title: Immunomagnetic enrichment and detection of micrometastases in colorectal cancer: correlation with established clinical parameters.
abstract: OBJECTIVE
  Micrometastatic disease in bone marrow is of prognostic significance in colorectal cancer patients. However, detection rates of standard immunocytology are relatively low. We used magnetic activated cell sorting (MACS), a highly sensitive method, to increase detection rates and correlated the presence of cytokeratin (CK)-expressing cells with clinical parameters.
  
  
  METHODS
  Bone marrow was obtained from 51 consecutive patients with newly diagnosed colorectal adenocarcinoma who underwent primary surgery and 18 control subjects. International Union Against Cancer (UICC) stage I disease was diagnosed in 11 patients, stage II disease was diagnosed in 14 patients, stage III disease was diagnosed in 12 patients, and stage IV disease was diagnosed in 14 patients. CK-positive cells were enriched and stained with magnetically labeled CAM 5.2 antibodies directed to CK 7 and 8.
  
  
  RESULTS
  CK-positive cells were found in 33 (65%) patients and were absent in 18 (35%). Four of 11 (36%) patients with UICC stage I disease, nine of 14 (64%) with stage II diease, eight of 12 (67%) with stage III disease, and 12 of 14 (86%) with stage IV disease were CK-positive. Epithelial cells were more frequently found in pT3/4 (72%) than in pT1/2 (36%) tumors (P =.026), but there was no difference for lymph node status. CK-positive patients had a higher chance for elevated carcinoembryonic antigen (85% v 15%, P = NS) and CA 19-9 levels (92% v 8%, P =.019). There were no significant differences in CA 72-4, sex, age, tumor grading, or tumor localization regarding the presence of CK-positive cells. All control subjects were CK-negative.
  
  
  CONCLUSIONS
  In searching for micrometastases in colorectal cancer patients, we have achieved high detection rates by using MACS. The presence of these cells correlated significantly with tumor stage, tumor extension, and the tumor marker CA 19-9.
authors.affiliation: Department of Internal Medicine I, University of Cologne, Germany. martin.weihrauch@uni-koeln.de
authors.forename: Martin R
authors.initials: MR
authors.lastname: Weihrauch
authors.forename: Edmund
authors.initials: E
authors.lastname: Skibowski
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Koslowsky
authors.forename: Wilfried
authors.initials: W
authors.lastname: Voiss
authors.forename: Daniel
authors.initials: D
authors.lastname: Re
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Kuhn-Regnier
authors.forename: Carolin
authors.initials: C
authors.lastname: Bannwarth
authors.forename: Michel
authors.initials: M
authors.lastname: Siedek
authors.forename: Volker
authors.initials: V
authors.lastname: Diehl
authors.forename: Heribert
authors.initials: H
authors.lastname: Bohlen
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000556:secondary*; D000368:Aged; D000369:Aged, 80 and over; D019046:Bone Marrow Neoplasms / Q000175:diagnosis / Q000556:secondary*; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods* / Q000592:standards; D007633:Keratins / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000175:diagnosis*; D009367:Neoplasm Staging / Q000379:methods; D012680:Sensitivity and Specificity
chemical_list: D007633:Keratins