title: Necessary circumferential resection margins to prevent rectal cancer relapse after abdomino-peranal (intersphincteric) resection.
abstract: OBJECTIVE
  The purpose of this study was to determine the adequate circumferential resection margin (CRM) for abdomino-peranal (intersphincteric) resection (ISR) that would prevent the relapse of rectal cancers.
  
  
  METHODS
  The records of 41 cases that underwent curative ISR for rectal cancer were retrospectively reviewed. The relapse-free survival rates and overall survival rates were evaluated and correlated with the maximum depth of the inner muscularis layer reached during ISR (i.e., the radial margin [RM] and distal margin [DM]). Cases were divided into three groups based on the sizes of the RM and DM: (1) group A (RM >2 mm and DM >1.5 cm), (2) group B (RM >2 mm or DM >1.5 cm but not both), and (3) group C (RM <2 mm and DM <1.5 cm).
  
  
  RESULTS
  The relapse-free survival rates of the cases in group C were lower than those in the cases of group A or group B (p = 0.002 and 0.037, respectively). The resection margins required to prevent rectal cancer relapse were >2 mm for the RM and >1.5 cm for the DM. For these margins, the intersphincteric space had to be entered (i.e., between the internal and external anal sphincters).
  
  
  CONCLUSIONS
  It is critical to enter the intersphincteric space to ensure an adequate CRM (RM >2 mm and DM >1.5 cm) for preventing rectal cancer recurrence after ISR.
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan. kkomori@aichi-cc.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Komori
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Kenya
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kinoshita
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ito
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Abe
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Senda
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Misawa
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Uemura
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Natsume
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kawai
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1, Kanokoden, Chikusa, Nagoya, Aichi, 464-8681, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimizu
mesh_terms: D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000517:prevention & control*; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D015996:Survival Rate
keywords: Abdomino-peranal (intersphincteric) resection of rectal cancers; Abdominoperineal resection; Circumferential resection margin; Distal margin; Radial margin