The U.S. has around 60,000 new cases of kidney cancer each year, and renal cell carcinoma (RCC) is by far the most common type in adults. Many patients opt for surgery to remove the cancer. Those who can’t or choose not to have surgery may not have successful results with chemotherapy or radiotherapy. In these cases, people may try targeted immunotherapy instead. Renal cell carcinoma immunotherapy is often the first choice for treating advanced kidney cancer. RCC immunotherapies can come with serious side effects, so it’s important to know what to expect before choosing this kidney cancer treatment option. Types of Immunotherapy for RCC Immunotherapy is also sometimes called biologic therapy because it uses the body’s own biological defense—the immune system—to help fight cancer cells. It can use natural or man-made materials to improve the effectiveness of the immune system. Types of renal cell carcinoma immunotherapy include: Interleukin-2: This is a type of cytokine, which is a hormone produced by white blood cells. The man-made version interleukin-2, or IL-2, improves immune system function and has been shown to shrink kidney tumors. Doctors have recommended this immunotherapy for advanced stage renal cell carcinoma for a long time, but because it comes with severe side effects, it’s now reserved for people who are healthy enough to tolerate them. Still, only a small number of people respond well to IL-2 treatment. Those who do respond, however, often have long-term benefits from the immunotherapy. Interferon-alfa: This treatment is also a type of cytokine and is used to treat metastasized kidney cancer. It has been shown to result in fewer, less severe side effects than interleukin-2. Unfortunately, it’s often not as effective as IL-2. Interferon-alfa may be used in combination with targeted drug treatments, which appear to improve its effectiveness. Immune checkpoint inhibitors: The body’s normal immune system uses certain proteins, called immune checkpoints, to make sure it doesn’t attack healthy cells. Sometimes cancer cells deceptively use these proteins to prevent an attack from the body’s immune system. Using immune checkpoint inhibitors blocks the proteins and allows the immune system to recognize and attack cancer cells. Side Effects of Immunotherapy Treatment Immunotherapy treatments are often given in high doses, which can result in some severe side effects. They can be fatal, but that’s rare. Each type of immunotherapy comes with its own specific side effects. Side effects will be different for every person, so talk to your doctor about managing adverse reactions to kidney cancer immunotherapy. Interleukin-2 side effects This type of RCC immunotherapy comes with the most severe side effects, but most people don’t experience all of them. Possible side effects include: Flulike symptoms, such as fever, chills, nausea and diarrhea Difficulty breathing or fluid buildup in the lungs Intestinal bleeding Rapid heartbeat or heart attack Lowered blood pressure Kidney damage Cognitive changes Interferon-alfa side effects These side effects are usually much less serious than those for IL-2. They include: Flulike symptoms Achiness Fatigue Immune checkpoint inhibitor side effects Because this immunotherapy works by liberating the body’s immune system, sometimes immune cells may begin attacking healthy cells. These symptoms are less common than other side effects, but they can indicate very serious problems with the lungs, liver, kidneys or intestines. It’s crucial to tell your doctor if you experience any new side effects because you may need to stop immune checkpoint inhibitor treatment if your immune system starts attacking healthy cells. Some of the more common, and less serious, side effects of immune checkpoint inhibitors include: Nausea, diarrhea or constipation Cough Loss of appetite Itching or skin rash Joint pain Fatigue Researchers continue to study renal cell carcinoma immunotherapies, conducting clinical trials to find new kidney cancer treatment options. On the horizon may be cell-based therapies, cancer vaccines, and new combinations of different immunotherapies and targeted therapies to improve patient outcomes.