title: Circulating tumor cells in colorectal cancer: correlation with clinical and pathological variables.
abstract: BACKGROUND
  The CellSearch System is a technique to detect circulating tumor cells (CTCs) in patients with cancer. Few data have been published concerning the role of CTCs detection by this method in colorectal cancer. The aim of this study was to correlate the presence of CTCs with the commonest clinical and morphological variables.
  
  
  METHODS
  Blood samples were collected from 97 patients and 30 healthy volunteers. Quantification of CTCs in 7.5 ml of blood was carried out with the CellSearch System. The results were expressed as number of CTCs/7.5 ml and the cut-off of >or=2 CTCs/7.5 ml was chosen to define the test as positive.
  
  
  RESULTS
  Positive CTCs were detected in 34 of 94 patients (36.2%). Correlation was not found among positive CTCs and location of primary tumor, increased carcinoembryonic antigen level, increased lactate dehydrogenase level or grade of differentiation. Only stage correlated with positive CTCs (20.7% in stage II, 24.1% in stage III and 60.7% in stage IV, P = 0.005).
  
  
  CONCLUSIONS
  CTCs detection by CellSearch is a highly reproducible method that correlates with stage but not with other clinical and morphological variables in patients with colorectal cancer. Colon cancer tumor cells are detectable in all stages. Further studies are warranted.
authors.affiliation: Department of Medical Oncology, Hospital Clínico San Carlos de Madrid, Madrid, Spain. jsastre.hcsc@salud.madrid.org
authors.forename: J
authors.initials: J
authors.lastname: Sastre
authors.forename: M L
authors.initials: ML
authors.lastname: Maestro
authors.forename: J
authors.initials: J
authors.lastname: Puente
authors.forename: S
authors.initials: S
authors.lastname: Veganzones
authors.forename: R
authors.initials: R
authors.lastname: Alfonso
authors.forename: S
authors.initials: S
authors.lastname: Rafael
authors.forename: J A
authors.initials: JA
authors.lastname: García-Saenz
authors.forename: M
authors.initials: M
authors.lastname: Vidaurreta
authors.forename: M
authors.initials: M
authors.lastname: Martín
authors.forename: M
authors.initials: M
authors.lastname: Arroyo
authors.forename: M T
authors.initials: MT
authors.lastname: Sanz-Casla
authors.forename: E
authors.initials: E
authors.lastname: Díaz-Rubio
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood; D001772:Blood Cell Count / Q000295:instrumentation; D002272:Carcinoembryonic Antigen / Q000032:analysis; D015179:Colorectal Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D018189:Immunomagnetic Separation / Q000295:instrumentation; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating; D010166:Palliative Care; D011446:Prospective Studies; D015203:Reproducibility of Results
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D007770:L-Lactate Dehydrogenase