Each year, more than 60,000 women are diagnosed with endometrial cancer or uterine sarcoma, the two primary types of uterine cancer. No one knows if or when uterine cancer will develop, so it is important to understand the risk factors of the disease.What causes uterine cancer?
Uterine cancer forms when the DNA in cells in the uterus mutate, disabling functions that control cell division and growth. In most cases, cancer cells in the uterus are found in the endometrium, the inner lining of the uterus. This is called endometrial cancer. While the exact cause of a woman’s uterine cancer may not be known, certain risk factors are strongly linked to the disease, including obesity and high blood sugar.
Uterine sarcoma and endometrial cancer have different risk factors. Having one risk factor for cancers of the uterus, or even several, does not mean you will get the disease. Likewise, having no common risk factors does not mean you will not develop cancer.
Known risk factors for uterine cancer include:General
Age: Most women diagnosed with endometrial cancer are over age 50 and have gone through menopause.
Increased number of menstrual cycles: Women who have had more menstrual cycles in their lifetime have an increased endometrial cancer risk. This includes those who started their periods before age 12 and who went through menopause after age 50.
No prior pregnancies: Researchers are investigating why pregnancy seems to reduce the risk of endometrial cancer. During pregnancy, a woman’s hormonal balance shifts, with her body producing more progesterone and less estrogen. Irregular menstrual cycles and infertility also may cause imbalances in estrogen and progesterone levels, which may increase the risk of endometrial cancer.Body
Obesity: Fat tissues tend to produce higher levels of estrogen, particularly after menopause, which increases the endometrial cancer risk for older, overweight women.
Metabolic syndrome: This syndrome occurs when a specific set of conditions develop at the same time, such as extra fat around the abdomen, high blood sugar, high blood pressure, high levels of triglycerides and low levels of high-density lipoproteins in the blood.
Endometrial hyperplasia: This condition occurs when a buildup of cells and glandular structures causes a thickening in the endometrium (the lining of the uterus). There are several types of endometrial hyperplasia, including:
Hyperplasia is not cancer, but the condition may increase the risk of developing cancer, depending on the type of hyperplasia, whether the cells in the endometrium have become abnormal, and other factors. Endometrial hyperplasia most often occurs in women after menopause and may be caused by an imbalance of excess estrogen without progesterone. Obesity, other medical conditions and a family history of hyperplasia may increase the risk of developing hyperplasia.
Other conditions: Diabetes, ovarian tumors and syndromesPrevious treatment
Estrogen replacement therapy: Replacing estrogen without increasing progesterone levels after menopause may increase a woman’s risk of developing endometrial cancer.
Tamoxifen: Women who are treated with the breast cancer drug tamoxifen have an increased risk of developing this disease.Genetic risk factors
Heredity plays a key role in the development of certain gynecologic cancers, because damage to genes involving cell growth and DNA repair accumulate over time.
A family history of cancer does not necessarily mean you are at high risk for developing the disease. About 5 percent of uterine cancers are linked to hereditary factors.
If several members of your family have had endometrial cancer or Lynch syndrome (also known as hereditary non-polyposis colorectal cancer) you may be a candidate for genetic testing. Lynch syndrome may be caused by a mutation in any of several mismatch repair genes. These genes are normally responsible repairing damaged DNA. When one of these genes isn’t working, cells may develop mistakes in their DNA, potentially leading to other gene mutations and, eventually, cancer.
Women who inherit mutations in the BRCA genes or the PTEN gene may also be at an increased risk for developing endometrial cancer.Uterine sarcoma risk factors
It is not yet known what causes most uterine sarcomas, but certain risk factors have been known to play a role. Risk factors for uterine sarcoma include:
Radiation therapy to the pelvic area: Such treatments, typically to target a different cancer type, increases a woman’s risk of uterine cancer later. Radiation damages even healthy cells, which may lead to cancer. Uterine sarcomas that develop because of radiation exposure typically occur five to 25 years after the treatment.
Race: Uterine sarcomas are about twice as common in African-American women as they are in white or Asian women.
History of retinoblastoma: This type of eye cancer is caused by an abnormal gene and is linked to a higher risk of uterine sarcoma.Prevention and screening
The exact cause of a woman’s endometrial cancer or uterine sarcoma may never be known. But there are steps women can take to prevent or reduce the risk of developing uterine cancer, including:
Consider birth control: Talk to your doctor about taking birth control pills that combine estrogen and progesterone. Using a progestin-secreting intrauterine device (IUD) may also reduce risk. Discuss the risks and benefits of hormone replacement therapy.
Know your family history: Women who have a hereditary cancer syndrome, such as Lynch syndrome, or a family history of uterine cancer or other cancers may be at higher risk. Knowing your genetics and family history may help you make decisions on screening regimens and prophylactic measures that may help prevent the disease or catch it early.
Lose weight: Obesity is a risk factor for developing uterine sarcoma and endometrial cancer. Regular exercise and maintaining a healthy weight may reduce your risk of developing these and other cancers.
Manage your diabetes: Maintaining blood sugar levels may help reduce your risk of developing uterine cancer.
See your doctor: Get regular checkups with a gynecologist and address issues such as abnormal bleeding or pain.
Next topic: What are the symptoms of uterine cancer?