title: The significance and clinical factors associated with a subcentimeter resection of colorectal liver metastases.
abstract: BACKGROUND
  Prognosis after resection of colorectal liver metastases is influenced by various factors. A positive margin of resection (MOR) has been shown to adversely influence prognosis. Although a 1-cm MOR has been accepted as adequate, the data to support this guideline are sparse.
  
  
  METHODS
  Our hepatobiliary database was queried for patients who underwent liver resection for colorectal metastases between January 1992 and July 2003. All patients were divided into three groups: MOR <.5 cm (group A), .5 to 1 cm (group B), and >1 cm (group C). Operative reports from each hepatic resection were analyzed to determine local factors that may have contributed to a subcentimeter MOR.
  
  
  RESULTS
  A total of 112 patients (67 men and 45 women) underwent liver resection for colorectal metastases with negative margins. Fifty-three patients were in group A, 26 patients were in group B, and 33 patients were in group C. Group C demonstrated decreased local recurrence (LR; P = .003), distant recurrence (DR; P = .008), and disease-free recurrence (P = .002). A significant difference in the overall time to LR (P = .003), time to DR (P = .003), and disease-free survival (P = .002) was also demonstrated. Factors associated with a subcentimeter MOR included nonanatomical resection (P = .043), proximity to a major vessel (P = .003), and central location (P = .002).
  
  
  CONCLUSIONS
  A <1-cm resection for colorectal liver metastases is associated with increased LR and DR, as well as decreased disease-free survival. When a nonanatomical resection is performed, a MOR >1 cm should be attempted, because an adequate margin is often underestimated. Considerations should be made for extended resections when tumors are centrally located or near major vessels.
authors.affiliation: Department of Surgery, Division of Surgical Oncology, University of Cincinnati Medical Center, 234 Goodman Street, ML 0772, Cincinnati, Ohio 45219, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Wray
authors.forename: A M
authors.initials: AM
authors.lastname: Lowy
authors.forename: J B
authors.initials: JB
authors.lastname: Mathews
authors.forename: S
authors.initials: S
authors.lastname: Park
authors.forename: K A
authors.initials: KA
authors.lastname: Choe
authors.forename: D W
authors.initials: DW
authors.lastname: Hanto
authors.forename: L E
authors.initials: LE
authors.lastname: James
authors.forename: D A
authors.initials: DA
authors.lastname: Soldano
authors.forename: S A
authors.initials: SA
authors.lastname: Ahmad
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies; D016019:Survival Analysis