What is Immunotherapy and How does it treat cancer?
While cancer treatment methods like chemotherapy and radiation therapy have been around for a while now, immunotherapy is a comparatively newer field of treatment that showed massive potential in 2018 and well into this year. Plus, recent FDA approval of various immunotherapy drugs has paved the way for better success rates in dealing with many types of breast, prostate, colorectal, ovarian, kidney and lung cancers.
Yet amidst the all the hype, there’s still a lack of clarity around what exactly immunotherapy is, how it works and how effective it actually is.
In this 3 part series, we breakdown all the moving parts of immunotherapy, starting with:
- Immunotherapy Part 1: What Is It and How does it Fight Cancer?
- Immunotherapy for Cancer Part 2: What are the Types of Immuno Treatment Methods
- Immunotherapy for Cancer Part 3: What are the Challenges and Side Effects?
Ready? Let’s go.
What is Immunotherapy?
Immunotherapy as the name implies, are a number of treatment methods that leverage the human body’s immune system to detect and fight against diseases like cancer.
Essentially, our immune cells power our natural defence mechanism. These cells continuously work to recognise and attack foreign and harmful cells that might suddenly start growing in our bodies.
Whenever any new infection or disease like cancer appears in our body, our immune cells immediately detects it and raise a flag! This flag then triggers the actual attack on these cancer cells.
The issue? Cancer cells can camouflage themselves. They hide from immune cells. They can adapt, grow and evolve without getting noticed. Plus, the shear rate at which they multiply can be daunting for our comparatively less in number immune cells.
This is where immunotherapy comes in.
Couple of ways in which immunotherapy is treats cancer are:
- Suppressing the ability of cancer cells to hide themselves from immune cells
- Helping immune cells better detect and “mark” cancer cells
- Boosting immune cells to either get rid of of or slow down cancerous activity
- Cutting off the resources that cancer cells need to survive and grow
As with other cancer treatment methods, patients treated with immunotherapy are monitored by their doctors or oncologists with periodic tests and scans.
How does Immunotherapy work?
To understand how immunotherapy treats cancer, we need to first understand how our immune system functions.
As mentioned earlier, our immune cells already know how to fight against parasites and diseases like cancer. This is essentially due to a simple 4-step process:
- Immune cells monitor and keep track of all the naturally occurring cells and substances found in our body.
- As a result, they find and detect any foreign substance that might suddenly appear.
- Once they detect any such cells or substances, they label or “mark” these cancer cells. This raises a signal and the immune cells that fight cancer migrate to the affected area.
- After migrating to the area, immune cells namely T cells and natural killer (NK) cells either attack, slow down or starve out these cancerous cells.
Unfortunately, cancer cells can mask themselves as naturally occurring cells, making it difficult for immune cells to recognize them. Plus, the rate at which immune cells can destroy cancer cells doesn’t compare to the rapid pace at which cancer cells can divide and multiply.
Now, immunotherapy treatments have been designed in keeping with these challenges.
Delivered to the patient through vaccines, pills or IV, immunotherapy boosts the body’s inherent immune response to cancer in various aspects.
Although a number of immunotherapy treatments are available, the basic principle behind how immunotherapy works is:
1.Collecting and analysing both cancerous and immune cells
First and foremost, for any immunotherapy treatment to work, the cancerous growth needs to be analysed. This is done through scans and tests and in some cases( more on this later) the cells are collected from the affected area.
2. Antibodies, vaccines or inhibitors introduced to find and mark cancer cells that are hiding themselves
Since of the biggest challenge of treating cancer is to actually be able to detect the disease, substances that mimic our immune cells are given to the patient.
These substances latch on and mark cancer cells, which is turn provides an alarm to the immune system. Once marked, it becomes easier for immune cells to recognise cancer cells and launch an attack on them.
3. Modifying and Multiplying immune cells with proteins and other substances
Once the biomarkers do their job, it becomes the responsibility of T cells and Natural Killer Cells to attack the marked cancer cells. However, the shear number of cancer cells can makes this extremely hard.
To combat this, either:
- man-made proteins are introduced (via pills or IV) directly into the patient. These boost the immune cells.
- initially collected immune cells(mainly T cells) are modified and multiplied before being reintroduced in the patient.
In other words, immune cells are modified so they can function smarter, faster and better.
Currently, a few types of immunotherapy treatments are in use and showing tremendous potential. Read more about the different kinds of immunotherapy treatments.
Immunotherapy has generated a lot of buzz in the last few years and with good reason. With the recent approval of viable drugs, countless clinical trials and ongoing research, we can only expect immunotherapy to generate higher success rates and become more mainstream.
Next up: Types of Immunotherapy Treatments(subscribe to our newsletter to get the entire guide)
That said, the global cancer research and oncology community meet this year to discuss the advances and challenges of immunotherapy at the European Congress on Clinical Oncology on 5th October. Grab your own seat at the conference!