Medicines are used to treat breast cancer and also to help relieve side effects of treatment.

Chemotherapy

A combination of medicines is typically used to treat breast cancer. The number of cycles of treatment will depend on the medicines that are used and how the medicines are given. Chemotherapy often uses several medicines together. Some of the most commonly used medicines are:

• Carboplatin.
• Cyclophosphamide.
• Docetaxel.
• Doxorubicin.
• Fluorouracil.
• Paclitaxel.

Breast Cancer: Should I Have Chemotherapy for Early-Stage Breast Cancer?

The side effects of chemotherapy depend mainly on the medicines you receive. As with other types of treatment, side effects vary from person to person. Your doctor may also prescribe medicines to control and prevent nausea and vomiting.

Hormone therapy

Tamoxifen or an aromatase inhibitor is recommended for estrogen receptor-positive (ER+) breast cancer. These medicines stop estrogen from fueling ER+ breast cancer.

• Tamoxifen is a medicine that blocks the effect of estrogen on breast cancer cells and normal breast cells. But this medicine may also increase other risks, such as for endometrial cancer, stroke, and blood clots in veins and in the lungs.
• Aromatase inhibitors, such as letrozole (Femara), anastrozole (Arimidex), and exemestane (Aromasin), are medicines that stop estrogen production in postmenopausal women. Aromatase inhibitors are used to treat early estrogen receptor-positive (ER+) breast cancer. They are also used to treat metastatic or recurrent ER+ breast cancer. An aromatase inhibitor can be used alone or after tamoxifen treatment.

Hormone-blocking treatments, such as tamoxifen or an aromatase inhibitor, may cause fewer side effects than chemotherapy. If you are deciding what type of medicine to use, weigh the benefits and risks of these medicines for your type of cancer.

Targeted therapies

Targeted therapies use medicines or substances that go directly to the cancer cells and don't harm normal cells. They include monoclonal antibodies and tyrosine kinase inhibitors.

• Trastuzumab (Herceptin) is recommended after surgery and chemotherapy for HER-2/neu breast cancer. This medicine is a monoclonal antibody that targets the HER-2 protein. It helps chemotherapy work better.
• Lapatinib, a tyrosine kinase inhibitor, may be used to treat women who have HER-2+ cancer that has progressed even after they have taken trastuzumab.
• PARP inhibitor therapy is another kind of targeted therapy for triple-negative breast cancer (cancer cells that do not have estrogen or progesterone receptors or large amounts of HER2/neu).