title: Serum HER2 extracellular domain levels and HER2 circulating tumor cell status in patients with metastatic breast cancer.
abstract: OBJECTIVE
  To shed light on the clinical role of HER2 status in serum as extracellular domain (ECD) and corresponding circulating tumor cells (CTCs) in metastatic breast cancer patients.
  
  
  METHODS
  68 patients were analyzed. Serum HER2 was determined by ADVIA Centaur(®) Serum HER2 test. CellSearch System was performed for CTC quantification.
  
  
  RESULTS
  HER2 was overexpressed in 21 primary tumors. In total, 19 patients had ECD >15 ng/ml (the cut-off used), 48 patients had at least one CTC. ECD positivity was associated with CTC number (p = 0.01), HER2-positive CTC (p = 0.01) and the ratio HER2-positive CTC/total CTC (p = 0.02). ECD was not associated with survival.
  
  
  CONCLUSIONS
  ECD in combination with HER2 CTC status would deserve further investigation in larger series for addressing its putative prognostic relevance.
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Aurilio
authors.affiliation: European Institute of Oncology, Laboratory of Medicine, via Ripamonti 435, Milan, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Sandri
authors.affiliation: European Institute of Oncology, Division of Pathology & Laboratory Medicine, via Ripamonti 435, Milan, Italy & School of Medicine, University of Milan, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pruneri
authors.affiliation: European Institute of Oncology, Laboratory of Medicine, via Ripamonti 435, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Zorzino
authors.affiliation: European Institute of Oncology, Division of Epidemiology & Biostatistics, via Ripamonti 435, Milan.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Botteri
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Munzone
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Adamoli
authors.affiliation: European Institute of Oncology, Laboratory of Medicine, via Ripamonti 435, Milan, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Facchi
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Cullurà
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Verri
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Maria Cossu
authors.initials: MC
authors.lastname: Rocca
authors.affiliation: European Institute of Oncology, Division of Senology, via Ripamonti 435, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zurrida
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Iacovelli
authors.affiliation: European Institute of Oncology, Medical Oncology, via Ripamonti 435, Milan, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Nolè
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005110:Extracellular Space; D005260:Female; D006801:Humans; D007118:Immunoassay; D053208:Kaplan-Meier Estimate; D008163:Luminescent Measurements; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: HER2 CTC status; metastatic breast cancer; serum HER2 ECD levels; survival