title: Clinical significance of circulating tumor cells and free DNA in non-small cell lung cancer.
abstract: OBJECTIVE
  This pilot study assessed correlations between circulating tumor cells (CTCs) and circulating free DNA (cfDNA) of metastatic non-small cell lung cancer (NSCLC) after acquisition of resistance to epidermal growth factor receptor tyrosine kinase inhibitors.
  
  
  METHODS
  CTCs were counted using the CellSearch system (Veridex). cfDNA was analyzed for EGFR mutation status by the Cycleave real-time PCR assay.
  
  
  RESULTS
  Twenty-four patients participated in this study. CTCs were detected in 8 of 24 cases (33.3%), at a mean of 2.6 CTCs per 7.5 ml blood (range: 1-24). EGFR mutations in cfDNA were detected in 6 out of 24 cases (25%). The EGFR mutation detection rates in cfDNA were significantly higher in patients with ≥ 2 CTCs per 7.5 ml (100%) than in those with <2 CTCs per 7.5 ml (10%) (p=0.0001).
  
  
  CONCLUSIONS
  The presence of CTCs was correlated with the positivity of EGFR mutation in cfDNA.
authors: Department of Respiratory Medicine, Toho University Omori Medical Center, 6-11-1 Omori-Nishi, Ota-ku, Tokyo 143-8541, Japan. kazutoshiisobe@aol.com
authors: Kazutoshi
authors: K
authors: Isobe
authors: Yoshinobu
authors: Y
authors: Hata
authors: Kunihiko
authors: K
authors: Kobayashi
authors: Nao
authors: N
authors: Hirota
authors: Keita
authors: K
authors: Sato
authors: Go
authors: G
authors: Sano
authors: Keishi
authors: K
authors: Sugino
authors: Susumu
authors: S
authors: Sakamoto
authors: Yujiro
authors: Y
authors: Takai
authors: Kazutoshi
authors: K
authors: Shibuya
authors: Keigo
authors: K
authors: Takagi
authors: Sakae
authors: S
authors: Homma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood* / Q000473:pathology; D004273:DNA, Neoplasm / Q000097:blood*; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D010865:Pilot Projects; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D004273:DNA, Neoplasm; D066246:ErbB Receptors