title: A multimarker QPCR-based platform for the detection of circulating tumour cells in patients with early-stage breast cancer.
abstract: BACKGROUND
  The detection of circulating tumour cells (CTCs) has been linked with poor prognosis in advanced breast cancer. Relatively few studies have been undertaken to study the clinical relevance of CTCs in early-stage breast cancer.
  
  
  METHODS
  In a prospective study, we evaluated CTCs in the peripheral blood of 82 early-stage breast cancer patients. Control groups consisted of 16 advanced breast cancer patients and 45 healthy volunteers. The CTC detection was performed using ErbB2/EpCAM immunomagnetic tumour cell enrichment followed by multimarker quantitative PCR (QPCR). The CTC status and common clinicopathological factors were correlated to relapse-free, breast cancer-related and overall survival.
  
  
  RESULTS
  Circulating tumour cells were detected in 16 of 82 (20%) patients with early-stage breast cancer and in 13 out of 16 (81%) with advanced breast cancer. The specificity was 100%. The median follow-up time was 51 months (range: 17-60). The CTC positivity in early-stage breast cancer patients resulted in significantly poorer relapse-free survival (log rank test: P=0.003) and was an independent predictor of relapse-free survival (multivariate hazard ratio=5.13, P=0.006, 95% CI: 1.62-16.31).
  
  
  CONCLUSIONS
  The detection of CTCs in peripheral blood of early-stage breast cancer patients provided prognostic information for relapse-free survival.
authors.affiliation: Division of Experimental Therapy, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
authors.forename: T J
authors.initials: TJ
authors.lastname: Molloy
authors.forename: L A
authors.initials: LA
authors.lastname: Devriese
authors.forename: H H
authors.initials: HH
authors.lastname: Helgason
authors.forename: A J
authors.initials: AJ
authors.lastname: Bosma
authors.forename: M
authors.initials: M
authors.lastname: Hauptmann
authors.forename: E E
authors.initials: EE
authors.lastname: Voest
authors.forename: J H M
authors.initials: JH
authors.lastname: Schellens
authors.forename: L J
authors.initials: LJ
authors.lastname: van't Veer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation; D008875:Middle Aged; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating; D016133:Polymerase Chain Reaction / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies