Diabetes mellitus and outcomes of colorectal cancer

Background. Patients with diabetes mellitus have an increased risk of colorectal cancer. However, there is limited information on the outcome for diabetic patients diagnosed with this type of cancer. Methods. The health records of all 1 194 patients treated for colorectal adenocarcinoma at Levanger Hospital from 1980 - 2004 were reviewed. Diabetes status and prognostic factors were registered. Primary endpoints were cancer specific survival and overall survival. Results. There were no significant differences between diabetic patients and non-diabetic patients concerning stage, grade, treatment, infective or non-infective postoperative complications, hospital stay, or 30 days mortality after laparotomy. After a curative resection, the estimated 5-year cancer specific survival in 97 diabetic patients was 73% (95% CI 60-87) and 79% (95% CI 75-82) in 1097 non-diabetic patients (not significant). The estimated overall 5-year survival in patients treated with curative intent was 46% (95% CI 33-59) in diabetic patients and 65% (95% CI 62-69) in non-diabetic patients (p0.001). The diabetic patients were significantly older and more frequently had cardiac diseases. Conclusion. Diabetes mellitus did not affect the short-term survival or the cancer specific survival. A shorter overall survival was associated with cardiac diseases and higher age.