Unfortunately, the exact causes of uterine cancer are not known. However, women who develop uterine cancer are more likely than other women to have certain risk factors. A risk factor is something that increases a person’s chance of developing the disease. It’s important to note that most women who have known risk factors for uterine cancer do not develop the disease.
The known risk factors for uterine cancer include:
- Age: Uterine cancer occurs most often in women over the age of 50.
- Endometrial hyperplasia: The risk of uterine cancer is higher if a woman has endometrial hyperplasia, which is a condition that occurs when the lining of the uterus, called the endometrium, grows too much.
- Hormone replacement therapy (HRT): HRT is used to control the symptoms of menopause, to prevent osteoporosis, or weakening of the bones, and to reduce the risk of heart disease or stroke. Women who use estrogen without progesterone have an increased risk of uterine cancer. Long-term use and large doses of estrogen seem to increase this risk. Women who use a combination of estrogen and progesterone have a lower risk of uterine cancer than women who use estrogen alone. The progesterone serves to protect the uterus. Women should discuss the risks and benefits of HRT with their providers. Use of HRT should not cause bleeding in menopause. Having regular checkups while undergoing HRT may improve the chance that the provider will find uterine cancer at an early stage, if it does develop.
- Obesity and related conditions: The body makes some of its estrogen in fatty tissue. For this reason, obese women are more likely than thin women to have higher levels of estrogen in their bodies. High levels of estrogen may be the reason that obese women have an increased risk of developing uterine cancer. The risk of this disease is also higher in women with diabetes or high blood pressure, conditions that are prevalent in many obese women.
- Tamoxifen: Women taking the drug tamoxifen to prevent or treat breast cancer have an increased risk of uterine polyps and uterine cancer. This risk is related to the estrogen-like effect of this drug on the uterus. Providers follow women taking tamoxifen closely for possible signs or symptoms of uterine cancer. Although each woman is different, the benefits of tamoxifen to treat breast cancer usually outweigh the risk of developing other cancers. Women considering taking tamoxifen should discuss any concerns with their provider. Any abnormal bleeding should be evaluated.
- Race: White women are more likely than black women to get uterine cancer.
- Colorectal cancer: Women who have had an inherited form of colorectal cancer have a higher risk of developing uterine cancer than other women.
Other risk factors are related to how long a woman’s body is exposed to estrogen. Women who have no children, begin their periods at a very young age, or enter menopause late in life are exposed to estrogen longer and have a higher risk of developing uterine cancer.
Women with known risk factors and those who are concerned about uterine cancer should ask their provider about the symptoms to watch for and how often to have checkups.