Safety and Efficacy of Pembrolizumab Monotherapy in Patients With Previously Treated Advanced Gastric and Gastroesophageal Junction Cancer: Phase 2 Clinical KEYNOTE-059 Trial

Study of immunosenescence in the occurrence and immunotherapy of gastrointestinal malignancies

In human beings heterogenous, pervasive and lethal malignancies of different parts of the gastrointestinal (GI) tract viz., tumours of the oesophagus, stomach, small intestine, colon, and rectum, represent gastrointestinal malignancies. Primary treatment modality for gastric cancer includes chemotherapy, surgical interventions, radiotherapy, monoclonal antibodies and inhibitors of angiogenesis. However, there is a need to improve upon the existing treatment modality due to associated adverse events and the development of resistance towards treatment. Additionally, age has been found to contribute to increasing the incidence of tumours due to immunosenescence-associated immunosuppression. Immunosenescence is the natural process of ageing, wherein immune cells as well as organs begin to deteriorate resulting in a dysfunctional or malfunctioning immune system. Accretion of senescent cells in immunosenescence results in the creation of a persistent inflammatory environment or inflammaging, marked with elevated expression of pro-inflammatory and immunosuppressive cytokines and chemokines. Perturbation in the T-cell pools and persistent stimulation by the antigens facilitate premature senility of the immune cells, and senile immune cells exacerbate inflammaging conditions and the inefficiency of the immune system to identify the tumour antigen. Collectively, these conditions contribute positively towards tumour generation, growth and eventually proliferation. Thus, activating the immune cells to distinguish the tumour cells from normal cells and invade them seems to be a logical strategy for the treatment of cancer. Consequently, various approaches to immunotherapy, viz., programmed death ligand-1 (PD-1) inhibitors, Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors etc are being extensively evaluated for their efficiency in gastric cancer. In fact, PD-1 inhibitors have been sanctioned as late late-line therapy modality for gastric cancer. The present review will focus on deciphering the link between the immune system and gastric cancer, and the alterations in the immune system that incur during the development of gastrointestinal malignancies. Also, the mechanism of evasion by tumour cells and immune checkpoints involved along with different approaches of immunotherapy being evaluated in different clinical trials will be discussed.

Deep learning radiomics analysis for prediction of survival in patients with unresectable gastric cancer receiving immunotherapy

Objective

Immunotherapy has become an option for the first-line therapy of advanced gastric cancer (GC), with improved survival. Our study aimed to investigate unresectable GC from an imaging perspective combined with clinicopathological variables to identify patients who were most likely to benefit from immunotherapy.

Method

Patients with unresectable GC who were consecutively treated with immunotherapy at two different medical centers of Chinese PLA General Hospital were included and divided into the training and validation cohorts, respectively. A deep learning neural network, using a multimodal ensemble approach based on CT imaging data before immunotherapy, was trained in the training cohort to predict survival, and an internal validation cohort was constructed to select the optimal ensemble model. Data from another cohort were used for external validation. The area under the receiver operating characteristic curve was analyzed to evaluate performance in predicting survival. Detailed clinicopathological data and peripheral blood prior to immunotherapy were collected for each patient. Univariate and multivariable logistic regression analysis of imaging models and clinicopathological variables was also applied to identify the independent predictors of survival. A nomogram based on multivariable logistic regression was constructed.

Result

A total of 79 GC patients in the training cohort and 97 patients in the external validation cohort were enrolled in this study. A multi-model ensemble approach was applied to train a model to predict the 1-year survival of GC patients. Compared to individual models, the ensemble model showed improvement in performance metrics in both the internal and external validation cohorts. There was a significant difference in overall survival (OS) among patients with different imaging models based on the optimum cutoff score of 0.5 (HR = 0.20, 95 % CI: 0.10-0.37, P < 0.001). Multivariate Cox regression analysis revealed that the imaging models, PD-L1 expression, and lung immune prognostic index were independent prognostic factors for OS. We combined these variables and built a nomogram. The calibration curves showed that the C-index of the nomogram was 0.85 and 0.78 in the training and validation cohorts.

Conclusion

The deep learning model in combination with several clinical factors showed predictive value for survival in patients with unresectable GC receiving immunotherapy.

Programmed cell death 1 inhibitor combined with chemotherapy compared to chemotherapy alone as first-line treatment in advanced gastric cancer patients: A real-world study

OBJECTIVE

Previous trials have revealed better treatment efficacy of programmed cell death 1 (PD-1) inhibitors combined with chemotherapy as first-line treatments than chemotherapy alone in advanced gastric cancer (GC) patients, but real-world evidence is still lacking. Hence, this real-world study aimed to investigate the efficacy and safety of PD-1 inhibitors plus chemotherapy as first-line treatments compared with chemotherapy alone in advanced GC patients.

METHODS

In total, 102 advanced GC patients were allocated into a combination group (receiving chemotherapy combined with a PD-1 inhibitor as a first-line treatment) (n = 48) or a chemotherapy group (receiving chemotherapy only as a first-line treatment) (n = 54) according to their actual treatment regimens.

RESULTS

The objective response rate (ORR) was greater in the combination group than in the chemotherapy group (25.0 % versus 9.3 %, P = 0.033), whereas the disease control rate (DCR) was not different between the groups (83.3 % versus 66.7 %, P = 0.054). Progression-free survival (PFS) was prolonged in the combination group than in the chemotherapy group (P = 0.018). The median (95 % confidence interval) PFS was 19.7 (12.2-27.2) months in the combination group and 16.5 (7.3-25.7) months in the chemotherapy group. Multivariate logistic regression analyses revealed that PD-1 inhibitors combined with chemotherapy were independently associated with an increased ORR (odds ratio: 4.180, P = 0.024), increased DCR (odds ratio: 2.928, P = 0.049), and prolonged PFS (hazard ratio: 0.388, P = 0.030). No difference was found in total or each specific grade III-IV adverse reaction between the groups (all P > 0.05).

CONCLUSION

Treatment with a PD-1 inhibitor plus chemotherapy as a first-line treatment shows better treatment efficacy with similar safety to that of chemotherapy alone in advanced GC patients.

The Evolving Role of Immunotherapy for Gastroesophageal Malignancies

The incorporation of immunotherapy has transformed the treatment landscape for advanced, unresectable, or metastatic gastroesophageal cancers (GECs), with improved survival outcomes. These improvements in outcomes for advanced GECs have led to clinical trials evaluating the role of immunotherapy in patients with resectable early-stage GECs. However, there remains a high burden of morbidity and mortality, and ongoing trials utilizing novel immunotherapy agents and combinations are underway. This review summarizes the findings of previous and ongoing clinical trials related to immunotherapy for patients with early- and late-stage GECs.

Reshaping the immune microenvironment and reversing immunosenescence by natural products: Prospects for immunotherapy in gastric cancer

Gastric cancer (GC) represents a global health-care challenge. Recent progress in immunotherapy has elicited attracted considerable attention as a viable treatment option through modulating the host immune system and unleashing pre-existing immunity, which has profoundly revolutionized oncology, especially GC. Nonetheless, low clinical response and intrinsic and acquired resistance remain persistently challenging. The microenvironment of GC comprising multifarious stromal cell types has remarkable immunosuppressive elements that may impact the efficacy of immunotherapy. Immunosenescence is increasingly regarded as a factor that contributes to cancer development, remodels the tumor microenvironment and affects the efficacy of immunotherapy. Natural products are at the forefront of traditional medicine. Senotherapeutics is a class of drugs and natural products capable of delaying, preventing, or reversing the senescence process (i.e., senolytics) or suppressing senescence-associated secretory phenotype (i.e., senomorphics). Emerging evidence supports that natural products can improve the efficacy of existing immunotherapy and expand their indications in GC mainly based upon remodeling the immunosuppressive microenvironment and reversing immunosenescence. The review provides an integrated review of previously reported and ongoing clinical trials with immunotherapeutic regimens in GC and discusses current challenges. Next, we focus on natural compounds that exert anti-GC functions and possess immunomodulatory properties. More attention is paid to the potential of these natural compounds in modulating the immune microenvironment and immunosenescence. Lastly, we discuss the nanomedicine that can overcome the deficiencies of natural products. Altogether, our review suggests the enormous potential of natural compounds in GC immunotherapy, and provides an important direction for future research.

Identification of CD66c as a potential target in gastroesophageal junction cancer for antibody-drug conjugate development

BACKGROUND

Gastroesophageal junction (GEJ) cancer exhibits unique biological characteristics and currently lacks specific targeted therapies. Given the clinical efficacy of antibody-drug conjugates (ADCs) in solid tumor treatment, we aimed to identify a novel ADC target and suitable payload for GEJ-targeted therapy.

METHODS

In this study, we conducted bioinformatic analyses of multi-omics data, including transcriptomics, proteomics, and phosphoproteomics, to identify CD66c as a promising ADC target for GEJ cancer. We then engineered a CD66c-directed antibody-drug conjugate (CD66c-DXd) incorporating a GGFG linker. The preclinical efficacy of CD66c-DXd was determined in multi GEJ xenograft models.

