Regional lymph node metastasis in gastric cancer: evaluation with endoscopic US

Endoscopic ultrasound (EUS) was performed in 83 patients with gastric cancer to evaluate regional lymph node metastasis. Histopathologic findings were compared with preoperative EUS findings in a total of 1,519 resected lymph nodes. In lymph node staging, the prevalence of metastatic adenopathy was 31.3% (26 of 83 patients); EUS had an accuracy of 83.1% (69 of 83 patients), sensitivity of 53.8% (14 of 26 patients), specificity of 96.5% (55 of 57 patients), positive predictive value of 87.5% (14 of 16 patients), and negative predictive value of 82.1% (55 of 67 patients). The greater the maximum diameter of the node with metastasis, or the larger the ratio of the metastatic area to the cross-sectional area of the node, the higher the detection rate. In tumors classified on the basis of depth of invasion according to the 1987 TNM system, the rate of detection of metastasis in individual nodes was 0% in pT1 tumors (none of five nodes), 20% in pT2 tumors (17 of 85 nodes), 29% in pT3 tumors (20 of 70 nodes), and 10% in pT4 tumors (three of 31 nodes). It is concluded that the most important use of EUS will be in diagnosis of regional lymph node metastasis.