title: Improved survival for older patients undergoing surgery for colorectal cancer between 2008 and 2011.
abstract: BACKGROUND
  Older colorectal cancer patients have a higher risk of postoperative complications, and the impact of adverse events on survival is also significantly higher. Innovations like laparoscopic surgery which improve short-term outcome for older patients can also benefit their overall prognosis. We set out to analyse the impact of an increased utilisation of laparoscopic surgery for colorectal cancer in the Netherlands on overall survival.
  
  
  METHODS
  All patients diagnosed with stages I-III colorectal cancer in the Netherlands between 2008 and 2011 were selected from the Netherlands Cancer Registry. Changes in perioperative mortality, 3-month mortality and 1-year mortality rates were analysed using year of diagnosis as an instrumental variable.
  
  
  RESULTS
  Over 33,000 patients were included in the analyses. Data on surgical approach were not precisely known for 2008 and 2009; in 2010, 36.6 % of definitive surgical procedures were performed laparoscopically and 45.9 % in 2011. A laparoscopic approach was used less frequently in the patients aged ≥75 years (in 2011, 40.3 versus 49.2 % of younger patients; p < 0.001). Between 2008 and 2011, perioperative mortality decreased from 2.0 to 1.5 % (p = 0.02), 3-month mortality from 4.8 to 3.9 % (p = 0.01) and 1-year mortality from 9.6 to 8.3 % (p < 0.001). The absolute risk reduction was greatest for patients aged ≥75 years, reaching 2.1 % for 1-year mortality.
  
  
  CONCLUSIONS
  Between 2008 and 2011, the utilisation of a laparoscopic approach increases significantly, resulting in reduced mortality rates, particularly for the elderly. Therefore, a laparoscopic approach should be used whenever possible, which may allow for further improvement of outcomes.
authors.affiliation: Department of Geriatric Medicine, Diakonessenhuis, Professor Lorentzlaan 76, Zeist, Utrecht, 3707 HL, The Netherlands, mhamaker@diakhuis.nl.
authors.forename: M E
authors.initials: ME
authors.lastname: Hamaker
authors.forename: A H
authors.initials: AH
authors.lastname: Schiphorst
authors.forename: N M
authors.initials: NM
authors.lastname: Verweij
authors.forename: A
authors.initials: A
authors.lastname: Pronk
mesh_terms: D000367:Age Factors; D000368:Aged; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000601:surgery*; D005260:Female; D006801:Humans; D010535:Laparoscopy / Q000706:statistics & numerical data*; D008297:Male; D009426:Netherlands; D011183:Postoperative Complications; D012042:Registries; D012307:Risk Factors; D016896:Treatment Outcome