Side Effects of Immunotherapy

What is immunotherapy?

Immunotherapy is a type of cancer treatment that works with your body’s immune system to weaken or kill cancer cells. 

What do I need to know about the side effects of immunotherapy?

Immunotherapy works differently than chemotherapy. There are different side effects linked with immunotherapy medications. In some cases, the immune system may not only attack cancer cells but may also attack healthy cells. Some side effects are common and mild, while some side effects can be severe or even life-threatening.  

Side effects can happen at any time during the course of your treatment. Side effects can start shortly after starting immunotherapy treatment, at any time during treatment, or even after treatment is done. Keep in mind that no matter where your cancer started, side effects from immunotherapy can affect almost any of your body. It is also important to talk with your care team about any history of immune disorders since these can make you more at risk of developing side effects due to immunotherapy. 

You and your oncology team will work together to look for side effects before, during, and after your treatment. Remember to tell your care team as soon as you feel or notice a change in your body. Your care team will likely be able to manage and relieve many side effects that you may have, but there are some side effects that need closer monitoring and sometimes other medications. 

What are the most common side effects of immunotherapy?

There are many different immunotherapy medications available. Each one may affect your body in different ways, and at different times during your treatment. Tell your care team about all your medical conditions, including those that are autoimmune in nature (Crohn’s disease, lupus, rheumatoid arthritis, etc.), as these can get worse with immunotherapy. 

Talk with your care team about your treatment plan so that you know about possible side effects, which may include:

• Lung problems: (Pneumonitis- inflammation of the lung) New or worsening cough, shortness of breath, having a hard time breathing, or chest pain. Call your provider right away or call 911.
• Liver problems: (Hepatitis- inflammation of the liver) Yellowing of the skin or eyes, your urine appears dark or brown, pain in your abdomen (belly), bleeding or bruising more easily than normal, or nausea and vomiting that doesn’t go away.
• Diarrhea / Intestinal problems: (Colitis- inflammation of the bowel) Abdominal pain, diarrhea, cramping, mucus or blood in the stool, dark or tar-like stools, fever. Diarrhea means different things to different people. Any increase in your normal bowel patterns can be defined as diarrhea and should be reported to your healthcare team.
• Bowel obstruction or perforation: Abdominal pain, fever, constipation, bloating, and cramping. Any decrease in your normal bowel patterns should be reported.
• Kidney problems: (Kidney inflammation or failure) Decreased urine output, blood in the urine, swelling in the ankles, loss of appetite.
• Skin reactions: Report rash, with or without itching (pruritis), sores in your mouth, blistering or peeling skin, as these can become severe and you may need treatment with corticosteroids.
• Brain and/or nerve problems: Report any headache, drooping of eyelids, double vision, trouble swallowing, weakness of arms, legs, or face, or numbness or tingling in the hands or feet to your healthcare team.
• Pancreas problems: (Pancreatitis- inflammation of the pancreas) Bloating, indigestion, fatty stools, loss of appetite, sweating, abdominal pain, and weight loss. Notify your care provider if you have any of these symptoms.
• Eye problems: Report any changes in vision, blurry or double vision, and eye pain or redness.
• Hormone changes: Immune reactions can affect the pituitary, thyroid, pancreas and adrenal glands, leading to inflammation of these glands. This can affect the production of certain hormones. Some hormone levels can be monitored with blood work. It is important that you report any changes in how you are feeling to your care team. 
  • Symptoms of these hormonal changes can include: headaches, nausea, vomiting, constipation, rapid heart rate, increased sweating, extreme fatigue, weakness, changes in your voice, changes in memory and concentration, increased hunger or thirst, increased urination, weight gain, hair loss, dizziness, feeling cold all the time, and changes in mood or behavior (including irritability, forgetfulness and decreased sex drive). 

Most of these side effects, if caught early, are treatable and can be managed. However, there are times when your provider may need to add medications to support you through symptoms you may have. A commonly added medication is a corticosteroid, which provides relief for inflamed areas of the body. Do not take any medication to treat your side effects without first speaking to your provider. If the side effects of immunotherapy become severe, it is possible that your provider will hold or change your treatment plan. Be sure to talk with your care team during and even after your treatment.