中文摘要：

目的探讨外周血循环微小RNA-21（miR-21）在乳腺癌患者中的表达及其临床意义。方法收集76例乳腺浸润性导管癌患者及20名健康体检者的静脉血，血清分离后，运用实时定量PCR检测miR-21的表达。比较乳腺癌患者与健康对照者以及患者术前与术后miR-21表达差异。受试者工作特征（ROC）曲线法分析miR-21对乳腺癌的诊断效能。结果乳腺癌患者血清miR-21表达比健康人高（P〈0．001），乳腺癌患者接受手术治疗后血清miR-21表达量下降（P〈0．001）。随着乳腺癌分期的增加，血清miR-21表达水平逐渐上升（P〈0．001）。血清miR-21区分乳腺癌患者与健康者ROC曲线下面积为0．934。结论血清miR-21可能是诊断乳腺癌的一个无创标记物。

英文摘要：

Objective To investigate the potential of circulating miR-21 as a novel primary breast cancer biomarker. Methods Serum samples were collected from 76 pathologically proven invasive ductal carcinoma breast cancer （BC） patients and 20 healthy women. Relative real-time quantitative polymerase chain reaction was employed to measure the serum miR-21 expression level. The receiver operating characteristic curve （ROC） was carried out to estimate the diagnostic accuracy of the serum miR-21 for BC. Results Serum miR-21 level of BC patients was higher as compared with healthy controls （P 〈 0.001）. Increased levels of miR-21 were associated with advanced clinical stage （P 〈 0.001）. Moreover, postoperative level of miR-21 was lower than that of presurgery （P 〈 0.001）. Area under the curve score of ROC was 0.934 for miR-21 to discriminate the BC patients from the healthy individuals. Conclusion Serum miR-21 may serve as a noninvasive biomarker of diagnosis in BC patients.