Atlas of Metastatic Gastric Cancer Links Ferroptosis to Disease Progression and Immunotherapy Response.

BACKGROUND & AIMS: Metastases from gastric adenocarcinoma (GAC) lead to high morbidity and mortality. Developing innovative and effective therapies requires a comprehensive understanding of the tumor and immune biology of advanced GAC. Yet, collecting matched specimens from advanced, treatment-naïve patients with GAC poses a significant challenge, limiting the scope of current research, which has focused predominantly on localized tumors. This gap hinders deeper insight into the metastatic dynamics of GAC. METHODS: We performed in-depth single-cell transcriptome and immune profiling on 68 paired, treatment-naïve, primary metastatic tumors to delineate alterations in cancer cells and their tumor microenvironment during metastatic progression. To validate our observations, we conducted comprehensive functional studies both in vitro and in vivo, using cell lines and multiple patient-derived xenograft and novel mouse models of GAC. RESULTS: Liver and peritoneal metastases exhibited distinct properties in cancer cells and dynamics of tumor microenvironment phenotypes, supporting the notion that cancer cells and their local tumor microenvironments co-evolve at metastatic sites. Our study also revealed differential activation of cancer meta-programs across metastases. We observed evasion of cancer cell ferroptosis via GPX4 up-regulation during GAC progression. Conditional depletion of Gpx4 or pharmacologic inhibition of ferroptosis resistance significantly attenuated tumor growth and metastatic progression. In addition, ferroptosis-resensitizing treatments augmented the efficacy of chimeric antigen receptor T-cell therapy. CONCLUSIONS: This study represents the largest single-cell dataset of metastatic GACs to date. High-resolution mapping of the molecular and cellular dynamics of GAC metastasis has revealed a rationale for targeting ferroptosis defense in combination with chimeric antigen receptor T-cell therapy as a novel therapeutic strategy with potential immense clinical implications.

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.

Presence of Fusobacterium nucleatum in relation to patient survival and an acidic environment in oesophagogastric junction and gastric cancers.

BACKGROUND: Fusobacterium nucleatum inhabits the oral cavity and affects the progression of gastrointestinal cancer. Our prior findings link F. nucleatum to poor prognosis in oesophageal squamous cell carcinoma via NF-κB pathway. However, its role in oesophagogastric junction and gastric adenocarcinoma remains unexplored. We investigated whether F. nucleatum influences these cancers, highlighting its potential impact. METHODS: Two cohorts of EGJ and gastric adenocarcinoma patients (438 from Japan, 380 from the USA) were studied. F. nucleatum presence was confirmed by qPCR, FISH, and staining. Patient overall survival (OS) was assessed based on F. nucleatum positivity. EGJ and gastric adenocarcinoma cell lines were exposed to F. nucleatum to study molecular and phenotypic effects, validated in xenograft mouse model. RESULTS: In both cohorts, F. nucleatum-positive EGJ or gastric adenocarcinoma patients had notably shorter OS. F. nucleatum positivity decreased in more acidic tumour environments. Cancer cell lines with F. nucleatum showed enhanced proliferation and NF-κB activation. The xenograft model indicated increased tumour growth and NF-κB activation in F. nucleatum-treated cells. Interestingly, co-occurrence of F. nucleatum and Helicobacter pylori, a known risk factor, was rare. CONCLUSIONS: F. nucleatum can induce the NF-κB pathway in EGJ and gastric adenocarcinomas, leading to tumour progression and poor prognosis.

Targeted and combination immunotherapies using biologics for gastric cancer: the state-of-the-art.

INTRODUCTION: Gastric adenocarcinoma (GAC) remains a prevalent cancer worldwide and its incidence is increasing in South America. The heterogenous nature of GAC makes advances in management challenging. AREAS COVERED: Despite challenges, recent therapeutic targets are individualizing treatment. For localized disease with microsatellite-instability-high/deficient mismatch repair, immunotherapy is now an adopted practice. In the advanced unresectable setting, those harboring human epidermal growth factor receptor-2 (HER2) expression continue to be a separate entity. EXPERT OPINION: Future targets are developing. Among these include claudin 18.2 (CLDN18.2), fibroblast growth factor receptor 2b (FGFR2b), and trophoblast cell surface antigen-2 (TROP-2). FDA approval of zolbetuximab's, an anti-CLDN 18.2 monoclonal antibody, is expected soon. Additionally, bemarituzumab, ananti-FGFR2b monoclonal antibody, has shown improvements in combination with chemotherapy in those with HER2 negative GAC with FGFR2 overexpression. This combination is now being investigated in a phase 3 trial. Lastly, TROP-2 has emerged as an exciting solid tumor target and study is expected in GAC. All three of these therapeutic targets have seen an abundance of drug development in recent years, and we anticipate newer targeted agents driving therapeutic decisions in GAC in the coming years.

SMARCA4 Mutations in Gastroesophageal Adenocarcinoma: An Observational Study via a Next-Generation Sequencing Panel.

