How Our Immune Systems Are Used to Treat Cancer

Our immune system best recognizes threats that originate outside of the body rather than abnormalities that originate from within, so our natural defense system doesn’t normally detect cancer. In addition, cancer cells themselves can give off substances that keep the immune system from finding and destroying them. The immunotherapy treatments being used today are ways of “waking up” our immune system, either by stimulating the patient’s own natural defenses or by using lab-made substances to assist our immune system. This enables the body to recognize and fight cancer in ways that it normally wouldn’t be able to do. 

The Benefits of Immunotherapy 

One reason cancer cells can keep growing and spreading is that they are able to hide from your immune system. So a key benefit of certain immunotherapy treatments is how they can "mark" your cancer cells. This makes it easier for your immune system to find and destroy specific cells, with less harm to healthy cells. Other types of immunotherapy work by boosting your immune system to better mobilize against cancer.

As a biological therapy, immunotherapy side effects are generally less than other treatments: No hair loss and less fatigue. Sometimes the side effects are superior to those of older chemotherapies. Doctors don't yet use immunotherapy as often as other cancer treatments, such as surgery, chemotherapy and radiation, but sometimes use it in conjunction with chemotherapy to augment the response your body will have. The most common side effects of immunotherapy are skin reactions at the needle site, if given intravenously (IV). Other side effects may include flu-like symptoms. Severe reactions are rare.

Immunotherapy vs. Traditional Treatments

The optimal cancer treatment for you depends on the type of cancer you have and its stage, or how far it has spread. Your doctor will consider your age and any other health problems you may have when deciding upon treatment methods. The CDC provides a detailed list of cancer treatments, including surgery, chemotherapy, radiation therapy, hormone therapy and stem cell (bone marrow) transplant, as well as immunotherapy. Sometimes immunotherapy is favored over chemotherapy, and other times the treatments are used together — the protocol depends on your particular situation. 

Immunotherapy may be delivered by IV, or in pills or a skin cream. It may be given on a daily, weekly or monthly basis, or in cycles. Again, protocols depend upon your type of cancer, how advanced it is, the type of immunotherapy you get and how well it is working. 

Advice for Cancer Patients

Recently, immunotherapy has become a crucial aspect of treating certain cancers. New immunotherapy treatments are being tested and approved, and new ways of working with the immune system are rapidly being discovered. Talk to your physician about your treatment options. Keep in mind that immunotherapy doesn’t work for every cancer, and certain patients may not be good candidates, including those who take certain medications or have autoimmune conditions, for example.