Background and aim: Endoscopic ultrasonography (EUS) is established as a standard approach for locoregional staging of esophageal cancer. However, only a few published studies have attempted to correlate the station of the abnormal lymph nodes detected by EUS with the definitive histology. We compared EUS and computed tomography (CT) in the initial staging of esophageal squamous cell carcinoma.
Methods: Consecutive patients with esophageal cancer undergoing EUS were evaluated. EUS findings and patient data including histopatology were collected prospectively and analyzed retrospectively. Lymph node locations were divided into three groups; abdominal (A), paraesophageal (B), and thoracic paratracheal (C).
Results: A total of 365 consecutive patients underwent EUS and 159 patients underwent esophagectomy without neoadjuvant chemotherapy. Thirty-eight patients were excluded (insufficient EUS, etc.), and 121 patients were enrolled. The overall accuracy of EUS was 64% (sensitivity 68%, specificity 58%, positive predictive value [PPV] 68%), CT was 51% (sensitivity 33%, specificity 75%, PPV 64%), and CT + EUS was 64% (sensitivity 74%, specificity 50%, PPV 66%). The accuracy of EUS was higher than CT in Groups A and C. Sensitivity of CT was lower than that of EUS alone and CT + EUS.
Conclusions: This study has demonstrated that EUS is a more accurate technique than contrast-enhanced CT for detecting abnormal lymph nodes. Sensitivity of CT was lower than that of EUS alone and CT + EUS. But some metastatic lymph nodes in neck and abdominal fields are only detectable by CT. Therefore, both EUS and CT should be undertaken for routine examination prior to treatment of esophageal cancer.