A Q & A about Immunotherapy for Breast Cancer

• Cancer treatments are changing all the time. One of the most exciting options is immunotherapy. Researchers are studying who can best benefit from this treatment because research is moving quickly.

  Elias Obeid, MD, MPH, a medical oncologist at Fox Chase Cancer Center, answers questions about immunotherapy and its current role in treating breast cancer.

  Q: What is immunotherapy?

  A: This treatment uses the body’s immune system to fight cancer. Immunotherapy may work by:

  • Slowing the growth of cancer cells or stopping it altogether

  • Preventing cancer from spreading to other parts of the body

  • Enabling the immune system to destroy cancer cells more effectively

  “The most common type of immunotherapy unblocks some of the blockages that cancer puts on our immune cells,” Obeid said. “These blockages stop the immune cells from attacking the cancer cells. Unblocking them means the immune cells can start attacking the cancer cells again.”

  Q: How is immunotherapy used to treat breast cancer?

  A: “Right now we know that triple negative breast cancer and metastatic breast cancer might benefit from this treatment,” Obeid said. “Most studies have not been very conclusive, but they are pointing to some benefit.”

  To determine whether you're a good candidate for immunotherapy trials or treatments, doctors look for certain biomarkers. Biomarkers are any measurable characteristic of your body and this includes certain proteins and gene mutations that affect your cancer risk.

  The immunotherapies available for breast cancer depend on biomarkers found within a tumor. 

  Q: How can someone with breast cancer research his/her immunotherapy options? 

  A: Talk to your medical oncologist. And ask the right questions.

  “Patients should be checking to see if they are candidates for any clinical trials,” Obeid said. “Most clinical trials are going to provide something more than the standard of care. It’s the standard of care—such as chemotherapy or radiation therapy—plus something else, like immunotherapy.”

  Obeid also encourages anyone who has been diagnosed with a metastatic cancer to get tested for the expression of the biomarker microsatellite instability or MSI. People with this marker are often good candidates for immunotherapy, no matter what kind of cancer they have.

  Q: How is immunotherapy given?

  A: It depends on the drug. Immunotherapy can be injected, given as pills or a vaccine, or administered topically as a cream. You could receive treatment in your doctor’s office or in the outpatient unit of a hospital.

  How long you receive treatment depends on your cancer, the type of immunotherapy, and how your body responds to treatment.

  Q: Does immunotherapy have side effects?

  A: Like many drugs, these therapies affect people in different ways. Your health before treatment, the type of cancer you have, and the dose of the immunotherapy all play a role in side effects.

  In general, the most common side effects are skin reactions at the injection site. You may also experience flu-like symptoms.

  Learn more about immunotherapy at Fox Chase Cancer Center.