title: Detection of cancer cells in mesenteric vein and peripheral vessels by measuring telomerase activity in patients with colorectal cancer.
abstract: BACKGROUND
  Liver metastasis is an important factor determining prognosis in colorectal cancer. The objective of this study was to assess whether colorectal cancer cells in the drainage veins can be detected by measuring telomerase activity and its detection is correlated with liver metastasis.
  
  
  METHODS
  Telomeric repeat amplification protocol assay in combination with an immunomagnetic sorting was used for measuring telomerase activity of epithelial cells in blood samples collected from mesenteric (tumor-drainage) vein and peripheral vessels of 41 colorectal cancer patients. Telomerase activity was calculated as relative telomerase activity (RTA) against a control template and analyzed in terms of liver metastasis.
  
  
  RESULTS
  RTA of mesenteric blood samples was significantly higher in patients with liver metastasis (60.8%; n=7) than in those without metastasis (19.7%; n=34; P=.019). The RTA of peripheral blood sample was also higher in patients with liver metastasis (26.8%) than in those without metastasis (11.1%; p=.17). Moreover, 57% of cases with liver metastasis exhibited a positive telomerase activity in mesenteric blood sample, whereas it was 18% in cases without metastasis.
  
  
  CONCLUSIONS
  Our assay was proven to be a feasible method for detecting cancer cells in tumor-drainage veins. High telomerase activity of mesenteric blood samples reflected the existence of liver metastasis of colorectal cancer.
authors.affiliation: Department of Surgical Oncology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nozawa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tada
authors.forename: Giichiro
authors.initials: G
authors.lastname: Tsurita
authors.forename: Shin
authors.initials: S
authors.lastname: Sasaki
authors.forename: Joji
authors.initials: J
authors.lastname: Kitayama
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nagawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000235:genetics; D015179:Colorectal Neoplasms / Q000201:enzymology*; D005260:Female; D006801:Humans; D007633:Keratins / Q000235:genetics; D008113:Liver Neoplasms / Q000556:secondary; D008297:Male; D008642:Mesenteric Veins / Q000201:enzymology*; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000097:blood*
chemical_list: D002272:Carcinoembryonic Antigen; D007633:Keratins; D019098:Telomerase