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Biological therapy for breast cancer

Biological therapy is sometimes used to treat breast cancer. It is also called biotherapy or biological response modifiers (BRMs).

Biological therapy uses natural or manufactured substances to kill, control or change the behaviour of cancer cells. Different types of biological therapies work in different ways.

Biological therapy may be used:

  • for high risk, advanced or metastatic breast cancer in combination with other chemotherapy or hormonal therapy drugs
  • to treat bone marrow suppression caused by chemotherapy

Drugs, doses and schedules vary from person to person. For more detailed information on specific drugs, go to sources of drug information.

The most common biological therapy drugs used to treat breast cancer are:


ERBB2 is a gene that has changed (mutated) so it helps a tumour grow (oncogeneoncogeneA gene involved in the control of cell growth and division that may cause the growth of cancer cells.). It is more commonly known as HER2 (or HER2/neu). HER2 stands for human epidermal growth factor receptor 2. HER2 controls a growth-promoting protein on the surface of breast cells. Each healthy cell contains 2 copies of the HER2 gene. Sometimes too many copies of the HER2 gene are present in a cell and the body makes too much HER2 protein. This is called overexpression of HER2.

Trastuzumab (Herceptin) is specially designed to attach to the extra HER2 proteins and stop the growth of the cancer in women with HER2-positive breast cancer. At present, it is thought that women with HER2-negative breast cancer do not benefit from trastuzumab.

Trastuzumab is given as an intravenous drug injected into a vein. It may be used:

  • in combination with chemotherapy drugs as adjuvant therapyadjuvant therapyTreatment given in addition to the first-line therapy (the first or standard treatment) to help reduce the risk of a disease (such as cancer) coming back (recurring). after surgery to treat women with high-risk, invasive or locally advanced breast cancer
    • Trastuzumab may be given at the same time as or following chemotherapy.
    • It may be continued for up to a year after chemotherapy is finished.
  • alone to treat metastatic breast cancer
    • Trastuzumab is continued until the cancer progresses.

Pertuzumab (Perjeta)

Pertuzumab (Perjeta) is another drug designed to target HER2 proteins that is used with trastuzumab and taxane chemotherapy for treatment of metastatic HER2-positive breast cancer. It is given as an intravenous drug injected into a vein and can be used in women who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease.

Trastuzumab emtansine (Kadcyla or T-DM1)

Trastuzumab emtansine (Kadcyla or T-DM1) is made up of the drugs trastuzumab and emtansine (DM1), a newly developed anticancer (cytotoxic) drug.

Trastuzumab emtansine is given as an intravenous drug injected into a vein. It may be used to treat women with HER2-positive metastatic breast cancer who have received prior treatment with trastuzumab and taxane chemotherapy, separately or in combination.


Lapatinib (Tykerb) is a type of tyrosine kinase inhibitor that stops cells from growing and dividing. It is given by mouth (orally) as a pill.

Lapatinib may be given in combination with the following drugs to treat women with metastatic breast cancer:

  • capecitabine (Xeloda)
    • This combination is used to treat women who have HER2-positive breast cancer, when other types of chemotherapy or trastuzumab are no longer working.
  • letrozole (Femara)
    • This combination is used to treat post-menopausal women with HER2-positve and estrogen receptor–positive metastatic breast cancer
    • Letrozole is a type of hormonal therapy.

Colony-stimulating factors

Colony-stimulating factors (CSFs) are used to lessen some of the side effects of cancer treatments, especially bone marrow suppression. They work to stimulate the bone marrow to increase the production of blood cells. This helps reduce the risk of infection, anemia and bleeding because of low blood counts.

Usually, CSFs allow for cancer treatment to proceed at full doses that may otherwise be delayed due to low blood counts. In some cases, having CSF treatment allows higher doses of chemotherapy or radiation therapy to be given.

With breast cancer, CSFs may be given to increase the number of blood cells so that the chemotherapy treatment with certain drugs can continue. They are usually given as an injection into the tissue just under the skin (subcutaneous injection).

The types of colony-stimulating factors that may be given with breast cancer are:

  • Granulocyte growth factors stimulate the production of white blood cells and reduce the risk of infection.
    • filgrastim (Neupogen)
    • pegfilgrastim (Neulasta)
  • Erythrocyte growth factors stimulate the production of red blood cells and are used to treat anemia.
    • epoetin (Eprex, erythropoietin)
    • darbepoetin (Aranesp)

See a list of questions to ask your doctor about biological therapy.


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