Multi-omics landscapes across the gastritis-to-carcinoma sequence: Stage-specific molecular evolution and microenvironmental remodeling.

The progression from chronic gastritis to gastric cancer is a complex and multistep process. Early detection of this transition is critical for improving patient survival; however, the underlying molecular mechanisms remain incompletely understood. Recent advances in multi-omics technologies have provided powerful tools for high-resolution characterization of disease-associated molecular alterations. In this review, we summarize studies investigating the gastritis-to-carcinoma sequence using genomics, epigenomics, transcriptomics, proteomics, metabolomics, and microbiome analyses. Particular emphasis is placed on evidence from human cohorts, single-cell sequencing, and spatial transcriptomics, which have helped characterize cellular heterogeneity, immune microenvironment remodeling, and cell-cell interactions. We also discuss the role of the microbiome, particularly Helicobacter pylori, in disease progression. Integration of these multi-layered datasets can generate mechanistic hypotheses and candidate biomarkers, but most findings require independent validation before clinical implementation. Overall, multi-omics approaches provide valuable insights into gastric carcinogenesis while highlighting the need for cautious interpretation and translational validation.