目的 探讨术前血清CA19-9水平对淋巴结阴性的胃癌患者发生淋巴结微转移的预测价值,及其对预后的影响.方法 回顾性收集2006年1月至2011年12月期间在笔者所在医院行胃癌D2根治性术的176例胃癌患者的临床病理学资料,同时收集这些患者的淋巴结组织标本,所有患者经病理学检查证实淋巴结阴性.采用实时荧光定量PCR (quantitative real-time PCR,qRT-PCR)法检测淋巴结组织中是否存在淋巴结微转移.选择其中60例胃癌患者,构建术前血清CA19-9水平预测淋巴结微转移的受试者工作特征曲线(ROC),以评估术前血清CA19-9水平预测淋巴结微转移的价值并确立界值,余1 16例患者用于验证该界值的合理性.此外,探索术前血清CA19-9水平对淋巴结阴性胃癌患者预后的影响,并探索淋巴结微转移的影响因素.结果 ①ROC曲线结果:术前血清CA19-9水平预测淋巴微转移最佳效果时对应的界值为15.5 U/mL,此时灵敏度为93.1％,特异度为63.6％,曲线下面积(AUC)为0.84 (P=0.003).进一步以15.5 U/mL作为界点,将116例验证患者分为阳性组和阴性组,2组患者的淋巴结微转移发生率不同,阳性组高于阴性组(P＜0.001).②术前血清CA19-9水平对预后的影响:以15.5 U/mL作为界点将患者分为阳性组和阴性组,log-rank检验结果表明,阴性组患者的生存情况优于阳性组(P=0.001).③淋巴结微转移的影响因素分析:非条件logistic回归模型结果显示,术前血清CA19-9阳性是淋巴结阴性胃癌患者发生淋巴结微转移的危险因素[OR=1.860,95％ CI为(1.720,2.343),P＜0.001].结论 术前血清CA19-9水平可用于术前预测淋巴结阴性胃癌患者的淋巴结微转移情况.“,”Objective This study aimed to investigate the predictive value of preoperative serum CA19-9 level for lymph node micrometastasis in patients with lymph node metastasis-negative gastric cancer and its effect on prognosis.Methods Clinicopathological data were retrospectively collected from 176 cases of gastric cancer who underwent D2 radical surgery in our hospital between January 2006 and December 2011,and also collected the patients' lymph node tissue specimens.All patients were confirmed by pathologic examination of lymph node metastasis-negative.Quantitative real-time PCR (qRT-PCR) was used to detect the presence of lymph node micrometastasis in lymph node tissues.Sixty cases of gastric cancer were selected to construct the receiver operating characteristic curve (ROC) of preoperative serum CA19-9 level to predict lymph node micrometastasis,then established the threshold value.The remaining 116 cases were used to validate the rationality of this threshold.In addition,we explored the impact of preoperative serum CA19-9 level on the prognosis of patients with lymph node metastasis-negative gastric cancer,and explored the risk factors of lymph node micrometastasis.Results ① Results of ROC curve:the preoperative serum CA19-9 level of 15.5 U/mL was the threshold for predicting lymph node micrometastasis,with a sensitivity of 93.1％,specificity of 63.6％,and area under the curve (AUC) of 0.84 (P=0.003).With 15.5 U/mL as the threshold,116 patients were divided into positive group and negative group.The lymph node micrometastasis rates in the 2 groups were different,which was higher in the positive group than that in the negative group (P＜0.001).② Effect of preoperative serum CA19-9 level on prognosis:the patients were divided into the positive group and the negative group with 15.5 U/mL as the threshold,and the log-rank test showed that the survival of the negative group was better than that of the positive group (P=0.001).③ The risk factors for lymph node micrometastasis:the logistic regression model showed that preoperatively positive serum CA19-9 was an independent risk factor for lymph node micrometastasis in patients with gastric cancer [OR=1.860,95％ CI was (1.720,2.343),P＜0.001].Conclusion Preoperative serum CA19-9 level can be used to predict lymph node micrometastasis in lymph node metastasis-negative patients with gastric cancer.