title: Correlation of hormone receptor status between circulating tumor cells, primary tumor, and metastasis in breast cancer patients.
abstract: OBJECTIVE
  Estrogen receptor (ER) and progesterone receptor (PR) status is prognostic and predictive in breast cancer. Because metastatic breast tumor biopsies are not routinely feasible, circulating tumor cells (CTCs) offer an alternative source of determining ER/PR tumor status.
  
  
  METHODS
  Peripheral blood was collected prospectively from 36 patients with metastatic breast cancer. CTCs were isolated using the microfluidic OncoCEE™ platform. Detection was accomplished with an expanded anti-cytokeratin (CK) cocktail mixture and anti-CD45. ER/PR protein expression was assessed by immunocytochemistry (ICC) on the CK+ cells and compared to the primary and/or metastatic tumor by immunohistochemistry (IHC).
  
  
  RESULTS
  Among the 24 CK + CTC cases, a concordance of 68 % (15/22) in ER/PR status between primary breast tumor and CTCs and 83 % (10/12) between metastatic tumor and CTCs was observed. An overall concordance of 79 % (19/24) was achieved when assessing CTC and metastatic tumor (primary tumor substituted if metastatic breast biopsy not available). A test sensitivity of 72 % and specificity of 100 % was identified when comparing CTCs to tumor tissue. Of the 7 discordant cases between CTCs and primary tumor tissue, 2 were concordant with the metastatic biopsy.
  
  
  CONCLUSIONS
  CTC ER/PR status using the OncoCEE™ platform is feasible, with high concordance in ER/PR status between tumor tissue (IHC) and CTCs (ICC). The prognostic and predictive significance of CTC ER/PR protein expression needs further evaluation in larger trials.
authors.affiliation: Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York, USA, kk2693@columbia.edu.
authors.forename: K
authors.initials: K
authors.lastname: Kalinsky
authors.forename: J A
authors.initials: JA
authors.lastname: Mayer
authors.forename: X
authors.initials: X
authors.lastname: Xu
authors.forename: T
authors.initials: T
authors.lastname: Pham
authors.forename: K L
authors.initials: KL
authors.lastname: Wong
authors.forename: E
authors.initials: E
authors.lastname: Villarin
authors.forename: T J
authors.initials: TJ
authors.lastname: Pircher
authors.forename: M
authors.initials: M
authors.lastname: Brown
authors.forename: M A
authors.initials: MA
authors.lastname: Maurer
authors.forename: F Z
authors.initials: FZ
authors.lastname: Bischoff
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001859:Bone Neoplasms / Q000378:metabolism* / Q000556:secondary; D001932:Brain Neoplasms / Q000378:metabolism / Q000556:secondary; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000378:metabolism / Q000556:secondary; D008175:Lung Neoplasms / Q000378:metabolism* / Q000556:secondary; D008198:Lymph Nodes / Q000473:pathology; D061986:MCF-7 Cells; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000378:metabolism* / Q000473:pathology; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012983:Soft Tissue Neoplasms / Q000378:metabolism* / Q000556:secondary; D035441:Thoracic Wall / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone