Exercise, along with diet and nutrition, benefits cancer patients in many ways. The body strengthens prior to treatment and recovers quicker after surgery or chemotherapy. Mental health and quality of life also improves with regular physical activity.
Is there a deeper biological effect from exercise? Is exercise one of the ways to make the immune system stronger?
Scientists in Denmark have started a clinical trial to test if high-intensity aerobic exercise and training can mobilize immune cells. Can the immune system react quicker and more effectively to cancer treatment if the patient is working up a sweat? If the answer is yes – that exercise turns on some switch for the immune system – then it’s another reason to exercise before treatment starts, during treatment and even after treatment ends.
The study is specifically for non-small-cell lung cancer, which is the most common type of lung cancer. However, the results may translate to other types of cancer, including the rare cancer mesothelioma.
Mesothelioma and lung cancer share many similarities, including proximity in where they form. Mesothelioma most often starts in the pleural lining, which is a thin layer of tissue near the lungs.
Mesothelioma and lung cancer share another link: asbestos. Mesothelioma is only caused by asbestos. A percentage of lung cancer cases are due to asbestos exposure.
While the clinical trial is solely for lung cancer, any benefit exercise creates for the immune system would translate to the immune cells fighting mesothelioma as well.
How the Immune System Works
The immune system is made up of fighter cells tasked with protecting the human body from unwanted diseases, infections and other intruders. These cells are usually T cells and natural killer (NK) cells.
Cancer is a tricky opponent for T cells and NK cells, though. Mutated cancer cells often subdue the cells in various ways or slow down their response to cancer, usually thanks to a phenomenon called the tumor microenvironment. This environment includes mutated genes, cancerous proteins and other biological elements with the capability of stifling immune activity.
An example is tumor cells can tire T cells and NK cells, eventually exhausting the cells. This allows the tumor to spread without resistance. Another example is cancer cells possess specific protein receptors that link to T cell proteins to shut down the immune cells.
Lung Cancer and Mesothelioma Versus the Immune System
Lung cancer is the third most common type of cancer, with more than 2 million cases worldwide each year. Non-small-cell lung cancer is credited with 85% of all lung cancer cases. The five-year survival rate is around 25%.
Mesothelioma affects around 2,500 people in the U.S. each year. The five-year survival rate is less than 10%, and the median survival is usually around 10-14 months.
Immunotherapy for mesothelioma and lung cancer is growing in popularity among patients and doctors. Immunotherapy aims to help the immune system naturally, without the cell destruction caused by chemotherapy. There are a handful of immunotherapy drugs approved for non-small-cell lung cancer. Opdivo and Yervoy are approved for malignant mesothelioma.
Since immunotherapy is becoming more relevant, exercising regularly may work in conjunction with therapy.
High-Intensity Exercise Makes Immune Cells More Active
Researchers in Denmark expect regular exercise to cause “an adrenalin-mediated increased influx of T and NK cells into the tumor, altering the tumor microenvironment and leading to reduced tumor growth.”
The study has up to 70 spots for non-small-cell lung cancer patients. Half receive an exercise regimen of supervised and group exercise activities. These patients participate in physical training three times a week for six weeks, for around 40 minutes per session. The other half in the trial do not partake in the exercises.
The exercise regimen is:
- 15 minutes of warm-up
- 17 minutes of interval training
- 2 minutes of cool down
The exercises included bicycling, rowing, cross training, step up and step down training, and more. They were done on machines or equipment.
The study began in August 2020 but paused due to the COVID-19 pandemic, which stopped many clinical trials for cancers like mesothelioma and lung cancer. It restarted and now has enrolled 23 patients as of January 2022.
All patients receive immunotherapy checkpoint inhibitor treatment, possibly combined with chemotherapy. The primary measurements to determine if exercise impacts the immune system are:
- Number of circulating NK cells in or near the tumor microenvironment
- Number of other immune cells in or near the tumor location
- Infiltration of immune cells into the tumor
The theory is T cells and NK cells become more mobile with upticks in adrenaline. Since exercise causes adrenaline, the belief is exercise can make T cells and NK cells more active. This leads to elevated numbers of T cells in the area.
Add in an immune checkpoint inhibitor treatment – therapies that alter the tumor microenvironment to aid the NK cells and T cells – and exercise “may increase the chance for response to treatment.”
Our patient advocates can explain further about the benefits of exercise for cancer patients. Contact our registered nurse, Karen Ritter, for exercise tips and other health habits to begin. Email Karen at email@example.com with any questions about fighting your cancer or how to help a loved one with a cancer diagnosis.
Sources & Author
- High Intensity Aerobic exercise training and Immune cell Mobilization in patients with lung cancer (HI AIM)—a randomized controlled trial. BMC Cancer. Retrieved from: https://bmccancer.biomedcentral.com/articles/10.1186/s12885-022-09349-y. Accessed: 04/21/2022.
Sources & Author