title: Clinical significance of telomerase activity in peripheral blood of patients with esophageal squamous cell carcinoma.
abstract: BACKGROUND
  The presence of tumor cells in the blood stream is considered evidence of a high risk of distant organ metastasis. We examined the usefulness of telomerase activity in peripheral blood polymorphonuclear cells as an indicator of distant metastasis in patients with esophageal squamous cell carcinoma.
  
  
  METHODS
  Telomerase activity was measured in the peripheral blood mononuclear cell and polymorphonuclear cell fractions obtained from blood samples of healthy volunteers mixed with squamous cell carcinoma cell lines, and cell distribution was analyzed by flow cytometry. Then telomerase activity of forty-two polymorphonuclear cell fractions obtained from esophageal squamous cell carcinoma patients was measured.
  
  
  RESULTS
  Telomerase activity was detected in polymorphonuclear cell fractions and cell distribution analysis revealed the presence of esophageal squamous cell carcinoma cells. Organ metastasis was detected in 7 (78%) of the 9 patients with telomerase-positive polymorphonuclear cell fractions as opposed to only five (15%) of the 33 with telomerase-negative cases, and there was a significant positive correlation between telomerase activity and organ metastasis (p < 0.0008).
  
  
  CONCLUSIONS
  Measurement of telomerase activity in the polymorphonuclear cell fractions is useful for identifying a high risk group for distant organ metastasis in patients with esophageal squamous cell carcinoma.
authors.affiliation: Department of Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Koyanagi
authors.forename: Soji
authors.initials: S
authors.lastname: Ozawa
authors.forename: Nobutoshi
authors.initials: N
authors.lastname: Ando
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Masakazu
authors.initials: M
authors.lastname: Ueda
authors.forename: Masaki
authors.initials: M
authors.lastname: Kitajima
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D004938:Esophageal Neoplasms / Q000201:enzymology*; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000201:enzymology*; D008297:Male; D008875:Middle Aged