Breast Cancer Multidisciplinary Clinic
Lifespan Cancer Institute

Targeted Drug Therapy for Breast Cancer Treatment

Breast cancer can be treated with targeted drug therapy in certain cases. This treatment uses medicines to attack cancer cells without harming normal cells.

What is targeted drug therapy?

Cancer cells have abnormalities and areas of weakness, just as any cell does. Targeted therapy uses these weak areas to destroy cancer cells, block their growth, or prevent them from spreading. Some targeted therapies use antibodies created in a laboratory instead of medicine to target cancer cells in the same way as antibodies made by our immune system.

When is it used?

Targeted drug therapy is most often used for metastatic breast cancer, usually in combination with chemotherapy. Targeted drug therapy is used in three main ways:

To work against HER2-positive breast cancers by blocking the cancer cells' ability to receive signals telling them to grow. This type of therapy also prompts the body to attack the cancer cells on its own and works with chemotherapy to prevent cancer cells from repairing themselves.

To work against HER2-positive breast cancers by blocking the proteins on cancer cells that cause uncontrolled cell growth.

To work against all breast cancers by blocking the growth of new blood vessels in the tumor, which cancer cells depend on to grow and function. Cancer cells will die without new blood vessels and the oxygen and nutrients they bring to the tumor.

How is drug therapy performed?

Targeted drug therapy is administered by infusion, and many times can be combined with chemotherapy for one infusion session. In rare cases, this type of treatment can be given in pill form.

Are there side effects to targeted drug therapy?

Targeted drug therapy can cause side effects, but specific symptoms and their severity depend on the exact medicines used.

Common side effects include:

  • Allergic reactions
  • Difficulty breathing
  • Swelling
  • Nausea
  • Fever/chills
  • Dizziness/weakness
  • High blood pressure
  • Abdominal pain
  • Kidney problems

What should you do if you experience side effects?

Call your doctor or nurse immediately if you have:

  • A temperature higher than 100 degrees Fahrenheit
  • New mouth or throat abnormalities, such as sores or feeling swollen
  • A new cough that produces mucus
  • Changes in bladder function, such as increased frequency
  • Changes in gastrointestinal function that last more than three days

Learn more about treatment options for breast cancer