After completing chemotherapy, cancer survivors who exercise for several weeks are helping their immune systems become more effective, which in turn, prevents cancer from developing in the future.
The finding, which came from a preliminary study that is being presented at The Integrative Biology of Exercise VI meeting from October 10th to 13th, may help scientists understand why exercise can greatly decrease the risk of secondary cancers in survivors, or in the case where individuals have never been diagnosed, why it can decrease the risk of cancer altogether.
A team of experts, led by Laura Bilek, from the University of Nebraska Medical Center, had a group of 16 cancer survivors participate in a twelve week exercise program for their study. The T cells in the volunteers’ blood was examined before the exercise course, and after it was completed.
Analysis showed that a large portion of the immune cells changed from a senescent form to a naïve form. This means that they went from a form that is not as efficient in fighting against cancer to a form that is prepared to protect against disease and infections.
Prior studies have found many associations between exercise and cancer, including:
- that exercise can decrease the chance of developing several different cancers
- that it can improve prognosis in people with cancer
- that it can decrease the chance of recurrence and secondary cancers from developing
However, since the cause of these links has been unknown, and some reports have implied that exercise can improve the immune system’s ability to protect against disease, the experts in the current study set out to determine how it specifically impacts the immune system of cancer patients.
T cells, a type of immune cell that protects against infectious agents and cancer cells, were the focal point in the investigation of the cancer survivors who had just finished chemotherapy.
Past trials have shown that T cells become senescent after chemotherapy, leaving the patient less able to fight disease and infections.
However, Bilek explained, reconstructing the population of naïve T cells is important for the immune system to function properly and be able to fight cancer.
In order to identify the number of senescent and naïve T cells each person had, blood samples were taken, and analyzed, from all participants.
They then took part in an exercise program at the Rocky Mountain Cancer Rehabilitation Institute which lasted twelve weeks.
The programs were individually made for the subjects, consisting of strength and endurance training, cardiovascular exercise, and exercises for posture, flexibility and balance, with extra work in areas where they were weakest.
The experts took blood from the subjects after the 12 weeks, and performed another test to examine their T cells.
The second analysis revealed that the proportion of senescent to naïve T cells changed for the better in most of the patients, showing more naïve forms.
Bilek explained, “What we’re suggesting is that with exercise, you might be getting rid of T cells that aren’t helpful and making room for T cells that might be helpful.”
This research is important because it not only emphasizes the advantages of exercise for cancer patients and cancer survivors, but it also demonstrates how it can benefit healthy individuals.
However, the increased “cancer surveillance”, or the power of the immune system to stop emerging cancers, is particularly beneficial for those struggling with cancer, or who have just survived it.
“There’s a litany of positive benefits from exercise. If exercise indeed strengthens the immune system and potentially improves cancer surveillance, it’s one more thing we should educate patients about as a reason they should schedule regular activity throughout their day and make it a priority in their lives.”
Written by Sarah Glynn