Sentinel lymph node concept in gastric cancer with solitary lymph node metastasis

To study the localization of the solitary metastases in relation to the primary gastric cancers and the feasibility of sentinel lymph node (SLN) concept in gastric cancer.

Eighty-six patients with gastric cancer, who had only one lymph node involved, were regarded retrospectively as patients with a possible sentinel node metastasis, and the distribution of these nodes were assessed. Thirteen cases with jumping metastases were further studied and followed up.

The single nodal metastasis was found in the nearest perigastric nodal area in 65.1% (56/86) of the cases and in 19.8% (17/86) of the cases in a fairly remote perigastric area. Out of 19 middle-third gastric cancers, 3 tumors at the lesser or greater curvatures had transverse metastases. There were also 15.1% (13/86) of patients with a jumping metastasis to N2-N3 nodes without N1 involved. Among them, the depth of invasion was mucosal (M) in 1 patient, submucosal (SM) in 2, proper-muscular (MP) in 4, subserosal (SS) in 5, and serosa-exposed (SE) in 1. Five of these patients died of gastric cancer recurrence at the time of this report within 3 years after surgery.

These results suggest that nodal metastases occur in a random and multidirectional process in gastric cancer and that not every first metastatic node is located in the perigastric region near the primary tumor. The rate of "jumping metastasis" in gastric cancer is much higher than expected, which suggests that the blind examination of the nodal area close to the primary tumor can not be a reliable method to detect the SLN and that a extended lymph node dissection (ELND) should be performed if the preoperative examination indicates submucosal invasion.