Mo1487 Endoscopic Grade of Peritumoral Atrophy Is Associated With Low Accuracy of Endoscopic Ultrasound in the Staging of Early Gastric Cancer

predicting the depth of invasion from Mar 1, 2010 to Dec 31th, 2012 in PUMCH. All patients underwent endoscopic or surgical resention after EUS. Assessed the diagnostic sensitivity, specificity and accuracy of EUS by comparing the pre-treatment EUS results with the postoperative histopathological findings. The clinico-pathological factors may influencing the accuracy of EUS were also analyzed. Results: 59 lesions were evaluated by EUS for 59 patients (39 males and 20 females, mean age: 62.2+8.4 years old). Among these lesions, 10 cases located in the upper 1/3 stomach, 13 in the middle 1/3 and 27 in the lower 1/3. The maximal diameters of lesions distributed from 0.7cm to 5.5cm, and 21 lesions were bigger than 2.0cm in diameter. For the macroscopic type, 30 cases showed as 0-IIc, 13 cases were 0-IIa. 49 lesions were confirmed by histopathologic exam to be limited within mucosal layer (M) and the rest 10 invaded to the submucosal layer (SM). The overall diagnostic sensitivity, specificity and accuracy of EUS for the depth of early gastric cancer invasion were 79.7%, 81.4% and 79.7%, respectively. (M: sensitivity 66.1%, specificity 80.0%, accuracy 79.7%, SM: sensitivity 80.0%, specificity 81.6%, accuracy 81.4%, there were no obvious diference between the two groups). The overgrading rate was 16.9%, which mainly happened in leisons located in upper third (20.0%) and middle third (27.3%),with macroscopic elevated type (0-I:25%,0-IIa:38.5%) or with histologically confirmed ulcer (33.3%). The above mentioned lesions had a relatively lower diagnostic accurancy. The overall undergradeing rate was 3.4%. Conclusions: EUS has a quite high diagnostic accuracy in evaluating the depth of early gastric cancer invasion which helps the planning of treatment strategy. The location, macroscopic type and coexisting ulcer of lesion will affect the dignostic accurancy. The comparation of the depths of tumor invasion assessed by endoscopic ultrasonography (EUS) with the pathologic results for early gastric cancer AB438 GASTR EUS results OINTESTINAL END Pathologic results OSCOPY V Number of cases olume 8 Percentage(%) EUS agree with pathologic