title: A circumferential resection margin of 1 mm is a negative prognostic factor in rectal cancer patients with and without neoadjuvant chemoradiotherapy.
abstract: BACKGROUND
  There is ongoing debate about the appropriate criterion for defining a positive circumferential resection margin after radical surgery for rectal cancer.
  
  
  OBJECTIVE
  The purpose of this work was to determine the importance of the extent of the circumferential resection margin with regard to outcomes in patients with rectal cancer who underwent total mesorectal excision with and without neoadjuvant chemoradiotherapy.
  
  
  METHODS
  This was a retrospective review of prospectively collected data.
  
  
  METHODS
  The study was conducted in a tertiary care hospital.
  
  
  METHODS
  We reviewed the medical charts of 780 patients with rectal cancer who underwent radical surgery from 2004 to 2009. There were 599 patients (76.8%) who did not receive neoadjuvant chemoradiotherapy and 181 patients (23.2%) who did.
  
  
  METHODS
  The relationship between the extent of the circumferential resection margin (0.5, 1.0, 2.0, and 3.0 mm) and recurrence and survival was assessed.
  
  
  RESULTS
  Among circumferential resection margins ≤0.5, ≤1.0, ≤2.0, and ≤3.0 mm, the HR was highest and disease-free survival was longest for a circumferential resection margin ≤1 mm in both the chemoradiotherapy and nonchemoradiotherapy groups. A circumferential resection margin ≤1 mm, lymphatic invasion, histology, pathologic T category, pathologic N category, preoperative CEA, and adjuvant chemotherapy were independent predictors of disease-free survival in the nonchemoradiotherapy group. In the chemoradiotherapy group, a circumferential resection margin ≤1 mm and histology were independent predictors of disease-free survival. Multivariate analysis revealed that a circumferential resection margin ≤1 mm was an independent prognostic factor for overall survival in both of the 2 groups.
  
  
  CONCLUSIONS
  This was a single-institution, retrospective study.
  
  
  CONCLUSIONS
  A circumferential resection margin of ≤1 mm had a strong association with disease-free survival compared with circumferential resection margins ≤0.5, ≤2.0, and ≤3 mm. A circumferential resection margin ≤1 mm was an independent predictor of a poor outcome in both the nonchemoradiotherapy and chemoradiotherapy groups.
authors.affiliation: 1Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea 2Department of Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jong Seob
authors.initials: JS
authors.lastname: Park
authors.forename: Jung Wook
authors.initials: JW
authors.lastname: Huh
authors.forename: Yoon Ah
authors.initials: YA
authors.lastname: Park
authors.forename: Yong Beom
authors.initials: YB
authors.lastname: Cho
authors.forename: Seong Hyeon
authors.initials: SH
authors.lastname: Yun
authors.forename: Hee Cheol
authors.initials: HC
authors.lastname: Kim
authors.forename: Woo Yong
authors.initials: WY
authors.lastname: Lee
authors.forename: Ho-Kyung
authors.initials: HK
authors.lastname: Chun
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery* / Q000628:therapy; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome