives

Background: The prognosis of patients diagnosed with locally advanced and metastatic gastric and esophago-gastric junction cancer is critical. The optimal choice of systemic therapy is essential to optimize survival outcomes. Methods: A comprehensive literature review via PubMed and analysis of major oncology congresses (European Society for Medical Oncology and American Society of Clinical Oncology websites) were conducted to ascertain the current status and latest developments in the systemic treatment of patients with localized or advanced gastric and esophago-gastric junction adenocarcinoma. Results: While neoadjuvant and perioperative chemotherapy for localized tumor stages is the preferred approach in the Western Hemisphere, adjuvant chemotherapy remains the preferred course of action in East Asia. The administration of chemotherapy, typically in the form of combinations comprising platinum and fluoropyrimidine compounds in combination with docetaxel, represents a standard of care. Investigations are underway into the potential of immunotherapy and other biologically targeted agents in the perioperative setting. To select the most appropriate therapy for advanced gastric cancer, including adenocarcinoma of the esophago-gastric junction, it is essential to determine biomarkers such as HER2 expression, PD-L1 combined positive score (CPS) (combined positive score), Claudin 18.2, and microsatellite instability (MSI). In the present clinical context, the standard first-line therapy is a combination of fluoropyrimidine and a platinum derivative. The selection of chemotherapy in combination with antibodies is contingent upon the specific biomarker under consideration. Conclusions: This article reviews the current state of the art based on recent clinical trial results and provides an outlook on the future of systemic therapy.

Gastric Cancer: An Up-to-Date Review with New Insights into Early-Onset Gastric Cancer

Gastric cancer (GC) is the fifth most frequently diagnosed cancer and the fifth most common cause of cancer death in the world. Regarding the age at which the diagnosis was made, GC is divided into early-onset gastric cancer (EOGC-up to 45 years of age) and conventional GC (older than 45). EOGC constitutes approximately 10% of all GCs. Numerous reports indicate that EOGC is more aggressive than conventional GC and is often discovered at an advanced tumor stage, which has an impact on the five-year survival rate. The median survival rate for advanced-stage GC is very poor, amounting to less than 12 months. Risk factors for GC include family history, alcohol consumption, smoking, Helicobacter pylori, and Epstein-Barr virus infection. It has been shown that a proper diet and lifestyle can play a preventive role in GC. However, research indicates that risk factors for conventional GC are less correlated with EOGC. In addition, the unclear etiology of EOGC and the late diagnosis of this disease limit the possibilities of effective treatment. Genetic factors are considered a likely cause of EOGC, as young patients are less exposed to environmental carcinogens. Research characterizing GC in young patients is scarce. This comprehensive study presents all aspects: epidemiology, risk factors, new treatment strategies, and future directions.

Potent therapeutic strategy in gastric cancer with microsatellite instability-high and/or deficient mismatch repair

Gastric cancer (GC) is a common malignancy that presents challenges in patient care worldwide. The mismatch repair (MMR) system is a highly conserved DNA repair mechanism that protects genome integrity during replication. Deficient MMR (dMMR) results in an increased accumulation of genetic errors in microsatellite sequences, leading to the development of a microsatellite instability-high (MSI-H) phenotype. Most MSI-H/dMMR GCs arise sporadically, mainly due to MutL homolog 1 (MLH1) epigenetic silencing. Unlike microsatellite-stable (MSS)/proficient MMR (pMMR) GCs, MSI-H/dMMR GCs are relatively rare and represent a distinct subtype with genomic instability, a high somatic mutational burden, favorable immunogenicity, different responses to treatment, and prognosis. dMMR/MSI-H status is a robust predictive biomarker for treatment with immune checkpoint inhibitors (ICIs) due to high neoantigen load, prominent tumor-infiltrating lymphocytes, and programmed cell death ligand 1 (PD-L1) overexpression. However, a subset of MSI-H/dMMR GC patients does not benefit from immunotherapy, highlighting the need for further research into predictive biomarkers and resistance mechanisms. This review provides a comprehensive overview of the clinical, molecular, immunogenic, and therapeutic aspects of MSI-H/dMMR GC, with a focus on the impact of ICIs in immunotherapy and their potential as neoadjuvant therapies. Understanding the complexity and diversity of the molecular and immunological profiles of MSI-H/dMMR GC will drive the development of more effective therapeutic strategies and molecular targets for future precision medicine.

Improving individualised therapies in localised gastro-oesophageal adenocarcinoma

Despite our increased understanding of the biological and molecular aspects of gastro-oesophageal tumourigenesis, the identification of prognostic or predictive factors remains challenging. Patients with resectable gastric and oesophageal adenocarcinoma are often treated similarly after surgical resection, regardless of their tumour biology, clinical characteristics, and histological treatment response. Substantial progress has been made in the past 5 years in managing patients with gastric or oesophageal adenocarcinoma, including the use of immune checkpoint inhibitors and new targeted therapies, leading to substantial improvements in clinical outcomes. These advancements have primarily been established in advanced and metastatic disease, while the management framework for local and locoregional disease is just beginning to shift. We provide an overview of existing data on biomarkers and tumour-related and host-related factors that are relevant to stratify patients into low-risk and high-risk recurrence groups, both before and after surgery, paving the way for more personalised treatment approaches.

The mechanism of RGS5 regulating gastric cancer mismatch repair protein

The incidence and mortality rates of gastric cancer (GC) remain alarmingly high worldwide, imposing a substantial healthcare burden. In this study, we utilized data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. A 4-gene prognostic model was developed to predict patient prognosis, and its accuracy was validated across multiple datasets. Patients with a low-risk score exhibited improved prognosis, elevated tumor mutation burden, heightened sensitivity to both immunotherapy and conventional chemotherapy. Notably, our investigation revealed that the key gene RGS5 positively modulates the expression of mismatch repair proteins via c-Myc. Furthermore, co-immunoprecipitation (COIP) assays demonstrated the interaction between RGS5 and c-Myc. Additionally, we confirmed that RGS5 regulates c-Myc through the ubiquitin-proteasome pathway. Moreover, RGS5 was identified as a positive regulator of PD-L1 expression and exhibited a negative correlation with the majority of immune cells. These findings underscore the potential of RGS5 as a novel biomarker and therapeutic target in the context of GC.

Management of esogastric cancer in older patients

Although esogastric cancers often affect patients over 75, there are no specific age-related guidelines for the care of these patients. Esogastric cancers have a poor prognosis and require multimodal treatment to obtain a cure. The morbidity and mortality of these multimodal treatments can be limited if care is optimized by selecting patients for neoadjuvant treatment and surgery. This can include a geriatric assessment, prehabilitation, renutrition, and more extensive use of minimally invasive surgery. Denutrition is frequent in these patients and is particularly harmful in older patients. While older patients may be provided with neoadjuvant chemotherapy or radiotherapy, it must be adapted to the patient's status. A reduction in the initial dose of palliative chemotherapy should be considered in patients with metastases. These patients tolerate immunotherapy better than systemic chemotherapy, and a strategy to replace chemotherapy with immunotherapy whenever possible should be evaluated. Finally, better supportive care is needed in patients with a poor performance status. Prospective studies are needed to improve the care and prognosis of elderly patients.

Combination of transcriptome and Mendelian inheritance reveals novel prognostic biomarker of CTLA-4-related lncRNAs and protective role of nitrogen metabolism pathway in lung adenocarcinoma development

OBJECTIVE

Since in the cancer setting, tumor cells may use cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) to evade the immune system. This study aimed to identify CTLA-4-related long non-coding RNAs (lncRNAs) and assess their roles in lung adenocarcinoma (LUAD) development.

METHODS

Clinical and genomic data were obtained from The Cancer Genome Atlas (TCGA), MSigDB and Gene Weaver. CTLA-4-related lncRNA-based gene signatures (CTLA4LncSigs) were identified using Cox regression, establishing a risk score model and an independent prognostic model. Enrichment analysis (GO/KEGG) was performed. Mendelian randomization (MR) analysis investigated the nitrogen metabolism and lung cancer relationship, with Bayesian weighted MR (BWMR) addressing uncertainties. Correlations with tumor microenvironment and drug sensitivity were explored.

RESULTS

Nineteen CTLA4LncSigs significantly influenced LUAD prognosis. The risk score demonstrated independence as a prognostic factor. Functional analysis revealed lncRNAs' impact on nitrogen metabolism. MR and BWMR confirmed the protective role of the nitrogen metabolism pathway in lung cancer.

