title: Prognostic impact of peritonealisation in rectal cancer treated with preoperative chemoradiotherapy: extraperitoneal versus intraperitoneal rectal cancer.
abstract: OBJECTIVE
  The oncologic outcomes of extraperitoneal (EP) rectal cancer are known to differ from those of intraperitoneal (IP) rectal cancer; however, these differences have not been studied in rectal patients treated by preoperative chemoradiotherapy (CRT). The aim of this study is to evaluate the prognostic impact of peritonealisation in rectal patients treated by preoperative CRT.
  
  
  METHODS
  This study analyzed the data of 362 patients who received preoperative CRT and underwent curative surgery for locally advanced rectal cancer at 3-9 cm above the anal verge. Patients were categorised into EP and IP groups based on whether peritonealisation was present, according to pathology reports. The oncologic outcomes between the two groups were compared.
  
  
  RESULTS
  Peritonealisation was absent in 330 patients and present in 32 patients. In univariate analysis, disease-free survival was significantly worse in the EP group than in the IP group (73.0% versus 93.5%, p=0.035). Multivariate analysis revealed the following independent risk factors for recurrence: the absence of peritonealisation (p=0.023), ypT stage (p=0.015) and ypN stage (p<.0001).
  
  
  CONCLUSIONS
  Peritonealisation of rectal cancer may be a prognostic factor of disease-free survival in patients with rectal cancer treated by preoperative CRT and surgery.
authors.affiliation: Research Institute & Hospital, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Mi Ri
authors.initials: MR
authors.lastname: Hwang
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Park
authors.forename: Dae Yong
authors.initials: DY
authors.lastname: Kim
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Chang
authors.forename: Yong Sang
authors.initials: YS
authors.lastname: Hong
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Hyo Seong
authors.initials: HS
authors.lastname: Choi
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Jeong
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Oh
mesh_terms: D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010537:Peritoneum / Q000473:pathology / Q000601:surgery; D011379:Prognosis; D012004:Rectal Neoplasms / Q000145:classification / Q000188:drug therapy* / Q000532:radiotherapy*