Characteristics and survival outcomes related to the infra-pyloric lymph node status of gastric cancer patients.

Background: To study metastasis to the infra-pyloric (no. 6) lymph nodes and their subgroups and the related risk factors of gastric cancer patients.
Methods: Gastric cancer patients who underwent gastrectomy with complete postoperative pathological information on the no. 6 lymph node station and its subgroups from January 1, 2008, to December 31, 2011, were included. The clinicopathological characteristics and survival outcomes were analyzed.
Results: A total of 121 patients were included; they had 6.1 ± 7.7 positive lymph nodes, and 35.1 ± 14.2 lymph nodes were examined. The overall lymph node positivity rate was 67.8% (82/121) with a positivity rate of 28.1% (34/121) for the no. 6 lymph nodes. The metastasis rate was 6.6% for the no. 6a nodes, 6.6% for the no. 6b nodes, and 21.5% for the no. 6c nodes. Also, no. 8a (OR = 1.329, p = 0.017) and no. 9 (OR = 1.250, p = 0.022) nodal positivity and lower third tumor location (OR = 1.278, p = 0.001) were independent risk factors for no. 6 lymph nodal metastasis. There was a significant survival difference between patients with positive and negative no. 6 lymph nodes and patients with metastasis to other lymph node stations (p <  0.001).
Conclusions: Patients with no. 6 lymph node metastasis have poor survival outcomes. Complete infra-pyloric lymphadenectomy is necessary and crucial for gastric cancer patients.