Diabetes raises risk of cancer, with women at even greater likelihood

A global review involving almost 20 million people has shown that people with diabetes are at significantly increased risk of developing cancer, and for women the risk is even higher.

Researchers from The George Institute for Global Health found that diabetes conferred an additional risk for women, compared to men, for leukaemia and cancers of the stomach, mouth and kidney, but less risk for liver cancer. They analysed data from 47 studies around the world.

The findings published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) highlight the need for more research into the role diabetes plays in developing cancer. They also demonstrate the increasing importance of sex specific research.

Lead author Dr Toshiaki Ohkuma, research fellow with The George Institute for Global Health, said: “This review provides strong evidence for a link between diabetes and the risk of developing cancer. We have demonstrated for the first time that women with diabetes are more likely to develop any form of cancer, and have a significantly higher chance of developing kidney, oral and stomach cancers and leukaemia.

“The number of people with diabetes has doubled globally in the last 30 years but we still have much to learn about the condition. It’s vital that we undertake more research into discovering what is driving this, and for both people with diabetes and the medical community to be aware of the heightened cancer risk for women and men with diabetes.”

Key findings

  • Women with diabetes were 27 per cent more likely to develop cancer than women without diabetes. For men the risk was 19 per cent higher.
  • There were significantly higher risks for women with diabetes for developing cancer of the kidney (11 per cent higher), oral cancer (13 per cent higher), stomach cancer (14 per cent higher) and leukaemia (15 per cent higher) compared to men with the condition.
  • For liver cancer, the risk was 12 per cent lower for women with diabetes compared to men with diabetes.

Diabetes affects more than 415 million people worldwide, with five million deaths every year.  In India, it is the fastest growing chronic condition with 72 million cases recorded in 2017; this figures is expected to double by 2025.

Co-author Dr Sanne Peters of The George Institute for Global Health at the University of Oxford, said there were several possible reasons why women were subject to an excess risk of cancer. Women are in a state of impaired glucose tolerance (called prediabetes) on average for two years longer compared to men.

“Historically we know that women are often undertreated when they first present with symptoms of diabetes, are less likely to receive intensive care and are not taking the same levels of medications as men. All of these could go some way into explaining why women are at greater risk of developing cancer. But, without more research we can’t be certain.

“The differences we found are not insignificant and need addressing. The more we look into gender specific research the more we are discovering that women are not only undertreated, they also have very different risk factors for a whole host of diseases, including stroke, heart disease and now diabetes”, said Dr Peters.

Read the full study article in Diabetelogia.