title: Distal bowel surgical margin shorter than 1 cm after preoperative radiation for rectal cancer: is it safe?
abstract: BACKGROUND
  The primary end-point of our randomized trial was sphincter preservation. The secondary aim was to evaluate whether distal bowel clearance < or =1 cm is safe after radiation.
  
  
  METHODS
  The study randomized 312 patients with cT3-4 resectable low-lying and mid-rectal cancer to receive either preoperative irradiation (5 x 5 Gy) with immediate total mesorectal excision (TME) or chemoradiation (50.4 Gy, bolus 5-fluorouracil and leucovorin) with delayed TME. After anterior resection, pathologists prospectively measured macroscopic and microscopic distal bowel clearance.
  
  
  RESULTS
  Macroscopic and microscopic distal bowel clearance, distal intramural spread, sphincter preservation, local control, disease-free survival, and overall survival did not differ in the two randomized groups. Pooled analysis of the two groups showed that the incidence of local recurrence at 4 years (median follow-up) for patients with macroscopic clearance < or =1 cm (n = 42) and >1 cm (n = 124) was 11.3% and 15.4%, respectively (P = 0.514); the hazard ratio (HR) was 0.70, and the 95% confidence interval (CI) was 0.23-2.07. The corresponding values for patients with microscopic clearance < or =1 cm (n = 51) and >1 cm (n = 101) were 9.6% and 17.6% (P = 0.220; HR 0.51; 95% CI 0.17-1.53).
  
  
  CONCLUSIONS
  After preoperative radiotherapy, distal bowel clearance < or =1 cm did not compromise local control.
authors.affiliation: Department of Colorectal Cancer, The Maria Sklodowska-Curie Memorial Cancer Centre, W. K. Roentgena 5, 02 781 Warsaw, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Rutkowski
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Bujko
authors.forename: Marek P
authors.initials: MP
authors.lastname: Nowacki
authors.forename: Ewa
authors.initials: E
authors.lastname: Chmielik
authors.forename: Anna
authors.initials: A
authors.lastname: Nasierowska-Guttmejer
authors.forename: Andrzej
authors.initials: A
authors.lastname: Wojnar