BACKGROUND: The clinical impact of SMARCA4 mutations (SMARCA4ms) in gastroesophageal adenocarcinoma (GEA) remains underexplored. This study aimed to examine the association of SMARCA4ms with clinical outcomes and co-occurrence with other gene mutations identified through a next-generation sequencing (NGS) panel in GEA patients. METHODS: A total of 256 patients with metastatic or recurrent GEA who underwent NGS panel profiling at the MD Anderson Cancer Center between 2016 and 2022 were included. Comparative analyses were performed to assess clinical outcomes related to SMARCA4ms. The frequency and types of SMARCA4ms and their co-occurrence with other gene mutations were also examined. RESULTS: SMARCA4ms were identified in 19 patients (7.4%). These SMARCA4ms were significantly associated with non-signet ring cell subtype (p = 0.044) and PD-L1 positive expression (p = 0.046). No difference in survival between the SMARCA4m and SMARCA4-normal group was observed (p = 0.84). There were significant associations between SMARCA4ms and FANCA, IGF1R, KRAS, FANCL, and PTEN alterations. Notably, 15 of the 19 SMARCA4m cases involved SNV missense mutations, with frequent co-occurrences noted with TP53, KRAS, ARID1A, and ERBB2 mutations. CONCLUSIONS: These results serve as the first comprehensive examination of the relationship between SMARCA4ms and clinical outcomes in GEA.

Chemotherapy Plus Atezolizumab Pre- and Post-Resection in Localized Esophageal or Gastroesophageal Junction Adenocarcinomas: A Phase I/II Single-Arm Study.

Efforts to improve the prognosis for patients with locally advanced esophageal or gastroesophageal junction (GEJ) adenocarcinoma have focused on neoadjuvant approaches to increase the pathological complete response (pathCR) rate, improve surgical resection, and prolong event-free and overall survival (OS). Building on the recent evidence that PD-1 inhibition plus chemotherapy improves the OS of patients with metastatic GEJ adenocarcinoma, we evaluated whether the application of this strategy in the neoadjuvant setting would improve the pathological response. This single-center phase I/II trial evaluated the safety, toxicity, and efficacy of neoadjuvant atezolizumab with oxaliplatin and 5-fluorouracil (modified FOLFOX) followed by esophagectomy followed by atezolizumab. The primary objective goal was to achieve 20% pathCR. From the twenty enrolled patients, eighteen underwent resection and two (10%, 95% CI: 1.24-31.7%) achieved pathCR. After a median follow-up duration of 40.7 months, 11 patients had disease recurrence and 10 had died. The median disease-free and OS were 28.8 (95% CI: 14.7, NA) and 38.6 months (95% CI: 30.5, NA), respectively. No treatment-related adverse events led to death. Although modified FOLFOX plus atezolizumab did not achieve the expected pathCR, an acceptable safety profile was observed. Our results support the continued development of a more refined strategy (neoadjuvant chemotherapy plus perioperative immunotherapy/targeted agents) with molecular/immune profiling in parallel.

Human Epidermal Growth Factor Receptor-2 Gastric Adenocarcinoma: Expanding Therapy of a Recognized Target.

Human epidermal growth factor receptor-2 (HER2) is a well-known cancer target. Many HER2-targeted agents are marketed and being investigated. Unfortunately, these therapies lack consistent responses and outcomes amongst different tumors. Questions remain as to why HER2 biology is different in different tumor types. Gastric adenocarcinomas (GACs) demonstrate both intra- and inter-tumor HER2 expression heterogeneity and show discordance amongst primary and metastatic disease sites. This creates barriers in determining HER2 agents' effectiveness and contributes to the failure of some HER2-targeted agents in the treatment of HER2-positive advanced GACs. Trastuzumab deruxtecan, an antibody drug conjugate of trastuzumab with a topoisomerase inhibitor, was recently approved for the treatment of refractory HER2-positive advanced GAC patients. There are exciting and newer therapies under investigation. Examining resistance patterns (both adaptive and acquired) along with establishing a better understanding of the intra- and inter-tumor heterogeneity is necessary to ensure successful progress. Here we review the current status of HER2-targeted therapy in GACs. We additionally review newer therapies under investigation and their potential role in HER2 GACs.

Therapeutic Advances in the Treatment of Gastroesophageal Cancers.

Gastroesophageal cancers are a group of aggressive malignancies that are inherently heterogeneous with poor prognosis. Esophageal squamous cell carcinoma, esophageal adenocarcinoma, gastroesophageal junction adenocarcinoma, and gastric adenocarcinoma all have distinct underlying molecular biology, which can impact available targets and treatment response. Multimodality therapy is needed in the localized setting and treatment decisions require multidisciplinary discussions. Systemic therapies for treatment of advanced/metastatic disease should be biomarker-driven, when appropriate. Current FDA approved treatments include HER2-targeted therapy, immunotherapy, and chemotherapy. However, novel therapeutic targets are under development and future treatments will be personalized based on molecular profiling. Herein, we review the current treatment approaches and discuss promising advances in targeted therapies for gastroesophageal cancers.

