Meta-Analysis of Complete Mesocolic Excision Hemicolectomy Versus Standard Hemicolectomy: A Pause for Reflection?

Abstract

Background: Complete mesocolic excision(CME) hemicolectomy, in comparison to standard/conventional hemicolectomy(NCME), has previously shown improved pathologic specimen with higher lymph node(LN) yield. However, no studies confirm whether CME yields higher positive LN, increases cancer up-staging or improves oncological outcomes. \n \nAim: To perform systematic review and meta-analysis comparing histopathologic and oncologic outcomes of CME versus NCME. \n \nMethods We searched PubMed, Scopus, Embase, and Cochrane Library up to October 2020 to include comparative studies of CME versus NCME for colonic carcinoma that reported number of positive LN. The main outcome measure was number of positive LN and secondary outcome measures were oncological outcomes, including overall survival (OS), disease-free survival(DFS), disease-specific survival(DSS), local recurrence and distant metastasis.\xa0 \n \nResults: Out of 1795 studies, 160 potentially eligible studies underwent full-text review. 21 studies were chosen after final review. CME did not show increase in positive LN when compared to NCME (p=0.86). CME had better histopathologic specimen for large bowel length (p<0.0001), tumour distance to high-tie (p<0.00001), mesentery area (p<0.00001), and higher number of overall LN(p<0.00001). There was no statistical significance favouring CME for OS (p=0.285), DFS (p=0.071), and DSS (p=0.91). There was inconclusive data to analyse loco-regional recurrence and distant metastasis. \n \nConclusions: CME did not result in higher positive LN nor up-stage migration despite better histo-pathological specimen for bowel length, tumour distance to high-tie, mesentery area and overall LN yield. Furthermore, CME did not show statistical significance for improved OS, DFS and DSS. Current evidence does not support oncologic superiority of CME over NCME for hemicolectomy. \n \nFunding Statement: Duke-NUS Academic Medicine Ethos Grant \n \nDeclaration of Interests: None.