Early detection of gastric cancer beyond endoscopy - new methods.

Early detection of gastric cancer is remaining a challenge. This review summarizes current knowledge on non-invasive methods that could be used for the purpose. The role of traditional cancer markers such as CEA, CA 72-4, CA 19-9, CA 15-3, and CA 12-5 lies mainly in therapy monitoring than early detection. Most extensive studied biomarkers (pepsinogens, ABC method) are aiming at the detection of precancerous lesions with modest sensitivity for cancer. Tests based on the detection of cancer-specific methylation patterns (PanSeer), circulating proteins and mutations in circulating tumour DNA (CancerSEEK), as well as miRNA panels have demonstrated promising results bringing those closer to practice. More extensive research is required before tests based on the detection of circulating tumour cells, extracellular vesicles and cell-free RNA could reach the practice. Detection of volatile organic compounds in the human breath is a promising development; sensor technologies for this purpose could be very attractive in screening settings.