Pharmaceutical advances in the treatment of gastric adenocarcinoma.

INTRODUCTION: Gastric adenocarcinoma (GAC) continues to be a prevalent global concern. Differences in incidence are predominantly due to geographic locations with Asia contributing to majority of cases. Another parallel challenge is due to heterogenous molecular and immune profiles of GAC along with varying clinicopathological features of patients. In most countries, GACs are diagnosed late in an advanced stage as the early detection infrastructure cannot be implemented or not feasible. Future advances in liquid biopsies could change all that. AREAS COVERED: The authors focus on the recent advances in the management of advanced GAC patients w but also address localized GAC. Herein, the authors review the most contemporary treatments and promising breakthroughs. EXPERT OPINION: The addition of immunotherapy to standard of care has changed the outlook of advanced GAC patients. The authors anticipate continued advances in the development of immunotherapy both in surgically resectable and unresectable GACs. Targeting the ERBB2 (HER2) protein pathway remains uniquely important in GACs with ERBB2 (HER2) protein positivity. Currently, many novel anti-ERBB2 (HER2) protein therapies are under investigation. The next generation of GAC patients will derive considerably more benefit as the therapeutic landscape becomes more complex coupled with challenges in biomarker platforms and new drug development.

Esophageal cancer: emerging therapeutics.

INTRODUCTION: Esophageal cancer (EC) is a worldwide healthcare concern and represents an aggressive malignancy. Squamous cell carcinoma (ESCC) and adenocarcinoma (EAC) are the two primary histological subtypes but have yet to vastly differ in management. Outcomes remain poor with current treatment approaches; however, recent progress is focused on distinguishing separate targets based on thistology. AREAS COVERED: Here we provide an overview of EC management via a historical review and recent discoveries. As noted in this review, targeted therapy has lagged behind other solid tumors. Over the previous decade, for EACs there were only two targeted therapies used in the advanced setting with limited benefits. ESCC progress was rather non-existent. We present current ongoing advancements that have occurred in the realm of immunotherapy and emerging new agents. EXPERT OPINION: It is becoming clearer that segregating these two histological subtypes in trials should be the goal of future trial designs. ESCC appears to be more amenable to immune modulation than EAC; however, we are navigating in exciting times as molecular interrogations of EC has expanded with the hope of making more rapid progress. There is still hard work ahead of us to painfully define subsets representing heterogeneity and then finding appropriate agents.

Nivolumab with or without chemotherapy for metastatic gastroesophageal cancers and future perspectives.

INTRODUCTION: Gastroesophageal cancers (GEC) are frequently found at the advanced stage. GEC treatment advancements have been limited and prognosis, therefore, remains poor. Through numerous clinical trials, the addition of immune checkpoint inhibitors, including nivolumab, to conventional therapy has demonstrated a survival benefit. AREAS COVERED: Here, we focus on the function of nivolumab in patients with advanced GECs. We discuss the most recent trials that led to nivolumab's incorporation into therapy and pathways forward. EXPERT OPINION: Nivolumab in combination with chemotherapy appears well tolerated, with only a small number of patients reporting severe toxicity; therefore, it may be possible to add additional biological agents to improve outcomes. A number of 'nivolumab plus other agents' is currently being investigated, and we anticipate continued advancement in GEC management in the coming years.

Preoperatively Treated Diffuse-Type Gastric Adenocarcinoma: Glucose vs. Other Energy Sources Substantially Influence Prognosis and Therapy Response.

Diffuse type of gastric adenocarcinoma (dGAC) generally confers a poor prognosis compared to intestinal type. Some dGACs are not avid on fluorine-18 fluoro-2-deoxy-D-glucose PET (FDG-PET) while others seem to consume glucose avidly. We analyzed the outcomes based on the avidity (high with standardized uptake value (SUV) > 3.5 or low with SUV ≤ 3.5) of the primary on baseline FDG-PET. We retrospectively selected 111 localized dGAC patients who had baseline FDG-PET (all were treated with preoperative chemotherapy and chemoradiation). FDG-PET avidity was compared with overall survival (OS) and response to therapy. The mean age was 59.4 years and with many females (47.7%). The high-SUV group (58 (52.3%) patients) and the low-SUV group (53 (47.7%) patients) were equally divided. While the median OS for all patients was 49.5 months (95% CI: 38.5-98.8 months), it was 98.0 months (95% CI: 49.5-NE months) for the low-SUV group and 36.0 months for the high-SUV (p = 0.003). While the median DFS for all patients was 38.2 months (95%CI: 27.7-97.6 months), it was 98.0 (95% CI: 36.9-NE months) months for the low-SUV group was and only 27.0 months (95% CI: 15.2-63.2 months) for the high-SUV group (p = 0.005). Clinical responses before surgery were more common in the low-SUV group but overall we observed only 4 pathologic complete responses in 111 patients. Our unique data suggest that if dGACs used glucose as an energy source then the prognosis was very poor while non-glucose sources improved prognosis. Multi-platform (including metabolomics) profiling of dGACs would yield useful biologic understanding.