title: Circulating tumor cell (CTC) count and epithelial growth factor receptor expression on CTCs as biomarkers for cetuximab efficacy in advanced colorectal cancer.
abstract: OBJECTIVE
  The purpose of this study was to establish whether CTC count and epidermal growth factor receptor (EGFR) expression in CTCs predicted outcome in patients with advance colorectal cancer (ACC) receiving cetuximab as third-line treatment.
  
  
  METHODS
  Between October 2008 and March 2011, 63 patients with KRAS wild-type ACC were treated with cetuximab-containing chemotherapy at the Cancer Institute Hospital. We measured the CTC count and EGFR expression on CTCs using the CellSearch System (Veridex LLC, NJ, USA).
  
  
  RESULTS
  Nineteen patients (30%) with a high number of CTCs had a significantly lower overall survival compared with 44 patients with a low number of CTCs. No significant difference was observed in progression-free survival between the two groups. Out of the 33 patients positive for CTCs (one or more CTC), seven patients (21%) were positive for EGFR expression. No statistically significant difference was observed in clinical outcome between EGFR-positive and EGFR-negative patients.
  
  
  CONCLUSIONS
  A high CTC count predicted reduced overall survival in patients with ACC treated with cetuximab-combination chemotherapy as third-line treatment. These results suggest that the assessment of CTCs might provide with important prognostic information for such patients.
authors.affiliation: Gastroenterological Center, Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo 135-8550, Japan. satoshi.matsusaka@jfcr.or.jp.
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Kuboki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsusaka
authors.forename: Sayuri
authors.initials: S
authors.lastname: Minowa
authors.forename: Harumi
authors.initials: H
authors.lastname: Shibata
authors.forename: Mitsukuni
authors.initials: M
authors.lastname: Suenaga
authors.forename: Eiji
authors.initials: E
authors.lastname: Shinozaki
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Mizunuma
authors.forename: Masashi
authors.initials: M
authors.lastname: Ueno
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Hatake
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000378:metabolism*
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D066246:ErbB Receptors; D000068818:Cetuximab
keywords: cetuximab; circulating tumor cells; colorectal cancer; mCRC