Impact of endoscopic ultrasonography on the accuracy of T staging in esophageal cancer and factors associated with its accuracy: A retrospective study

The sensitivity and specificity of endoscopic ultrasound (EUS) for esophageal cancer are variable. The aim of the present study was to determine the accuracy of EUS for the T staging of esophageal cancer and to explore the factors that affect the accuracy. This was a retrospective study of patients with esophageal cancer who underwent EUS between January 2018 and September 2019 at the author's hospital. All patients underwent EUS, surgery, and pathological examination. The diagnostic value of ultrasound-based T (uT) staging was evaluated using the pathological T (pT) staging as the gold standard. Finally, 169 patients were included. Among the 169 patients, 37 were overstaged by EUS, 33 were understaged, and 99 were correctly staged. The overall accuracy of EUS was 58.6%. Sensitivity was low, at 0% to 70.8% depending upon the pT stage, but specificity was higher, at 71.0% to 100.0%, also depending upon the pT stage. The multivariable analysis revealed that highly differentiated tumors (odds ratio = 9.167, P = .041) and pT stage ≥T2 (odds ratio = 2.932, P = .004) were independent factors of accurate uT stage. The staging of esophageal cancer using EUS has low sensitivity but high specificity. Highly differentiated tumors and pT stage ≥2 tumors were associated with the accuracy of uT staging.