Older women who suffer from type 2 diabetes are more likely to develop breast cancer than those without the condition, according to new research published in the British Journal of Cancer.
The study discovered that type 2 diabetes increases the risk of breast cancer, which kills more than 12,000 in Britain every year, in post-menopausal women by more than a quarter (27 per cent).
However, no increase in risk was reported among type 2 diabetics who had not reached menopause or for women (pre and post- menopausal) with type 1 diabetes.
Being overweight or obese is linked to both type 2 diabetes and breast cancer. But the findings, which were based on analysis of 40 separate studies involving over 56,000 breast cancer cases, suggest there may be a direct connection between the two conditions.
Lead author of the study Professor Peter Boyle, president of the International Prevention Research Institute (i-PRI) in Lyo, said: “We don’t yet know the mechanisms behind why type 2 diabetes might increase the risk of breast cancer.
“On the one hand, it’s thought that being overweight, often associated with Type 2 diabetes, and the effect this has on hormone activity may be partly responsible for the processes that lead to cancer growth. But it’s also impossible to rule out that some factors related to diabetes may be involved in the process.”
Martin Ledwick, head information nurse at Cancer Research UK, commented: “From this study, it’s not clear whether there’s a causal link between diabetes and the risk of breast cancer in post-menopausal women.
“But as we know that having a high BMI can contribute to an increased risk of both type 2 diabetes and breast cancer, it makes sense for women to try and maintain a healthy weight.”

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