Clinical application of radial endoscopic ultrasonography on preoperative T and N staging for advanced gastric cancer

Abstract

Objective To assess the value of endoscopic ultrasonography (EUS) and abdominal CT scan on preoperative T and N staging of advanced gastric cancer. Methods A total of 188 patients with advanced gastric cancer received EUS and CT scan to evaluate the T and N staging and lymphatic metastasis before surgical operation. The postoperative pathologic results acted as gold standard for comparison of the two methods. The results consistent with pathologic results were considered as correct otherwise were incorrect. The accuracy of EUS and CT and the each consistency of two methods with pathology were analyzed. Results For T staging, the accuracy of EUS and CT was 87.2%(164/188), 76.6%(144/188), respectively, and Kappa value of EUS and CT was 0.726 and 0.509, respectively. There was a statistical difference between the two methods(χ2=7.181, P=0.007). For lymph node metastasis, the accuracy of EUS and CT was 72.9%(137/188) and 79.8%(150/188), respectively, and Kappa value of EUS and CT was 0.397 and 0.487, respectively. No statistical difference was found between them(χ2=0.963, P=0.326). The consistency test between the two methods for T and N staging and lymph node metastasis revealed that the Kappa value was 0.507 and 0.649, respectively. The accuracy of EUS on T staging was 93.0%, 93.3%, 96.8% and 91.5% in cardiac cancer, gastric fundus cancer, gastric corpus cancer, and gastric antrum cancer, respectively. Corresponding Kappa value in the 4 different positions were 0.843, 0.881, 0.940 and 0.710, respectively according to consistency tests. The accuracy of gastric antrum cancer with pylorus invasion was 63.2% and the consistency test Kappa value was 0.340. Conclusion EUS is an accurate method for T staging and lymphatic metastasis of advanced gastric cancer, but there is a lower accuracy for T staging of gastric antrum cancer with pylorus invasion. Key words: Endoscopic ultrasonography; Advanced gastric cancer; Neoplasm staging