BACKGROUND: Comorbidity has a negative influence on the long-term prognosis in patients with colorectal cancer, whereas its impact on the postoperative course is less clear.

OBJECTIVES: The aim of this study was to investigate the influence of comorbidity on anastomotic leak and short-term outcomes after resection for colonic cancer.

DESIGN: This is a retrospective nationwide cohort study

SETTING: : Data were obtained from the Danish Colorectal Cancer Group and the National Patient Registry.

PATIENTS: Patients with colonic cancer undergoing elective resection between 2001 and 2008 were selected.

MAIN OUTCOME MEASURES: The primary outcome was the ability of comorbidity to predict anastomotic leak. Secondary outcomes were 30-day mortality and length of stay. Comorbidity was assessed by the Charlson Comorbidity Index. Multivariable logistic regression and receiver operating characteristics curves were used to adjust for confounding.

RESULTS: The rate of anastomotic leak was 535/8597 (6.2%). The mean (95% CI) Charlson score was 0.83 (0.72-0.94) and 0.63 (0.61-0.66) for patients with and without anastomotic leak, p < 0.001. The Charlson score, as assessed in the multivariable analysis (adjusted OR, 1.07; 95% CI, 0.99-1.15; p = 0.077) and by receiver operating characteristics curves (area under the curve = 0.548), failed to predict anastomotic leak. Thirty-day mortality was 425/8587 (4.9%). In patients with anastomotic leakage, a Charlson score of ≥ 2 was associated with increased mortality in comparison with a Charlson score of <2 (adjusted HR, 1.58; 95% CI, 1.00-2.51; p = 0.047). Mean length of stay was 8.7 days (95% CI, 8.4-9.2 days) for patients without an anastomotic leak in comparison with 23.3 days (95% CI, 21.5-25.1 days) for patients with anastomotic leak and 25.5 days (95% CI, 21.7-29.3 days) in patients with anastomotic leak and a Charlson score of >2, p < 0.001.

LIMITATIONS: This study is limited by the accuracy of the coding used to generate the Charlson Comorbidity Index and the retrospective study design.

CONCLUSION: Comorbidity failed to predict anastomotic leak, but it was associated with an inferior short-term outcome in patients with this surgical complication.