Impact on long-term survival of the number of lymph nodes resected in patients with pT1N0 gastric cancer after R0 resection: A multicenter study in China.

Although studies on the association between the number of lymph nodes resected and prognosis in patients with pT2-4N0 stages of gastric cancer have reported consistent results, there is no consensus on the optimal number of lymph nodes to be examined for pT1N0 stage gastric cancer. The aim of this study was to evaluate the long-term effect of the number of lymph nodes removed on the outcomes of patients with pT1N0 stage gastric cancer after R0 resection. From December 2009 to December 2011, 227 patients undergoing R0 resection of pT1N0 stage gastric cancer at 4 Chinese centers were enrolled in this study. Patients were assigned to 2 groups according to the number of lymph nodes dissected (<= 15 or >15). Standard survival methods and restricted multivariable Cox regression models were applied. More women (P=0.031) were in the <= 15 group than in the >15 group. The mean number of lymph nodes removed from women was greater than that from men (P=0.007). The 5-year survival rate was significantly higher in the >15 lymph nodes resected group than the <= 15 group. The number of lymph nodes resected was identified as an independent prognostic factor and was significantly correlated with overall survival (OS). A lymphadenectomy with dissection of more than 15 lymph nodes improved the long-term survival of patients with pT1N0 gastric cancer after R0 resection. Therefore, it is necessary to consider removing more than 15 lymph nodes among such patients.