A prospective multicenter study of the magnifying endoscopic evaluation of the invasion depth of superficial esophageal cancers.

Background Treatment strategies for superficial esophageal squamous cell carcinoma (SESCC) are determined mainly on the basis of the invasion depth. The Japan Esophageal Society (JES) developed a simplified magnifying endoscopic classification for estimating the invasion depth of SESCC. We aimed to evaluate its accuracy. Methods We prospectively applied the JES classification for estimating the invasion depth of SESCC to 204 consecutive lesions from 6 hospitals in Japan between April 2016 and October 2018. We analyzed the accuracy of the endoscopic diagnosis by adding the following two categories to the JES classification: ≥ 7 mm lesion in B2 vessels (defined as B2 ≥ 7 mm) and B2 vessels with inflammation (defined as B2i). Results After applying the exclusion criteria, 201 lesions remained in the analysis. The diagnostic value of type B1, B2, B3 vessels were as follows: sensitivity, 93.9%, 68.0%, 25.0%; specificity, 81.1%, 89.2%, 99.4%; positive predictive value (PPV), 95.6%, 47.2%, 75.0%; negative predictive value (NPV), 75.0%, 95.1%, 95.4%; and accuracy, 91.5%, 86.5%, 95.0%, respectively. A retrospective analysis showed that the diagnostic accuracy was higher in type B2 vessels (86.5% to 92.0%). An avascular area (AVA) was found in 55 (27%) of the 201 lesions, which tended to be associated with a deeper pathological diagnosis of each Type B vessel. In an additional analysis, B2 ≥ 7 mm and B2i improved the diagnostic accuracy of type B2 vessels from 86.5% to 92.0%. Conclusions The JES classification is useful for estimating the invasion depth of SESCC. The diagnostic accuracy for type B2 vessels was low, which may be improved by using B2 ≥ 7 mm and B2i.