When it comes to treating cancer, many of us are familiar with treatments such as chemotherapy and radiation therapy which use external forces to help combat the effects of cancer. Immunotherapy, however, seeks to use the body’s own defense system and rally it against the invader. A big advantage to this form of treatment is that while chemotherapy and radiation target cells indiscriminately, immunotherapy can be more precise and target only those cells that have cancer.
How Does Your Immune System Work?
Every person has an immune system that is innate to their own body. This system recognizes substances that are native to your unique body and allows them to continue on with their tasks and get to wherever they’re going. Sometimes, a foreign object called an antigen enters your private domain. This can be anything from something relatively benign like an allergen to something more sinister like a virus. At some point, the antigen attaches itself to a receptor on the immune cells, which causes it to activate your body’s defenses against the invader. When it’s the first time your body has come across this particular invader, your response time might be slower. But the immune cells automatically store the information about what this invader is and how to fight it so the start-up time is much faster the next time it comes across this particular disease.
With cancer, however, your immune system has difficulty recognizing that the cells are invaders, because they very often start out in normal cells. Or they’re not in normal cells but simply are not different enough for the immune system to boot up defense mechanisms. Or the immune system might recognize the cells as invaders, but its defense system might not be strong enough to combat the disease. On top of that, cancer cells can be very sneaky and find their way around your body’s defenses, even if they get activated.
How Does Immunotherapy Work?
The goal of immunotherapy for cancer is to get the body’s own defenses to recognize and fight against cancer cells just like it would any other virus or bacterial infection. To achieve this, there are several different forms of immunotherapy that are being used, researched, and further developed. If you are a candidate for this type of treatment, you and your doctor will discuss the correct form of treatment for your specific situation.
For starters, there actually are such things as cancer vaccines. A vaccine for something like the flu is given to a healthy person to get the immune system to recognize and mount a defense against the flu before you get sick with it. But a cancer vaccine is given to someone who is already sick. It is hoped that by stimulating the defense system, the immune cells will remember this invader and keep working on their own to combat it for a while.
Another type of immunotherapy is immune checkpoint inhibitors. These inhibitors work with the immune system by helping it recognize the cancer cells. T-cell therapy acts like a truffle-sniffing dog. You give the dog the scent of the truffle, and let it loose. When the dog smells the truffle in the ground, he digs it up and gives it to you. Here, T-cells are taken from the patient and mixed with a virus that teaches them how to attach themselves to tumor cells. They are then released back into the patient to sniff out and kill those cells.
Immunomodulators are effective for certain forms of cancer–they are a class of drugs that boost your immune system function. Cytokines are messenger proteins that are used to rally the immune cells into attacking the cancer cells.
How is Immunotherapy Delivered?
There are several different ways to deliver immunotherapy–in an IV directly into your vein, orally in the form of swallowable capsules, topical in the form of a cream (especially effective against skin cancers), or intravesical, directly into the bladder for bladder cancer.
Frequency of treatment depends on your individual status. You could go from every single day to once a month. As with most forms of cancer treatment, immunotherapy does come with side effects, such as pain, swelling, itching, fever, and nausea. However, these side effects are generally treatable.
Thanks to advancements in science, different forms of cancer treatments are constantly being developed and researched, helping to improve the lives of those diagnosed with it.
References
- How does the immune system work? – InformedHealth.org – NCBI Bookshelf
- Immunotherapy for Cancer
- Cancer Vaccines and Their Side Effects
- Side Effects of Immunotherapy – National Cancer Institute
- Introduction to Cancer Therapy (Radiation Oncology)
- Understanding Immunotherapy | Cancer.Net
- Types of chemotherapy: MedlinePlus Medical Encyclopedia
- How Immunotherapy Is Used to Treat Cancer
