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 (p<0.001). 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.