Mid-term oncological outcomes after complete versus conventional mesocolic excision for right-sided colon cancer: a propensity score matching analysis

Background: The correct extent of mesocolic dissection for right-sided colon cancer (RCC) is still under debate. Complete mesocolic excision (CME) has not gained wide diffusion, mainly due to its technical complexity and unclear oncological superiority. This study aims to evaluate oncological outcomes of CME compared with non-complete mesocolic excision (NCME) during resection for I-III stage RCC.

Method: Prospectively collected data of patients who underwent surgery between 2010 and 2018 were retrospectively analysed. 1:1 Propensity score matching (PSM) was used to balance baseline characteristics of CME and NCME patients. The primary endpoint of the study was local recurrence-free survival (LRFS). The two groups were also compared in terms of short-term outcomes, distant recurrence-free survival, disease-free survival, and overall survival.

Results: Of the 444 patients included in the study, 292 were correctly matched after PSM, 146 in each group. The median follow-up was 45 months (IQR 33-63). Conversion rate, complications, and 90-day mortality were comparable in both groups. The median number of lymph nodes harvested was higher in CME patients (23 vs 19, p = 0.034). 3-year LRFS rates for CME patients was 100% and 95.6% for NCME (log-rank p = 0.028). At 3 years, there were no differences between the groups in terms of overall survival, distant recurrence-free survival, and disease-free survival.

Conclusion: Our PSM cohort study shows that CME is safe, provides a higher number of lymph nodes harvested, and is associated with better local recurrence-free survival.