Gastric Neoplasms

Background: \- Recent advances in cancer research have led to new therapies to treat the disease. It is important to continue these advances and discover new ones. To do that, researchers need tissue samples from solid tumors. This study will collect such samples from people already scheduled to have a procedure at the National Institutes of Health Clinical Center (NIHCC). Objectives: \- To collect tissue samples for use in studying new ways to treat tumors. Eligibility: * Adults 18 years and older, with a precancerous or cancerous solid tumor who are scheduled to have surgery or a biopsy at the NIHCC. * Children under the age of 18 but who are older than 2 years of age are eligible to be enrolled on the research sample collection portion of this study if they will have a biopsy or surgery as part of their medical care. Design: * Before their procedure, participants will have a small blood sample taken. * Some participants will undergo leukapheresis. In this procedure, blood is removed through a tube in one arm and circulated through a machine that removes white blood cells. The blood, minus the white blood cells, is returned through a tube in the other arm. The procedure takes 3-4 hours. * For all participants, during the surgery or biopsy, pieces of the tumor and pieces of normal tissue near it will be removed for this study. The rest of the tumor or precancerous growth will be sent to a lab for analysis. * Participants will return to the clinic about 6 weeks after the operation for a routine checkup. Some may have to return for additional follow-up.

The goal of this clinical trial is to learn if Trastuzumab Rezetecan can treat advanced solid tumors with HER-2 expression in adult participants. The main question it aims to answer is: What is the objective response rate of Trastuzumab Rezetecan in adult patients with HER-2 expressed advanced solid tumors? Participants will receive intravenous infusion of Trastuzumab Rezetecan on Day 1 of each 21-day treatment cycle. The dosage is 4.8 mg/kg per cycle; participants with a body weight of 85 kg or above will receive a fixed dose of 408 mg every 3 weeks.

Estimating the prevalence of Helicobacter Pylori infection in newly diagnosed stomach cancers in the West-Indies will help to understand the epidemiology of this cancer, which is over-incident in the West Indies compared to France. In addition, the constitution of a biobank (tumor tissues, healthy tissues and serum) will allow to set up in a second time etiological studies to identify other risk factors in particular in connection with the exposure to environmental pollutants to adapt the prevention measures.

Endoscopic submucosal dissection (ESD) is an established treatment for early gastric cancer and precancerous lesions. Post-ESD artificial ulcers may lead to complications including delayed bleeding (3-15%) and prolonged healing. Current guidelines recommend high-dose proton pump inhibitors (PPIs), but evidence for additional mucosal protective agents remains limited. This study aims to evaluate whether combining sucralfate suspension with standard intravenous esomeprazole therapy improves ulcer healing and reduces complications after gastric ESD compared to esomeprazole alone. This is a prospective, randomized, controlled, outcome-assessor-blinded trial. A total of 120 patients undergoing gastric ESD will be randomly assigned 1:1 to receive either: * Intervention group: Intravenous esomeprazole 40mg twice daily (3 days) followed by oral esomeprazole 40mg once daily PLUS sucralfate suspension 1g twice daily for 8 weeks * Control group: Intravenous esomeprazole 40mg twice daily (3 days) followed by oral esomeprazole 40mg once daily for 8 weeks The primary outcome is ulcer reduction rate at 4 weeks post-ESD, assessed by endoscopy. Secondary outcomes include complete ulcer healing rate at 8 weeks, delayed bleeding rate, symptom scores, and safety parameters. This study will provide high-quality evidence regarding the role of sucralfate as an adjunctive therapy for post-ESD ulcer management and may inform future clinical guidelines.

The goal of this clinical trial is to evaluate the diagnostic accuracy of the AI-integrated Capsule Gastroscopy (ACG) system in simulated home-use conditions for detecting upper gastrointestinal (UGI) abnormalities. It will also compare the diagnostic accuracy and time efficiency of AI-assisted interpretation versus manual reading of ACG data. The main questions it aims to answer are: What is the diagnostic accuracy of the ACG system, using conventional esophagogastroduodenoscopy (EGD) as a standard of reference? Does AI-assisted ACG reading improve diagnostic accuracy or reduce reading time compared to manual ACG video reading? Researchers will compare ACG results to conventional EGD findings (standard of reference) to determine if ACG can serve as a reliable method for UGI disease detection in home scenarios. Participants will: Undergo an ACG examination in a simulated home environment. Complete an EGD procedure within 24 hours post-ACG ingestion.

This research study aims to evaluate the safety and determine the optimal dose of a new experimental drug, vvDD-hIL2 (vaccinia virus double-deleted human interleukin 2), in patients with advanced abdominal cancer. The study will involve three dose levels, with three to six patients enrolled at each level. vvDD-hIL2 is a genetically modified vaccinia virus, derived from the virus previously used for smallpox vaccination. The modification is intended to target and destroy tumors while minimizing harm to healthy tissues by stimulating the body's immune response. Participants will receive an injection of vvDD-hIL2 directly into their abdominal tumors at AHN West Penn. The study team will monitor for side effects and assess tumor response to the treatment. Active participation will last up to two months, involving seven clinic visits and approximately four lab visits at AHN West Penn Hospital. Visits will include standard of care procedures as well as study-specific tests and exams. Most visits will last one to two hours, with some extending to two to three hours. The drug administration day will require a twelve-hour visit. Effectiveness and side effects will be evaluated through blood draws, oral swabs, urinalysis and tissue biopsies. Tissue samples will be used for genomic analysis and stored for potential future research. Data collected may also be used for future research purposes. Previous human trials of vvDD-hIL2 have reported side effects such as pain, rash or inflammation at the injection site, low-grade fevers, flu-like symptoms, and fatigue. There is a rare risk of rash transmission to close contacts with skin openings, and information on limiting contact and managing rash development will be provided.

This study is a multicenter, prospective cohort study, which are planned to enroll at least 600 patients who diagnosed the primary gastric cancer (GC); around 50 patients with premalignant gastric lesions (PGLs) and early gastric neoplasias (EGC) treated by endoscopy resection; and no less than 600 healthy normal cohort participants, for more than 18 months in the Spanish population. All participants who enrolled in this registry will be questioned by the life habits survey; and clinical data and biological samples of these participants were analyzed in order to look for new diagnostic tools. The aim of this study is to evaluate clinical, endoscopic and molecular approaches to identify individuals with high-risk of GC. Thus, it would be allow the adoption of preventive measures to reduce mortality through early detection and/or the reduction of its incidence.