Gastric Cancer Biomarkers: From Cellular Identity to Precision Oncology

Abstract

Simple Summary Gastric cancer (GC) contains remarkable biological diversity, making it difficult to predict tumor behavior and select the most appropriate treatment. Although numerous biomarkers have been identified, they are usually discussed individually or grouped according to molecular pathways, which does not fully reflect how GC develops over time. This review proposes a different perspective by organizing biomarkers according to five fundamental biological questions that capture interconnected dimensions of gastric cancer biology, including gastric lineage identity, stemness, epithelial plasticity, immune evasion, and actionable oncogenic dependencies. Rather than representing a fixed sequence of events, these biological domains interact dynamically throughout tumor development and progression. By integrating biomarkers within a biology-oriented framework, this review provides a more coherent interpretation of tumor progression while linking tumor biology with diagnostic pathology and precision oncology. This approach may facilitate biomarker interpretation, support future multimarker strategies, and offer a practical framework for both researchers and clinicians investigating GC.