title: Evaluation of a multi-marker immunomagnetic enrichment assay for the quantification of circulating melanoma cells.
abstract: BACKGROUND
  Circulating melanoma cells (CMCs) are thought to be valuable in improving measures of prognosis in melanoma patients and may be a useful marker of residual disease to identify non-metastatic patients requiring adjuvant therapy. We investigated whether immunomagnetic enrichment targeting multiple markers allows more efficient enrichment of CMCs from patient peripheral blood than targeting a single marker. Furthermore, we aimed to determine whether the number of CMCs in patient blood was associated with disease stage.
  
  
  METHODS
  We captured CMCs by targeting the melanoma associated markers MCSP and MCAM as well as the melanoma stem cell markers ABCB5 and CD271, both individually and in combination, by immunomagnetic enrichment. CMCs were enriched and quantified from the peripheral blood of 10 non-metastatic and 13 metastatic melanoma patients.
  
  
  RESULTS
  Targeting all markers in combination resulted in the enrichment of more CMCs than when any individual marker was targeted (p < 0.001-0.028). Furthermore, when a combination of markers was targeted, a greater number of CMCs were enriched in metastatic patients compared with non-metastatic patients (p = 0.007).
  
  
  CONCLUSIONS
  Our results demonstrated that a combination of markers should be targeted for optimal isolation of CMCs. In addition, there are significantly more CMCs in metastatic patients compared with non-metastatic patients and therefore quantification of CMCs may prove to be a useful marker of disease progression.
authors.affiliation: School of Medical Sciences, Edith Cowan University, Perth, WA, Australia.
authors.forename: James B
authors.initials: JB
authors.lastname: Freeman
authors.forename: Elin S
authors.initials: ES
authors.lastname: Gray
authors.forename: Michael
authors.initials: M
authors.lastname: Millward
authors.forename: Robert
authors.initials: R
authors.lastname: Pearce
authors.forename: Melanie
authors.initials: M
authors.lastname: Ziman
mesh_terms: D005455:Fluorescent Antibody Technique; D006801:Humans; D018189:Immunomagnetic Separation / Q000592:standards*; D008545:Melanoma / Q000097:blood* / Q000473:pathology; D009362:Neoplasm Metastasis; D009360:Neoplastic Cells, Circulating