Postoperative complications following colonic resection for cancer are associated with impaired long‐term survival

Surgery for colorectal cancer is associated with a high incidence of postoperative complications. The aim of this study was to analyse whether postoperative complications following radical resection for colorectal cancer are associated with increased recurrence rate and impaired survival.Patients operated for colon cancer between 2007 and 2009 with curative intent were identified through the Swedish Colorectal Cancer Registry. The cohort was divided into three subgroups: patients who developed severe postoperative complications, patients who developed non-severe complications and patients who did not develop any complication (controls).Of 6779 patients included in the study, 640 (9%) developed severe complications, 994 (15%) non-severe complications and 5145 (76%) had no complications. The 5-year overall survival rate was 60.3% in the severe complication group, 64.2% in the non-severe complication group and 72.8% in the control group (P < 0.01). The 3-year disease-free survival rate was 66.8%, 70.9% and 77.8% respectively (P < 0.01). The recurrence rate did not differ between the three groups. In multivariate analysis, both severe and non-severe complications were found to be risk factors for decreased overall survival at 5 years [hazard ratio (HR) 1.38, 95% CI 1.47-1.92, and HR 1.18, 95% CI 1.27-1.60 respectively; P < 0.05) as well as for decreased 3-year disease-free survival (HR 1.37, 95% CI 1.14-1.65, and HR 1.26, 95% CI 1.08-1.48 respectively; P < 0.05).Complications after colonic resection for cancer are associated with impaired 5-year overall survival and 3-year disease-free survival and exhibit more severe postoperative complications, mainly via mechanisms other than cancer recurrence.