Prognosis analysis of 310 patients with pathological stage pN3 gastric cancer

OBJECTIVE: To investigate the clinicopathological characteristics and prognostic factors of patients with pathological stage pN3 gastric cancer. METHODS: A retrospective study of 310 patients with histologically confirmed pN3 stage gastric cancer undergoing radical gastrectomy from January 2000 to December 2006 in our department was performed. The Kaplan-Meier method was used to analyze the survival. Log-rank test and Cox regression model were carried out for univariate and multivariate analyses. RESULTS: All the patients were followed up for 2 to 103 (mean 35.7) months. The overall 5-year survival rate was 14.6%. There were 201 cases with stage pN3a and 109 cases with stage pN3b, and the 5-year survival rates were 16.8% and 10.3% respectively (P=0.013). Univariate analysis showed that tumor location, Borrmann type, depth of tumor invasion, surgical method, metastatic lymph node ratio, and pN stage were associated with postoperative survival (all P<0.05). The multivariate analysis revealed that depth of tumor invasion, surgical method and metastatic lymph node ratio were independent prognostic factors, while the pN stage was not. The difference of 5-year survival rate between pN3a and pN3b subgroups was significant in pT4a patients (16.1% vs. 12.8%, P=0.001), while such difference was not significant in pT4b patients (8.6% vs. 3.1%, P=0.137). CONCLUSIONS: Prognosis of patients with pN3 stage gastric cancer after radical resection is poor. Depth of tumor invasion and surgical method are independent prognostic factors for pN3 stage gastric cancer. Metastatic lymph node ratio is valuable to predict the prognosis of pN3 stage patients. The pN3 staging of the 7th UICC provides a more accurate prediction of prognosis.