Immunotherapy (AKA Immuno-Oncology) 101

Currently, Canadian breast cancer patients are presented with a standard of care that often includes treatments like chemotherapy, radiation, surgery, and hormone therapy. We have even seen breakthrough targeted treatment drugs like trastuzumab (Herceptin) and CDK4 inhibitors, but breast cancer is still the second leading cause of death in females (under age 50) next to lung cancer. So what is the new frontier for breakthrough cancer treatment? A new type of treatment is currently in the works, known as Immuno-Oncology (immunotherapy), that causes less damage to surrounding healthy tissue and target tumors that modern technology is incapable of even recognizing. Here is what you need to know!

What is Immuno-Oncology?

Immuno-Oncology (I-O), sometimes known as cancer immunotherapy or just immunotherapy, is a method of treatment that activates your body’s natural immune system to fight cancer cells more efficiently and effectively. While naturally fighting off viral, bacterial and fungal infections, your immune system can be re-directed to target cancerous cell growth through intervention with synthetic, or natural materials.

How does it work?

In order for the immune system to provide an effective defense, it must first be able to identify these cancerous cells. Immunotherapy allows the body to recognize these cells, and stimulate a subsequent immune response. The immune system can be tricked by cancer cells. Cancer cells are mutated from normal cells and they develop ways to escape from being recognized by immune system detector cells. In addition, immune system fighter cells can be deactivated by cancer cells.

How does it differ from chemotherapy?

Chemotherapy works by targeting, and killing, cells that are in the process of cell division. While all cells go through this process, the rapid life cycle of cancer cells lends its self to a much higher frequency of division. Unfortunately, other cells such as hair follicles, and gastro-intestinal cells also grow at this fast pace, making them more susceptible to the effects of chemotherapy drugs. Unlike Chemotherapy, immunotherapy aims to increase the capabilities of the immune system, by promoting the body’s natural defense mechanisms, rather than killing the cancer directly. While its affects are not yet as conclusive as the former, immunotherapy has greater potential to be customized to individual cases.

Are there promising immunotherapy trials for breast cancer?

There are many ongoing clinical trials researching the application of immunotherapy as a breast cancer treatment option. In particular, there are two studies currently under way assessing the efficacy of a combination of immunotherapy, and chemotherapy. These trials are incredibly important, as they allow new treatment methods to enter the global market, and may positively impact those who have not responded to traditional treatment methods. (More information on these trials is located here and here)

How does one become eligible for such trials?

Each trial will have its own set of specification, and eligibility criteria for determining participants. These qualifications may include past treatment methods, the type of breast cancer they are looking to treat, as well as the stage the cancer has progressed to. There are a wide variety of trials available, so it’s important to do your research, and consult your health care team to be sure the trial is right for you.

What is the future potential of immunotherapy?

While immunotherapy is relatively new in its application of treating breast cancer, we’ve seen great results with its other uses in treating other types of cancers including melanoma and lung cancer. Clinical trials are an important part in determining immunotherapy’s potential as a breast cancer treatment method, and whether it could become the potential standard of care down the line.

What are the potential challenges or pitfalls?

Although it’s exciting to consider the benefits of this course of treatment, it’s also important to explore the downsides. Unfortunately, the efficacy of immunotherapy is difficult to predict, only rendering positive results in specific types of cancer, where success rates have still been low. Additional clinical trials will be required to determine other biomarkers, while resistance to these therapies, high treatment costs, and potential patient reactions, present further barriers to success.