Breast and Ovarian Cancer Screening
What Is Screening?
Screening is looking for cancer before a person has any symptoms. This can help find
cancer at an early stage. When abnormal tissue or cancer is found early, it may be easier to
treat. By the time symptoms appear, cancer may have begun to spread.
Scientists are trying to better understand which people are more likely to get certain types
of cancer. They also study the things we do and the things around us to see if they cause
cancer. This information helps doctors recommend who should be screened for cancer,
which screening tests should be used, and how often the tests should be done.
It is important to remember that your doctor does not necessarily think you have cancer if
he or she suggests a screening test. Screening tests are given when you have no cancer
symptoms.
If a screening test result is abnormal, you may need to have more tests done to find out if
you have cancer. These are called diagnostic tests.
Breast Cancer Screening
Different tests are used to screen for cancer.
Some screening tests are used because they have been shown to be helpful both in finding
cancers early and in decreasing the chance of dying from these cancers. Other tests are
used because they have been shown to find cancer in some people; however, it has not
been proven in clinical trials that use of these tests will decrease the risk of dying from
cancer.
Scientists study screening tests to find those with the fewest risks and most benefits.
Cancer screening trials also are meant to show whether early detection (finding cancer
before it causes symptoms) decreases a person’s chance of dying from the disease. For
some types of cancer, finding and treating the disease at an early stage may result in a
better chance of recovery.
Three tests are commonly used to screen for breast cancer:
Mammogram
A mammogram is an X-ray of the breast. This test may find tumors that are too small to
feel. A mammogram also may find ductal carcinoma in situ, abnormal cells in the lining of a
breast duct, which may become invasive cancer in some women. The ability of a
mammogram to find breast cancer may depend on the size of the tumor, the density of the
breast tissue and the skill of the radiologist.
Clinical Breast Exam (CBE)
A clinical breast exam is an exam of the breast by a doctor or other health professional. The
doctor will carefully feel the breasts and under the arms for lumps or anything else that
seems unusual.
Breast Self-Exam (BSE)
Breast self-exam is an exam to check your own breasts for lumps or anything else that
seems unusual.
If a lump or other abnormality is found using one of these three tests, ultrasound may be
used to learn more. It is not used by itself as a screening test for breast cancer. Ultrasound
is a procedure in which high-energy sound waves (ultrasound) are bounced off internal
tissues or organs and make echoes. The echoes form a picture of body tissues called a
sonogram.
New screening tests are being studied in clinical trials.
MRI (Magnetic Resonance Imaging)
MRI is a procedure that uses a magnet, radio waves and a computer to make a series of
detailed pictures of areas inside the body. This procedure also is called nuclear magnetic
resonance imaging (NMRI). Screening trials of MRI in women with a high genetic risk of
breast cancer have shown that MRI is more sensitive than mammography for finding breast
tumors.
MRI scans are used to make decisions about breast masses that have been found by a
clinical breast exam or a breast self-exam. MRIs also help show the difference between
cancer and scar tissue. MRI does not use any X-rays.
Tissue Sampling
Breast tissue sampling is taking cells from breast tissue to examine under a microscope.
Abnormal cells in breast fluid have been linked to an increased risk of breast cancer in some
studies. Scientists are studying whether breast tissue sampling can be used to find breast
cancer at an early stage or predict the risk of developing breast cancer. Three methods of
tissue sampling are under study:

Fine-needle aspiration. A thin needle is inserted into the breast tissue around the
areola (darkened area around the nipple) to withdraw cells and fluid.

Nipple aspiration. The use of gentle suction to collect fluid through the nipple. This
is done with a device similar to the breast pumps used by nursing women.

Ductal lavage. A hair-size catheter (tube) is inserted into the nipple and a small
amount of salt water is released into the duct. The water picks up breast cells and is
removed.
Risks of Breast Cancer Screening
Screening tests have risks.
Decisions about screening tests can be difficult. Not all screening tests are helpful and most
have risks. Before having any screening test, you may want to discuss the test with your
doctor. It is important to know the risks of the test and whether it has been proven to
reduce the risk of dying from cancer.
The risks of breast cancer screening tests include the following:
Finding breast cancer may not improve health or help a woman live longer.
Screening may not help you if you have fast-growing breast cancer or if it has already
spread to other places in your body. Also, some breast cancers found on a screening
mammogram may never cause symptoms or become life-threatening. When such cancers
are found, treatment would not help you live longer and may instead cause serious
treatment-related side effects. At this time, it is not possible to be sure which breast
cancers found by screening will cause symptoms and which breast cancers will not.
False-negative test results can occur.
Screening test results may appear to be normal even though breast cancer is present. A
woman who receives a false-negative test result (one that shows there is no cancer when
there really is) may delay seeking medical care even if she has symptoms.
One in five cancers may be missed by mammography. False-negatives occur more often in
younger women than in older women because the breast tissue of younger women is more
dense. The size of the tumor, the rate of tumor growth, the level of hormones, such as
estrogen and progesterone, in the woman’s body, and the skill of the radiologist also can
affect the chance of a false-negative result.
False-positive test results can occur.
Screening test results may appear to be abnormal even though no cancer is present. A
false-positive test result (one that shows there is cancer when there really isn’t) can cause
anxiety and is usually followed by more tests (such as biopsy), which also have risks.
Most abnormal test results turn out not to be cancer. False-positives are more common in
younger women, women who have had previous breast biopsies, women with a family
history of breast cancer, and women who take hormones, such as estrogen and
progesterone. The skill of the doctor also can affect the chance of a false-positive result.
Mammograms expose the breast to radiation.
Being exposed to radiation is a risk factor for breast cancer. The risk of developing breast
cancer from radiation exposure, such as screening mammograms or X-rays, is greater with
higher doses of radiation and in younger women. For women older than 40 years, the
benefits of an annual screening mammogram may be greater than the risks from radiation
exposure.
The risks and benefits of screening for breast cancer may be different for different groups of
people.
The benefits of breast cancer screening may vary among age groups:

