What is cancer of the uterus?

The uterus is part of a woman's reproductive system. It is the hollow, pear-shaped organ in the pelvis. The wall of the uterus has two layers of tissue. The inner layer or lining is the endometrium, and the outer layer is muscle tissue called the myometrium. The most common type of cancer of the uterus begins in the lining (endometrium). Although the exact cause is unknown, increased levels of estrogen appear to have a role. Estrogen helps stimulate the buildup of the epithelial lining of the uterus.

What are some symptoms of uterine cancer?

Uterine cancer usually occurs after menopause, typically between the ages of 60 and 70. It also may occur around the time that menopause begins. Abnormal vaginal bleeding is the most common symptom of uterine cancer. Bleeding may start as a watery, blood-streaked flow that gradually contains more blood. Women should not assume that abnormal vaginal bleeding is part of menopause. A woman should see her doctor if she has any of the following symptoms:

• unusual vaginal bleeding or discharge not related to menstruation, most commonly postmenopausal bleeding

• thin white or clear vaginal discharge after menopause

• extremely long, heavy or frequent episodes of vaginal bleeding after age 40

• difficult or painful urination

• pain during intercourse

• pain in the pelvic area

These symptoms can be caused by cancer or other less serious conditions. Most often they are not cancer, but only a doctor can tell for sure.

What are some risk factors for uterine cancer?

Women who get this disease are more likely than other women to have certain risk factors. A risk factor is something that increases the chance of developing the disease. Risk factors for uterine cancer include:

• being older than 50 years of age

• having endometrial hyperplasia — an increase in the number of cells in the lining of the uterus

• using estrogen without progesterone

• being obese or having related conditions, such as diabetes or high blood pressure

• using tamoxifen to prevent or treat breast cancer

• having an inherited form of colorectal cancer

• having a history of endometrial polyps or other benign growths of the uterine lining

• never being pregnant or being infertile

• starting menstruation before age 12

• starting menopause after age 50

Other risk factors relate to how long a woman’s body is exposed to estrogen. Women who have no children, begin menstruation at a young age, or enter menopause late in life are exposed to estrogen longer and have a higher risk. The endometrium can be stimulated by the increased estrogen levels related to obesity, liver disease or other sources such as postmenopausal estrogen.

How is uterine cancer diagnosed?

The ideal method for screening asymptomatic women has not yet been devised. If a woman has symptoms that suggest uterine cancer, her doctor may check general signs of health and may order blood and urine tests. The doctor also may perform one or more of the following exams or tests:

• Pelvic exam - the doctor checks the vagina, uterus, bladder and rectum for any lumps or changes in their shape or size. To see the upper part of the vagina and the cervix, the doctor inserts an instrument called a speculum into the vagina.

• Pap test - the doctor collects cells from the cervix and upper vagina. Because uterine cancer begins inside the uterus, it does not usually show up on a Pap test. However, postmenopausal women with endometrial cells on a Pap, particularly if they are atypical, need further evaluation.

• Transvaginal ultrasound - the doctor inserts an instrument into the vagina which aims high-frequency sound waves at the uterus. The pattern of the echoes creates a picture. If the endometrium looks too thick, the doctor can do a biopsy.

• Biopsy - the doctor removes a sample of tissue from the uterine lining. This usually can be done in the doctor's office.

How is uterine cancer treated?

Endometrial cancer is highly curable. Treatment options involve surgery, radiation therapy and chemotherapy.

More information about uterine cancer can be obtained by contacting:

National Cancer Institute, U.S. National Institutes of Health
http://www.cancer.gov/cancertopics/types/endometrial

National Women’s Health Information Center
800-994-9662
www.4woman.gov/faq/cuterine.htm