Diagnostic Value of Miniprobe Endoscopic Ultrasonography in Assessment of Tumor Invasion Depth in Early Gastric Cancer

  Objective  To evaluate the role of miniprobe endoscopic ultrasonography (EUS) in assessing the depth of tumor invasion in early gastric cancer and to analyze the factors affecting the accuracy of EUS.

  Methods  This retrospective study included 59 cases of pathologically confirmed early gastric cancer diagnosed and hospitalized in Peking Union Medical College Hospital in the period of March 2010 to December 2012. They all received miniprobe EUS for predicting the depth of invasion before endoscopic or surgical resection. We assessed the diagnostic sensitivity, specificity and accuracy of EUS by comparing the pre-treatment EUS results with the postoperative histopathological findings. The endoscopic features and pathological factors possibly influencing the accuracy of EUS were also analyzed.

  Results  The overall diagnostic sensitivity, specificity and accuracy of EUS in assessing the depth of early gastric cancer invasion were 79.7%, 81.4% and 79.7%, respectively. The sensitivity, specificity and accuracy for mucosal layer lesion were 66.1%, 80.0% and 79.7%, respectively; and the sensitivity, specificity and accuracy for submucosal lesion were 80.0%, 81.6% and 81.4%, respectively, showing no significant diference(P > 0.05). The overgrading rate of EUS was 16.9%, and the overgrading mainly happened in leisons located in upper third (20.0%) and middle third (27.3%) of the stomach, with a superficial appearance of elevated type (0-Ⅰ:25.0%, 0-Ⅱa:38.5%) or with ulcers (33.3%). The above mentioned lesions were also associated with a relatively lower diagnostic accuracy of EUS. The undergrading rate of EUS was 3.4%.

  Conclusions  Miniprobe EUS has a fairly high diagnostic accuracy in assessing the depth of gastric cancer invasion, which helps the planning of treatment strategy. The location, macroscopic type of lesions and coexisting ulcer would affect the dignostic accuracy of EUS.