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 20 percent of breast cancers are HER2-positive [88-89]. 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.
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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