title: Matched case-control analysis comparing oncologic outcomes between preoperative and postoperative chemoradiotherapy for rectal cancer.
abstract: OBJECTIVE
  To investigate patterns of recurrence and oncologic outcomes after recurrence between preoperative and postoperative chemoradiotherapy (CRT).
  
  
  METHODS
  Records of patients with stage II or III locally advanced rectal cancer seen between January 2000 and December 2010 were analyzed. The outcomes for patients undergoing preoperative CRT followed by radical resection (n = 466) were compared with outcomes of patients matched for sex, age, and stage who had surgery and then postoperative CRT (n = 466). Recurrence rates and sites, treatment of recurrence, and oncologic outcomes after recurrence were investigated. The rate of sphincter preservation and permanent stoma formation were also evaluated.
  
  
  RESULTS
  Recurrence occurred in 124 and 140 patients in the pre- and postoperative CRT groups, respectively. The local and systemic recurrence rates were 3.6% and 20.8%, respectively, in the preoperative CRT group and 3.0% and 25.3%, respectively, in the postoperative CRT group (P = 0.245). Time to recurrence was longer in the postoperative CRT group (19 monthsvs. 24.2 months, P = 0.029). The overall rates of sphincter preservation (sphincter preservation operation and postoperative permanent stoma formation) did not significantly different between the two groups (P = 0.381). The 5-year overall survival rate after recurrence did not differ between the two groups (25.6%vs. 18.6%, P = 0.051).
  
  
  CONCLUSIONS
  Preoperative and postoperative CRT are both safe and suitable treatment methods for rectal cancer, so the choice can be tailored to the patient's situation.
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Byoung Chul
authors.initials: BC
authors.lastname: Lee
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: In Ja
authors.initials: IJ
authors.lastname: Park
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chan Wook
authors.initials: CW
authors.lastname: Kim
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Seok-Byung
authors.initials: SB
authors.lastname: Lim
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chang Sik
authors.initials: CS
authors.lastname: Yu
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jin Cheon
authors.initials: JC
authors.lastname: Kim
keywords: Chemoradiotherapy; Colorectal surgery; Rectal neoplasms; Recurrence; Treatment outcome