Cancer immunotherapy (CI) is a category of cancer treatments whose goal is to stimulate the body’s own immune system to find and fight cancer cells and malignant tumors. Because CI encourages the body itself to fight the disease, researchers believe it holds the promise of delivering safer, more effective cancer treatments, cures, and preventive measures.
The human immune system, on its own, normally does detect and destroy cancer cells as they appear. But sometimes, the occurrence of these cancer cells overwhelms a person’s immune system, and disease and tumors develop. Cancer immunotherapy boosts the immune system’s ability to wage this fight, and when successful, gives it back the upper hand. While research into CI has been taking place for decades, advancements in the field have now allowed it to take its place next to the better-known, long-standing categories of cancer treatments – such as surgery, radiation therapy, and chemotherapy - as an effective cancer fighter.
More excitingly, many in the scientific community now believe that as it develops and evolves, cancer immunotherapy’s significant advantages may allow it stand out among the other categories of cancer treatment.
What exactly are these advantages?
Its Power.
Because cancer immunotherapy employs the body’s immune system, it has the advantage of being a powerful treatment since the cancer is attacked systemically throughout the body. This differs from surgery, for example, which can only be performed on specific parts of the body to remove tumors.
Its Specificity.
Some types of cancer immunotherapy also employ greater precision in attacking cancer cells, causing fewer and less objectionable side effects. The immune system is trained to attack only cancer cells, not healthy cells, as chemotherapy and radiation therapy often do.
Its Durability.
Once the immune system is properly stimulated and “trained” to fight cancer cells, it can maintain this ability over time and remember how to fight them. So, unlike surgery, radiation therapy, and chemotherapy that act on the body for a limited period of time, cancer immunotherapy maintains its effectiveness over time.
Its Applicability.
With continued research, cancer immunotherapy should be effective for use against almost all types of cancers.
It’s important to remember that the term, “cancer immunotherapy,” refers to a category of cancer-fighting treatments. The five most common, cancer immunotherapies currently in use are:
1. Monoclonal Antibodies – These are antibodies made in the lab that can stop cancer. Antibodies protect against bacteria, viruses, and cancers. They bind to antigens (molecules on the surfaces of harmful cells) and mark their targets for destruction by other cells in the immune system. They also prevent growth signals from binding to cancer cells and telling them to grow.
2. Checkpoint Inhibitors – These prevent cancer cells from binding to the immune system’s “braking” receptors. Since the immune system’s “stop signals” aren’t activated, the immune system’s killer T-cells are allowed to “go,” attack, and destroy the cancer cells.
3. Cancer Vaccines – Not just used to prevent viruses that lead to cancer (like HPV and cervical cancer), these can be used to stimulate the immune system’s response to treat cancer that’s already present in the body.
4. Adoptive Cell Therapy – T-cells are removed from the body, grown in the lab, and reinjected into the patient in much larger numbers. In CAR T-cell therapy, an antibody is joined to a T-cell receptor making the T-cell a “super” cancer fighter.
5. Oncolytic Virus Therapy – Viruses are used directly to target and infect cancer cells, causing them to burst and die. When they burst, antigens are released into the body, which alert the immune system’s T-cells to seek out and kill more cancer cells.
For more detailed information about cancer, the immune system, and cancer immunotherapy, take a look at this publication from the Cancer Research Institute entitled “Cancer and the Immune System – The Vital Connection.”
It discusses cell division and the way cancer develops, the connection between innate and adaptive immunity, the differences between humoral and cellular immune response, and the five cancer immunotherapies highlighted above.
