Overview

Precision medicine for breast cancer is a way of finding the treatment that is most likely to help you. This approach may involve looking at your DNA or testing your cancer cells to see which treatments might work best.

Precision medicine for breast cancer also can help with diagnosis and prevention.

Precision medicine for breast cancer might be used to:

Look for variations in your DNA that might increase your risk of breast cancer and other types of cancer.
Understand how your body is likely to respond to a medicine by testing your DNA.
Choose the medicine that's most likely to work on your cancer cells by testing the DNA inside the cancer cells.
Look at other things that make up your cancer cells, such as certain proteins or markers on the surface of the cells. These things can tell your healthcare team whether a certain medicine is likely to work on your cancer.

Precision medicine also is called personalized medicine and individualized medicine.

Cancer care was one of the first medical specialties to use precision medicine. Some ways of using precision medicine in cancer care are commonly used in medical centers. Others might be available only in specialized medical centers. Many ways of using precision medicine are only available in clinical trials. This is an active area of cancer research.

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Why it's done

Precision medicine for breast cancer is used to find the treatment that is most likely to help you. It also might be used in the diagnosis and prevention of breast cancer.

Risks

The risks of precision medicine for breast cancer depend on the procedure involved. For example, genetic testing may involve taking a blood sample. Taking a sample of blood has a small risk of bleeding and infection.

Testing your cancer cells may require a biopsy to collect some cells. A biopsy procedure also has some risks. For example, using a needle to get the sample may cause bruising and soreness in the area. Talk with your healthcare team about the procedures you'll have and the related risks.

What you can expect

What you can expect with precision medicine will depend on why it's being done. Precision medicine for breast cancer is often used to find the treatment that is most likely to help you. It also might be used in the diagnosis and prevention of breast cancer.

Examples of precision medicine for breast cancer include:

Testing your DNA to find the right medicine

The DNA inside your cells gives the cells the instructions they need to do their jobs. Variations in your DNA can affect how your cells work. For example, cells that help your body process medicines might work in different ways, depending on your DNA. Variations in your DNA could make a medicine less effective for you. Or because of the variations, you may be more likely to have certain side effects.

Precision medicine can help your healthcare team select the right medicine for you based on your DNA. Genetic testing to find the right medicine is sometimes called pharmacogenomics.

Testing your cancer cells to find the right medicine

Cancer often starts when healthy cells become cancer cells. The healthy cells develop changes in their DNA that turn them into cancer cells. Tests can look for these changes inside the cancer cells.

Through the use of precision medicine, your healthcare team can select the medicine that likely will be most effective against your cancer cells. Sometimes this type of testing is used to select targeted therapy medicines. This testing is sometimes called tumor sequencing or biomarker testing.

Looking for DNA changes that run in your family

Some DNA changes are passed from parents to children. A number of these DNA changes can increase the risk of breast cancer. The most well-known DNA changes related to breast cancer are BRCA1 and BRCA2. People with these DNA changes have a very high risk of breast cancer and other cancers.

Precision medicine might offer information that your healthcare team can use to create a personalized prevention and screening plan based on the results of your genetic testing. Medicines and operations to lower the risk of cancer might be options for you if you have these DNA changes.

Results

The result of precision medicine for breast cancer is treatment or care that is personalized for you. Discuss your treatment plan with your healthcare team. Your care team can explain when you might start to see some results from your treatment.

By Mayo Clinic Staff

Precision medicine for breast cancer care at Mayo Clinic

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Oct. 23, 2024

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