Overweight and obesity

Being overweight or obese is associated with an increased risk of endometrial cancer.

Body fatness is often measured as body mass index (BMI*). For each 5-unit increase in BMI, the risk of endometrial cancer increases by 50%. This means that a woman who is overweight is around 1.5 times more likely to develop endometrial cancer than a woman of healthy weight. A woman whose BMI is in the ‘obese’ range is between 2 and 10 times more likely to develop endometrial cancer than a woman of healthy weight.

Over one-quarter of cases of endometrial cancer in Australia are estimated to be due to overweight and obesity.

Other ways of measuring body fatness include waist circumference, weight gain in adulthood and waist-to-hip ratio (the circumference of the waist compared to the circumference of the hips). Increases in all these measures have been associated with an increased risk of endometrial cancer. For example:

for every 10 cm increase in waist circumference, the risk of endometrial cancer increases by 27%.
for every 5 kg of weight gained in adulthood, the risk of endometrial cancer increases by 16%.

There are various ways in which body fatness may increase the risk of endometrial cancer. Weight gain is associated with higher levels of the hormone oestrogen, which can promote the development of endometrial cancer. People who are obese or overweight also have higher levels of certain proteins and other factors in their blood caused by inflammation. In women, these factors may also increase the risk of endometrial cancer.

*Body mass index (BMI) is a measure of body fatness based on a person’s weight in relation to their height. It applies to most adult men and women aged 20 years and over.

Commonly accepted BMI ranges are: underweight, under 18.5 kg/m²; normal weight, 18.5 to 25 kg/m²; overweight, 25 to 30 kg/m²; obese, over 30 kg/m².

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