CONCLUSION

Our study identifies CTLA-4-related lncRNAs associated with LUAD prognosis and uncovers a previously undiscovered protective role of the nitrogen metabolism pathway in combating LUAD development, providing new insights into potential therapeutic targets and prognostic biomarkers for this aggressive cancer subtype.

Adjuvant nivolumab plus chemotherapy versus placebo plus chemotherapy for stage III gastric or gastro-oesophageal junction cancer after gastrectomy with D2 or more extensive lymph-node dissection (ATTRACTION-5): a randomised, multicentre, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

In Asia, adjuvant chemotherapy after gastrectomy with D2 or more extensive lymph-node dissection is standard treatment for people with pathological stage III gastric or gastro-oesophageal junction (GEJ) cancer. We aimed to assess the efficacy and safety of adjuvant nivolumab plus chemotherapy versus placebo plus chemotherapy administered in this setting.

METHODS

ATTRACTION-5 was a randomised, multicentre, double-blind, placebo-controlled, phase 3 trial conducted at 96 hospitals in Japan, South Korea, Taiwan, and China. Eligible patients were aged between 20 years and 80 years with histologically confirmed pathological stage IIIA-C gastric or GEJ adenocarcinoma after gastrectomy with D2 or more extensive lymph-node dissection, with an Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1 and available tumour tissue for PD-L1 expression analysis. Patients were randomly assigned (1:1) to receive either nivolumab plus chemotherapy or placebo plus chemotherapy via an interactive web-response system with block sizes of four. Investigational treatment, either nivolumab 360 mg or placebo, was administered intravenously for 30 min once every 3 weeks. Adjuvant chemotherapy was administered as either tegafur-gimeracil-oteracil (S-1) at an initial dose of 40 mg/m2 per dose orally twice per day for 28 consecutive days, followed by 14 days off per cycle, or capecitabine plus oxaliplatin consisting of an initial dose of intravenous oxaliplatin 130 mg/m2 for 2 h every 21 days and capecitabine 1000 mg/m2 per dose orally twice per day for 14 consecutive days, followed by 7 days off treatment. The primary endpoint was relapse-free survival by central assessment. The intention-to-treat population, consisting of all randomly assigned patients, was used for analysis of efficacy endpoints. The safety population, defined as patients who received at least one dose of trial drug, was used for analysis of safety endpoints. This trial is registered with ClinicalTrials.gov (NCT03006705) and is closed.

FINDINGS

Between Feb 1, 2017, and Aug 15, 2019, 755 patients were randomly assigned to receive either adjuvant nivolumab plus chemotherapy (n=377) or adjuvant placebo plus chemotherapy (n=378). 267 (71%) of 377 patients in the nivolumab group and 263 (70%) of 378 patients in the placebo group were male; 110 (29%) of 377 patients in the nivolumab group and 115 (31%) of 378 patients in the placebo group were female. 745 patients received assigned treatment (371 in the nivolumab plus chemotherapy group; 374 in the placebo plus chemotherapy group), which was the safety population. Median time from first dose to data cutoff was 49·1 months (IQR 43·1-56·7). 3-year relapse-free survival was 68·4% (95% CI 63·0-73·2) in the nivolumab plus chemotherapy group and 65·3% (59·9-70·2) in the placebo plus chemotherapy group; the hazard ratio for relapse-free survival was 0·90 (95·72% CI 0·69-1·18; p=0·44). Treatment-related adverse events occurred in 366 (99%) of 371 patients in the nivolumab plus chemotherapy group and 364 (98%) of 374 patients in the placebo plus chemotherapy group. Discontinuation due to adverse events was more frequent in the nivolumab plus chemotherapy group (34 [9%] of 371 patients) than the placebo plus chemotherapy group (13 [4%] of 374 patients). The most common treatment-related adverse events were decreased appetite, nausea, diarrhoea, neutrophil count decreased, and peripheral sensory neuropathy.

INTERPRETATION

The results of this trial do not support the addition of nivolumab to postoperative adjuvant therapy for patients with untreated, locally advanced, resectable gastric or GEJ cancer.

FUNDING

Ono Pharmaceutical and Bristol Myers Squibb.