title: The presence of circulating tumor cells (CTCs) correlates with lymph node metastasis in nonresectable squamous cell carcinoma of the head and neck region (SCCHN).
abstract: BACKGROUND
  The mechanisms regulating tumor cell dissemination in locally advanced squamous cell carcinoma of the head and neck region (SCCHN) are largely unresolved. We assessed the frequency of circulating tumor cells (CTCs), their association with clinicopathologic parameters and their kinetics during radiochemotherapy.
  
  
  METHODS
  Peripheral blood samples from 42 patients with locally advanced SCCHN were included. CTCs were detected using flow cytometric analysis of CD45-epithelial cell adhesion molecule+cytokeratin+ cells and results were validated by nested RT-PCR analysis of circulating epidermal growth factor receptor transcripts. The association between the presence of CTCs and T stage, tumor volume, N stage and human papillomavirus status was evaluated. The influence of radiochemotherapy on CTC numbers was determined.
  
  
  RESULTS
  CTCs were detected in 18 of 42 SCCHN patients (43%), with a mean ± standard deviation of 1.7 ± 0.9 CTCs per 3.75 ml blood. We observed no significant correlation between the presence of CTCs and T stage or tumor volume. However, a nodal stage of N2b or higher was associated with higher frequency of CTCs. Though concurrent radiochemotherapy reduced their frequency, CTCs persisted during treatment in 20% of cases.
  
  
  CONCLUSIONS
  Detection of CTCs correlates with regional metastasis in inoperable SCCHN. Further follow-up is needed to evaluate the prognostic significance of CTC detection, in addition to clinical staging of lymph nodes, for regional or distant recurrence.
authors.affiliation: Translational Radiobiology and Radiooncology Research Laboratory, Department of Radiotherapy, Charité Campus Mitte, Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Hristozova
authors.forename: R
authors.initials: R
authors.lastname: Konschak
authors.forename: C
authors.initials: C
authors.lastname: Stromberger
authors.forename: A
authors.initials: A
authors.lastname: Fusi
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.forename: W
authors.initials: W
authors.lastname: Weichert
authors.forename: A
authors.initials: A
authors.lastname: Stenzinger
authors.forename: V
authors.initials: V
authors.lastname: Budach
authors.forename: U
authors.initials: U
authors.lastname: Keilholz
authors.forename: I
authors.initials: I
authors.lastname: Tinhofer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D015870:Gene Expression; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D027383:Papillomaviridae / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; C512478:EGFR protein, human; D066246:ErbB Receptors