Breast Cancer: Immunotherapy

What is immunotherapy?

Immunotherapy is the use of medicines to help your body’s immune system fight cancer. The medicines help boost your immune system in ways that help it find and kill cancer cells. It’s not the same as chemotherapy (chemo). Immunotherapy medicines work in different ways. They can cause different side effects.

When is immunotherapy used for breast cancer?

Your doctor can tell you if immunotherapy is right for you. Immunotherapy may be used for certain types of breast cancer. It may be used in these ways:

• With chemo before surgery and on its own after surgery, to help prevent the cancer coming back

• With chemo if this cancer has come back and has spread, or can’t be removed with surgery

• To treat certain advanced breast cancers when other treatments aren’t an option

Your cancer doctor will tell you what your cancer status is. They will talk with you about the treatment plan that makes sense for you.

What immunotherapy medicine is used for breast cancer?

The type of medicine available is called an immune checkpoint inhibitor. This type of medicine blocks proteins on cancer cells that stop them being killed by the immune system. Checkpoint inhibitor medicine helps the immune system find and attack cancer cells.

There are different medicines that block different proteins. Immunotherapy medicines for breast cancer include pembrolizumab (Keytruda) and dostarlimab-gxly (Jemperli).

These medicines are given by intravenous (IV) infusion every 3 or 6 weeks.

What are possible side effects of immunotherapy?

Immunotherapy may have fewer or different side effects than chemo. Side effects can vary for each person and depend on the medicine and dose you receive. Your healthcare team will work with you during treatment to manage any side effects you have. It is common to have more than 1 side effect. Side effects can include:

• Tiredness

• Cough

• Skin rash, itching, and dryness

• Diarrhea

• Constipation

• Nausea, vomiting, or loss of appetite

Less often, you may have an infusion reaction, such as fever, chills, flushing, rash, dizziness, and trouble breathing. Tell your care team right away if you have any of these symptoms.

In rare cases, immunotherapy can cause the immune system to attack healthy tissues. This is called an autoimmune reaction. It can lead to side effects that affect various organs. Your doctor will tell you what signs and symptoms to look for. Report these to your care team right away if you have them.

Report side effects to your care team right away. If you have serious side effects, they may stop your treatment and give you corticosteroid medicine to suppress your immune system.

How to work with your doctor

• Learn your medicines. Write down the names of all your medicines. Ask your doctor how they work and what side effects they might cause.

• Ask what symptoms to watch for. Ask your doctor when to contact them.

• Find out what number to call with questions or problems. Ask if there is a different number to call when the clinic is closed, such as on weekends or holidays.

• Keep a diary of your side effects. Write down physical, thinking, and emotional changes. A written list will make it easier for you to ask questions at appointments. You can work with your doctor on a plan to manage your side effects.

During your treatment

You are an important part of your own care team. During this time, make sure to:

• Talk with your healthcare team. Discuss any concerns, side effects, or changes in your condition right away with your team.

• Stick to your treatment schedule. Follow the treatment plan and don’t miss appointments.

• Keep all follow-up appointments. This is to make sure the treatment is working.

• Practice self-care. Focus on your well-being by keeping a healthy lifestyle. Eat healthy foods, and move your body every day.

• Ask for support. Reach out to friends, family, and support groups. Share your experiences and get emotional help during your treatment journey.