title: Elevated levels of circulating endothelial progenitor cells in head and neck cancer patients.
abstract: OBJECTIVE
  Measurement of circulating endothelial cells (CECs) and progenitor cells (EPCs) has potential as a surrogate marker for monitoring anticancer treatment. This study evaluated the significance of CECs and EPCs in the blood of patients with head and neck squamous cell carcinoma.
  
  
  METHODS
  In a prospective trial fresh blood samples from 22 tumor patients and 18 controls were tested using multiparametric flow-cytometry. CECs were defined as CD31(+)/CD146(+) and CD45(-)/7AAD(-). EPCs were defined as CD133(+)/KDR(+) and CD3(-)/CD19(-)/CD33(-)/7AAD(-).
  
  
  RESULTS
  Median levels (min/max) of CECs in the tumor group were 2 (0/5) at the time of diagnosis, 1 (0/5) 1 year after therapy and 2 (0/6) in the control cohort. Median levels of EPCs were 5 (1/41) before and 10 (0/21) after treatment in the tumor group compared to 2 (0/7) in the control cohort (P < 0.001 and P = 0.03). CEC and EPC levels showed no apparent correlation with tumor size and response to radiotherapy after 18 months of observation.
  
  
  CONCLUSIONS
  In this pilot study CD133(+)/KDR(+) EPCs were significantly elevated in head and neck tumor patients before and after therapy. Our results warrant further studies on the use of EPCs as a surrogate marker for anticancer therapies in these patients.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Brunner
authors.forename: Dietmar
authors.initials: D
authors.lastname: Thurnher
authors.forename: Gregor
authors.initials: G
authors.lastname: Heiduschka
authors.forename: Matthaeus Ch
authors.initials: MCh
authors.lastname: Grasl
authors.forename: Christine
authors.initials: C
authors.lastname: Brostjan
authors.forename: Boban M
authors.initials: BM
authors.lastname: Erovic
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000941:Antigens / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000097:blood; D002294:Carcinoma, Squamous Cell / Q000097:blood* / Q000401:mortality / Q000628:therapy; D016022:Case-Control Studies; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006258:Head and Neck Neoplasms / Q000097:blood* / Q000401:mortality / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D013234:Stem Cells / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D000941:Antigens; D014408:Biomarkers, Tumor; D040301:Vascular Endothelial Growth Factor Receptor-2