Grant: Operating Grant

Diabetes and cancer are two conditions affecting more and more Canadians. They share many risk factors, including diet, physical inactivity, smoking and obesity. It is not surprising then that people with diabetes have a higher risk of many types of cancer, such as breast, liver, endometrial and colorectal cancers, than people without diabetes. One possible reason for the link between diabetes and cancer is how much insulin is circulating in the body. People with type 2 diabetes, which is generally seen in older adults and associated with overweight and obesity, actually have high levels of insulin in their blood. Their tissues are resistant to the actions of insulin, so the body tries to produce more insulin to overcome that resistance. While insulin has many benefits, like so many other things in life, you can sometimes have too much of a good thing. High levels of insulin can have bad consequences as well, and past research suggests that this might include more rapid growth of cancer cells. If this is true, then the drugs we use to reduce blood sugar in type 2 diabetes may also play a role in changing the risk of cancer in those patients. Our past research on this topic has been the center of attention in the diabetes community around the world. Our new research will use health care records from the population in British Columbia, to see if diabetes drugs that increase the amount of insulin in the body are associated with an increased risk of cancer and if drugs that improve insulin sensitivity are associated with a reduced risk of cancer. The questions may also have important implications for treating patients with cancer, regardless of whether they have diabetes.