淋巴结转移阳性比率在预测T_3期胃癌患者预后中的价值

The value of metastatic lymph node ratio in predicting the prognosis of patients with T_3 gastric cancer

背景与目的:现有的TNM分期以转移淋巴结数作为淋巴结分期的标准,故对清扫的淋巴结数目有要求的同时,也可能因淋巴结清扫范围的不同而产生分期偏移。本研究将探讨淋巴结转移阳性比率在预测T3期胃癌患者预后中的应用价值。方法:回顾性分析273例接受胃癌D2根治手术且淋巴结清扫总数≥15枚的T3期胃癌患者的临床资料,分析淋巴结转移阳性比率及淋巴结转移阳性枚数与清扫的淋巴结总数间的相关性及淋巴结转移阳性比率在预测T3期胃癌患者预后中的价值。结果:当清扫的淋巴结≥15枚时,淋巴结转移阳性比率的高低与检出的淋巴结总数无相关性(r=0.069,P>0.05),而淋巴结转移阳性枚数与检出的淋巴结总数具有相关性(r=0.237,P<0.05)。单因素分析发现淋巴结转移阳性比率影响T3期胃癌患者预后(Log-rankχ2=92.414,P<0.01),多因素分析显示淋巴结转移阳性比率是影响T3期胃癌患者预后的独立因素之一。淋巴结转移阳性比率预测T3期胃癌患者预后的ROC曲线下面积与淋巴结转移阳性枚数预测结果的差异无显著性(P>0.01)。结论:淋巴结转移阳性比率是影响T3期胃癌患者预后的独立因素;在淋巴结清扫范围足够的情况下,淋巴结转移阳性比率预测T3期胃癌患者预后的准确性与淋巴结转移阳性枚数的预测能力相当,在预测T3N3期胃癌预后方面,淋巴结转移阳性比率较淋巴结转移阳性个数更为准确、客观。

Background and purpose： Since 1997, the UICC/AJCC TNM system redefined the N categories based on the number of metastatic lymph nodes. Although this is a simple method for staging, it needs the examination of at least 15 lymph nodes and the variety of lymphadenectomy score may also cause a stage shift. This study was to evaluate the prognostic significance of metastatic lymph nodes ratio in patients with T3 stage gastric cancer. Methods： Clinical data of 273 patients with T3 stage gastric cancer who underwent radical gastrectomy and D2 lymphadenectomy were analyzed retrospectively. Spearman correlation analysis was used to determine the correlation coefficient. Survival was determined by the Kaplan-Meier method and differences were assessed by the Log-rank test. Multivariate analysis was performed using the Cox proportional hazard regression model. Receiver operator characteristic curve was used to compare the accuracy of the number of metastatic lymph nodes to that of metastatic lymph node ratio. Results：The metastatic lymph node ratio did not correlate with the total number of lymph nodes when more than 15 nodes were dissected （r=0.069, P〉0.05）, whereas the number of metastatic lymph nodes did （r=0.237, P〈0.05）. Univariate analysis showed that the metastatic lymph node ratio influenced significantly the survival time （Log-rank 2,2=92.414, P〈0.01）. Multivariate analysis showed that the metastatic lymph node ratio was a major independent prognostic factor for the patients with T3 gastric cancer. There was no significant difference between the area under the receiver working characteristic curve of metastatic lymph node ratio and that of the number of metastatic lymph nodes in predicting the 5-year survival rate. Conclusion： The metastatic lymph node ratio in T3 gastric cancer patients were not correlated with the total lymph nodes dissected. The metastatic lymph node ratio is a major independent prognostic factor for the patients with T3 gastric cancer. The ability of the metastatic lymph node ratio in predicting 5-year survival rate is the same as that of the number of metastatic lymph nodes, but the former is more accurate than the latter in predicting 5-year survival rate with T3N3 gastric cancer.