The drug trastuzumab (Herceptin) is used to treat metastatic breast cancer and early breast cancer (including lymph node-positive and some lymph node-negative cancers).
Some breast cancers have high amounts of a protein called HER2 on the surface of the cancer cells (called HER2-positive breast cancer). The HER2 protein is important for cancer cell growth.
Trastuzumab is a specially made antibody that targets HER2-positive cancer cells. When attached to the HER2 protein, trastuzumab can slow or stop the growth of these cancer cells.
The HER2 status of a tumor is determined by testing tissue removed during a biopsy. All newly diagnosed breast cancers are tested for HER2 status.
About 10-15 percent of newly diagnosed breast cancers are HER2-positive . These breast cancers can be treated with trastuzumab.
Learn more about HER2 status.
Trastuzumab is only used to treat HER2-positive cancers and has no role in the treatment of HER2-negative cancers.
Studies show chemotherapy plus trastuzumab cuts the risk of recurrence in half compared to chemotherapy alone among women with HER2-positive early breast cancers [90-92].
Trastuzumab is also used to treat HER2-positive locally advanced and metastatic breast cancers.
Learn more about treatment for HER2-positive metastatic breast cancers.
For a summary of research studies on trastuzumab and overall survival in early breast cancer, visit the Breast Cancer Research Studies section.
For a summary of research studies on trastuzumab and treatment for metastatic breast cancer, visit the Breast Cancer Research Studies section.
Trastuzumab use is linked to congestive heart failure, a serious heart condition.
In clinical trials, about 2-3 percent of those treated with chemotherapy plus trastuzumab had heart failure, compared to fewer than one percent of those treated with chemotherapy alone [90-91].
This risk of heart problems may be higher with chemotherapy regimens containing an anthracycline compared to regimens without an anthracycline . The risk of heart problems may also be higher for women older than 65 and for those who already have heart problems.
For most people who develop a heart problem while taking trastuzumab, the condition improves after stopping trastuzumab. For a few people, however, it may be permanent.
Your heart will be checked before and during treatment with trastuzumab to help ensure there are no problems.
Adopting a lifestyle that includes a healthy diet, regular exercise and for those who smoke, quitting smoking may help protect the heart while taking trastuzumab .
To learn more about trastuzumab, visit the National Institutes of Health’s Medline Plus website.
Some drugs contain biological products such as antibodies. A biosimilar drug is very similar to a brand name drug that contains biological products.
To be approved by the U.S. Food and Drug Administration (FDA), the biosimilar drug must work the same way as the brand name drug and it must have the same :
Biosimilar drugs cost less than brand name drugs.
Some biosimilar drugs for breast cancer are under study. However, today, none are FDA-approved.
A large study found a biosimilar form of trastuzumab is as safe and effective as trastuzumab in the treatment of HER2-positive metastatic breast cancer .
However, this biosimilar form of trastuzumab is not yet FDA-approved.
Komen Support Resources
Breast Cancer 101:Targeted Therapy
Research Fast Facts: Breast Cancer Therapies
Research Fast Facts: HER2-Positive Breast Cancer
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