Uterine Cancer / Endometrial Cancer Causes and Risk Factors
The cause of uterine cancer is unknown. Chronic exposure to estrogen (i.e., a female hormone produced by the ovaries) increases the risk for developing the disease and estrogen often affects tumor growth. The following factors increase estrogen exposure:
- Early menarche (beginning menstruation before age 12)
- Hormone replacement therapy (HRT) with exogenous estrogen (i.e., without progesterone)
- Late menopause (after age 52)
- Presence of an estrogen-secreting tumor (e.g., some types of breast cancer)
- Nulliparity (having never given birth) or low parity
Endometrial hyperplasia is a condition that increases the risk for uterine cancer. About one-third of patients with hyperplasia develop endometrial cancer. Symptoms of endometrial hyperplasia include heavy or prolonged menstrual periods, bleeding between menstrual periods, and prolonged amenorrhea (i.e., absence of menstruation for longer than 90 days). Postmenopausal women with hyperplasia may experience vaginal bleeding or spotting.
Long-term use of tamoxifen (e.g., Nolvadex) increases the risk for uterine cancer. Tamoxifen is used to treat breast cancer and to decrease the risk for the disease in certain high-risk patients. Women undergoing treatment with tamoxifen are monitored carefully for uterine abnormalities.
Medical conditions such as obesity, gall bladder disease, diabetes mellitus, and high blood pressure (hypertension) increase the risk for cancer of the uterus.
Other risk factors include the following:
- Age (more common after age 50)
- Family history of uterine cancer
- Personal history of breast, colorectal, or ovarian cancer
- Prior pelvic radiation therapy
- Race (endometrial cancer is more common in Caucasian women and uterine sarcoma is more common in African American women)