RESULTS

Proteomic analyses of 103 cases of GEJ cancer revealed that CD66c expression was significantly higher in tumoral tissues compared to normal tissues. Proteomic and phosphoproteomic analyses identified deruxtecan (DXd) as a potentially potent payload for ADCs targeting GEJ cancer. Furthermore, high CD66c expression in GEJ was associated with a significantly lower proportion of plasma cells. The drug-to-antibody ratio (DAR) of CD66c-DXd was determined to be 3.6. CD66c-DXd effectively and selectively ablated multiple human GEJ cell lines (OE-19, OE33 and SK-GT-4) without affecting non-malignant cells (GES-1) in vitro. Eventually, CD66c-DXd mediated potent and durable tumor regression in vivo with excellent safety profiles.

CONCLUSIONS

This preclinical study provides a strong rationale for the further development of CD66c-DXd as promising therapeutic candidates to treat advanced GEJ cancer. Additionally, the study demonstrates the robustness of the multi-omics data in identifying novel potential ADC targets and payloads.

RBBP8 Is a Prognostic Biomarker Associated With Response to Immune Checkpoint Inhibitors in Advanced Gastric Cancer

The current biomarkers for immune checkpoint inhibitor (ICI) therapy have several limitations, and new ones are being explored. Retinoblastoma-binding protein 8 (RBBP8) is associated with tumor-infiltrating immune cells (TIIC) and immune checkpoint molecules. Therefore, RBBP8 may serve as a novel biomarker for ICI therapy. Thus, in this study, we investigated the relationship between RBBP8 expression and the tumor immune environment in 58 patients with pathologic T3-4 gastric cancer who underwent radical gastrectomy. Immunohistochemistry of primary tumor specimens was performed to evaluate RBBP8, TIIC, and programmed cell death ligand 1 expression. Kaplan-Meier survival and prognostic factor analyses were also performed using Cox proportional hazards regression models. Patients were divided into RBBP8 high (HG, n=29) and low (LG, n=29) expression groups, using the median RBBP8 expression as the cutoff. The LG had a significantly worse overall survival rate than the HG (log-rank test, P =0.029). Furthermore, the overall survival rate of patients in LG who were treated with ICI (n=7) was worse than that of those in HG (n=9; log-rank P =0.005). Multivariate analysis identified extensive lymph node metastasis and low RBBP8 expression as independent prognostic factors. The HG and LG showed no significant difference in the number of TIICs; however, there was a difference in the number ratios of CD4+/CD8+ ( P =0.012) and CD4+/CD3+ cells ( P <0.001). Therefore, RBBP8 expression in patients with advanced gastric cancer is a prognostic marker that affects the proportion of CD4+ T-cell infiltration and may also be a biomarker for predicting ICI treatment response.

Discovery of mutations predictive of survival benefit from immunotherapy in first-line NSCLC: A retrospective machine learning study of IMpower150 liquid biopsy data

Predictive biomarker identification in cancer treatment has traditionally relied on pre-defined analyses, limiting discoveries to expected biomarkers and potentially overlooking novel ones predictive of therapy response. In this work, we develop a novel machine-learning approach capable of exploring full landscape of mutations and combinations and identify potentially new predictive biomarkers for chemoimmunotherapy. Utilizing the liquid biopsy dataset from 313 non-small cell lung cancer (NSCLC) patients in the Phase 3 Impower150 trial (NCT02366143), we developed the HRdiffRF algorithm with a novel hazard ratio-splitting criterion. Predictive mutations and combinations were identified for overall survival (OS) improvement with atezolizumab plus bevacizumab plus carboplatin and paclitaxel (ABCP) compared to bevacizumab plus carboplatin and paclitaxel (BCP). Our analysis confirms the predictive role of KRAS mutations and reveals the predictive value of PTPRD and SMARCA4 mutations in chemoimmunotherapy efficacy. Unlike other KRAS wild-type NSCLC patients, NSCLC patients with KRAS wild-type status and mutations in FAT1, ERBB2, or PTPRD may benefit from chemoimmunotherapy, while NTRK3 and GNAS mutations could negatively impact survival. Patients harboring concurrent KRAS and KEAP1 mutations may not benefit from chemoimmunotherapy. These findings highlight the complex genetic factors influencing treatment response for chemoimmunotherapy in NSCLC. In summary, the proposed machine-learning tool identified potential predictive biomarkers for first-line chemoimmunotherapy in NSCLC and can be readily applied to other tumor types and studies. It can also be extended to explore predictive biomarkers beyond mutations.

The role and clinical significance of tumor-draining lymph nodes in tumor progression and immunotherapy

Tumor-draining lymph nodes (TDLNs) play a pivotal role in tumor growth and the immune response, activating immune cells such as CD8 + T cells and natural killer cells to combat tumors. However, tumors can subvert TDLNs to avoid immune attack. Initially, TDLNs stimulate a robust antitumor response, but as tumor evolve, they infiltrate with immunosuppressive cells that alter the TDLN environment and potentially promote metastasis. Immunotherapy, including immune checkpoint inhibitor (ICI), have emerged as a potential solution to this challenge by reconfiguring the TDLN environment to enhance immune responses and influence the immune status of the primary tumor. The integrity of the TDLNs is crucial for the efficacy of immunotherapy. Conventional surgery often removes TDLNs, but this may impede immune system function and the effectiveness of immunotherapy. It is therefore recommended that removal of TDLNs be considered after neoadjuvant treatment rather than before adjuvant treatment. Accurate identification of patients who require post-neoadjuvant TDLN removal and the determination of metastatic nodes is of paramount importance in tailoring treatment plans, optimizing of patient outcomes, and improving quality of life.

Artificial intelligence networks for assessing the prognosis of gastrointestinal cancer to immunotherapy based on genetic mutation features: a systematic review and meta-analysis

BACKGROUND AND AIM

Artificial intelligence (AI) networks offer significant potential for predicting immunotherapy outcomes in gastrointestinal cancers by analyzing genetic mutation profiles. Their application in prognosis remains underexplored. This systematic review and meta-analysis aim to evaluate the effectiveness of AI-based models, which refers to systems utilizing artificial intelligence to analyze data and make predictions, in predicting immunotherapy responses in gastrointestinal cancers using genetic mutation features.

METHODS

This study, adhering to PRISMA guidelines, aimed to evaluate AI networks for predicting gastrointestinal cancer prognosis in response to immunotherapy using genetic mutation features. A search in PubMed, WOS, and Scopus identified relevant studies. Data extraction and quality assessment were conducted, and statistical analysis included pooled estimates for sensitivity, specificity, accuracy, and AUC. Regression models and imputation methods addressed missing values, ensuring accurate and robust results. STATA version 18 was used to analyze the data.

RESULT

A total of 45 studies, all published in 2024, involving 14,047 participants in training sets and 10,885 participants in test sets, were included. The pooled results of AI model performance for gastrointestinal cancers based on genetic mutation features were: AUC = 0.86 (95% CI: 0.86-0.87), Sensitivity = 83% (95% CI: 83%-84%), Specificity = 72% (95% CI: 72%-73%), and Accuracy = 82% (95% CI: 82%-83%). Heterogeneity was low to moderate, and no publication bias was detected. Subgroup analysis showed higher AUC for gastric cancer models (AUC: 0.87) and lower for pancreatic cancer models (AUC: 0.52).

CONCLUSION

AI networks demonstrate promising potential in predicting immunotherapy outcomes for gastrointestinal cancers based on genetic mutation features. This systematic review highlights their effectiveness in stratifying patients and optimizing treatment decisions. However, further large-scale studies are needed to validate AI models and integrate them into clinical practice for improved precision in cancer immunotherapy.

Immune evasion strategies in AFP-producing gastric carcinoma: characterized by HLA-G expression and HLA class I deficiency

Alpha-fetoprotein-producing gastric carcinoma (AFPGC) is an aggressive subtype of gastric cancer characterized by a primitive cellular phenotype and poor prognosis. The tumor immunology of AFPGC remains largely unexplored. Given its embryonic-like properties, AFPGC is hypothesized to employ distinct immune evasion strategies, with the oncofetal protein human leukocyte antigen (HLA)-G-a key mediator of maternal-fetal immune tolerance-likely playing a pivotal role. To test this, we assessed the expression of HLA-G, along with other key immune evasion markers, including HLA class I (HLA-I) deficiency and PD-L1 expression, in 39 cases of AFPGC, and compared them with those of 44 Epstein-Barr virus (EBV)-positive, 57 microsatellite instability (MSI), 54 intestinal-type, and 45 diffuse-type gastric carcinomas. HLA-G expression was significantly higher in AFPGCs (71%) than in other subtypes (7-28%; P < 0.001). HLA-I deficiency (≥ 1% of tumor cells) was most prevalent in AFPGC (69%), followed by MSI tumors (56%), with lower rates in other subtypes (22-29%). PD-L1 positivity (combined positive score ≥ 5) was observed in 41% of AFPGCs, lower than in EBV-positive (77%) and MSI tumors (44%), but higher than in intestinal-type (13%) and diffuse-type (9%) carcinomas. Furthermore, CD8-positive T-cell infiltration was found to be lowest in AFPGC compared to the other subtypes. These findings suggest that AFPGC employs multiple immune evasion mechanisms, notably through increased HLA-G expression and HLA-I deficiency, likely linked to its primitive cellular phenotype and reactivation of immunogenic oncofetal antigens. Such immune evasion features may underlie the aggressiveness of AFPGC and present promising targets for immunotherapeutic interventions.

T-bet+CD8+ T cells govern anti-PD-1 responses in microsatellite-stable gastric cancers

More than 90% of advanced gastric cancers (GC) are microsatellite-stable (MSS). Compared to the high response rate of immune checkpoint inhibitors (ICI) in microsatellite-instability-high (MSI-H) GCs, only 10% of unstratified MSS GCs respond to ICIs. In this study, we apply semi-supervised learning to stratify potential ICI responders in MSS GCs, achieving high accuracy, quantified by an area under the curve of 0.924. Spatial analysis of the tumor microenvironment of ICI-sensitive GCs reveals a high level of T-bet+ CD8 + T cell infiltration in their tumor compartments. T-bet+ CD8 + T cells exhibit superior anti-tumor activity due to their increased ability to infiltrate tumors and secrete cytotoxic molecules. Adoptive transfer of T-bet+ CD8 + T cells boosts anti-tumor immunity and confers susceptibility to ICIs in immune-ignorant MSS GCs in a humanized mouse model. Spatial RNA sequencing suggests a positive-feedback loop between T-bet+ T cells and PD-L1+ tumor cells, which eventually drives T cell exhaustion and can therefore be leveraged for ICI therapy. In summary, our research provides insights into the underlying mechanism of anti-tumor immunity and deepens our understanding of varied ICI responses in MSS GCs.

Multiple primary tumors patient developed microsatellite stable gastric cancer after cadonilimab treatment for liver cancer: A case report

BACKGROUND

Multiple primary malignant tumors refer to the occurrence of two or more primary malignant tumors in the same organ or multiple organs or tissues at the same time or successively in the same patient, and can occur anywhere in the body. The treatment guidelines for patients with multiple primary malignant tumors are currently controversial.

CASE SUMMARY

A 51-year-old male patient with liver cancer and portal hypertension received 42 months of co-treatment with atezolizumab and bevacizumab. After that, the disease was rated stable disease. The patient was then diagnosed with gastric cancer. Since the patient was not sensitive to anti-programmed death ligand 1 immunosuppressive agents, a co-treatment with oxaliplatin, tegafur, apatinib, and cadonilimab was selected after multidisciplinary consultation and the patient's agreement. After four cycles of treatment, partial response and stable disease were observed in gastric and liver cancers, respectively. Surgical treatment was performed considering the high-risk factors of gastrointestinal bleeding in patients with gastroesophageal varices. Postoperative pathology showed that the Tumor Regression Grade was 1. Moreover, the genetic testing of postoperative tumor specimens indicated negative programmed death ligand 1 and microsatellite stability. In addition, the latest follow-up indicated an 8 and 40-month progression-free survival in gastric and liver cancer patients, respectively. Currently, the patient is receiving postoperative immunotherapy with cadonilimab.

CONCLUSION

Cadonilimab not only treats microsatellite stability gastric cancer patients but can also be used for liver cancer treatment.

First-Line Sugemalimab Plus Chemotherapy for Advanced Gastric Cancer: The GEMSTONE-303 Randomized Clinical Trial

Importance

Gastric cancer, including gastroesophageal junction cancer, is one of the most commonly diagnosed cancers worldwide, with high mortality. Sugemalimab is a fully human anti-programmed death-ligand 1 (PD-L1) antibody. The combination of sugemalimab and chemotherapy showed promising antitumor activity and safety in a phase 1b study among patients with treatment-naive, unresectable, locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. This combination was further evaluated in the GEMSTONE-303 phase 3 trial.

Objective

To evaluate the efficacy of sugemalimab in combination with capecitabine and oxaliplatin (CAPOX) compared with placebo plus CAPOX as first-line treatment for patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 combined positive score (CPS) of 5 or greater.

Design, Setting, and Participants

GEMSTONE 303 is a phase 3, randomized, double-blind, placebo-controlled study conducted at 54 sites in China that enrolled patients from April 9, 2019, through December 29, 2021, with follow-up to July 9, 2023. A total of 479 eligible patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 CPS of 5 or greater who did not receive any prior systemic therapy were randomized.

Intervention

Patients received sugemalimab (1200 mg intravenously) (n = 241) or placebo (n = 238) every 3 weeks for up to 24 months, plus CAPOX every 3 weeks for up to 6 cycles.

Main outcomes and Measures

Primary outcomes were overall survival and investigator-assessed progression-free survival.

Results

Baseline characteristics were well balanced between the 2 groups. Most patients were male (71.4% in sugemalimab group, 74.8% in placebo group). Median follow-up was 25.1 months in the sugemalimab group and 26.3 months in the placebo group. The sugemalimab group demonstrated significant improvements in overall survival (median, 15.6 months [95% CI, 13.3-17.8] vs 12.6 months [95% CI, 10.6-14.1]; hazard ratio, 0.75 [95% CI, 0.61-0.92]; P = .006) and progression-free survival (median, 7.6 months [95% CI, 6.4-7.9] vs 6.1 months [95% CI, 5.1-6.4]; hazard ratio, 0.66 [95% CI, 0.54-0.81]; P < .001). Grade 3 or higher treatment-related adverse events occurred in 53.9% of patients in the sugemalimab group and 50.6% in the placebo group.

Conclusions and Relevance

Sugemalimab plus chemotherapy significantly prolonged overall survival and progression-free survival with a manageable safety profile in previously untreated patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma.

Trial Registration

ClinicalTrials.gov Identifier: NCT03802591.

The role of the tumor microenvironment and inflammatory pathways in driving drug resistance in gastric cancer: A systematic review and meta-analysis

Tumor microenvironment (TME) plays a pivotal role in progression and low responsiveness to chemotherapy of gastric cancer (GC). The cascade of events that culminate with a sustained and chronic activation of inflammatory pathways underlies gastric tumorigenesis. Infiltrating immune cells enrolling in crosstalk with cancer cells that regulate inflammatory and immune status, generating an immunosuppressive TME that influences the response to therapy. Here we discuss the role of TME and the activation of inflammatory pathways to comprehend strategies to improve drug response. Furthermore, we provides systematic insight the role of TME cytotypes and related signatures reinforcing the critical roles of TAMs and Tregs, in promoting GC chemoresistance and tumor progression.

Epidemiology, pathogenesis, biology and evolving management of MSI-H/dMMR cancers

Deficiency in DNA mismatch repair (dMMR) is a common pathway of carcinogenesis across different tumour types and confers a characteristic microsatellite instability-high (MSI-H) molecular phenotype. The prevalence of the MSI-H/dMMR phenotype is highest in endometrial and colorectal cancers, and this phenotype is associated with a distinct tumour biology, prognosis and responsiveness to various anticancer treatments. In a minority of patients, MSI-H/dMMR cancers result from an inherited pathogenic variant in the context of Lynch syndrome, which has important implications for familial genetic screening. Whether these hereditary cancers have a different biology and clinical behaviour to their sporadic counterparts remains uncertain. Interest in this tumour molecular subtype has increased following the discovery of the high sensitivity of metastatic MSI-H/dMMR cancers to immune-checkpoint inhibitors (ICIs) in a histology-agnostic manner, which reflects the genomic hypermutation resulting from dMMR that renders these tumours highly immunogenic and immune infiltrated. This vulnerability is now also being exploited in early stage disease settings. Despite this common biological foundation, different MSI-H/dMMR cancers have histotype-specific features that correspond to their particular cell or tissue of origin, which might be associated with differences in prognosis and sensitivity to ICIs. In this Review, we provide an overview of the epidemiology, biology, pathogenesis, clinical diagnosis and treatment of MSI-H/dMMR tumours as a histology-agnostic cancer phenomenon. We also highlight peculiarities associated with specific pathogenetic alterations and histologies of MSI-H/dMMR tumours.

