Obese postmenopausal women have an increased risk of developing breast cancer comp- ared with women ...
Obese postmenopausal women have an increased risk of developing breast cancer comp- ared with women with a healthy weight, claims a new study by Cancer Research UK.
Scientists have found that females who avoid becoming obese are cutting their risk of breast cancer by a fifth. The study suggests that sex hormones, particularly oestrogens, are the root cause behind how obesity increases the risk of breast cancer. The research showed that a form of the hormone called oestradiol was highlighted as being especially associated with increased risk.
The study looked at eight separate cases worldwide and drew comparisons between body mass index (BMI) and sex hormone levels in 624 breast cancer patients and 1,669 healthy women.
The women were split into five BMI groups - less than 22.5kg/m2, 22.5-24.9kg/m2, 25.0-27.4kg /m2, 27.5-29.9kg.m2 and over 30kg/m2 - with a BMI range of 18.5-25, 25-30 and 30 plus, representing healthy, overweight and obese respectively.
Scientists found that breast cancer risk is 18% higher for obese women compared to those with a healthy weight. This increase was seen over the weight difference between the upper level of healthy weight (25kg/m2) and lower level of obese weight (30kg/m2).
Dr Tim Key of the Cancer Research UK Epidemiology Unit at Oxford University said the findings should encourage many women to exercise a healthy diet later in life.
"Obesity is something that women have a level of control over. Maintaining a healthy weight avoids extra breast cancer risk in obese postmenopausal women. We know that hormonal factors are central to the development of breast cancer.
"This study helps us to better understand the role obesity and certain hormones play in the mechanism that increases risk of the disease. Obesity may be the principal contributing factor for a number of breast cancer cases," he said.
