Propensity-score-matched analysis of D2 and D3 right hemicolectomy for colon cancer

Background Complete mesocolic excision with D3 lymph node dissection in right-sided colon cancer is associated with improved oncological outcomes, but can potentially be associated with higher rates of complications compared to conventional D2 right hemicolectomy. This study aims to evaluate the oncological and perioperative outcomes of patients who underwent D3 right hemicolectomy, comparing to conventional right hemicolectomy. Methods From 2015 to 2020, 360 patients underwent right hemicolectomy for colonic malignancies. Data was retrospectively analysed from a prospectively collected database. A propensity-score-matched analysis was performed between the two groups to evaluate their outcomes. Results About 88(24.4%) patients underwent D3 right hemicolectomy, with the rest undergoing D2 right hemicolectomy. After propensity-matched analysis, D3 right hemicolectomy had a higher lymph node yield (median of 26 versus 23, p = 0.005), lower overall recurrence rate (11.7% versus 25.7%, p = 0.03), and lower overall mortality rate (14.5% versus 30.1%, p = 0.02) There were no significant differences in the complication rates. There were no anastomotic leaks. D3 right hemicolectomy was associated with an improved 3-year disease-free survival (DFS) with a hazard ratio of 0.63 (P = 0.21), and also an improved 3-year overall survival (OS) with a hazard ratio of 0.68 (P = 0.31). Conclusion D3 right hemicolectomy is associated with a higher lymph node yield, without increasing morbidity or mortality. It is also associated with significantly lower recurrence and overall mortality rates in this study. Short term 3-year DFS and OS also trend towards favouring D3 right hemicolectomy. However, this study is limited by the small sample size and retrospective nature.