Clinical characteristics of gastric cancer with metastasis to the lymph node along the superior mesenteric vein (14v)

Aim: We investigated the clinical significance of metastasis to the lymph node (LN) along the superior mesenteric vein (14v) in gastric cancer. Methods: A retrospective study of 2,513 gastrectomy patients with a 14v dissection was done using the Ganken Igan Database. Results: The incidence of 14v metastasis correlated with tumor location, depth of tumor invasion, regional LN metastases, peritoneal metastasis, peritoneal cytology-positive, hepatic metastasis and postoperative recurrence (p < 0.01). Metastases to the infrapyloric LN (6), suprapyloric LN (5) and left paracardial LN (2) were independent variables affecting 14v metastasis (p < 0.05), and the 6 status was a useful predictive factor for a 14v-negative status with a low false-negative rate (1.9%). The patients with 14v metastasis after curative surgery demonstrated a significantly lower survival rate than those without (5-year overall survival rate; 11.3 vs. 60.2%, p < 0.0001). In them, LN around the abdominal aorta (16)-positive group showed a significantly lower survival rate than the negative group (p < 0.05). Conclusions: Advanced gastric cancer with invasion to the lower stomach often metastasizes to 14v, and the 6 status can predict 14v negative. Most patients with 14v metastasis have a poor prognosis, similar to those with systemic metastasis, although some such patients may benefit from a curative dissection.