Gastric cancer (GC) is one of the most common and deadly cancers worldwide. Early detection offers the best chance for curative treatment and reducing its mortality. However

the optimal population-based early screening for GC remains unmet. Aberrant DNA methylation occurs in the early stage of GC

exhibiting cancer-specific genetic and epigenetic changes

and can be detected in the media such as blood

gastric juice

and feces

constituting a valuable biomarker for cancer early detection. Furthermore

DNA methylation is a stable epigenetic alteration

and many innovative methods have been developed to quantify it rapidly and accurately. Nonetheless

large-scale clinical validation of DNA methylation serving as tumor biomarkers is still lacking

precluding their implementation in clinical practice. In conclusion

after a critical analysis of the recent existing literature

we summarized the evolving roles of DNA methylation during GC occurrence

expounded the newly discovered noninvasive DNA methylation biomarkers for early detection of GC

and discussed its challenges and prospects in clinical applications.