Immunotherapy Side Effects If you are currently experiencing side effects or unusual symptoms after receiving immunotherapy, contact your doctor immediately. Immunotherapy side effects may be different from those associated with conventional cancer treatments because they result from an overstimulated or misdirected immune response rather than the direct effect of a chemical or radiological therapy on cancer and healthy tissues. Immune-related side effects can, in principle, affect any tissue or organ in the body. These side effects can range from mild to moderate or severe and can become potentially life-threatening under certain circumstances. Fortunately, in most cases potential immunotherapy-related side effects can be managed safely with immunosuppressive drugs such as steroids as long as the potential side effects are recognized and addressed early. It is extremely important for patients to inform their medical care team as soon as possible if they experience any unusual symptoms during or after treatment with cancer immunotherapy. Common side effects of immunotherapy Immunotherapy side effects can vary according to the type of treatment and can also be influenced by the location and type of cancer as well as a patient’s overall health. Before treatment, patients should consult their oncologist and care team to gain a better and fuller understanding of the potential side effects and potential risks associated with specific immunotherapies. In general, the side effects most commonly experienced across the spectrum of the current FDA-approved immunotherapies may include but are not limited to: Arthritis Chills Constipation Coughing Decreased appetite Diarrhea Fatigue Fever and flu-like symptoms Headache Hypopituitarism Hypothyroidism Infusion-related reaction / injection site pain Itching Muscle aches Nausea Rash Vomiting Explore side effects specific to certain types of immunotherapies Severe side effects of immunotherapy While severe side effects are uncommon, when they do occur they may be life-threatening and require immediate medical intervention. Most of these severe side effects are linked to inflammation, and may include but are not limited to: Colitis Hepatitis Inflammation of the lung, or pneumonitis Kidney failure Myocarditis or inflammation of the heart Neuropathy, paralysis, meningitis, or encephalitis Pancreatitis Severe infections Severe skin reactions Type 1 diabetes Side effects for immunotherapy vs other cancer treatments Side effects vary according to each therapy and how it interacts with the body. While immunotherapy’s side effects stem from the immune system, other cancer treatments have a range of side effects with a wide range of risks and severity. Chemotherapy Side Effects The intended purpose of chemotherapy is to target growing cancer cells, so it may cause collateral damage to other growing normal cells in your body, such as hair follicles, taste buds, or the lining of the stomach or gut. Common side effects of chemotherapy may include but are not limited to: diarrhea, fatigue, hair loss, nausea, and skin rash. Learn more about the differences between immunotherapy and chemotherapy. Hormone Therapy Side Effects Hormone therapy disrupts hormone signaling in the body, either by blocking the production of hormones or preventing their activity once they’re produced. For women being treated for breast cancer, common side effects may include but are not limited to: decreased sex drive, fatigue, hot flashes, menstrual cycle changes, mood swings, nausea, and vaginal dryness. For men being treated for prostate cancer, common side effects may include but are not limited to: decreased sex drive, diarrhea, fatigue, hot flashes, increased size and sensitivity of breasts, nausea, and weakened bones. Radiation Therapy Side Effects Radiation uses radioactive particles to destroy cancer cells in a localized area, so it may damage other healthy cells in that area. Side effects may often be associated with the area of treatment, and may include difficulty breathing when aimed at the chest, or nausea when aimed at the stomach. Skin problems and fatigue are common. Surgery Side Effects The goal of surgery is to remove the cancerous tumor or tissue and varies according to the type of surgery performed. Common side effects may include but are not limited to: fatigue, numbness, pain, risk of infection, and swelling. Frequently asked questions How soon and how often should I expect to experience immunotherapy side effects? There is no set window of time during which patients might experience side effects from immunotherapy. Some immunotherapy side effects, such as infusion-related reactions or injection site pain, can occur shortly after treatment is administered. However, because immunotherapy treatments can take time to “kick in” and impact immune cell activity, most side effects may not occur until weeks or months or longer after treatment. As with time of onset, there is no standard frequency with respect to how often immunotherapy side effects occur, although frequency may depend on a particular patient’s treatment regimen (i.e., how often and how many treatments they receive). In general, the earlier side effects are reported and addressed, the better the chance that the side effects can be effectively managed in order to lessen their frequency and duration and minimize potential pain, discomfort, or damage. The likelihood of side effects is higher with combination immune therapies than single agents. What symptoms should I look out for? Some of the most common side effects associated with immunotherapy treatment may include but are not limited to: chills, constipation, coughing, decreased appetite, diarrhea, fatigue, fever and flu-like symptoms, headache, infusion-related reaction or injection site pain, itching, localized rashes and/or blisters, nausea, rash, shortness of breath, vomiting, and weight loss. If you experience any of these side effects, or any unusual changes to your health, you should notify your healthcare team as soon as possible. How long do immunotherapy side effects last? The long-term side effects of immunotherapy vary from patient to patient. While the majority of immunotherapy side effects often can be temporary and reversible, some of side effects may persist after treatment because immunotherapy can influence the activity of immune cells that remain in the body long after the drug has been cleared from the patient’s system. In rare cases, the consequences of immunotherapy side effects may be permanent. How are immunotherapy side effects treated or managed? Depending on the treatment, immunotherapy side effects can be treated in a number of ways. For example, patients may be taken off treatment, either temporarily or permanently, in order to allow the immune activity to quiet down. Additionally, especially with checkpoint inhibitor immunotherapies, patients may receive steroids or immunosuppressive antibodies as a more active measure in order to dampen immune activity and minimize potential damage from any further autoimmune reactions. In the case of the cytokine release syndrome (or cytokine storm), among potential CAR T cell therapy side effects, doctors may administer drugs to block the activity of certain cytokine signaling pathways, such as interleukin-1 (IL-1) or interleukin-6 (IL-6). In general, many of immunotherapy’s potential side effects can be managed with early intervention. Therefore, it is important for patients to report any adverse changes in their health or overall well-being to their healthcare team as soon as they are aware of them. Do side effects mean the immunotherapy is working? More work still needs to be done to definitively answer this important question, although some recent studies have found that patients who experience low-grade side effects after immunotherapy may be more likely to have better outcomes. How do doctors monitor side effects? There are a number of ways for doctors to monitor side effects. Patients, however, will often be aware of changes in their own bodies before their doctors have a chance to monitor and detect any side effects. It therefore is important for patients to report any adverse changes in their health or overall well-being to their healthcare team as soon as they are aware of them. When should I inform my doctor of side effects? Patients should notify their doctors as soon as they can if they experience any noticeable changes in their external body appearance, their health, or their overall physiological state after being treated with immunotherapy. The earlier side effects are reported and addressed, the better the chance that they can be effectively managed in order to minimize potential pain, discomfort, or damage. Should I speak with patients who have been treated with immunotherapy about their side effects? Cancer patients often help inform their fellow patients about their experiences. Gain a different perspective on side effects from patients who have been treated with various immunotherapies and discover how they managed side effects. Read patient immunotherapy side effects experiences Reviewer: Jeffrey S. Weber, MD, PhD, NYU Langone Health Sources: U.S. Food and Drug Administration (FDA) Online Label Repository; National Cancer Institute (Hormone Therapy); National Cancer Institute (Stem Cell Transplant) Updated November 2019 *Immunotherapy results may vary from patient to patient. Consult a healthcare professional about your treatment options. 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