title: Survival Impact of Primary Tumor Lymph Node Status and Circulating Tumor Cells in Patients with Colorectal Liver Metastases.
abstract: OBJECTIVE
  The aim of this study was to analyse the survival impact of primary tumor nodal status (N0/N+) in patients with resectable colorectal liver metastases (CLM), and to determine the value of circulating and disseminated tumor cells (CTCs/DTCs) in this setting.
  
  
  METHODS
  In this prospective study of patients undergoing resection of CLM from 2008 to 2011, peripheral blood was analyzed for CTCs using the CellSearch System®, and bone marrow was sampled for DTC analyses just prior to hepatic resection. The presence of one or more tumor cells was scored as CTC/DTC-positive. Following resection of the primary tumor, the lymph nodes (LNs) were examined by routine histopathological examination.
  
  
  RESULTS
  A total of 140 patients were included in this study; 38 patients (27.1%) were negative at the primary colorectal LN examination (N0). CTCs were detected in 12.1% of all patients; 5.3% of patients in the N0 group and 14.7% of patients in the LN-positive (N+) group (p = 0.156), with the LN-positive group (N+) consisting of both N1 and N2 patients. There was a significant difference in recurrence-free survival (RFS) when analysing the N0 group versus the N+ group (p = 0.007) and CTC-positive versus CTC-negative patients (p = 0.029). In multivariate analysis, CTC positivity was also significantly associated with impaired overall survival (OS) [p = 0.05], whereas DTC positivity was not associated with survival.
  
  
  CONCLUSIONS
  In this cohort of resectable CLM patients, 27% had primary N0 colorectal cancer. Assessment of CTC in addition to nodal status may contribute to improved classification of patients into high- and low-risk groups, which has the potential to guide and improve treatment strategies.
authors.affiliation: Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway. sbseel@siv.no.|Department of Gastrointestinal Surgery, Vestfold Hospital Trust, Tønsberg, Norway. sbseel@siv.no.
authors.forename: Lars Thomas
authors.initials: LT
authors.lastname: Seeberg
authors.affiliation: Oslo Centre of Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Brunborg
authors.affiliation: Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: Anne
authors.initials: A
authors.lastname: Waage
authors.affiliation: Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: Harald
authors.initials: H
authors.lastname: Hugenschmidt
authors.affiliation: Department of Pathology, Oslo University Hospital, Oslo, Norway.
authors.forename: Anne
authors.initials: A
authors.lastname: Renolen
authors.affiliation: Department of Pathology, Oslo University Hospital, Oslo, Norway.
authors.forename: Ingunn
authors.initials: I
authors.lastname: Stav
authors.affiliation: Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: Bjørn A
authors.initials: BA
authors.lastname: Bjørnbeth
authors.affiliation: Department of Pathology, Oslo University Hospital, Oslo, Norway.
authors.forename: Elin
authors.initials: E
authors.lastname: Borgen
authors.affiliation: Department of Oncology, Oslo University Hospital, Oslo, Norway.|Institute of Clinical Medicine, Oslo University Hospital, Oslo, Norway.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Naume
authors.affiliation: Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: Kristoffer W
authors.initials: KW
authors.lastname: Brudvik
authors.affiliation: Department of Gastrointestinal Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: Gro
authors.initials: G
authors.lastname: Wiedswang
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000097:blood / Q000401:mortality* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood / Q000401:mortality* / Q000556:secondary; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000401:mortality* / Q000473:pathology; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate