ABSTRACT
Gastric cancer is one of the most common tumors. It 5-year survival rate is low, mainly because of a late diagnosis. Endoscopy with gastric biopsies is suggested as the best and most effective diagnostic method for screening of gastric cancer. Because endoscopic screening is an invasive procedure and its higher inspection costs, technical requirements and poor patient compliance, it is difficult for a large-scale screening and early diagnosis of gastric cancer. Serology could be used as a non-invasive screening method for the detection of gastric cancer due to its convenience, relatively low cost, safety, high sensitivity and specificity. In this paper, micro RNA, long noncoding RNA, DNA methylation, circulating tumor cells, pepsinogen, gastrin and other serum markers are reviewed in the early diagnosis of gastric cancer.