In a Danish population-based cohort study reported in The Lancet Oncology, Bertelesen et al found that complete mesocolic lymph node excision was associated with reduced risk of recurrence vs noncomplete excision approaches among patients with stage I to III right-sided colon adenocarcinomas.
The study involved data from all patients undergoing elective curative-intent right-sided colon resections for Union for International Cancer Control (UICC) stage I to III colon cancer at four hospitals between June 2008 and December 2013. Outcomes were compared for 256 patients at one center that performed central lymph node dissection and vascular division after almost complete exposure of the proximal part of the superior mesenteric vein (complete mesocolic excision group) vs 813 patients from three centers that performed conventional resections with nonstandardized and limited lymph node dissection (noncomplete mesocolic excision). Patients were followed for a minimum of 5.2 years after surgery.
The primary outcome measure was the cumulative incidence of recurrence at 5.2 years. Inverse probability of treatment weighting (IPTW) and competing risk analyses were used to estimate possible causal effects of complete mesocolic excision on outcome.
Risk of Recurrence
The 5.2-year cumulative incidence of recurrence with IPTW was 9.7% (95% confidence interval [CI] = 6.3%–13.1%) in the complete mesocolic excision group vs 17.9% (95% CI = 15.3%–20.5%) in the noncomplete mesocolic excision group, yielding an absolute risk reduction of 8.2% (P = .00015). Rates were 0% vs 7.4%, 3.5% vs 11.1%, and 20.5% vs 32.5% in stage I, II, and III disease, respectively (all P < .05). Overall, recurrence was observed in 10% vs 18% of patients, and 29% vs 35% died during follow-up. Five-year mortality with IPTW was 28.4% vs 33.1% (P = .13).
Odds ratios for complete mesocolic excision vs noncomplete mesocolic excision calculated after IPTW were 0.94 (P = .85) for 30-day mortality, 1.18 (P = .57) for 90-day mortality, and 0.94 (P = .75) for risk of major postoperative complications within 60 days.
The investigators concluded, “This study shows a causal treatment effect of central mesocolic lymph node excision on risk of recurrence after resection for right-sided colon adenocarcinoma. Complete mesocolic excision has the potential to reduce the risk of recurrence and improve long-term outcome after resection for all UICC stage I–III of right-sided colon adenocarcinomas.”
Claus A. Bertelsen, PhD, of the Department of Surgery, Nordsjællands Hospital Hillerod, Denmark, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by The Tvergaard Fund, Helen Rude Fund, Krista and Viggo Petersen Fund, Olga Bryde Nielsen Fund, and Else and Mogens Wedell-Wedellsborg Fund. For full disclosures of the study authors, visit thelancet.com.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.