Research has led to the belief that people with diabetes who have been treated for colon cancer are more likely to have their cancer return and to die from their cancer than are those without diabetes. A study written up in the Journal of Clinical Oncology consisted of 3,759 people. The only difference between the participants was that 287 of them had diabetes. All participants received the same dose of chemotherapy, their cancers had advanced to the same stage and they were approximately the same age. But those with diabetes had a 21% higher chance of having their cancer return and a 42% higher chance of death from cancer. If diabetes is a risk factor for colon cancer, it is important to take steps to prevent the onset of diabetes. Talk with your health care provider about ways to increase your physical activity, eat healthfully and keep your blood glucose, blood pressure and blood cholesterol at normal levels.