title: [Serum HER2 ECD level and its clinical significance in advanced breast cancer patients with different molecular subtypes].
abstract: OBJECTIVE
  To evaluate the serum HER2 ECD level and its significance in advanced breast cancer patients with different molecular subtypes.
  
  
  METHODS
  A total of 322 advanced breast cancer patients were enrolled. The serum HER2 ECD concentrations were quantitatively detected by enzyme-linked immunosorbent assay(ELISA). Its relationship with clinicopathological characteristics and clinical significance were analyzed.
  
  
  RESULTS
  It was found that 55.9% (19/34)Luminal A, 42.7% (44/103) Luminal B-HER2(-), 70.6% (60/85) Luminal B-HER2(+), 73.8% (45/61)HER2-enriched and 23.1% (9/39) triple-negative patients had serum concentrations of HER2 ECD at least 15 ng/ml respectively. The prevalence of elevated ECD level in patients of different molecular subtypes differed significantly (P < 0.001). Tissue HER2 status, number of metastatic sites, visceral metastasis, CA15-3 and carcinoembryonic antigen(CEA) levels exhibited statistically significant correlations with the prevalence of elevated serum HER2 ECD level. The serum concentrations of HER2 ECD decreased after effective targeted therapy in tissue HER2-positive patients.
  
  
  CONCLUSIONS
  The prevalence of elevated serum levels of HER2 ECD differed significantly in advanced breast cancer patients with different molecular subtypes. The serum HER2 ECD level may reflect both histological HER2 status and tumor load. And the dynamic changes of ECD concentrations are somewhat correlated with the efficacies of targeted treatment.
authors.affiliation: Department of Breast Cancer, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Jinmei
authors.initials: J
authors.lastname: Zhou
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Huiqiang
authors.initials: H
authors.lastname: Zhang
authors.forename: Meng
authors.initials: M
authors.lastname: Du
authors.forename: Shaohua
authors.initials: S
authors.lastname: Zhang
authors.forename: Shikai
authors.initials: S
authors.lastname: Wu
authors.forename: Santai
authors.initials: S
authors.lastname: Song
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Email: jiangzf@hotmail.com.
authors.forename: Zefei
authors.initials: Z
authors.lastname: Jiang
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human