There has still not been a consensus in aspects of survival benefit and safety on No.12a lymph nodes (LNs) dissection for gastric cancer patients. This study was aimed to evaluate this issue for patients with distal or total gastrectomy. Patients were retrospectively divided into 12aD+ group (with No.12a dissection) and 12aD-group (without No.12a dissection). Clinicopathologic characteristics, survival rate, morbidity and mortality were compared. There were 670 patients in 12aD+ group, while 567 in 12aD-group. The baselines between the two groups were comparable. The No.12a LNs metastasis ratio was 11.6% and higher in lower third tumor. The metastasis of No.5 LNs, N stage and M stage were correlated to metastasis of No.12a LNs. There was no difference in morbidity nor mortality between the two groups. The 5-year overall survival rates (5-y OS) were 59.6% and 55.1% in 12aD+ group and 12aD-group respectively (P = 0.075). The 5-y OS of patients with negative and positive No.12a LNs were 62.3% and 24.1%. The survival of stage III patients with No.12a positive was better than that of stage IV patients. The 5-y OS were better in 12aD+ group for patients with ages more than 60, lower third tumor, distal gastrectomy, N3 status, or III stages compared with 12aD-group. No.12a lymphadenectomy was independently better prognostic factors for stage III patients. No.12a LNs metastasis should not be considered as distant metastasis. No.12a lymphadenectomy can be performed safely and should be indicated for potentially curable progressive stage tumors requiring distal gastrectomy and might be reserved in patients with stage I or II, or upper third tumor.
Keywords: No.12a lymph nodes; gastrectomy; gastric cancer; safety; survival.