As reported in Journal of Clinical Oncology by Lu et al, the Chinese phase III RELARC trial showed no significant improvement in disease-free survival with complete mesocolic excision vs D2 lymph node dissection in patients with right-sided colon cancer.
As stated by the investigators, “…[complete mesocolic excision] is being increasingly used for the treatment of right-sided colon cancer, although there is still no strong evidence that [complete mesocolic excision] provides better long-term oncological outcomes than D2 dissection. The controversy is mainly regarding the survival benefit from extended lymph node dissection emphasized by [complete mesocolic excision].”
Study Details
In the multicenter open-label trial, 995 evaluable patients with stage T2–T4aNanyM0 or TanyN+M0 right-sided colon cancer were randomly assigned between January 2016 and December 2019 to undergo complete mesocolic excision (n = 495) or D2 dissection (n = 500). The primary outcome measure was 3-year disease-free survival.
Key Findings
Disease-free survival at 3 years was 86.1% in the complete mesocolic excision group vs 81.9% in the D2 group (hazard ratio [HR] = 0.74, 95% confidence interval [CI] = 0.54–1.02, P = .06).
Overall survival at 3 years was 94.7% in the complete mesocolic excision group vs 92.6% in the D2 group (HR = 0.70, 95% CI = 0.43–1.16, P = .17).
The investigators concluded: “This trial failed to find evidence of superior [disease-free survival] outcome for [complete mesocolic excision] compared with standard D2 lymph node dissection in primary surgical excision of right-sided colon cancer. Standard D2 dissection should be the routine procedure for these patients. [Complete mesocolic excision] should only be considered in patients with obvious mesocolic lymph node involvement.”
Yi Xiao, MD, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the Beijing Municipal Science & Technology Commission and CAMS (Chinese Academy of Medical Sciences) Innovation Fund for Medical Sciences. For full disclosure of all study authors, visit ascopubs.org.
