When former President Jimmy Carter announced that his doctors could no longer find evidence of melanoma in his body, he brought public attention to a groundbreaking type of cancer treatment. One of the treatments he received was immunotherapy, which helps the body’s immune system fight cancer. Though the study of immunotherapy is more than a century old, the field has seen rapid advances in the past few years, and it has the potential to dramatically change cancer treatment. In Carter’s case, doctors combined an immunotherapy drug with surgery and radiation therapy. Within months, this approach eliminated the cancer in Carter’s liver and brain.
Immunotherapy is one of the major focuses of cancer research today, and results like these are being recognized by some very visible advocates. In his 2016 State of the Union speech, President Barack Obama asked Vice President Joe Biden to lead Cancer Moonshot, a plan aimed at making 10 years’ worth of progress in cancer research within five years. The Moonshot goals are to improve treatment as well as find cancer earlier and prevent it when possible.
As part of this initiative, the National Cancer Institute (NCI) committed to 10 recommendations a commission of scientists believe will help meet the goal. One of the recommendations is to create a national network of cancer immunotherapy clinical trials, which would help researchers share information as they find and test new treatments. NCI also plans to form a similar network specifically for pediatric immunotherapy clinical trials to speed the process of testing immunotherapy in children.
Although immunotherapy is making notable progress, the work of researchers continues. The U.S. Food and Drug Administration has approved a number of immunotherapy drugs, with more in the pipeline. Immunotherapy is quickly becoming a standard first-line treatment for some types of cancer, and clinical trials are ongoing in every cancer type.
In addition to showing how immunotherapy can fight cancer, research also focuses on personalizing treatment. Recent studies explore how doctors can best predict outcomes for specific patients with specific drugs. These studies also may help doctors understand why some immunotherapies work for certain people but not for others.
As treatment strategies continue to evolve, some doctors point to prevention as the next big leap toward eliminating cancer. The vaccine for human papillomavirus (HPV), which has been successful at protecting against some cancer strains, might become a model for the development of more vaccines, which could engage the immune system’s defenses before cancer begins.
Ask your doctor about immunotherapy and if it is an option for you. The more you know, the more prepared you will be to make informed treatment decisions.
The 3 E's: Cancer vs. The Body
In the 1950s, some researchers thought that in addition to protecting your body against bacteria and viruses, the immune system looked for abnormal cells and killed them before they could become tumors. This theory, called cancer immunosurveillance, was initially rejected. In the last 10 years, however, studies have shown that immune cells are indeed important in the prevention of cancer. Although tumors may develop in a functioning immune system, the way a tumor grows and develops is influenced by the body’s immune response. Based on this new evidence – and confirmed by mouse tumor studies conducted by Dr. Robert Schreiber – the theory has been renamed “cancer immunoediting.”
The three E's of Dr. Schreiber’s theory of cancer immunoediting are elimination, equilibrium (balance) and escape.
ELIMINATION. The immune system sees and destroys cancer cells. In this phase, our bodies may be regularly introduced to cancerous changes, and our immune systems are capable of handling and eliminating them.
EQUILIBRIUM. If the cancer cells are not destroyed right away, they may exist in a delicate balance between growth and control by the immune system. During equilibrium, the body’s immune system is able to keep the cancer cells in check but unable to kill them completely. In this phase, a tumor may remain dormant for an unknown length of time and evade medical testing. According to the theory, however, the constant interactions between the tumor cells and the T-cells of the immune system may lead to tumors that can adapt to the immune response (see Immune System for more information). This means the immune system may no longer be able to find tumors and attack them. Tumors that avoid the immune response can no longer be controlled and move on to the third phase.
ESCAPE. The escape phase refers to the disruption of equilibrium that leads to immunosuppression. This allows tumors to escape and begin growing in an environment of immune “tolerance.” It’s at this point that the symptoms of cancer begin to appear. Tumors in the escape phase use a number of methods to alter the body’s immune response in a way that allows them to grow.