In women who have a life expectancy of five years or less, finding and treating early
stage breast cancer may reduce their quality of life without helping them live longer.

In women older than 65 years, the results of a screening test may lead to more
diagnostic tests and anxiety while waiting for the test results. Also, the breast
cancers found are usually not life-threatening.

In women 35 years or younger who go to the doctor for breast symptoms,
mammogram results may not be helpful in managing their care.
Routine breast cancer screening is advised for women who have had radiation treatment to
the chest, especially at a young age. The benefits and risks of mammograms and MRIs for
these women are not known. There is no information on the benefits or risks of breast
cancer screening in men.
No matter how old you are, if you have risk factors for breast cancer you should ask for
medical advice about when to begin having mammograms and how often to be screened.
Ovarian Cancer Screening
Tests are used to screen for different types of cancer.
Some screening tests are used because they have been shown to be helpful both in finding
cancers early and in decreasing the chance of dying from these cancers. Other tests are
used because they have been shown to find cancer in some people; however, it has not
been proven in clinical trials that use of these tests will decrease the risk of dying from
cancer.
Scientists study screening tests to find those with the fewest risks and most benefits.
Cancer screening trials also are meant to show whether early detection (finding cancer
before it causes symptoms) decreases a person's chance of dying from the disease. For
some types of cancer, finding and treating the disease at an early stage may result in a
better chance of recovery.
There is no standard or routine screening test for ovarian cancer. Screening for ovarian
cancer is under study and there are screening clinical trials taking place in many parts of the
country.
Tests that may detect (find) ovarian cancer are being studied:
Pelvic Exam
A pelvic exam is an exam of the vagina, cervix, uterus, fallopian tubes, ovaries and rectum.
The doctor or nurse inserts one or two lubricated, gloved fingers of one hand into the vagina
and the other hand is placed over the lower abdomen to feel the size, shape and position of
the uterus and ovaries. A speculum also is inserted into the vagina and the doctor or nurse
looks at the vagina and cervix for signs of disease.
Ovarian cancer usually is advanced when detected by a pelvic exam.
Transvaginal Ultrasound
Transvaginal ultrasound is a procedure used to examine the vagina, uterus, fallopian tubes
and bladder. An ultrasound transducer (probe) is inserted into the vagina and used to
bounce high-energy sound waves (ultrasound) off internal tissues or organs and make
echoes. The echoes form a picture of body tissues called a sonogram.
CA-125 Assay
A CA 125 assay is a test that measures the level of CA 125 in the blood. CA 125 is a
substance released by cells into the bloodstream. An increased CA-125 level is sometimes a
sign of certain types of cancer, including ovarian cancer, or other conditions.
Scientists at the National Cancer Institute are studying the combination of ultrasound and
CA-125 levels as a way to get more accurate results from the screening tests.
Risks of Ovarian Cancer Screening
Screening tests have risks.
Decisions about screening tests can be difficult. Not all screening tests are helpful and most
have risks. Before having any screening test, you may want to discuss the test with your
doctor. It is important to know the risks of the test and whether it has been proven to
reduce the risk of dying from cancer.
The risks of ovarian screening tests include the following:
Finding ovarian cancer may not improve health or help a woman live longer.
Screening may not improve your health or help you live longer if you have advanced
ovarian cancer or if it has already spread to other places in your body.
Some cancers never cause symptoms or become life-threatening, but if found by a
screening test, the cancer may be treated. It is not known if treatment of these cancers
would help you live longer than if no treatment were given, and treatments for cancer may
have serious side effects.
False-negative test results can occur. Screening test results may appear to be normal
even though ovarian cancer is present. A woman who receives a false-negative test result
(one that shows there is no cancer when there really is) may delay seeking medical care
even if she has symptoms.
False-positive test results can occur. Screening test results may appear to be abnormal
even though no cancer is present. A false-positive test result (one that shows there is
cancer when there really isn't) can cause anxiety and is usually followed by more tests
(such as a laparoscopy or a laparotomy to see if cancer is present), which also have risks.
An unnecessary oophorectomy (removal of one or both ovaries) may also result.
Your doctor can advise you about your risk for ovarian cancer and your need for screening
tests.
Source: Excerpted from the National Cancer Institute, National Institutes of Health
Updated: Ovarian cancer information, January 10, 2008; Breast cancer information, June
14, 2007