What is breast cancer?
Breast cancer is a malignant tumor that starts from cells of the breast. A malignant tumor is a group of
cancer cells that may grow into (invade) surrounding tissues or spread (metastasize) to distant areas of the
body. The disease occurs almost entirely in women, but men can get it, too.
The remainder ofthis document refers only to breast cancer in women. For information on breast
cancer in men, see our document, Breast Cancer in Men.
The normal breast
To understand breast cancer,it helps to have some basic knowledge about the normal structure of the
breasts,shown in the diagram below.
The female breast is made up mainly of lobules (milk-producing glands), ducts (tiny tubes that carry the
milk from the lobules to the nipple), and stroma (fatty tissue and connective tissue surrounding the ducts
and lobules, blood vessels, and lymphatic vessels).
Most breast cancers begin in the cells that line the
ducts (ductal cancers). Some begin in the cells that
line the lobules (lobular cancers), while a small
number start in other tissues.
Benign breast lumps
Most breast lumps are not cancerous (benign). Still,
some may need to be sampled and viewed under a
microscope to prove they are not cancer.
Most lumps turn out to be fibrocystic changes. The
term fibrocystic refers to fibrosis and cysts. Fibrosis
is the formation of scar-like (fibrous) tissue, and
cysts are fluid-filled sacs. Fibrocystic changes can
cause breast swelling and pain. This often happens
just before a woman's menstrual period is about to begin. Her breasts may feel lumpy and,
sometimes, she may notice a clear or slightly cloudy nipple discharge.
Other benign breast lumps
Benign breast tumors such as fibroadenomas or intraductal papillomas are abnormal growths,
but they are not cancerous and do not spread outside of the breast to other organs. They are not
life threatening. Still, some benign breast conditions are important because women with these
conditions have a higher risk of developing breast cancer.
For more information see the section, "What are the risk factors for breast cancer?" and our
document, Non-cancerous Breast Conditions.
How is breast cancer diagnosed?
Breast cancer is sometimes found after symptoms appear, but many women
with early breast cancer have no symptoms. This is why getting the
recommended screening tests (as described in the section, "Can breast cancer
be found early?") before any symptoms develop is so important.
If something suspicious is found during a screening exam, or if you have any
of the symptoms of breast cancer described below, your doctor will use one
or more methods to find out if the disease is present. If cancer is found, other
tests will be done to determine the stage (extent) of the cancer.
Signs and symptoms
Widespread use of screening mammograms has increased the number of breast cancers found
before they cause any symptoms, but some breast cancers are not found by mammogram, either
because the test was not done or because, even under ideal conditions, mammograms do not find
every breast cancer.
The most common sign of breast cancer is a new lump or mass. A painless, hard mass that has
irregular edges is more likely to be cancerous, but breast cancers can be tender, soft, or rounded.
For this reason, it is important that any new breast mass or lump be checked by a health care
professional experienced in diagnosing breast diseases.
Other possible signs of breast cancer include:
Swellingof all orpart of a breast(evenif nodistinctlumpisfelt)
Breastor nipple pain
Nipple retraction (turninginward)
Redness,scaliness,orthickeningof the nippleorbreastskin
Nipple discharge (otherthanbreastmilk)
Sometimes a breast cancer can spread to underarm lymph nodes and cause a lump or swelling
there, even before the original tumor in the breast tissue is large enough to be felt.
Medical history and physical exam
If you have any signs or symptoms that might be due to breast cancer, be sure to see your doctor
as soon as possible. Your doctor will ask you questions about your symptoms, any other health
problems, and possible risk factors for benign breast conditions or breast cancer.
Your breasts will be thoroughly examined for any lumps or suspicious areas and to feel their
texture, size, and relationship to the skin and chest muscles. Any changes in the nipples or the
skin of your breasts will be noted. The lymph nodes in the armpit and above the collarbones may
be palpated (felt), because enlargement or firmness of these lymph nodes might indicate spread
of breast cancer. Your doctor may also probably do a complete physical exam to judge your
general health and whether there is any evidence of cancer that may have spread.
