cancer of the uterus
The most common type of cancer of the uterus
begins in the lining of the uterus, known as the endometrium.
It is called endometrial cancer, uterine cancer, or cancer of the uterus.
In this entry, the terms uterine cancer or cancer of the uterus will refer
to cancer that begins in the endometrium.
A different type of cancer, uterine sarcoma,
develops in the muscle of the uterus, known as the myometrium. Cancer that
begins in the cervix is also a different
type of cancer. This entry does not deal with uterine sarcoma or with cancer
of the cervix.
Who is at risk from cancer of the uterus?
No one knows the exact causes of uterine cancer. However, it is clear that
this disease is not contagious. No one can "catch" cancer from another person.
Women who get this disease 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.
Most women who have known risk factors do not get uterine cancer. On the
other hand, many who do get this disease have none of these factors. Doctors
can seldom explain why one woman gets uterine cancer and another does not.
Studies have found the following risk factors:
Other risk factors are related to how long a woman's body is exposed to
estrogen. Women who have no children, begin menstruation at a very young
age, or enter menopause late in life are exposed to estrogen longer and
have a higher risk.
- Age. Cancer of the uterus occurs mostly in women
over age 50.
- Endometrial hyperplasia. The risk of uterine cancer
is higher if a woman has endometrial hyperplasia. For more about this
condition, see disorders of the
- Hormone replacement therapy (HRT). HRT is used to
control the symptoms of menopause, to prevent osteoporosis
(thinning of the bones), and to reduce the risk of heart disease or
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 protects the uterus.
Women should discuss the benefits and risks of HRT with their doctor.
Also, having regular checkups while taking HRT may improve the chance
that the doctor will find uterine cancer at an early stage, if it does
- Obesity and related conditions. The body makes some
of its estrogen in fatty tissue. That's why 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 occur in many obese women).
- Tamoxifen. Women taking the drug tamoxifen to prevent
or treat breast cancer have an
increased risk of uterine cancer. This risk appears to be related to
the estrogen-like effect of this drug on the uterus. Doctors monitor
women taking tamoxifen for possible signs or symptoms of uterine cancer.
The benefits of tamoxifen to treat breast cancer outweigh the risk of
developing other cancers. Still, each woman is different. Any woman
considering taking tamoxifen should discuss with the doctor her personal
and family medical history and her concerns.
- Race. White women are more likely than African-American
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.
Women with known risk factors and those who are concerned about uterine
cancer should ask their doctor about the symptoms to watch for and how often
to have checkups. The doctor's advice will be based on the woman's age,
medical history, and other factors.
What are the signs and symptoms of uterine cancer?
Uterine cancer usually occurs after menopause. But it may also 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:
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.
- Unusual vaginal bleeding or discharge
- Difficult or painful urination
- Pain during intercourse
- Pain in the pelvic area
How is uterine cancer diagnosed?
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 exams or tests described below.
- Pelvic exam. A woman has a pelvic exam to check the
vagina, uterus, bladder, and rectum. The doctor feels these organs 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. A medical laboratory checks for abnormal cells. Although
the Pap test can detect cancer of the cervix, cells from inside the
uterus usually do not show up on a Pap test. This is why the doctor
collects samples of cells from inside the uterus in a procedure called
- Transvaginal ultrasound.
The doctor inserts an instrument into the vagina. The instrument aims
high-frequency sound waves at the uterus. The pattern of the echoes
they produce 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.
In some cases, however, a woman may need to have a dilation and curettage
(D&C). A D&C is usually done as same-day surgery with anesthesia
in a hospital. A pathologist examines the tissue to check for cancer
cells, hyperplasia, and other conditions. For a short time after the
biopsy, some women have cramps and vaginal bleeding.
Staging the disease
If uterine cancer is diagnosed, the doctor needs to know the stage, or extent,
of the disease to plan the best treatment. Staging is a careful attempt
to find out whether the cancer has spread, and if so, to what parts of the
The doctor may order blood and urine tests and chest
X-rays. The woman also may have other X-rays, CT
scans, an ultrasound test, magnetic
resonance imaging (MRI), sigmoidoscopy,
In most cases, the most reliable way to stage this disease is to remove
the uterus (hysterectomy). After the uterus has been removed, the surgeon
can look for obvious signs that the cancer has invaded the muscle of the
uterus. The surgeon also can check the lymph nodes and other organs in the
pelvic area for signs of cancer. A pathologist uses a microscope to examine
the uterus and other tissues removed by the surgeon.
These are the main features of each stage of the disease:
- Stage I. The cancer is only in the body of the uterus.
It is not in the cervix.
- Stage II. The cancer has spread from the body of
the uterus to the cervix.
- Stage III. The cancer has spread outside the uterus,
but not outside the pelvis (and not to
the bladder or rectum). Lymph nodes in the pelvis may contain cancer
- Stage IV. The cancer has spread into the bladder
or rectum. Or it has spread beyond the pelvis to other body parts.
How is uterine cancer treated?
Read about how cancer of the
uterus is treated.
• disorders of the