Background: Previous assessments of endoscopic ultrasound (EUS) classification of esophageal cancer are dominated by symptomatic patients with advanced stage disease. Fewer data exist on EUS errors in a cohort balanced between early and advanced disease.
Purpose: Assess EUS errors in classification of esophageal cancer in a more balanced cohort, and identify clinical and tumor characteristics associated with EUS errors.
Methods: A total of 266 patients underwent EUS and esophagectomy without preoperative chemoradiotherapy. Pathologic classification of disease extent: 108 (41%) tumors were confined to the esophageal wall (pTis-pT2, pN0, pM0); 158 (59%) were advanced beyond (pT3-pT4, pN1, or pM1). Logistic regression analysis was performed to identify correlates of error in T classification and disease extent using 10 clinical and tumor characteristics (gender, age, dysphagia, weight loss, tumor length, location, traversability, morphology, histopathologic type, and histologic grade).
Results: EUS erroneously predicted pathologic T (pT) in 119 patients (45%). When T classification was dichotomized into tumors whose depth of invasion was not beyond the muscularis propria (pTis-pT2) and those beyond (pT3-pT4), errors occurred in 42 patients (16%). EUS erroneously predicted N classification in 67 patients (25%), and was insensitive to the presence of distant metastases. EUS misclassified disease extent in 40 patients (15%). Logistic regression analysis indicated that weight loss and tumor length were the only clinical and tumor characteristics correlated with EUS errors; more weight loss was associated with decreased odds of misclassification, while the odds of misclassification were four to six times greater for intermediate length tumors than for shorter tumors.
Conclusions: EUS errors, particularly in predicting pT, are more frequent than previously reported. Weight loss and tumor length are the only clinical and tumor characteristics correlated with EUS errors.