Accuracy of endoscopic ultrasound in the diagnosis of T2N0 esophageal cancer

Abstract

Background: Accurate staging of esophageal carcinoma (EC) is important since it directs further management. Endoscopic ultrasound (EUS) is the best tool available in the locoregional staging of EC; however, differentiating depth of tumor invasion (T) and nodal involvement (N) can be challenging. Accurate staging is particularly important to differentiate T1-2 N0 cancers, which can proceed directly to surgical resection versus TXN1 or T3N0/1 cancers, which benefit from induction chemoradiation prior to surgery. We report the accuracy of EUS staging for cT2N0 lesions.

Patients and interventions: Six hundred six patients underwent EUS for staging of EC between October 2003 and February 2013 by a single interventional endoscopist specially trained in endoscopic ultrasound. Thirty-eight patients were diagnosed with T2N0 tumors and underwent surgical resection without preoperative chemoradiation. EUS staging was compared to surgical pathology to evaluate accuracy. Patient follow-up was obtained from a retrospective chart review.

Results: Thirty-eight patients (34 men, mean age 65.8 ± 10.5 years) with cT2N0 tumors by EUS underwent surgical resection of EC without chemoradiation after a mean of 22.4 ± 13.7 days post-EUS. When compared with final pathologic outcomes, 12 (32%) were understaged by EUS and 18 (47%) were overstaged. Understaging occurred due to tumor depth (T) in two patients (17%), nodal disease (N) in six (50%), and both in four (33%). Overstaging occurred due to pathology consistent with pT1b tumors instead of T2 tumors in all 17 cases. Based on EUS, 74% were referred for appropriate therapy.

Conclusion: While EUS is highly accurate in staging EC, it is less accurate in staging tumors which are not on either ends of the spectrum (mucosally based or clearly transmural). In this challenging group of patients, EUS understaged EC in 32% of cases resulting in surgical resection when neoadjuvant chemoradiation may have been beneficial. We suspect that newer generation EUS systems, which provide better imaging, will result in improved accuracy in staging this group of patients.