COLOR
For resectable colon cancer, is laparoscopic colectomy oncologically non-inferior to open colectomy?
Reported outcome visualization
Key results
The primary analysis found 3-year DFS of approximately 74.2% after laparoscopic surgery versus 76.2% after open surgery; the confidence interval for the difference was within the prespecified non-inferiority boundary (7 percentage points). Long-term outcomes were broadly similar.
Absolute Effect
This is a non-inferiority question, not a superiority benefit. The 2-point numerical difference should not be called treatment harm or benefit; the prespecified margin and confidence interval govern interpretation.
NNT: Not quantifiable or not appropriate for this design/end point.
NNH: Not quantifiable from the verified fixed-time toxicity data used in this summary; see toxicity and treatment burden below.
Time-to-event interpretation: Hazard ratios and median survival are relative/time-to-event measures; they are not converted into NNT unless a fixed-time absolute event estimate is available.
Toxicity and treatment burden
Laparoscopy generally reduced blood loss and recovery time in this trial family, but operative time may be longer and conversion to open surgery can occur. Surgical complications depend on experience and case selection.
Follow-up, limitations and maturity
Follow-up: Primary disease-free survival landmark 3 years; subsequent long-term follow-up available.
Trial conducted during the adoption of laparoscopic colorectal surgery; results depend on surgical expertise and do not automatically generalize to every tumour location, bulky disease or emergency presentation.
Clinical interpretation
When performed by trained teams in appropriate patients, laparoscopic colectomy preserves oncological outcomes while offering recovery advantages; this is non-inferiority, not proof of superior cancer control.
Primary publication and sources
COLOR Study Group. Lancet Oncol. 2009;10:44–52; initial trial report.
Current-practice context · reviewed 15 October 2026
Laparoscopic colectomy is an accepted approach for appropriately selected colon cancer when performed by an experienced team and when oncologic resection principles are maintained. The COLOR result addresses the surgical approach; it does not justify compromising margins, lymph-node assessment or conversion when needed. Robotic and other minimally invasive approaches are separate evidence questions.