Excess weight almost doubles a woman’s risk of developing womb cancer, new research suggests.
The Cancer Research UK-funded study found that for every five body mass index units, or kilogram of weight per height in metres squared, the risk increased by 88 per cent.
This is equivalent to a woman who is 1.65 metres tall gaining about 13 kilograms.
Researchers analysed genetic samples from about 120,000 women from Australia, Belgium, Germany, Poland, Sweden, the UK and the USA, of whom about 13,000 had endometrial cancer.
Looking at markers of 14 traits that could link obesity and womb cancer, they found two hormones – fasting insulin and testosterone – that increased the likelihood of having the condition.
By identifying precisely how hormones could increase the risk, scientists could in future use drugs to regulate levels of those hormones in people who are already in greater danger of developing the cancer.
The paper’s lead author, Emma Hazelwood, said: “This study is an interesting first step into how genetic analyses could be used to uncover exactly how obesity causes cancer, and what can be done to tackle it.
“Links between obesity and womb cancer are well known, but this is one of the largest studies which has looked into exactly why that is on a molecular level.
“We look forward to further research exploring how we can now use this information to help reduce the risk of cancer in people struggling with obesity.”
The peer-reviewed study from the University of Bristol, which was published in BMC Medicine, is one of only a handful to look at the effect of lifelong higher BMI on womb cancer risk rather than a snapshot in time.
Being overweight or obese is the second-most common preventable cause of cancer in the UK, with more than one in 20 cases estimated to be a result of this.
Dr Julie Sharp, head of health information at Cancer Research UK, said: “Studies like this bolster the fact that being overweight or obese is the second biggest cause of cancer in the UK and can help us start to pinpoint why.
“This will play a pivotal role in uncovering how to prevent and treat cancer in the future.”
A BMI of 18 to 25 is considered healthy, 25 to 30 is overweight and over 30 is obese.
The 2019 Health Survey for England estimated 28 per cent of adults were obese and 36 per cent were overweight.
