Emergency resection or diverting stoma followed by elective resection in patients with colonic obstruction due to locally advanced cancer: a national cohort study.

Aim: The aim was to assess long-term prognosis after emergency resection versus primary diverting stoma followed by elective tumour resection.

Method: A national-register-based cohort study with retrospective analysis of prospectively collected data was performed. All Swedish patients with non-metastatic obstructive locally advanced colon cancer treated with emergency resection or diverting stoma, followed by an elective resection, between 2007 and 2017 were included. The Kaplan-Meier method and Cox proportional hazards model were used to compare all-cause mortality between patients with emergency resection and elective right- and left-sided resection. The multivariable model was adjusted for year of diagnosis, age at diagnosis, sex, Charlson Comorbidity Index, American Society of Anesthesiologists class, tumour location and pN stage.

Results: In all, 751 patients with a tumour in the right colon and 700 patients with a tumour in the left colon were included. Emergency resection was more common in patients with right-sided colon tumours (681/751) than in patients with left-sided colon tumours (483/700). The 5-year overall survival in patients with right-sided tumours was 25% after emergency resection and 46% after diverting stoma followed by elective resection (log-rank test P = 0.001). The corresponding numbers for patients with left-sided colon tumours were 40% and 64% (P < 0.001). Emergency resection was independently associated with increased all-cause mortality in patients with left-sided tumour (hazard ratio 1.63, 95% CI 1.21-2.19) but not in patients with right-sided tumour (hazard ratio 1.21, 95% CI 0.80-1.81).

Conclusion: Diverting stoma followed by elective resection is associated with improved survival compared with emergency resection in patients with left-sided colonic obstruction due to locally advanced tumours.