title: What is the effect of laparoscopic colectomy on pattern of colon cancer recurrence? A propensity score and competing risk analysis compared with open colectomy.
abstract: BACKGROUND
  Variability in colon cancer recurrence after laparoscopic colectomy (LAC) remains poorly understood. The aim of our study was to quantify the influence of LAC on colon cancer recurrence patterns.
  
  
  METHODS
  We included 986 patients undergoing curative colectomy at our institution between 1992 and 2008. Kaplan-Meier, multivariable Cox regression, propensity score adjustment, and competing risks modeling were used to evaluate the influence of laparoscopic surgery on the site of colon cancer recurrence, including the following: liver metastasis, lung metastasis, local recurrence, peritoneal dissemination, other, and multiple sites. We estimated the risk factors for each recurrence site.
  
  
  RESULTS
  Laparoscopic surgery was used in 419 (42.5 %) of 986 patients, with an overall median follow-up time of 5.0 years (interquartile range 3.5). The overall 5-year disease-free survival rate was 86.1 % (open surgery 81.8 % vs. laparoscopic surgery 92.0 %; p < 0.001). However, after covariates and propensity score adjustment, laparoscopic surgery was not a significant risk factor for each type of recurrence: liver hazard ratio (HR) 0.93 (95 % CI 0.45-1.89), p = 0.84; lung HR 0.67 (95 % CI 0.26-1.70), p = 0.39; local HR 0.56 (95 % CI 0.12-2.63), p = 0.46; peritoneal HR 2.49 (95 % CI 0.75-8.27), p = 0.14; others HR 0.47 (95 % CI 0.04-5.13), p = 0.53; multiple HR 0.88 (95 % CI 0.25-3.14), p = 0.84. The risk factors for each type of recurrence were variable and characterized by specific clinicopathological features.
  
  
  CONCLUSIONS
  Our study reveals that LAC and open colectomy demonstrate comparable overall colon cancer recurrence rates and recurrence sites. Specific clinicopathological characteristics may have a stronger influence on colon cancer recurrence site compared with the surgical technique.
authors.affiliation: Department of Surgery, School of Medicine, Keio University, Tokyo, Japan, hasegawa@z8.keio.jp.
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Koji
authors.initials: K
authors.lastname: Okabayashi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.forename: Hutan
authors.initials: H
authors.lastname: Ashrafian
authors.forename: Leanne
authors.initials: L
authors.lastname: Harling
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishii
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sugiyama
authors.forename: Ryo
authors.initials: R
authors.lastname: Seishima
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D000368:Aged; D003082:Colectomy / Q000009:adverse effects*; D003110:Colonic Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects*; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery; D008175:Lung Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D009367:Neoplasm Staging; D010534:Peritoneal Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D011379:Prognosis; D057216:Propensity Score; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate