CURRENT CONCEPTS OF CLASSIFICATION AND MOLECULAR BIOLOGICAL FEATURES OF GASTROESOPHAGEAL JUNCTION TUMORS: A LITERATURE REVIEW

Marzhan A. Aitmagambetova, A. Tulyaeva, Nurgul M. Kereyeva, V. Begunov, A. Shengelbayeva

2026

Full text Open access: Hybrid Metadata (CSL-JSON)
DOI 10.52532/3135-3940-2026-2-789
Data confidence 70 medium
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Abstract

Relevance: Small intestinal bacterial overgrowth (SIBO) is a common disorder of the intestinal microbiota that can significantly affect gastrointestinal function, immune response, and metabolism. In patients with colorectal cancer (CRC), the risk of developing SIBO is increased due to anatomical and functional alterations of the intestine, the oncological process itself, surgical interventions, and chemo- and radiotherapy. Despite the growing interest in the role of the gut microbiota in CRC carcinogenesis and disease course, the prevalence, pathogenetic significance, and clinical consequences of SIBO in this patient population remain insufficiently studied.The study aimed to analyze and summarize current literature data on the prevalence, mechanisms of development, diagnostic approaches, and clinical significance of small intestinal bacterial overgrowth in patients with colorectal cancer.Materials and Methods: A structured narrative literature review was conducted for the period from January 2016 to June 2026. Publications were searched in the PubMed and Google Scholar databases using the following keywords: esophagogastric junction, adenocarcinoma, Siewert classification, American Joint Committee on Cancer/Tumor-Node-Metastasis (AJCC/TNM), molecular subtypes, The Cancer Genome Atlas (TCGA), proteomics, and personalized therapy. Full-text English-language publications containing data on the anatomical and topographic classification, molecular heterogeneity, clinicoprognostic significance, and therapeutic perspectives of esophagogastric junction tumors were included in the review.Results: The literature analysis demonstrated a high prevalence of SIBO in patients with CRC, particularly after surgical treatment and during anticancer therapy. SIBO was associated with increased gastrointestinal symptoms, impaired nutritional status, reduced quality of life, and a potential impact on the effectiveness of oncological treatment. Current diagnostic methods and approaches to the management of SIBO are discussed.Conclusion: SIBO is a clinically significant condition in patients with CRC and requires timely diagnosis and a comprehensive treatment approach. Further studies are needed to develop standardized management algorithms for this patient population.