title: Clinicopathological analysis of distal margin for rectal cancer after preoperative chemoradiation therapy.
abstract: OBJECTIVE
  Preoperative chemoradiation therapy (CRT) for advanced rectal cancer allows anal sphincter preservation in some patients who would require an abdominoperineal resection. But adequate distal margin in patients with locally advanced rectal cancer requiring preoperative CRT is unclear. The objective was to evaluate necessary distal margin from reduced tumor by preoperative CRT for anal sphincter preservation.
  
  
  METHODS
  This study included 11 consecutive patients who performed low anterior resection and abdominoperineal resection for rectal cancer after preoperative CRT. Distal margin length from reduced tumor by preoperative CRT to residual viable cancer, tumor grade, lymph-node-metastasis stage and pathological changes of tumors were examined.
  
  
  RESULTS
  Length from anal side edge of reduced tumor by preoperative CRT to pathological residual tumor ranged from +6 mm to -9 mm. Tumor stages were as follows: T0-2, N0, M0=3, T3, N0, M0=5, T4, N0, M0=1 and T3, N0, M+1=2. Median follow-up was 19 months. Recurrence occurred in one patient and was distant and not local. Pathological examinations showed that no patient had lymph-node-metastasis and residual tumors by preoperative CRT.
  
  
  CONCLUSIONS
  This study suggests that for patients with locally advanced rectal cancer undergoing resection and preoperative CRT, distal margins ≥1 cm from reduced tumor by preoperative CRT seem to compromise pathological outcome.
authors.affiliation: Department of Surgery, Institute of Health Biosciences, University of Tokushima, Tokushima, Japan. mnishioka@clin.med.tokushima-u.ac.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Nishioka
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Shimada
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Kurita
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwata
authors.forename: Shinya
authors.initials: S
authors.lastname: Morimoto
authors.forename: Kouzu
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Jun
authors.initials: J
authors.lastname: Higashijima
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Miyatani
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D001003:Anal Canal / Q000473:pathology / Q000601:surgery*; D059186:Chemoradiotherapy, Adjuvant; D003113:Colonoscopy; D013505:Digestive System Surgical Procedures; D006801:Humans; D008207:Lymphatic Metastasis; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D059351:Organ Sparing Treatments; D018579:Patient Selection; D011351:Proctoscopy; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden