Being overweight substantially increases the risk of developing uterine cancer, research suggests.
If a 1.65-metre (5-foot-5) woman is 12.7 kilograms (28 pounds) above a healthy weight, her risk is nearly doubled, for example, the BBC reports.
The Cancer Research UK (CRUK)-funded research involved 120,000 women in the U.K., U.S. and five other countries. The organization says keeping a healthy weight can cut the risk of 13 cancers. Genes and hormones may be other risk factors.
One theory holds that fat cells can send out signals telling other cells to divide more often, which can lead to cancer. The growth of some breast cancers is linked to the female hormone estrogen, which fat cells also produce, for example.
The CRUK study, led by a team at the University of Bristol and published in BMC Medicine, is one of the largest into the link between fat and uterine cancer.
It looked at the effect of lifelong weight gain and uncovered two hormones, fasting insulin and testosterone, linked with obesity and uterine cancer.
The researchers hope scientists could in future use drugs to regulate levels of those hormones in people at risk of developing the cancer.
Lead investigator Dr 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.”
One in 36 U.K. women develops uterine cancer, and one in four people diagnosed is pre-menopausal. The most common symptom is abnormal vaginal bleeding.