Cancer immunotherapy harnesses the immense power of the body’s own immune system to attack and destroy cancerous cells. The immune system is normally highly effective at protecting the body against infection by recognizing and eliminating many harmful invaders, such as bacteria and viruses. Although cancerous cells are also harmful invaders, some have unique properties that allow them to disguise themselves as healthy cells and evade detection by the immune system. As a result, tumors can more easily grow and spread throughout the body.

Immunotherapy drugs work by “teaching” the immune system to recognize, “remember” and continually attack cancerous cells. The resulting “immunomemory” can provide lasting protection against a cancer recurrence, even long after the treatment ends.

Does immunotherapy have side effects?

Like any cancer treatment, immunotherapy can have both short- and long-term side effects. Although the treatment is designed to help the immune system identify and attack cancerous cells, the immune response is sometimes overly robust. As a result, the immune system may mistakenly attack healthy cells in addition to cancerous cells. Known as an immune-related adverse effect, this can cause inflammation throughout the body. Depending on the type of immunotherapy used and the area of the body affected by the inflammation, the side effects can vary:

Skin

An allergic reaction in the skin can cause:

Itchy rashes
Cracks and blisters
Painful sores and ulcers
Photosensitivity

Liver

Inflammation in the liver can lead to hepatitis, which can cause:

Jaundice
Dark-colored urine
Stomach pain on the right side
Nausea and vomiting
Easy bleeding and bruising

Gastrointestinal system

Inflammation in the gastrointestinal tract can lead to colitis, which can cause:

Diarrhea
Stomach pain
Bloody, dark, tarry or slick stools

Lungs

Inflammation in the lungs can lead to pneumonitis, which can cause:

Coughing
Chest pain
Shortness of breath

Endocrine system

Inflammation in the endocrine system can cause hormonal imbalances, such as hypothyroidism and hyperthyroidism. The symptoms can include:

Hair loss
Dizziness
Headaches
Constipation
Overwhelming fatigue
Weight fluctuations
Excessive sweating
Rapid heartbeat
Faintness
Increased hunger or thirst

Brain

Inflammation in the brain can lead to encephalitis, which can cause:

Fever
Stiff neck
Unusual behavior
Moodiness
Seizures
Light sensitivity

Nervous system

Inflammation in the nervous system can lead to neuropathy, which can cause uncomfortable symptoms in the face, hands and feet, such as:

Muscle weakness
Numbness
Tingling sensations

Cardiovascular system

Inflammation in the cardiovascular system can cause:

Arrhythmias
Myocarditis
Pericarditis
Vasculitis

Joints

Inflammation in the joints can lead to arthritis, which can cause:

Joint pain
Joint swelling

Most side effects of immunotherapy are short-lived and relatively mild. However, some are long-term or potentially serious and therefore warrant immediate medical attention. It is important to discuss any side effects with a physician, who may pause the immunotherapy, prescribe an immunosuppressant to lessen the immune response or suggest other ways to manage the resulting inflammation.

How Moffitt Cancer Center approaches immunotherapy

Firmly positioned on the leading edge of cancer treatment, Moffitt is proud to offer the latest options in personalized medicine, including immunotherapy. Our multispecialty team provides outstanding, individualized care to each patient, carefully evaluating their progress and continually finetuning their treatment as necessary to achieve the best possible outcome and quality of life.

If you would like to explore the immunotherapy options available to you at Moffitt—which may include groundbreaking clinical trials—you can request an appointment by calling 1-888-663-3488 or completing a new patient registration form online.

Immunotherapy FAQs