Learning About Breast Cancer Screening

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What is breast cancer screening?

Breast cancer happens when cells that are not normal grow in one or both of your breasts. Screening tests can help find breast cancer early. They can find some cancers that are too small to feel or before they cause other symptoms. Breast cancer may be easier to treat when it's found early.

Having concerns about breast cancer is common. That's why it's important to talk with your doctor about when to start and how often to get screened for breast cancer.

How is breast cancer screening done?

Screening tests for breast cancer include:


This test uses X-rays. During a mammogram, a machine squeezes your breasts to make them flatter and easier to X-ray. With a screening digital mammogram (DM), one picture is taken from the top and one is taken from the side. With a 3D mammogram, X-rays are taken from many angles to make a 3D image of the breast. A 3D mammogram is also called digital breast tomosynthesis, or DBT.

Clinical breast exam (CBE).

In this exam, your doctor carefully feels your breasts and under your arms to check for lumps or other changes. Your doctor may do a CBE if you have a high risk of breast cancer.

MRI (magnetic resonance imaging) of the breast.

A standard MRI may be used as a screening test if you have a high risk of breast cancer. Your breast cancer screening center may offer you an abbreviated breast MRI (sometimes called a "fast MRI").

When should you get screened?

Mammograms are the best screening test for people at average risk of breast cancer. But experts don't all agree on the age at which screening should start. And they don't agree on whether it's better to be screened every year or every two years.

Here are some of the recommendations from experts:

  • Start at age 40 and have a mammogram every 1 or 2 years.
  • Start at age 45 and have a mammogram each year.
  • Start at age 50 and have a mammogram every 1 or 2 years.

When to stop having mammograms is another decision. You and your doctor can decide on the right age to start and stop screening based on your personal preferences and overall health.

What is your risk for breast cancer?

If you don't already know your risk of breast cancer, you can ask your doctor about it. You can also go to www.cancer.gov/bcrisktool to find out. Age is one factor that affects your risk for breast cancer. The risk for breast cancer goes up as you get older.

If your doctor says that you have a high risk, ask about ways to reduce your risk. These could include taking medicine or having surgery. If you have a strong family history of breast cancer, ask your doctor about genetic testing.

You may have extra screening for breast cancer if you have a high risk.

How can you lower your risk?

Some things that increase your risk of breast cancer, such as your age and your genes, cannot be controlled. But you can do some things to help reduce your risk of breast cancer.

  • Try to stay physically active. Being active often may help protect you from breast cancer.
  • If possible, breastfeed your children.
  • If you drink alcohol, limit how much you drink. Any amount of alcohol may increase your risk for some types of cancer.
  • Do not smoke. When you quit smoking, you lower your chances of getting many types of cancer. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.
  • If you are at high risk for breast cancer, talk with your doctor about recommend medicines or surgeries to lower your risk of breast cancer.

Eating healthy foods like fruits and vegetables and being at a weight that's healthy for you may lower your risk of cancer and have other health benefits.

What are the risks of screening?

Screening helps find breast cancer early. This can help save lives. But screening also has some possible risks.

  • Screening may give false-positive results.

    This means the test seems to find cancer even though no cancer is there. This may lead to more tests or a biopsy to make sure you don't have cancer. False-positive results can lead to distress and unneeded tests.

  • Screening may find types of breast cancer that would never cause symptoms or be life-threatening.

    There are some cancers that never cause harm. But doctors can't always tell which cancer will cause problems and which won't. This means that you could have tests and cancer treatments that you don't need. These could cause serious side effects and be costly and stressful.

  • Sometimes screening gives false-negative results.

    This means the test misses breast cancer that is there. This could delay your getting treatment.

  • Like all X-rays, mammograms expose you to a small amount of radiation.

    The amount from mammograms is very small. For most people, the benefits of regular mammograms far outweigh the low risk from radiation.

Your doctor can help you compare the benefits of screening to the possible risks.

Where can you learn more?

Go to https://www.healthwise.net/patientEd

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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.