If breast symptoms and/or the results of your physical exam suggest breast cancer might be
present, more tests will likely be done. These might include imaging tests, looking at samples of
nipple discharge, or doing biopsies of suspicious areas.
What is a mammogram?
A mammogram is an X-ray picture of the breast. Doctors use a mammogram to look for
early signs of breast cancer.
Why should I get a mammogram?
Regular mammograms are the best tests doctors have to find breast cancer early,
sometimes up to three years before it can be felt. When their breast cancer is found
early, many women go on to live long and healthy lives.
When should I get a mammogram?
Women should have mammograms every twoyears from age 50 to 74 years. Talk to
your health professional if you have any symptoms or changes in your breast, or if breast
cancer runs in your family. He or she may recommend that you have mammograms
before age 50 or more often than usual.
How is a mammogram done?
You will stand in front of a special X-ray machine. A technologist will place your breast
on a clear plastic plate. Another plate will firmly press your breast from above. The
plates will flatten the breast, holding it still while the X-ray is being taken. You will feel
some pressure. The other breast will be X-rayed in the same way. The steps are then
repeated to make a side view of each breast. You will then wait while the technologist
checks the four X-rays tomake sure the pictures do not need to be re-done. Keep in
mind that the technologist cannot tell you the results of your mammogram.
What does having a mammogram feel like?
Having a mammogram is uncomfortable for most women. Some women find it painful.
A mammogram takes only a few moments, though, and the discomfort is over soon.
What you feel depends on the skill of the technologist, the size of your breasts, and how
much they need to be pressed. Your breasts may be more sensitive if you are about to get
or have your period.
Before you get a mammogram, you may want to ask the following
What will happen? How long will I be there?
Do you have my previous mammograms?
When will my doctor get the results?
When and how will I learn about the results?
When will I need to have my next mammogram?
What does a mammogram look like?
An example of a normal mammogram is shown here. Each woman's
mammogram may look a little different because all breasts are a little
different. A doctor with special training, called a radiologist, will read
the mammogram. He or she will look at the X-ray for early signs of
breast cancer or other problems.
When will I get the results of my mammogram?
You will usually get the results within a few weeks, although it depends
on the facility. A radiologist reads your mammogram and then reports
the results to you or your doctor. If there is a concern, you will hear
from the mammography facility earlier. Contact your health
professional or the mammography facility if you do not receive a
report of your results within 30 days.
Tips for getting a mammogram—
Try not to have your mammogram the week before you get your period or during
your period. Your breasts may be tender or swollen then.
On the day of your mammogram, don't wear deodorant, perfume, or powder.
These products can show up as white spots on the X-ray.
Some women prefer to wear a top with a skirt or pants, instead of a dress. You
will need to undress from your waist up for the mammogram.
What happens if my mammogram is normal?
Continue to get regular mammograms. Mammograms work best when they can be
compared with previous ones. This allows your doctor to compare them to look for
changes in your breasts.
What happens if my mammogram is abnormal?
If it is abnormal, do not panic. An abnormal mammogram does not always mean that
there is cancer. But you will need to have additional mammograms, tests, or exams
before the doctor can tell for sure. You may also be referred toa breast specialist or a
surgeon. It does not necessarily mean you have cancer or need surgery. These doctors
are experts in diagnosing breast problems.
Where can I get a mammogram and who can I talk to if I have questions?
If you have a regular doctor, talk to him or her.
Call the National Cancer Institute's Cancer Information Service (CIS) at 1-800-
4-CANCER (1-800-422-6237). For TTY: 1-800-332-8615.
For Medicare information, you can call 1-800 MEDICARE (1-800-633-4227) or
visit The Centers for Medicare and Medicaid Services.
The Centers for Disease Control and Prevention (CDC) has a program called the
National Breast and Cervical Cancer Early Detection Program, which works with
health departments and other groups to provide low-cost or free mammograms
to women who qualify. For more information, call your health department or 1-
800-CDC-INFO (1-800-232-4636), or call your local program.
Video on how to spot breast cancer:
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