title: Laparoscopic surgery should be considered in T4 colon cancer.
abstract: BACKGROUND
  Laparoscopy in T4 colon cancers is not widely advocated due to concerns regarding safety and oncologic efficacy. We conducted this study to compare the short- and long-term oncological outcomes between laparoscopic and open approaches in T4 colon cancers.
  
  
  METHODS
  A retrospective analysis of all patients who underwent surgery for T4 colon cancer from 2008 to 2014 was performed. Margin positive rate, lymph node yield, local or distant recurrence and overall survival were analysed.
  
  
  RESULTS
  A total of 59 patients received open surgery, whilst 93 underwent laparoscopic surgery, with a conversion rate of 8.6%. There was no difference in the various measured outcomes between the laparoscopic and open groups. The relative risks of positive margins and inadequate lymph node yield for staging were 0.95 (0.74-1.23, p = 0.692) and 1.01 (0.97-1.05, p = 0.710), respectively, for the laparoscopic group when compared to the open approach. Regarding long-term outcomes, the relative risk of local recurrence in the laparoscopic group was 0.99 (0.96-1.02, p = 0.477), whilst there were also no increased risks of developing distal recurrences at the liver (RR 1.19, 0.51-2.82, p = 0.684), lungs (RR 1.20, 0.50-2.87, p = 0.678) and peritoneum (RR 1.22, 0.51-2.95, p = 0.653) in the laparoscopic group. There was also no difference in the overall survival (RR 0.70, 0.42-1.16, p = 0.168). Patients were followed up for a median of 73.3 months (range 34.8-144.7).
  
  
  CONCLUSIONS
  Laparoscopic surgery does not compromise oncological outcomes in T4 colon cancers compared to the open approach. Because of its proven associated benefits, laparoscopy should be considered in selected T4 colon cancers.
authors.affiliation: Division of Colorectal Surgery, University Surgical Cluster, National University Health System, 1E Kent Ridge Road, Singapore, 119228, Singapore.
authors.forename: Dedrick Kok Hong
authors.initials: DK
authors.lastname: Chan
authors.affiliation: Division of Colorectal Surgery, University Surgical Cluster, National University Health System, 1E Kent Ridge Road, Singapore, 119228, Singapore. ker_kan_tan@nuhs.edu.sg.|Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. ker_kan_tan@nuhs.edu.sg.
authors.forename: Ker-Kan
authors.initials: KK
authors.lastname: Tan
mesh_terms: D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D010535:Laparoscopy; D009367:Neoplasm Staging
keywords: Colon cancer; Laparoscopic surgery; Locally advanced; Outcomes