Relevance of lymph node metastasis along the superior mesenteric vein in gastric cancer

BACKGROUND: The purpose of this study was to evaluate the prognostic value of lymph node metastasis along the superior mesenteric vein (station 14v) to determine the need for 14v dissection in gastric cancer surgery. METHODS: A total of 1104 patients with gastric cancer who underwent gastrectomy including 14v dissection were enrolled. Patients were categorized into two groups: those with and those without 14v lymph node involvement by metastasis. RESULTS: Of the total study population, 73 patients (6·6 per cent) had 14v-positive gastric cancer. These patients were more likely to have advanced tumour (T), node (N) and distant metastatic (M) status, and histologically undifferentiated gastric cancers. The 3- and 5-year survival rates of patients with 14v-positive disease were 24 and 9 per cent respectively. Survival in this group was similar to that of patients who had gastric cancer with distant metastasis (M1). Multivariable analysis demonstrated that 14v status was a significant prognostic factor for gastric cancer (hazard ratio 2·13; P < 0·001). After histologically complete (R0) resection, the overall survival of 14v-positive patients with any stage of cancer was significantly worse than that for 14v-negative patients with stage IV cancer (P = 0·006). CONCLUSION: 14v status is an independent prognostic factor for gastric cancer, with 14v-positive gastric cancer having a poor prognosis, similar to that of M1 disease. The exclusion of 14v in regional lymph node dissection should be considered.ope