Endoscopic prediction model for differentiating upper submucosal invasion (< 200 μm) and beyond in superficial esophageal squamous cell carcinoma

Esophageal endoscopic submucosal dissection (ESD) can be attempted in superficial esophageal squamous cell carcinoma (SESCC) invading the upper submucosal layer (SM1: invasion < 200 μm). This study aimed to determine endoscopic predictive features associated with beyond SM1 invasion in SESCC and establish a predictive model using the identified features. This study retrospectively analyzed 203 esophageal ESD for SESCC. Endoscopic images were reviewed by two endoscopists. Tumors were evaluated for main shape, sizes, and surface characteristics. The association between each endoscopic feature and beyond SM1 invasion was evaluated. Using the significant endoscopic features in multivariate analysis, a predictive model for beyond SM1 invasion in SESCC was established. Among 203 SESCCs, 40 (19.7%) invaded beyond SM1. Multivariate analysis revealed that surface nodularity [odds ratio (OR) 41.340, 95% confidence interval (CI) 8.492–201.252, p < 0.001], surface granularity (OR 18.682, 95% CI 4.818–72.440, p < 0.001), surface unevenness, (OR 4.107, 95% CI 1.160–14.543, p = 0.029), deep depression (OR 27.490, 95% CI 2.897–260.853, p = 0.004), and thick notch (OR 41.701, 95% CI 6.646–261.672, p < 0.001) were independently associated with beyond SM1 invasion. An established model showed an area under the curve of 0.921 with 95% CI 0.881–0.960. The best cut-off value showed the following: sensitivity, 0.85; specificity, 0.83; positive predictive value, 0.55; and negative predictive value, 0.96. In conclusion, endoscopic features can predict beyond SM1 invasion in SESCC. Our prediction model is potentially useful for screening ESD candidates in SESCC.