Host Tissue Factors Predict Immune Surveillance and Therapeutic Outcomes in Gastric Cancer

The immune composition of solid tumors is typically inferred from biomarkers, such as histologic and molecular classifications, somatic mutational burden, and PD-L1 expression. However, the extent to which these biomarkers predict the immune landscape in gastric adenocarcinoma-an aggressive cancer often linked to chronic inflammation-remains poorly understood. We leveraged high-dimensional spectral cytometry to generate a comprehensive single-cell immune landscape of tumors, normal tissue, and lymph nodes from patients in the Western Hemisphere with gastric adenocarcinoma. The immune composition of gastric tumors could not be predicted by traditional metrics such as tumor histology, molecular classification, mutational burden, or PD-L1 expression via IHC. Instead, our findings revealed that innate immune surveillance within tumors could be anticipated by the immune profile of the normal gastric mucosa. Additionally, distinct T-cell states in the lymph nodes were linked to the accumulation of activated and memory-like CD8+ tumor-infiltrating lymphocytes. Unbiased reclassification of patients based on tumor-specific immune infiltrate generated four distinct subtypes with varying immune compositions. Tumors with a T cell-dominant immune subtype, which spanned The Cancer Genome Atlas molecular subtypes, were exclusively associated with superior responses to immunotherapy. Parallel analysis of metastatic gastric cancer patients treated with immune checkpoint blockade showed that patients who responded to immunotherapy had a pretreatment tumor composition that corresponded to a T cell-dominant immune subtype from our analysis. Taken together, this work identifies key host-specific factors associated with intratumoral immune composition in gastric cancer and offers an immunological classification system that can effectively identify patients likely to benefit from immune-based therapies.

Advancements in immunotherapy for gastric cancer: Unveiling the potential of immune checkpoint inhibitors and emerging strategies

Gastric cancer (GC) is linked to high morbidity and mortality rates. Approximately two-thirds of GC patients are diagnosed at an advanced or metastatic stage. Conventional treatments for GC, including surgery, radiotherapy, and chemotherapy, offer limited prognostic improvement. Recently, immunotherapy has gained attention for its promising therapeutic effects in various tumors. Immunotherapy functions by activating and regulating the patient's immune cells to target and eliminate tumor cells, thereby reducing the tumor burden in the body. Among immunotherapies, immune checkpoint inhibitors (ICIs) are the most advanced. ICIs disrupt the inhibitory protein-small molecule (PD-L1, CTLA4, VISTA, TIM-3 and LAG3) interactions produced by immune cells, reactivating these cells to recognize and attack tumor cells. However, adverse reactions and resistance to ICIs hinder their further clinical and experimental development. Therefore, a comprehensive understanding of the advancements in ICIs for GC is crucial. This article discusses the latest developments in clinical trials of ICIs for GC and examines combination therapies involving ICIs (targeted therapy, chemotherapy, radiotherapy), alongside ongoing clinical trials. Additionally, the review investigates the tumor immune microenvironment and its role in non-responsiveness to ICIs, highlighting the function of tumor immune cells in ICI efficacy. Finally, the article explores the prospects and limitations of new immunotherapy-related technologies, such as tumor vaccines, nanotechnologies, and emerging therapeutic strategies, aiming to advance research into personalized and optimized immunotherapy for patients with locally advanced gastric cancer.

Proton pump inhibitors reduce nivolumab efficacy in unresectable advanced or recurrent gastric cancer

BACKGROUND

Proton pump inhibitors (PPI) have been shown to decrease the efficacy of immune checkpoint inhibitors in patients with various cancer types. However, there are few reports on their effect on patients with gastric cancer (GC). Therefore, we investigated the efficacy of nivolumab in patients with GC receiving PPI.

METHODS

This retrospective study analyzed data of patients who received nivolumab monotherapy for unresectable advanced or recurrent GC at Osaka Metropolitan University Hospital between September 2017 and December 2021. The primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS), respectively. PPI use was defined as within 30 days before and after initiation of nivolumab monotherapy.

RESULTS

Seventy-seven eligible patients were included in this analysis. PPIs were used in 33 patients, while 36 patients had a previous gastrectomy. Multivariate analysis revealed that only PPI use was an independent predictor of PFS (hazard ratio [HR] 1.93, 95% confidence interval [CI] 1.03-3.64, p = 0.042). Contrastingly, PPI use was not an independent predictor of OS.

CONCLUSION

PPIs may reduce the efficacy of nivolumab, and their use should be carefully considered in patients receiving nivolumab.

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.

Advances in Immunotherapy and Targeted Therapy for Gastric Cancer: A Comprehensive Review

Gastric cancer remains one of the most prevalent and lethal malignancies worldwide, characterized by poor survival rates, particularly in advanced stages. In recent years, a paradigm shift in gastric cancer treatment has been witnessed with the introduction of immunotherapy and targeted therapies. This review provides a detailed examination of current immunotherapeutic strategies, including adoptive cell therapy (ACT), immune checkpoint inhibitors (ICIs), and cancer vaccines. Additionally, it explores advancements in targeted therapies, focusing on the human epidermal growth factor receptor 2 (HER2) and vascular endothelial growth factor receptor (VEGFR) signaling pathways, as well as emerging targets such as claudin 18.2. Clinical trials investigating chimeric antigen receptor T-cell (CAR-T) therapy, T-cell receptor-engineered T-cell (TCR-T) therapy, and natural killer (NK) cell-based treatments have shown promise, particularly when combined with conventional chemotherapeutic regimens. However, challenges such as cytokine release syndrome, immune-related toxicities, and scalability issues remain significant. The combination of immunotherapy with targeted therapies represents a promising approach to enhance treatment outcomes. Future directions emphasize the need to overcome resistance mechanisms and refine treatment strategies to improve efficacy while reducing adverse effects. This review aims to elucidate the current landscape of immunotherapy and targeted therapy in gastric cancer and to explore their potential in shaping the future of clinical management for this devastating disease.

Advances and challenges in gastric cancer testing: the role of biomarkers

Advances in the identification of molecular biomarkers and the development of targeted therapies have enhanced the prognosis of patients with advanced gastric cancer. Several established biomarkers have been widely integrated into routine clinical diagnostics of gastric cancer to guide personalized treatment. Human epidermal growth factor receptor 2 (HER2) was the first molecular biomarker to be used in gastric cancer with trastuzumab being the first approved targeted therapy for HER2-positive gastric cancer. Programmed death-ligand 1 positivity and microsatellite instability can guide the use of immunotherapies, such as pembrolizumab and nivolumab. More recently, zolbetuximab has been approved for patients with claudin 18.2-positive diseases in some countries. More targeted therapies, including savolitinib for MET-positive patients, are currently under clinical investigation. However, the clinical application of these diagnostic approaches could be hampered by many existing challenges, including invasive and costly sampling methods, variability in immunohistochemistry interpretation, high costs and long turnaround times for next-generation sequencing, the absence of standardized and clinically validated diagnostic cut-off values for some biomarkers, and tumor heterogeneity. Novel testing and analysis techniques, such as artificial intelligence-assisted image analysis and multiplex immunohistochemistry, and emerging therapeutic strategies, including combination therapies that integrate immune checkpoint inhibitors with targeted therapies, offer potential solutions to some of these challenges. This article reviews recent progress in gastric cancer testing, outlines current challenges, and explores future directions for biomarker testing and targeted therapy for gastric cancer.

CXCR2P1 enhances the response of gastric cancer to PD-1 inhibitors through increasing the immune infiltration of tumors

Background

Recent years, immunotherapy has emerged as a pivotal approach in cancer treatment. However, the response of gastric cancer to immunotherapy exhibits significant heterogeneity. Therefore, the early identification of gastric cancer patients who are likely to benefit from immunotherapy and the discovery of novel therapeutic targets are of critical importance.

Materials and methods

We collected data from European Nucleotide Archive (ENA) and Gene Expression Omnibus (GEO) databases. In project PRJEB25780, we performed WGCNA analysis and Lasso regression and chose CXCR2P1 for the subsequent analysis. Then, we compared the expression difference of CXCR2P1 among different groups. Kaplan-Meier curve was used to analyze the prognostic value of CXCR2P1, which was validated by project IMvigor210 and GEO datasets. ESTIMATE and CIBERSORT algorithm were used to evaluate the reshaping effect of CXCR2P1 to immune microenvironment of tumor. Differentially expressed genes (DEG) analysis, enrichGO analysis, Gene Set Enrichment Analysis (GSEA) and co-expression analysis were used to explore the cell biological function and signaling pathway involved in CXCR2P1.

Results

WGCNA identified CXCR2P1 as a hub gene significantly associated with immune response to PD-1 inhibitors in gastric cancer. CXCR2P1 expression was elevated in responders and correlated with better prognosis. Functional analysis revealed its role in reshaping the tumor immune microenvironment by promoting immune cell infiltration, including M1 macrophages, activated CD4+ T cells, and follicular helper T cells. CXCR2P1 enhanced antigen presentation via the MHC-II complex, influenced key immune pathways, such as Toll-like receptor signaling and T-cell activation, which led to the up-regulation of expression of PD-L1. GSEA showed CXCR2P1 were correlated with microRNAs. Through DEG analysis and expression analysis, MIR215 was identified as a potential direct target of CXCR2P1.

Conclusion

High expression of CXCR2P1 is correlated with better response to PD-1 inhibitor. It reshapes the immune microenvironment by increasing immune infiltration and changing the fraction of immune cells. In tumor immune microenvironment, CXCR2P1 can promote inflammation, enhance antigen presentation and activate the PD-1/PD-L1-related signaling pathway, which might be achieved by CXCR2P1-MIR215 axis.

