Abstract

Background: Colorectal cancer is a common disease, with a high incidence rate in the world as well as in Vietnam. Preoperative staging plays a vital role in prognosis and optimal treatment. In Vietnam, the number of official publications on the role of endoscopic ultrasound (EUS) in rectal cancer staging is still limited. Objectives: To describe the imaging features of endoscopic ultrasound in patients with rectal cancer and evaluate the correlation between endoscopic ultrasound results and clinical, endoscopic and magnetic resonance imaging characteristics. Methods and materials: Forty-eight patients with histologically confirmed rectal cancer underwent endoscopic ultrasound and preoperative staging. Results: The overall accuracy of T staging of EUS was 76.1%. The sensitivity, specificity and accuracy for T1 staging were 80.0%, 100.0%, 95.2% respectively. The sensitivity, specificity and accuracy for T2 staging were 55.6%, 91.7%, 76.2% respectively. The sensitivity, specificity and accuracy for T3 staging were 100.0%, 71.4%, 81.0% respectively. The sensitivity, specificity and accuracy for lymph node diagnosis were 40.0%, 93.8%, 81.0% respectively. There was no correlation between clinical manifestations of the patients and the T & N stages. There was a high agreement via EUS and magnetic resonance imaging (MRI) on evaluating tumor locations. The agreement between EUS and MRI in terms of evaluating the T and N stages was not significant, with Kappa coefficients of 0.182 and 0.39, respectively. Conclusion: EUS contributes to improving the accuracy in preoperative staging of rectal cancer. Therefore, EUS should be routinely ordered in clinical practice, especially in cases of early-stage rectal cancers when tumors are localized in the mucosa and submucosa, in order to optimize patient treatment