title: Frozen section examination may facilitate reconstructive surgery for mid and low rectal cancer.
abstract: BACKGROUND
  Distal margin >1 cm provides an oncologic safety in low-lying rectal cancers. We evaluated the accuracy of frozen section (FS) examination in estimating distal margins, and its impact on intraoperative decision making regarding restorative proctectomy.
  
  
  METHODS
  Retrospective study of patients who underwent surgery for adenocarcinoma of the mid or lower rectum during 2001-2010 and for whom a distal margin specimen was examined intraoperatively by FS, to confirm microscopically free margins. Intraoperative findings, and frozen and final paraffin section findings were retrieved from patient charts. A distal margin of ≤1 cm was compared with >1 cm, for free margins at final pathology and local recurrence (LR). The impact of a distal margin ≤5 mm was also assessed. The impact of FS on intraoperative decision making, in patients who did and did not receive preoperative chemoradiotherapy, was assessed.
  
  
  RESULTS
  The mean age of the 63 patients studied was 66.4 ± 11.8 years, and median tumor distance from the anal verge 6 cm (range 1-10 cm). Seven patients underwent abdominoperineal resection, 54 anterior resection, and two Hartman procedures. FS sensitivity and specificity were 83% and 98%, respectively. Accuracy of FS was high for the 41 patients treated with preoperative chemoradiotherapy, and the 22 who were not. Distal margin >5 mm at FS examination ensured a free margin at final pathology. LR rate was comparable between patients with distal margin >10 mm and ≤10 mm, 8% vs 11%, P = 0.65.
  
  
  CONCLUSIONS
  FS examination may help determine free distal margin and consequently, in selected cases, may facilitate a restorative procedure in patients with low rectal cancer.
authors.affiliation: Department of General Surgery, Colorectal Surgery Unit, Rambam Health Care Campus, and Bruce Rappaport School of Medicine, The Technion, Haifa, Israel.
authors.forename: Wisam
authors.initials: W
authors.lastname: Khoury
authors.forename: Wisam
authors.initials: W
authors.lastname: Abboud
authors.forename: Dov
authors.initials: D
authors.lastname: Hershkovitz
authors.forename: Simon D
authors.initials: SD
authors.lastname: Duek
mesh_terms: D000368:Aged; D059248:Chemoradiotherapy; D015331:Cohort Studies; D005260:Female; D005629:Frozen Sections; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D019651:Plastic Surgery Procedures / Q000379:methods*; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies
keywords: abdominoperineal resection; distal margin; frozen section; rectal cancer; restorative proctectomy