Applications and challenges of immunotherapy in the management of gastric adenocarcinoma: current status and future perspectives

Gastric adenocarcinoma (GAC) remains a significant global public health challenge, characterized by high incidence and mortality rates. Progress in tumor immunology has introduced immune checkpoint inhibitors (ICIs) targeting the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) pathways, demonstrating substantial potential in GAC therapy. Clinical research indicates that ICIs, particularly when combined with chemotherapy or targeted therapies, significantly enhance treatment efficacy in advanced GAC and specific molecular subtypes, including microsatellite instability-high (MSI-H) and human epidermal growth factor receptor 2 (HER2)-positive patients. However, immunotherapy is also associated with a range of immune-related adverse events (irAEs), necessitating effective management strategies to ensure treatment safety and maintain patients' quality of life. Future studies should focus on identifying new therapeutic targets, optimizing patient selection, and developing personalized treatment approaches to further improve the efficacy and safety of immunotherapy in GAC.

Comprehensive immunophenotyping of gastric adenocarcinoma identifies an inflamed class of tumors amenable to immunotherapies

BACKGROUND

Gastric adenocarcinoma (GAC) imposes a considerable global health burden. Molecular profiling of GAC from the tumor microenvironment perspective through a multi-omics approach is eagerly awaited in order to allow a more precise application of novel therapies in the near future.

METHODS

To better understand the tumor-immune interface of GAC, we identified an internal cohort of 82 patients that allowed an integrative molecular analysis including mutational profiling by whole-exome sequencing, RNA gene expression of 770 genes associated with immune response, and multiplex protein expression at spatial resolution of 34 immuno-oncology targets at different compartments (tumorous cells and immune cells). Molecular findings were validated in 595 GAC from the TCGA and ACRG external cohorts with available multiomics data. Prediction of response to immunotherapies of the discovered immunophenotypes was assessed in 1039 patients with cancer from external cohorts with available transcriptome data.

RESULTS

Unsupervised clustering by gene expression identified a subgroup of GAC that includes 52% of the tumors, the so-called Inflamed class, characterized by high tumor immunogenicity and cytotoxicity, particularly in the tumor center at protein level, with enrichment of PIK3CA and ARID1A mutations and increased presence of exhausted CD8+ T cells as well as co-inhibitory receptors such as PD1, CTLA4, LAG3, and TIGIT. The remaining 48% of tumors were called non-inflamed based on the observed exclusion of T cell infiltration, with an overexpression of VEGFA and higher presence of TP53 mutations, resulting in a worse clinical outcome. A 10-gene RNA signature was developed for the identification of tumors belonging to these classes, demonstrating in evaluated datasets comparable clinical utility in predicting response to current immunotherapies when tested against other published gene signatures.

CONCLUSIONS

Comprehensive immunophenotyping of GAC identifies an inflamed class of tumors that complements previously proposed tumor-based molecular clusters. Such findings may provide the rationale for exploring novel immunotherapeutic approaches for biomarker-enriched populations in order to improve GAC patient's survival.

Mapping the landscape of gastric cancer immunotherapy: Bibliometric insights into advances and hotspots

BACKGROUND

Immunotherapy has surfaced as a promising therapeutic modality for gastric cancer (GC). A comprehensive review of advancements, current status, and research trends in GC immunotherapy is essential to inform future investigative efforts.

AIM

To delineate the trends, advancements, and focal points in immunotherapy for GC.

METHODS

We performed a bibliometric analysis of 2906 articles in English concerning GC immunotherapy published from 2000 to December 20, 2023, indexed in the Web of Science Core Collection. Data analysis and visualization were facilitated by CiteSpace (6.1.6R), VOSviewer v.1.6.17, and GraphPad Prism v8.0.2.

RESULTS

There has been an increase in the annual publication rate of GC immunotherapy research. China leads in publication volume, while the United States demonstrates the highest citation impact. Fudan University is notable for its citation frequency and publication output. Co-citation analysis and keyword frequency revealed and highlighted a focus on GC prognosis, the tumor microenvironment (TME), and integrative immunotherapy with targeted therapy. Emerging research areas include gastroesophageal junction cancer, adoptive immunotherapy, and the role of Treg cell in immunotherapy.

CONCLUSION

GC immunotherapy research is an expanding field attracting considerable scientific interest. With the clinical adoption of immunotherapy in GC, the primary goals are to enhance treatment efficacy and patient outcomes. Unlike hematological malignancies, GC's solid TME presents distinct immunological challenges that may attenuate the cytotoxic effects of immune cells on cancer cells. For instance, although CAR-T therapy is effective in hematological malignancies, it has underperformed in GC settings. Current research is centered on overcoming immunosuppression within the TME, with a focus on combinations of targeted therapy, adoptive immunotherapy, Treg cell dynamics, and precise prognosis prediction in immunotherapy. Additionally, immunotherapy's role in treating gastroesophageal junction cancer has become a novel research focus.

Hypercoagulation after neoadjuvant immunochemotherapy as a new prognostic indicator in patients with locally advanced gastric cancer undergoing surgery

BACKGROUND

Coagulation status is closely related to the progression of malignant tumors. In the era of neoadjuvant immunochemotherapy (NICT), the prognostic utility of coagulation indicators in patients with locally advanced gastric cancer (LAGC) undergoing new treatments remains to be determined.

AIM

To determine whether hypercoagulation is an effective prognostic indicator in patients with LAGC who underwent radical resection after NICT.

METHODS

A retrospective analysis of clinical data from 104 patients with LAGC, who underwent radical resection after NICT between 2020 and 2023, was performed. D-dimer and fibrinogen concentrations were measured one week before NICT, and again one week before surgery, to analyze the association between these two indicators and their combined indices [non-hypercoagulation (D-dimer and fibrinogen concentrations within the upper limit of normal) vs hypercoagulation (D-dimer or fibrinogen concentrations above the upper limit of normal)] with prognosis. After radical resection, patients were followed-up periodically. The median follow-up duration was 21 months.

RESULTS

Data collected after NICT revealed that the three-year overall survival (OS) and disease-free survival (DFS) rates the non-hypercoagulation group were significantly better than those in the hypercoagulation group [94.4% vs 78.0% (P = 0.019) and 87.0% vs 68.0% (P = 0.027), respectively]. Multivariate analysis indicated that hypercoagulation after NICT was an independent factor for poor postoperative OS [hazard ratio (HR) 4.436, P = 0.023] and DFS (HR 2.551, P = 0.039). Pre-NICT data demonstrated no statistically significant difference in three-year OS between the non-hypercoagulation and hypercoagulation groups (88.3% vs 84.1%, respectively; P = 0.443).

CONCLUSION

Hypercoagulation after NICT is an effective prognostic indicator in patients with LAGC undergoing radical gastrectomy.

Efficacy and safety of pembrolizumab in advanced gastric and gastroesophageal junction cancer: a systematic review and meta-analysis

BACKGROUND

Pembrolizumab, a PD-1 inhibitor, has shown potential for treating advanced gastric and gastroesophageal junction (GEJ) cancer. This meta-analysis evaluates its efficacy and safety, alone or combined with chemotherapy, in this population.

METHODS

A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. Databases including PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science were searched up to October 31, 2024. Twelve studies comprising 4,069 patients were included. The primary outcomes were overall survival (OS) and progression-free survival (PFS); secondary outcomes included objective response rate (ORR), adverse events (AEs), and grade ≥ 3 AEs. Effect sizes were calculated using mean differences (MDs) and odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Pembrolizumab combined with chemotherapy significantly improved OS (MD = 1.92 months; 95% CI: 0.94 to 2.91) and ORR (MD = 11.05%; 95% CI: 6.29 to 15.82) compared to chemotherapy alone. Pembrolizumab monotherapy did not show a significant effect on OS (MD = 0.24 months; 95% CI: -1.15 to 1.63) and was associated with a significant reduction in PFS (MD = -2.28 months; 95% CI: -2.85 to -1.71) compared to chemotherapy alone. For safety, pembrolizumab monotherapy significantly reduced the risk of AEs (OR = 0.68; 95% CI: 0.57 to 0.81) and grade ≥ 3 AEs (OR = 0.39; 95% CI: 0.30 to 0.51) compared to chemotherapy. Pembrolizumab combined with chemotherapy did not significantly alter the risk of AEs (OR = 1.01; 95% CI: 0.90 to 1.13) or grade ≥ 3 AEs (OR = 1.12; 95% CI: 0.99 to 1.27) compared to chemotherapy alone.

CONCLUSION

Pembrolizumab combined with chemotherapy improves survival and response rates with a manageable safety profile in advanced gastric and GEJ cancers. Monotherapy shows limited efficacy, highlighting the need for combination strategies and patient selection.

