Additional healthcare when people receive a diagnosis of diabetes may lead to more cancer diagnoses around the same time.
Previous studies have suggested that people with type 2 diabetes have a higher risk of developing several different types of cancer.
The Centers for Disease Control and Prevention (CDC) note that, in 2014, 29.1 million people, or 9.3 percent of the population of the United States, had diabetes, more than 3 times higher than in 1980.
The American Cancer Society note that colon cancer, for example, is more likely to affect people with diabetes. Colon cancer shares many of the risk factors of diabetes, including body weight issues, a lack of physical activity, smoking, alcohol, and consuming a lot of red and processed meats. Colon cancer is also more likely to be fatal among people with type 2 diabetes.
Apart from shared risk factors, other suggestions to explain a link between various types of cancer and type 2 diabetes include the possibility of a biological link between the two, or that treatments for diabetes impact either the development or diagnosis of cancer.
Cancer diagnosis more likely within 3 months of diabetes diagnosis
A diagnosis of cancer often occurs immediately after a patient receives a diagnosis of diabetes. This may be because the discovery that they have diabetes means that they are more in contact with healthcare providers, and therefore more likely to undergo tests for other conditions.
Researchers from the University of Toronto, led by Dr. Iliana Lega, examined data for more than 1 million adults to assess the incidence of cancer at a variety of time points in their lives.
Findings showed that, compared with people without diabetes, patients with diabetes were 1.23 times more likely to have had a diagnosis of cancer in the 10 years before finding out they had diabetes.
People who received a diagnosis of diabetes were then more likely to receive a diagnosis of cancer, too, within the next 3 months. After this 3-month period, the likelihood of receiving a cancer diagnosis fell.
Dr. Lega suggests that this could be due to the extra screening that follows a diagnosis of diabetes.
She believes that as the prevalence of diabetes grows, this could imply an increase in the number of cancer cases.
She adds that the results support the idea that cancer and diabetes may have shared risk factors, and she suggests that lifestyle changes could help to reduce the incidence of both diseases.
"There is excellent evidence that diabetes can be prevented and that metabolic changes leading to diabetes can be reversed with lifestyle changes. Similarly, diet and exercise interventions have also been shown to reduce cancer risk and improve cancer outcomes in the general population."
Dr. Iliana Lega
The team believes that the findings are important because they emphasize the need for more research into the effect that exercise and a healthy diet can have on cancer risk, especially among patients who either have or are at risk of developing diabetes.