Recent advances in exploring new blood-based biomarkers for the early diagnosis of gastric cancer

Gastric cancer (GC) is a prevalent and lethal malignancy worldwide, and the 5-year survival rate is less than 30%. The absence of distinctive symptoms often leads to late-stage diagnosis, contributing to a grim prognosis. Early detection is pivotal for improving the survival rates and outcomes of GC patients. Traditional diagnostic methods, including gastroscopy and histopathological examination, are restricted in the early diagnosis of GC. Conventional protein biomarkers, such as carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 72-4 (CA72-4), exhibit insufficient sensitivity and specificity for GC screening, which diminishes their clinical value. Recently, novel circulating biomarkers, such as circulating tumor cells (CTCs), circulating tumor cell DNA (ctDNA), and circulating free RNA (cfRNA), have emerged as promising candidates in the burgeoning field of liquid biopsy due to their superior sensitivity and specificity. This review focuses on the latest research on blood-based biomarkers for GC diagnosis and examines the clinical potentials and challenges associated with these emerging biomarkers.