An interpretable machine learning model based on computed tomography radiomics for predicting programmed death ligand 1 expression status in gastric cancer

BACKGROUND

Programmed death ligand 1 (PD-L1) expression status, closely related to immunotherapy outcomes, is a reliable biomarker for screening patients who may benefit from immunotherapy. Here, we developed and validated an interpretable machine learning (ML) model based on contrast-enhanced computed tomography (CECT) radiomics for preoperatively predicting PD-L1 expression status in patients with gastric cancer (GC).

METHODS

We retrospectively recruited 285 GC patients who underwent CECT and PD-L1 detection from two medical centers. A PD-L1 combined positive score (CPS) of ≥ 5 was considered to indicate a high PD-L1 expression status. Patients from center 1 were divided into training (n = 143) and validation sets (n = 62), and patients from center 2 were considered a test set (n = 80). Radiomics features were extracted from venous-phase CT images. After feature reduction and selection, 11 ML algorithms were employed to develop predictive models, and their performance in predicting PD-L1 expression status was evaluated using areas under receiver operating characteristic curves (AUCs). SHapley Additive exPlanations (SHAP) were used to interpret the optimal model and visualize the decision-making process for a single individual.

RESULTS

Nine features significantly associated with PD-L1 expression status were ultimately selected to construct the predictive model. The light gradient-boosting machine (LGBM) model demonstrated the best performance for PD-L1 high expression status prediction in the training, validation, and test sets, with AUCs of 0.841(95% CI: 0.773, 0.908), 0.834 (95% CI:0.729, 0.939), and 0.822 (95% CI: 0.718, 0.926), respectively. The SHAP summary and bar plots illustrated that a feature's value affected the feature's impact attributed to the model. The SHAP waterfall plots were used to visualize the decision-making process for a single individual.

CONCLUSION

Our CT radiomics-based LGBM model may aid in preoperatively predicting PD-L1 expression status in GC patients, and the SHAP method may improve the interpretability of this model.

Cutting-Edge Therapy and Immune Escape Mechanisms in EBV-Associated Tumors

Epstein-Barr virus (EBV), the first identified human tumor virus, significantly influences the immune microenvironment of associated cancers. EBV-induced expression of viral antigens by tumor cells triggers immune recognition and elicits a pro-inflammatory response. While mild inflammation may help eliminate malignant cells, intense inflammation can accelerate tumor progression. Moreover, EBV can establish lifelong latency in human hosts, characterized by low immunogenicity of its proteins and noncoding RNAs. This enables tumor cells to evade immune detection and impair immune cell function, disrupting immune homeostasis. Consequently, EBV-associated malignancies pose a considerable public health challenge globally, often complicating the prognosis of cancer patients under conventional treatment. With deeper research into the oncogenic expressions and mechanisms of EBV, novel targeted therapies against EBV are gaining prominence. This review discusses recent advancements in understanding how EBV helps tumor cells evade immune surveillance and induce immune dysfunction. It also examines the clinical potential of targeting EBV-associated tumors, providing fresh perspectives on the mechanisms and therapeutic strategies for these cancers.

Development and Characterization of 4A7: A High-Affinity Monoclonal Antibody Targeting Claudin18.2

Purpose

Claudin18.2 has emerged as a promising therapeutic target due to its high expression in gastric (GC) and pancreatic cancers (PC). However, patients with advanced, unresectable, or metastatic GC or PC face poor prognoses, highlighting the urgent need for more effective Claudin18.2-targeted therapies.

Methods and Results

We developed 4A7, a fully human monoclonal antibody with superior affinity and specificity for Claudin18.2, using a rigorous positive and negative screening strategy to eliminate cross-reactivity with Claudin18.1. In vitro, 4A7 demonstrated significantly enhanced binding activity, as well as robust antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), outperforming IMAB362, a clinical investigational antibody. In vivo, 4A7 exhibited remarkable tumor growth inhibition both as a monotherapy and in combination with anti-mPD-1, achieving superior efficacy compared to IMAB362. Additionally, 4A7 demonstrated a higher degree of humanization and comparable stability, supporting its translational potential.

Conclusion

4A7 shows great promise as a next-generation therapeutic for Claudin18.2-positive cancers, offering improved efficacy and reduced immunogenicity. This study not only highlights 4A7's potential to address unmet clinical needs but also provides a foundation for future innovations in monoclonal antibody-based cancer therapy.

Society for Immunotherapy of Cancer (SITC) consensus statement on essential biomarkers for immunotherapy clinical protocols

Immunotherapy of cancer is now an essential pillar of treatment for patients with many individual tumor types. Novel immune targets and technical advances are driving a rapid exploration of new treatment strategies incorporating immune agents in cancer clinical practice. Immunotherapies perturb a complex system of interactions among genomically unstable tumor cells, diverse cells within the tumor microenvironment including the systemic adaptive and innate immune cells. The drive to develop increasingly effective immunotherapy regimens is tempered by the risk of immune-related adverse events. Evidence-based biomarkers that measure the potential for therapeutic response and/or toxicity are critical to guide optimal patient care and contextualize the results of immunotherapy clinical trials. Responding to the lack of guidance on biomarker testing in early-phase immunotherapy clinical trials, we propose a definition and listing of essential biomarkers recommended for inclusion in all such protocols. These recommendations are based on consensus provided by the Society for Immunotherapy of Cancer (SITC) Clinical Immuno-Oncology Network (SCION) faculty with input from the SITC Pathology and Biomarker Committees and the Journal for ImmunoTherapy of Cancer readership. A consensus-based selection of essential biomarkers was conducted using a Delphi survey of SCION faculty. Regular updates to these recommendations are planned. The inaugural list of essential biomarkers includes complete blood count with differential to generate a neutrophil-to-lymphocyte ratio or systemic immune-inflammation index, serum lactate dehydrogenase and albumin, programmed death-ligand 1 immunohistochemistry, microsatellite stability assessment, and tumor mutational burden. Inclusion of these biomarkers across early-phase immunotherapy clinical trials will capture variation among trials, provide deeper insight into the novel and established therapies, and support improved patient selection and stratification for later-phase clinical trials.

Revolutionary Cancer Therapy for Personalization and Improved Efficacy: Strategies to Overcome Resistance to Immune Checkpoint Inhibitor Therapy

Cancer remains a significant public health issue worldwide, standing as a primary contributor to global mortality, accounting for approximately 10 million fatalities in 2020 [...].

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.

Prognostic value of a novel myeloid-to-lymphoid ratio biomarker in advanced gastric cancer

BACKGROUND

Currently, immune checkpoint inhibitors (ICIs) have excellent performance in the clinical treatment of advanced gastric cancer (AGC). However, precisely selecting AGC patients who can benefit from immunotherapy is an urgent difficulty. In this study, we investigated the immunoprognostic role of myeloid-to-lymphocyte ratio (M:L) in AGC patients.

METHODS

We collected information on 268 AGC patients who were hospitalized in the Department of Medical Oncology of PLA General Hospital from December 2014 to May 2021. The patients were divided into low M: L group (< 3.76) and high M:L group (≥ 3.76). Survival differences between different M: L level groups at baseline and after treatment were analyzed by methods such as Kaplan-Meier, Cox or Logistic regression model.

RESULTS

Progression free survival (PFS) (5.8 months vs. 3.4 months, p = 0.001) and overall survival (OS) (14.1 months vs. 9.0 months, p = 0.001) were significantly longer in the low M:L group than in the high M:L group. After analyses of Cox regression modeling it was concluded that M:L was an independent prognostic factor for PFS (HR 1.371 95%CI 1.057-1.777 p = 0.017) and OS (HR 1.352 95%CI 1.003-1.824 p = 0.048), respectively. Subsequent subgroup analyses performed across immunotherapy lines, regimens, PD-1 inhibitor agents, and age groups revealed a poorer prognosis in the high M:L group. Notably, an increase in the value of M:L after treatment significantly increased the risk of poor prognosis.

CONCLUSIONS

M:L ≥ 3.76 is associated with poor prognostic outcomes in AGC patients receiving immunotherapy and may be a predictive biomarker of prognosis. This result needs to be confirmed by larger prospective studies.

Genomic Landscape of Late-Stage Gastric Cancer: Analysis From KEYNOTE-059, KEYNOTE-061, and KEYNOTE-062 Studies

PURPOSE

The Cancer Genome Atlas (TCGA) classifies gastric cancer (GC) into four molecular subtypes: Epstein-Barr virus-positive, microsatellite instability-high (MSI-H), genomically stable (GS), and chromosomal instability (CIN). This exploratory analysis compared the genomic landscape of late-stage GC from KEYNOTE-059, KEYNOTE-061, and KEYNOTE-062 studies with early-stage GC from TCGA and evaluated the genomic characteristics of late-stage GC in patients of Western and Asian origin.

MATERIALS AND METHODS

Using pretreatment tumor samples, bulk DNA was analyzed via whole-exome sequencing (WES; KEYNOTE-059/KEYNOTE-061) and FoundationOneCDx (KEYNOTE-062) to determine TCGA-defined molecular subtypes (only MSI-H is determinable from FoundationOneCDx), genomic alterations, homologous recombination deficiency (HRD), and tumor mutational burden (TMB); gene expression signatures were analyzed using RNA sequencing.

RESULTS

When comparing KEYNOTE-059/061/062 combined WES and FoundationOneCDx data with data from TCGA, the MSI-H subtype prevalence was numerically lower in patients of Western (5% v 22%) and Asian origin (5% v 19%). When comparing KEYNOTE-059/061 WES data with the TCGA data set, the GS subtype prevalence was numerically higher (36% v 21%) in patients of Western or Asian origin. Among subtypes in KEYNOTE-059/061, HRD scores and TMB trended highest in CIN and MSI-H subtypes, respectively. TP53 mutation was the most prevalent genomic characteristic per KEYNOTE-059/061/062 combined analysis in patients of Western or Asian origin. Gene expression signature distributions were generally similar between patients of Western and Asian origin.

CONCLUSION

Numerical differences in the prevalence of MSI-H and GS subtypes were observed between early-stage and late-stage GC. Genomic characteristics of late-stage GC were generally similar between patients of Western and Asian origin.

SUSD2+ cancer-associated fibroblasts in gastric cancer mediate the effect of immunosuppression and predict overall survival and the effectiveness of neoadjuvant immunotherapy

BACKGROUND

The expression patterns and functions of Sushi Domain Containing 2 (SUSD2) differ among various malignancies. This research aims to investigate the expression of SUSD2 and the role of the SUSD2+ cancer-associated fibroblasts (CAFs) for immunotherapy in gastric cancer.

METHODS

The expression of SUSD2 and specific markers (CD4, CD8, PD-1, TIGIT, TIM-3 and CD163) was determined using immunohistochemistry and multiplex immunofluorescence (mIHC) on paraffin sections. Flow cytometry and western blot were used to assess the expression of SUSD2 in fibroblasts from fresh samples. Also, analysis of single-cell and bulk RNA sequencing was employed to confirm the presence and characterize the function of SUSD2+ CAFs. The predictive power of indicators for neoadjuvant immunotherapy was evaluated via ROC curve analysis. Animal experiment was employed to validate the immunosuppressive effect of SUSD2+ CAFs.

RESULTS

SUSD2 is mainly expressed on fibroblasts within the tumors and the high infiltration of SUSD2+ CAFs went together with a poor survival and a more advanced tumor stage. Significantly, the joint use of SUSD2+ CAFs and CD8+ T cells demonstrated a remarkable ability to predict the efficacy of neoadjuvant immunotherapy superior to PD-L1 combined positive score. High SUSD2+ CAFs was correlated with resistance to immunotherapy as well as low CD8+ T infiltration and high exhausted T cell infiltration.

CONCLUSIONS

We have identified a novel subset of CAFs that could predict the survival and response to neoadjuvant immunotherapy of patients. The SUSD2+ CAFs have the potential to serve as a predictive biomarker and a promising target for immunotherapy.

Programmed cell death receptor 1 inhibitor Pembrolizumab in the treatment of advanced gastric cancer

This editorial discusses Christodoulidis et al's article, which appeared in the most recent edition. The clinical trials have demonstrated the programmed cell death receptor 1 (PD-1) inhibitor Pembrolizumab involved combination therapy can improve the efficacy of advanced gastric cancer (AGC). Pembrolizumab combined with chemotherapy can enhance its sensitivity, and further eliminate tumor cells that develop resistance to chemotherapy. The combination of Pembrolizumab and Trastuzumab targeting human epidermal growth factor receptor 2 showed improved prognosis. The overall toxic effects of Pembrolizumab are significantly lower than traditional chemotherapy, and the safety is controllable. PD-1 inhibitor Pembrolizumab sheds a light on the treatment of AGC and brings new hope to the clinical practice.

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.

Optimal early endpoint for second-line or subsequent immune checkpoint inhibitors in previously treated advanced solid cancers: a systematic review

BACKGROUND

The administration of second-line or subsequent immune checkpoint inhibitors (ICIs) in previously treated patients with advanced solid cancers has been clinically investigated. However, previous clinical trials lacked an appropriate primary endpoint for efficacy assessment. This systematic review aimed to explore the most optimal early efficacy endpoint for such trials.

METHODS

Phase 2 or 3 clinical trials involving patients with advanced solid cancers with disease progression following standard first-line therapy receiving second-line or subsequent ICI administration, with adequate survival outcome data, were included from PubMed, Embase, Web of Science, and Cochrane Library databases before February 2023. Quality assessment was conducted using the Cochrane tool and Newcastle-Ottawa Quality Assessment Scale for Cohort Studies for randomized controlled trials (RCTs) and non-randomized trials, respectively. Objective response rate (ORR) and progression-free survival (PFS) at 3, 6, and 9 months were investigated as potential early efficacy endpoint candidates for 12-month overall survival (OS), with a strong correlation defined as Pearson's correlation coefficient r ≥ 0.8.

RESULTS

A total of 64 RCTs comprising 22,725 patients and 106 non-randomized prospective trials involving 10,608 participants were eligible for modeling and external validation, respectively. RCTs examined 15 different cancer types, predominantly non-small-cell lung cancer (NSCLC) (17, 28%), melanoma (9, 14%), and esophageal squamous cell carcinoma (5, 8%). The median sample size of RCTs was 124 patients, and the median follow-up time was 3.2-57.7 months. The ORR (r = 0.38; 95% confidence interval [CI], 0.18-0.54) and PFS (r = 0.42; 95% CI, 0.14-0.64) exhibited weak trial-level correlations with OS. Within ICI treatment arms, the r values of ORR and 3-, 6-, and 9-month PFS with 12-month OS were 0.61 (95% CI, 0.37-0.79), 0.78 (95% CI, 0.62-0.88), 0.84 (95% CI, 0.77-0.90), and 0.86 (95% CI, 0.79-0.90), respectively. External validation of 6-month PFS indicated an acceptable discrepancy between actual and predicted 12-month OS.

CONCLUSIONS

In non-randomized phase 2 trials on second-line or subsequent ICI therapy in patients with advanced solid cancers, 6-month PFS could serve as an early efficacy endpoint. However, early efficacy endpoints are not recommended in RCTs to replace OS.

Efficacy and safety of sintilimab combined with trastuzumab and chemotherapy in HER2-positive advanced gastric or gastroesophageal junction cancer

Background

To evaluate the efficacy and safety of sintilimab in combination with trastuzumab and chemotherapy for HER2-positive advanced gastric/gastroesophageal junction cancer (GC/GEJC).

Methods

HER2-positive advanced GC/GEJC patients admitted to our department between January 2018 and October 2024 were included in this study. Patients who received sintilimab in combination with trastuzumab and chemotherapy were assigned to cohort A, while patients who received trastuzumab and chemotherapy alone were assigned to cohort B. The primary endpoints were progression-free survival (PFS) and overall survival (OS), while the secondary endpoints included disease control rate (DCR), objective response rate (ORR), and safety.

Results

A total of 103 patients were analyzed, with 46 in cohort A and 57 in cohort B. The ORR was 65.2% in cohort A compared to 40.4% in cohort B, while the DCR was 87.0% in cohort A and 70.2% in cohort B. The median follow-up duration was 14.0 months. Median PFS (mPFS) was 9.4 months (95% CI: 5.6-13.2) for cohort A and 7.4 months (95% CI: 6.1-8.7) for cohort B (p = 0.089). Median OS (mOS) was 16.4 months (95% CI: 11.5-21.3) in cohort A versus 14.2 months (95% CI: 11.2-17.2) in cohort B (p = 0.069). Adverse events were predominantly mild, and no treatment-related deaths occurred.

Conclusion

Sintilimab combined with trastuzumab and chemotherapy showed promising efficacy and acceptable safety in HER2-positive advanced GC/GEJC. However, no statistically significant improvement in survival outcomes was observed compared to trastuzumab and chemotherapy alone.

Metastatic gastric cancer in fit patients-a practical algorithm of treatment sequencing from the Brazilian Group of Gastrointestinal Tumours (GTG)

Recent advancements in biomarker-driven therapies have significantly transformed the treatment paradigm for unresectable metastatic gastric cancer (mGC). These innovations, however, have introduced not only issues related to accessibility but also complexities for treating physicians, particularly general oncologists, in selecting the most appropriate treatment for each patient and deciding on the best sequencing strategy. This manuscript presents an algorithm developed by the Brazilian Group of Gastrointestinal Tumours, designed to provide straightforward guidance in the management of unresectable mGC. This algorithm, grounded in evidence for fit patients, aims to streamline therapeutic decision-making in clinical practice, assuming the absence of access and resource constraints.

Association between adjuvant radiotherapy in adults with gastric cancer and risk of second primary malignancy: a retrospective cohort study using the Surveillance, Epidemiology and End Results database

OBJECTIVES

This study aims to assess the association between adjuvant radiotherapy and the development of second primary malignancies (SPMs) and identify its determinants in patients who have undergone surgical treatment for gastric cancer.

