Extended Right Sided Colon Resection Increases the Risk of Post-Operative Complications and Does Not Reduce the Risk of Colon Cancer Local-Regional Recurrence: Nation-Wide Population-Based Study from Danish Colorectal Cancer Group Database

Background: It is controversial whether extensive resection of right-sided colon cancer (RSCC) confer oncological benefits. The aim of this study was to examine short-and long terms outcomes of extended (ERHC) surgical removal of mesocolon compared to conventional approach (CRHC). Method: This was a retrospective population-based study based on a prospectively maintained Danish Colorectal Cancer Group database. Primary outcome measure was local-regional recurrence in patients who underwent curative resection for RSCC and secondary outcome measures was 30-day post-operative complications. Distant metastasis, unplanned intraoperative adverse events (UIAEs), 30-and 90-day post-operative mortality were also investigated. Patients who had palliative or compromised resection, emergency surgery and neo-adjuvant chemo-therapy were excluded. Results: Of the 12,855 patients with RSCC retrieved, 1,151 underwent ERHC. Patients who had ERHC were younger males with a lower ASA scores, operated by colorectal surgeons, using laparoscopic approach and had a significant higher number of harvested lymph nodes.The rate of local-regional recurrence was 1.1% (136/12,855). 1.5% (249/17.174) with no difference between CRHC and ERHC (OR 1.7 CI 95% 0.63-2.18). Post-operative complications were significantly higher in ERHC even after adjusting for age, comorbidity, access to abdomen and other covariates (OR 1.26 CI 95% 1.01-1.58). No significant difference was noticed between CRHC and ERHC in the rates of distant metastasis, UIAEs and mortality. Conclusion: This large population-based registry study showed no difference in local-regional recurrence of RSCC between conventional and extended right hemicolectomy with mesenteric resection and ligation of the middle colic vessels. Extended resection was associated with higher rates of postoperative complications. Funding Statement: None. Declaration of Interests: None Ethics Approval Statement: The data retrieved from DCCG database were fully anonymized so that none of the patient in the dataset could be traced. Data management was conducted according to the national ethical guidelines. Danish Data Protection Agency (Datatilsynet) approval was obtained (RN-2018-94).