title: Correlation between serum HER-2 oncoprotein and patients with breast cancer.
abstract: OBJECTIVE
  To detect serum HER-2 oncoprotein levels in patients with operable and metastatic breast cancers, and to study the correlations between serum HER-2 level and lymph node status as well as other clinical parameters.
  
  
  METHODS
  A total of 120 women were studied consisting of 10 healthy volunteers, 31 benign breast disease, 53 operable breast cancer, and 26 metastatic breast cancer patients. The levels of serum HER-2 were measured using an enzyme-liked immunosorbent assay (ELISA).
  
  
  RESULTS
  The mean serum HER-2 levels were 9.6 +/- 1.5 ng/mL in healthy volunteers, 11.9 +/- 1.6 ng/mL in benign breast disease, 13.2 +/- 4.2 ng/mL in operable breast cancer, and 30.5 +/- 30.8 ng/mL in metastatic breast cancer patients. The former is much lower than the latter three (P = 0.02, 0.001, 0.03, respectively). If using 15 ng/mL as a normal baseline, elevated serum HER-2 levels were observed in none of the healthy volunteers as well as patients with benign disease, but in 18.9% (10/53) operable breast cancer patients and 61.5% (16/26) metastatic patients. In patients with operable breast cancer, there was a positive correlation between serum concentrations of HER-2 and the size of primary tumor (P < 0.05), whereas there was no correlation between serum concentration and axillary lymph node or estrogen receptor status. In patients with metastatic disease, there was no correlation with site of metastases (P > 0.05).
  
  
  CONCLUSIONS
  Serum HER-2 level was strongly correlated with tumor loads and clinical stages, thus acting as a promising predictor of cancer recurrence in breast cancer patients.
authors.affiliation: Department of Medical Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021.
authors.forename: Peng
authors.initials: P
authors.lastname: Yuan
authors.forename: Bing-he
authors.initials: BH
authors.lastname: Xu
authors.forename: Da-tong
authors.initials: DT
authors.lastname: Chu
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000737:chemistry / Q000556:secondary; D008175:Lung Neoplasms / Q000737:chemistry / Q000556:secondary; D008198:Lymph Nodes / Q000473:pathology; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone