title: Clinical significance of macroscopic completeness of mesorectal resection in rectal cancer.
abstract: OBJECTIVE
  Local recurrence after resection of rectal cancer is usually regarded as being due to a 'failure' of surgery. The completeness of resection of the mesorectum has been proposed as an indicator of the 'quality' of the resection. We determined the prognostic value of macroscopic evaluation of rectal cancer resection specimens and the circumferential resection margin (CRM) after curative surgery.
  
  
  METHODS
  From 1999 to 2006, the macroscopic quality of the mesorectum and the CRM were prospectively assessed in 127 patients who underwent rectal cancer resection with curative intent (R0+R1). Chemoradiotherapy was administered for 61 tumours staged as locally advanced tumours (T3, T4 and N+). Univariate analysis of time to local recurrence and cancer-free survival were tested (Kaplan-Meier) and multivariate analysis calculated with a Cox regression model.
  
  
  RESULTS
  The mesorectum was incomplete in 34 (26.8%) patients. At a median follow up of 34 months (range, 9-96 months), in the group with an adequate mesorectal excision, the cumulative risk of local recurrence at 5 years was 10%. This was 25% if the mesorectum was incomplete (P < 0.01). Five-year cancer-free survival was 65% if the mesorectal excision was adequate and 47% if it was not (P < 0.05). Multivariate analysis identified T status, the CRM and the mesorectal score as independent factors for local recurrence, and T and N status and the mesorectal score as independent factors for disease-free survival.
  
  
  CONCLUSIONS
  The outcome of surgical treatment of rectal cancer is related to the completeness of mesorectal excision. It is a more discriminative prognostic factor than the classic tumour-node-metastasis (TNM) system.
authors.affiliation: Department of Surgery III, Coimbra University Medical School and Coimbra University Hospital, Coimbra, Portugal. julio.s.leite@gmail.com
authors.forename: J S
authors.initials: JS
authors.lastname: Leite
authors.forename: S C
authors.initials: SC
authors.lastname: Martins
authors.forename: J
authors.initials: J
authors.lastname: Oliveira
authors.forename: M F
authors.initials: MF
authors.lastname: Cunha
authors.forename: F
authors.initials: F
authors.lastname: Castro-Sousa
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D012307:Risk Factors; D016896:Treatment Outcome