The Diagnostic Accuracy of Endoscopic Ultrasonography for the Preoperative Staging of Gastric Cancer: the Risk of Overstaging and Understaging

Kim, Bo Hyun; Lee, Dong Ho; Kang, Hae Yeon; Koh, Seong Joon; Yang, Ki Young; Lee, Jeong Hoon; Lee, Kwang Hyuck; Park, Young Soo; Kim, Jin Wook; Jung, Sook Hyang; Kim, Nayoung; Hwang, Jin Hyeok; Jung, Hyun Chae; Song, In Sung

Abstract

BACKGROUND/AIMS
The preoperative staging of gastric cancer facilitates the planning of therapy. Preoperative endoscopic ultrasonography is a useful procedure for the staging of gastric cancer, but sometimes there can be problems with overstaging and understaging.
METHODS
Endoscopic ultrasonography was performed preoperatively on 171 patients with gastric cancer. The results of endoscopic ultrasonography were compared with the postoperative histological staging.
RESULTS
The overall accuracy of endoscopic ultrasonography for the determination of the T stage was 65.5%, the overall accuracy was 74.4%, 51.7% and 38.9% for determining the T1, T2 and T3 staging, respectively. Endoscopic ultrasonography had an accuracy of 67.3% for determining the absence of lymph node metastasis. In univariate analysis, the diagnostic accuracy was lower for infiltrative type and gastric cancer with microinvasion significantly. Multivariate analysis showed overstaging occurred for gastric cancers with concomitant ulcer, inflammation or submucosal fibrosis (p=0.004) and that understaging occurred for gastric cancers with infiltrative type or microinvasion (p=0.029, p<0.001).
CONCLUSIONS
Endoscopic ultrasonography is a valuable diagnostic tool for most gastric cancers with some exceptions due to the overstaging and understaging. Gastric cancers with concomitant ulcer, inflammation or submucosal fibrosis may contribute to overstaging. By contrast, gastric cancers with infiltrative type or microinvasion may result in understaging.