WOMEN who are overweight or have high blood sugar could be more at risk of developing aggressive breast cancer, research shows.
A new study is believed to be the first to look at how excess body fat and blood sugar levels affect the chance of developing different types of tumours.
It found women were less likely to suffer low-risk breast cancer if they were overweight or
suffered high blood sugar (insulin resistance), but were at higher risk of more aggressive tumours.
Experts at Umea University in Sweden carried out the study, funded by the World Cancer Research Fund, and published in the journal Breast Cancer Research and Treatment.
They looked at blood samples and measurements including body mass index (BMI) taken from more than 1,000 women. Of the group, 561 women had been diagnosed with breast cancer while 561 remained free of the disease and acted as a control.
The study found that the association of BMI, leptin (a hormone linked to body fat) and HbA1c (a blood sugar reading) and breast cancer risk differed significantly according to whether the tumour was diagnosed as early stage I or more advanced stages II to IV.
Dr Sarah Cant, policy manager at Breakthrough Breast Cancer, said: "We already know that being obese after the menopause increases the risk of developing breast cancer but this research is the first to suggest being overweight and having high blood sugar levels may affect the stage of breast cancer at diagnosis."