title: Clinical significance of circulating tumor cells in blood from patients with gastrointestinal cancers.
abstract: BACKGROUND
  Circulating tumor cells (CTCs) measured by the CellSearch system in metastatic breast cancer have been reported to correlate with shorter overall survival. The purpose of this study was to clarify the clinicopathologic characteristics of CTCs in gastrointestinal cancers.
  
  
  METHODS
  Pre- and postoperative CTCs from 130 gastrointestinal cancer patients and 41 healthy volunteers were measured by this system. Correlation between CTC counts and clinicopathologic variables was examined.
  
  
  RESULTS
  The number of CTCs in metastatic patients (n = 79) was larger than in nonmetastatic patients (n = 35) and in healthy donors (n = 41) (P < 0.001). CTC counts were larger in metastatic gastric cancer (n = 27) than in nonmetastatic gastric cancer (n = 14) (P = 0.016). Two or more CTCs was significantly correlated with advanced tumor stage in all gastrointestinal cancers (P < 0.001) and in gastric cancer (P = 0.032). Two or more CTCs had significant correlation with peritoneal dissemination of gastric or colorectal cancer (P = 0.007) and pleural dissemination of esophageal cancer (P = 0.033). The survival of patients with > or =2 CTCs was shorter than that of patients with <2 CTCs (P = 0.005). The change in CTCs tended to correlate with disease progression and chemotherapeutic effect.
  
  
  CONCLUSIONS
  This study suggests that measurement of CTCs in gastrointestinal cancer patients could be useful as a tool for judging tumor stage, predicting the presence of peritoneal or pleural dissemination and patients' survival, and monitoring response to cancer therapy.
authors.affiliation: Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Kunihiko
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authors.lastname: Hiraiwa
authors.forename: Hiroya
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authors.lastname: Takeuchi
authors.forename: Hirotoshi
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authors.lastname: Hasegawa
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Saikawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Suda
authors.forename: Takashi
authors.initials: T
authors.lastname: Ando
authors.forename: Koshi
authors.initials: K
authors.lastname: Kumagai
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Irino
authors.forename: Takahisa
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Sachiko
authors.initials: S
authors.lastname: Matsuda
authors.forename: Masaki
authors.initials: M
authors.lastname: Kitajima
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa