title: Clinical significance of serum miR-21 in breast cancer compared with CA153 and CEA.
abstract: OBJECTIVE
  MicroRNA-21 (miR-21) has been shown to be a key regulator of carcinogenesis. There were few reports about the comparison of serum miR-21 with conventional tumor markers. This study aimed to explore the diagnostic value of circulating miR-21 as a tumor marker in breast cancer (BC) and compare it with CA153 and carcinoembryonic antigen (CEA).
  
  
  METHODS
  Circulating miR-16 and miR-21 were amplified and quantitatively detected by real-time PCR in 89 BC patients and 55 healthy controls. The levels of CA153 and CEA were measured through electrochemiluminescence assays. Then the sensitivity in diagnosis of BC was compared among miR-21, CA153 and CEA.
  
  
  RESULTS
  The level of serum miR-21 was significantly higher in BC patients than controls (P<0.001). The sensitivity and specificity of miR-21 were 87.6% and 87.3%, respectively, whereas the sensitivities of CEA and CA153 were only 22.47% and 15.73%.
  
  
  CONCLUSIONS
  Compared with CEA and CA153, serum miR-21 has a higher sensitivity in diagnosis of BC. Although not correlated with the status of ER, PR and clinical stages, serum miR-21 may be a potential diagnostic indicator for BC, especially for the early stage.
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Clinical Laboratory, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Jianjian
authors.initials: J
authors.lastname: Gao
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Clinical Laboratory, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Clinical Laboratory, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Clinical Laboratory, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Guo
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Clinical Laboratory, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Li
keywords: MicroRNA-21 (miR-21); breast cancer (BC); real-time polymerase chain reaction (real-time PCR)