DESIGN

Retrospective cohort study using the Surveillance, Epidemiology and End Results (SEER) database.

SETTING

Cohorts (18 registries, 2000-2018, from SEER) were screened for any malignancy that developed after sufficient latency from diagnosis of surgically treated non-metastatic gastric cancer.

PARTICIPANTS

24 777 surgically treated gastric cancer cases were included in the cohort. Among them, 6128 patients underwent adjuvant radiotherapy.

OUTCOME MEASURES

The cumulative incidence of SPMs was estimated using Fine and Gray's competing risk model and the radiotherapy-correlated risks were calculated using Poisson regression analysis.

RESULTS

Among patients with sufficient latency, there was no significant association between radiotherapy and the risk of developing second primary solid malignancies (relative risk=1.05, 95% CI 0.83 to 1.33) or haematological malignancies (relative risk=1.17, 95% CI 0.62 to 2.11). Interestingly, radiotherapy was associated with a reduced cumulative incidence of second lung and bronchus cancer compared with no radiotherapy, with a 15-year incidence of 1.4%-3.17% (p<0.05). Radiotherapy was not associated with a significant increase in standardised incidence ratios of SPMs.

CONCLUSIONS

Adjuvant radiotherapy was not associated with an increased risk of developing SPMs in surgically treated patients with gastric cancer. Clinical trials are warranted to further verify the findings.

NALCN expression is down-regulated and associated with immune infiltration in gastric cancer

Background

NALCN has been identified as a tumor suppressor gene, and its role in human cancer progression has garnered significant attention. However, there is a paucity of experimental studies specifically addressing the relationship between NALCN and immune cell infiltration in gastric cancer (GC).

Methods

The expression levels of NALCN in tumor tissues, peripheral blood and gastric cancer cells lines from patients with GC were assessed using RNA sequencing, immunohistochemistry (IHC) staining and RT-qPCR. Data obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were utilized to investigate the correlation between NALCN expression and immune cell infiltration in GC. Subsequently, the relationship between NALCN expression and infiltrating immune cells in GC tissues was examined through immunofluorescence method. Additionally, in vitro experiments were conducted to evaluate the impact of NALCN knockdown on T cells function in GC cell lines.

Results

RNA sequencing analysis revealed that NALCN expression was significantly downregulated in GC tissues. Specifically, NALCN levels were lower in GC tumor tissues and plasma compared to adjacent non-tumor tissues and healthy controls. Consistent with these findings, the expression trend of NALCN mRNA in the GEO database mirrored the experimental results. Mechanistically, NALCN knockdown markedly enhanced cell proliferation, colony formation and migration while reducing apoptosis rates in AGS and GES-1 cells. Analysis of the TCGA database indicated a positive correlation between NALCN expression and the infiltration of B cells, cytotoxic cells, immature dendritic cells (iDC) cells, CD8+ T cells, and others in GC tissue. Conversely, Th17 and Th2 cells infiltration exhibited a negative correlation with NALCN expression. Immunofluorescence staining confirmed that B cells and CD8 T cells were more abundant in GC tumor tissues with high NALCN expression, whereas Th17 and Th2 cells were less prevalent. Subsequently, we co-cultured GC cells transfected with NALCN knockdown or control vectors along with their supernatants with T cells. The results demonstrated that NALCN knockdown in GC cells or their supernatants inhibited T cell proliferation compared to control conditions. Moreover, NALCN may play a role in glucose and glutamine uptake.

Conclusions

NALCN facilitates immune cell aggregation in GC and has potential as a biomarker for immune infiltration.

Targeted therapy and immunotherapy for gastric cancer: rational strategies, novel advancements, challenges, and future perspectives

Gastric cancer (GC) is one of the most common malignant tumors worldwide, and its treatment has been a focus of medical research. Herein we systematically review the current status of and advancements in targeted therapy and immunotherapy for GC, which have emerged as important treatment strategies in recent years with great potential, and summarize the efficacy and safety of such treatments. Targeted therapies against key targets in GC, including epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR), have shown remarkable therapeutic efficacies by inhibiting tumor progression and/or blood supply. In particular, markable breakthroughs have been made in HER2-targeting drugs for HER2-positive GC patients. To address intrinsic and acquired resistances to HER2-targeting drugs, novel therapeutic agents including bispecific antibodies and antibody-drug conjugates (ADC) targeting HER2 have been developed. Immunotherapy enhances the recognition and elimination of cancer cells by activating body anticancer immune system. Programmed cell death protein 1 (PD-1) and programmed cell death-ligand 1 (PD-L1) antibodies are the most commonly used immunotherapeutic agents and have been used with some success in GC treatment. Innovative immunotherapy modalities, including adoptive immune cell therapy, tumor vaccines, and non-specific immunomodulators therapy, and oncolytic viruses have shown promise in early-stage clinical trials for GC. Clinical trials have supported that targeted therapy and immunotherapy can significantly improve the survival and quality of life of GC patients. However, the effects of such therapies need to be further improved and more personalized, with advancement in researches on tumor immune microenvironment. Further studies remain needed to address the issues of drug resistance and adverse events pertaining to such therapies for GC. The combined application of such therapies and individualized treatment strategies should be further explored with novel drugs developed, to provide more effective treatments for GC patients.

Overcoming immunotherapy resistance in gastric cancer: insights into mechanisms and emerging strategies

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, with limited treatment options in advanced stages. Immunotherapy, particularly immune checkpoint inhibitors (ICIs) targeting PD1/PD-L1, has emerged as a promising therapeutic approach. However, a significant proportion of patients exhibit primary or acquired resistance, limiting the overall efficacy of immunotherapy. This review provides a comprehensive analysis of the mechanisms underlying immunotherapy resistance in GC, including the role of the tumor immune microenvironment, dynamic PD-L1 expression, compensatory activation of other immune checkpoints, and tumor genomic instability. Furthermore, the review explores GC-specific factors such as molecular subtypes, unique immune evasion mechanisms, and the impact of Helicobacter pylori infection. We also discuss emerging strategies to overcome resistance, including combination therapies, novel immunotherapeutic approaches, and personalized treatment strategies based on tumor genomics and the immune microenvironment. By highlighting these key areas, this review aims to inform future research directions and clinical practice, ultimately improving outcomes for GC patients undergoing immunotherapy.

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.

Predictable regulation of gut microbiome in immunotherapeutic efficacy of gastric cancer

Immunotherapy has showcased remarkable progress in the management of gastric cancer (GC), prompting the need to proactively identify and classify patients suitable for immunotherapy. Here, 30 patients were enrolled and stratified into three groups (PR, partial response; SD, stable disease; PD, progressive disease) based on efficacy assessment. 16S rRNA sequencing were performed to analyze the gut microbiome signature of patients at three timepoints. We found that immunotherapy interventions perturbed the gut microbiota of patients. Additionally, although differences at the enterotype level did not distinguish patients' immunotherapy response, we identified 6, 7, and 19 species that were significantly enriched in PR, SD, and PD, respectively. Functional analysis showed that betalain biosynthesis and indole alkaloid biosynthesis were significantly different between the responders and non-responders. Furthermore, machine learning model utilizing only bacterial biomarkers accurately predicted immunotherapy efficacy with an Area Under the Curve (AUC) of 0.941. Notably, Akkermansia muciniphila and Dorea formicigenerans played a significant role in the classification of immunotherapy efficacy. In conclusion, our study reveals that gut microbiome signatures can be utilized as effective biomarkers for predicting the immunotherapy efficacy for GC.

The Prognostic Significance of PD-L1 Expression and Associated Tumor-Infiltrating Lymphocytes in Supraglottic Laryngeal Squamous Cell Carcinoma

Laryngeal squamous cell carcinoma (LSCC) is characterized by diverse profiles of tumor-infiltrating lymphocytes (TILs). We aimed to investigate the potential prognostic role of TILs and programmed death-ligand 1 (PD-L1) in patients with supraglottic LSCC. The expression of PD-L1 and TILs was assessed using immunohistochemistry in 39 patients with primary supraglottic LSCC and correlated with clinicopathological characteristics and disease-free survival (DFS). Survival curves were measured using the Kaplan-Meier method, and differences in survival between the groups were estimated using the log-rank test. TIL density was significantly higher in PD-L1-positive (combined positive score: CPS ≥ 1) than in PD-L1-negative (CPS < 1) patients (p = 0.000). Lower PD-L1 expression was significantly associated with a locoregional recurrence (Fisher's exact test, p = 0.008). DFS was significantly longer in patients with CPS ≥ 1 than in those with CPS < 1 (Log-rank test, p = 0.004). Multivariate Cox regression analysis showed that a low CPS (p = 0.003) and positive nodal status (p = 0.012) were statistically significant and independent predictors of malignancy recurrence. PD-L1 represents a valuable marker for predicting recurrence and shorter survival after definitive therapy.