Application of Endoscopic Ultrasonography to Detect Lymph Node Metastasis in Gastric Cancer

Objective: To evaluate the application of endoscopic ultrasonography (EUS) to detect lymph node metastasis in gastric cancer.

Methods: 70 patients with gastric cancer underwent preoperative EUS. The accuracy of diagnosis of lymph node metastasis (N stage) by EUS was evaluated, compared with postoperative pathologic findings according to UICC (2002) TNM staging. The locations of the lymph nodes that may affect the accuracy of EUS were considered as well.

Results: The overall preoperative N staging accuracy by EUS was 61.4% (43/70). The accuracy was respectively 85.0% (18/21) for N0, 77.8% (14/18) for N1, 52.9% (9/17) for N2 and 14.3% (2/14) for N3. The evaluation of the metastatic lymph nodes by EUS was more accurate around the lesser curvature of 76.9% (30/39); in contrast, accuracy of the detection of lymph node metastasis was relatively poor around the pylorus of 36.1% (13/36) and around common hepatic artery of 38.9% (7/18). In most cases, deviation of EUS for the detection of lymph node metastasis was due to inefficiency of displaying the enlarged lymph nodes. Occasionally, the deviation was related to difficulties to distinguish inflammatory and tumor-bearing lymph nodes.

Conclusion: EUS is very valuable to diagnosis lymph node metastasis of gastric cancer before surgery, especially to relatively early gastric cancer with less metastatic lymph nodes. The finding of enlarged perigastric lymph nodes and accurate positioning is very crucial to improve the diagnosis of EUS for lymph node metastasis of gastric cancer.