Endoscopic diagnostics and treatment of neuroendocrine tumors of the stomach

Introduction: Neuroendocrine tumors (NETs) of the gastrointestinal tract have increasingly been diagnosed in clinical practice in the last decade. The stomach is one of the most common locations for NETs (g-NEN), which account for less than 2% of all gastric neoplasms with an increasing incidence worldwide. The recent increase in the incidence of g-NEN is partly due to the widespread introduction of modern video endoscopes into clinical practice. g-NENs are often diagnosed incidentally during endoscopy and, as a rule, macroscopically look like common gastric polyps. Today, various endoscopic methods are used in the treatment of g-NEN, which in most cases are radical. Since g-NEN type M is the most common, a conservative approach based on endoscopic mucosal resection (EMR) with subsequent observation is preferable to surgical intervention for small neoplasms with a diameter of no more than 5 mm that do not infiltrate the muscularis mucosa. Endoscopic ultrasound (EUS) was recommended for lesions > 10 mm to determine the exact depth of tumor infiltration, to assess regional lymph node involvement and thus to confirm the appropriateness of EMR. The aim of this publication: was to describe our experience in the treatment of gastric carcinoid syndrome using endoscopic polypectomies, submucosal resections, both as independent methods and in combination with argon plasma coagulation (APC) and photodynamic therapy (PDT). Materials and methods: from January to December 2024, we performed 48 endoscopic interventions for gastric carcinoids. Results: Of these, 12 patients underwent removal of formations by polypectomies, 10 patients underwent endoscopic resections with simultaneous APC of small carcinoid areas, and 28 patients underwent submucosal dissections. In two patients, PDT was additionally performed in the post-manipulation period after submucosal dissections, since the resection zone was performed along pathological tissues. No complications were noted during the manipulations and in the post-manipulation period. Tumor removal was performed with a preliminary injection of saline with adrenaline or hyaluronic acid solution. After R0 EMR type Ì g-NEN, follow-up with upper gastrointestinal endoscopy was recommended every 6-12 months for the first three years and annually thereafter; after EMR type II or IIIg-NEN, annual follow-up was recommended. Conclusion: NEO (g-NEN) of type I and type II stomach have a low potential for metastasis. Type III gastric NEOS are usually more aggressive than types I and II, and are often metastatic at the time of diagnosis with an overall 5-year survival rate of 50% [1]. Given the increasing incidence and prevalence of NEO (g-NEN), gastroenterology, endoscopists will encounter NEO throughout their professional careers. Determining the exact stage of NEO is crucial for evaluating and treating a patient, as well as for understanding the overall prognosis of the disease. Many stomach diseases can be successfully treated by gastroenterologists and oncologists in close collaboration with experienced endoscopists.