Before menopause, a woman’s ovaries normally produce two main types of hormones: estrogen and progesterone. Estrogen encourages the growth of endometrial cells in the uterus, whereas progesterone inhibits it. When a woman has high circulating levels of estrogen and low levels of progesterone over long periods of time, the risk for uterine (endometrial) cancer rises.
The cells in fatty tissue also make estrogen, which helps explain why obesity (50 pounds or more overweight) is the biggest risk factor for developing this cancer.
The risk for developing uterine cancer also rises if you:
- are between the ages of 50 and 60
- began menstruating before age 12
- entered menopause relatively late, after age 52
- never gave birth
- have a history of infertility (an inability to become pregnant)
- have an ovarian disease, such as polycystic ovarian syndrome, that could cause you to have higher than normal levels of the hormone estrogen and lower than normal levels of the hormone progesterone
- have elevated blood sugar (diabetes)
- have high blood pressure (hypertension)
- have a family history of endometrial carcinoma
- have taken the drug tamoxifen after menopause; the increased risk depends in part on the dose taken and the length of time it’s used. Women who take tamoxifen should discuss the risks and benefits of this drug with their doctors.
- have been diagnosed with endometrial hyperplasia
- take certain types of hormone replacement therapy (HRT)
Genetic Risk Factors
If several members of your family have had uterine or hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome, consider having genetic counseling and genetic testing through our Hereditary Cancer & Genetics Service.
Women who inherit mutations in the BRCA genes or the PTEN gene (Cowden’s syndrome) may also be at an increased risk of developing endometrial cancer.
In addition to getting regular annual checkups with your gynecologist and reporting any unexpected or abnormal vaginal bleeding, lifestyle measures, such as keeping your weight under control with physical activity and following a low-fat diet, may help to prevent uterine cancer. Using oral contraceptives has also been associated with a reduced risk.