The accuracy of endoscopic ultrasonography in differentiating mucosal from deeper gastric cancer

BACKGROUND AND AIM: With the advent of endoscopic mucosal resection and endoscopic submucosal dissection techniques, pretreatment differentiation between mucosal and deeper gastric cancer has become increasingly important. The aim of this study was to systematically review published data on the diagnostic performance of endoscopic ultrasonography (EUS) in differentiating between mucosal and deeper gastric cancer. METHODS: A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Two reviewers independently assessed the methodological quality of each study. Sensitivity and specificity of EUS were calculated for each study and a summary receiver operating characteristic curve (sROC) was constructed. Subgroup analyses were performed if results of individual studies were heterogeneous. RESULTS: The inclusion criteria were met by 18 studies. The studies had poor methodological quality. Sensitivity and specificity of EUS in detecting cancerous extension beyond the mucosa ranged from 18.2 to 100% (median 87.8%) and from 34.7 to 100% (median 80.2%), with an area under the sROC of 0.8924. There was significant heterogeneity in both sensitivities and specificities among the included studies (P < 0.0001). Studies which only included patients endoscopically suspected of having EGC and studies which only used transducer frequencies >= 15 MHz were homogeneous in sensitivities (P = 0.1828 and 0.4501, respectively). CONCLUSION: It is unclear yet whether EUS can accurately differentiate between mucosal and deeper gastric cancer. Factors that may influence its diagnostic performance should be further explored.