Efficacy of Endoscopic Ultrasonography for Determining Clinical T Category for Esophageal Squamous Cell Carcinoma: Data From 1434 Surgical Cases

The efficacy of endoscopic ultrasonography (EUS) for determining T category is variable for esophageal squamous cell carcinoma (ESCC). We aimed to assess the efficacy of EUS in accurately identifying T category for ESCC based on the 8th AJCC Cancer Staging Manual. A retrospective analysis was conducted using a prospectively collected ESCC database from January 2003 to December 2015, in which all patients underwent EUS examination followed by esophagectomy. The efficacy of EUS was evaluated by sensitivity, specificity, and accuracy compared with pathological T category as gold standard. Overall survival of different EUS-T (uT) categories was assessed. In total, 1434 patients were included, of whom 58.2% were correctly classified by EUS, with 17.9% being overstaged and 23.9% being understaged. The sensitivity and accuracy of EUS for Tis, T1a, T1b, T2, T3, and T4a categories were 15.8 and 98.8%, 16.3 and 95.7%, 33.1 and 89.3%, 56.8 and 65.0%, 65.8 and 70.0%, and 27.3 and 97.5%, respectively. The survival difference between uT1a and uT1b was not statistically significant (p = 0.90), nor was that between uT4a and uT4b (p = 0.34). However, when uT category was integrated as uTis, uT1, uT2, uT3, and uT4, overall survival was clearly distinguished between the categories (p < 0.01). EUS is in general feasible for classifying clinical T category for ESCC. However, EUS should be used with caution for discriminating between Tis, T1a, and T1b disease, as well as T4 disease.