People who have diabetes may have a higher chance of developing cancer either before or immediately after receiving a diagnosis of diabetes, according to a study published online in the American Cancer Society's journal, Cancer.
The results indicate that there is a need for better understanding of the association between cancer and diabetes.
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.
Diabetes has been linked to heart disease, stroke, and damage to nerves and eye issues. There is also growing evidence of a link between type 2 diabetes and some types of cancer.
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.