Endoscopic ultrasonography for staging depth of invasion in early gastric cancer: A meta-analysis

Background and aim: Endoscopic ultrasonography (EUS) is a widely used imaging modality for detecting the depth of early gastric cancer (EGC) invasion. However, the studies pertaining to EUS for staging early gastric cancer have reported widely varied sensitivities and specificities. This study was conducted to estimate the overall diagnostic accuracy of EUS for staging the depth in EGCs.

Methods: The literatures were identified by searching in PubMed, Embase, and Web of Knowledge databases. Two reviewers independently extracted the information from the literatures for constructing 2 × 2 table. A random-effect model or a fixed-effect model was used to estimate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. A summary receiver operating characteristic curve also was constructed. Meta-regression and subgroup analysis were used to explore the sources of heterogeneity.

Results: The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of EUS for M staging were 76% (95% confidence interval [CI], 74-78%), 72% (95% CI, 69-75%), 3.67 (95% CI, 2.48-5.44), and 0.31 (95% CI, 0.24-0.40), respectively. For SM staging, these results were 62% (95% CI, 59-66%), 78% (95% CI, 76-80%), 2.99 (95% CI, 2.26-3.96), and 0.43 (95% CI, 0.32-0.57), respectively. For M/SM1 staging, they were 90% (95% CI, 88-92%), 67% (95% CI, 61-72%), 3.14 (95% CI, 2.08-4.73), and 0.12 (95% CI, 0.07-0.22), respectively. The area under the curve for mucosal, submucosal, and mucosal/minimal submucosal invasion staging were 0.85, 0.82, and 0.81, respectively.

Conclusions: Endoscopic ultrasonography only has a relatively low accuracy for staging the depth of invasion in EGCs. Accordingly, EUS may be not indispensable in the staging of EGCs.