Risk of diabetes greater for breast cancer survivors

A new study suggests that postmenopausal women who survive breast cancer face a higher risk of becoming diabetic than those who have never had this type of cancer .
Dr Lorraine Lipscombe, of the Women’s College Research Institute in Toronto, Canada, and colleagues analysed data on nearly 25,000 breast cancer survivors aged 55 years or older, and compared diabetes incidence rates with those from a further 124,880 women of the same age who had never been diagnosed with breast cancer .
During the follow-up, they found that women who survived breast cancer had a 7 per cent increased risk of diabetes two years after diagnosis compared to those without the cancer – rising to 24 per cent after ten years since diagnosis .
However, they also discovered an opposite pattern for breast cancer patients who had undergone chemotherapy . The risk for this group was 24 per cent greater after two years but only 8 per cent higher after ten years.
“Chemotherapy treatment may bring out diabetes earlier in susceptible women,” said lead study author Dr Lipscombe.
“Estrogen suppression as a result of chemotherapy may also promote diabetes, however this may have been less of a factor in this study where most women were already post-menopausal.”
She added that the findings, published in the journal Diabetologia, support a need for greater diabetes screening among breast cancer survivors.
Previous research has shown that women diagnosed with diabetes are 20 per cent more likely to develop postmenopausal breast cancer than older, non-diabetic women.