Abstract:
Objective: To evaluate the impact of the number of negative lymph nodes on disease free survival (DFS) of patients with locally advanced gastric cancer. Methods:A total of 485 patients who underwent surgery for gastric cancer were enrolled in this study. We analyzed the data of these patients including complete information of follow-up and definite postoperative pathological results. The disease free survival of all patients was more than 6 months and was analyzed according to the pathological stage respectively. COX regression analysis was performed to screen the independent prognostic factors. Kaplan-Meier method was used to draw the disease free survival curve and the disease free survival rate was compared among subgroups. Results: Cox regression analysis showed that the disease free survival rate of gastric cancer patients with pathological stage T3N0-2M0 was significantly associated with age, degree of tumor differentiation, tumor location as well as the number of negative lymph nodes. In the T 3N0M0 subgroup, when the number of negative lymph nodes was 1 to 4 and 5 or more, the 2-year disease free survival rate was 8.3% and 55.6%, respectively, and the 3-year disease free survival rate was 0 and 24.9%, respectively (P=0.025 ). In the T3N1M0 subgroup, when the number of negative lymph nodes was 3 or less, 4 to 9, and 10or more, the 2-year disease free survival rate was 17.3% ,39.1% , and52.6% , respectively, and the3-year disease free survival rate was 4.2%,6.0%, and17.1%, respectively (P<0.001 ). In the T 3N2M0 subgroup, when the number of negative lymph nodes was 7 or less and8 or more, the 2-year disease free survival rate was 11.5% and 35% , respectively, and the 3-year disease free survival rate was 0.8% and5% , respectively (P=0.015 ). Conclusion:For gastric cancer patients with pathological stage T 3N0-2M0, the number of negative nodes could reflect the level of regional lymph node dissection. The number of negative nodes can be an index forevaluation of the accuracy of pathological staging and is considered as an independent prognostic factor for disease free survival of gastric cancer patients.