阴性淋巴结数目预测胃癌术后生存的临床价值

目的:评价局部进展期胃癌根治术后区域阴性淋巴结数目对术后无瘤生存期（disease free survival，DFS）的影响。方法:选取有明确术后病理资料且术后病理分期为T3N0～2M0、随访资料完整、术后无瘤生存时间超过6 个月的根治术后胃癌患者共485 例，按照不同术后病理分期进行单独分组分析。Cox 多因素回归分析筛选影响术后无瘤生存的因素，Kaplan-Meier 方法绘制术后无瘤生存曲线，并比较各组中无瘤生存率间的差异。结果:Cox 多因素回归分析表明，独立影响胃癌患者术后无瘤生存期的因素包括年龄、肿瘤分化程度、肿瘤部位以及术后病理中阴性淋巴结数目。在T3N0M0 组中，当阴性淋巴结分别为1～4 枚和≥5 枚时，患者2 年无瘤生存率分别为8.3% 和55.6% ，3 年无瘤生存率分别为0 和24.9%（P=0.025）；在T3N1M0 组中，当阴性淋巴结分别为≤3 枚、4～9 枚和≥10枚时，患者2 年无瘤生存率分别为17.3% 、39.1% 和52.6% ，3 年无瘤生存率分别为4.2% 、6.0% 和17.1%（P<0.001）；在T3N2M0 组中，当阴性淋巴结为≤7 枚和≥8 枚时，患者2 年无瘤生存率分别为11.5% 和35.0% ，3 年无瘤生存率分别为0.8% 和5.0%（P=0.015）。 结论:对于术后病理分期为T3N0～2M0 的胃癌病例，术后病理资料中阴性淋巴结数目可反映区域淋巴结清扫的彻底性以及评价术后病理分期的准确性，是影响根治术后无瘤生存期的独立预后因素。 

Association of the Number of Negative Lymph Nodes with Prognosis of Post-operative Gastric Cancer Patients

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 T_3N_(0～2)M_0 was significantly associated with age, degree of tumor differentiation, tumor location as well as the number of negative lymph nodes. In the T_3N_0M_0 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 T_3N_1M_0 subgroup, when the number of negative lymph nodes was 3 or less, 4 to 9, and 10 or more, the 2-year disease free survival rate was 17.3%, 39.1%, and 52.6%, respectively, and the 3-year disease free survival rate was 4.2%, 6.0%, and 17.1%, respectively (P<0.001). In the T_3N_1M_0 subgroup, when the number of negative lymph nodes was 7 or less and 8 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% and 5%, respectively (P=0.015).Conclusion: For gastric cancer patients with pathological stage T_3N_(0～2)M_0, the number of negative nodes could reflect the level of regional lymph node dissection. The number of negative nodes can be an index for evaluation of the accuracy of pathological staging and is considered as an independent prognostic factor for disease free survival of gastric cancer patients.