Abstract: Objective To explore the risk miRNAs during the development of gastric cancer, providing the evidence for early gastric cancer identification in upper gastrointestinal opportunistic screening. Methods The patients who underwent opportunistic screening population for upper gastrointestinal cancer in the Guangxi Medical University Cancer Hospital, the Affiliated Hospital of Youjiang Medical University for Nationalities, and Guilin People's Hospital from June 2021 to August 2023 were enrolled. A total of 107 healthy individuals, 71 patients with early gastric cancer, and 97 patients with advanced gastric cancer were selected. The differential expression of miRNAs was screened by using transcriptome sequencing, and the differential expression of miRNAs was validated by RT⁃qPCR in prospective blood samples of the 3 prospective groups. The diagnostic efficacy of miRNAs was evaluated by using receiver operating characteristic (ROC) curves. Results The differential gene analysis by transcriptome sequencing screened out 6 differentially expressed miRNAs in the development of gastric cancer development, including miR⁃3176, miR⁃885⁃5p, miR⁃203a⁃3p, miR⁃452⁃5p, miR⁃223⁃3p, and miR⁃219a⁃2⁃3p. RT⁃qPCR results showed that miRNA⁃452⁃5p was up⁃regulated in both the early gastric cancer and the advanced gastric cancer (all P<0.001). The ROC curves indicated that the area under the curve (AUC) of miRNA⁃452⁃5p for diagnosing early gastric cancer and advanced gastric cancer were 0.900 and 0.975, respectively. The AUC for distinguishing early gastric cancer and advanced gastric cancer was 0.843. Conclusions miRNA⁃452⁃5p demonstrates a good diagnostic efficacy in early gastric cancer, and may serve as a potential biomarker for the diagnosis of early gastric cancer by liquid biopsy.

Key words: Early gastric cancer, miRNA?452?5p, Biomarkers