To evaluate the diagnostic accuracy of oral contrast trans-abdominal ultrasonography (OCTU) for gastric cancer by performing a meta-analysis.

Research articles on the diagnosis of OCTU for gastric cancer published from January 2000 to December 2019 were comprehensively collected through searching PubMed, Web of Science, Wanfang Databases, and CNKI. The eligible articles were selected according to the inclusion and exclusion criteria. The QUADAS-2 scale was applied for methodology quality evaluation, R version 3.6.1 software was used to perform meta-analysis for diagnostic accuracy rate, and STATA 15 software was used to perform meta-analysis for the 2 × 2 table data.

Thirty articles consisting of 3613 patients were enrolled in this meta-analysis. The diagnostic accuracy of OCTU for gastric cancer and early gastric cancer was 94% (95%CI: 92%-95%) and 81% (95%CI: 74%-87%), respectively. Meta-regression analysis suggested that the research design might be a major heterogeneous source for accuracy rate. After subgroup analysis, the diagnostic accuracy for prospective studies was 96% (95%CI: 95%-97%). According to the searching criteria, 5 out of the 30 articles were finally included with complete data of the four-grid diagnostic table, including a total of 1675 subjects. The sensitivity of OCTU was 0.93 (95%CI: 0.89-0.95), specificity was 0.98 (95%CI: 0.86-1.00), positive likelihood ratio (LR +) was 37.19 (95%CI: 6.40-216.23), negative likelihood ratio (LR -) was 0.07 (95%CI: 0.05-0.11), and diagnostic advantage ratio (DOR) was 507.18 (95%CI: 91.18-2821.10). The area under the SROC (symmetric receiver operator characteristic curve) curve was 0.95 (95%CI: 0.92-0.96).

Our meta-analysis result indicated that OCTU is an accurate method for the diagnosis of gastric cancer. As a low-cost, non-invasive diagnostic technology, OCTU is recommended as a preliminary screening and risk stratification method for gastric cancer among asymptomatic populations.