Findings of a preliminary study help to explain exercises effects on cancer
Past research has shown that exercise reduces the risk of cancer such as breast, colon and lung however; the influence behind the phenomena is unknown until now. Researchers believe they may have an explanation that may help answer the reason why exercise significantly reduces the risk of secondary cancers in cancer survivors or reduce the risk of cancer for those who have never had the disease.View slideshow: Cancer and Exercise
Researchers Dr. Laura Bilek, PT, PhD, Dr. Graham Sharp, PhD, Dr. Jeffrey Thiele, PhD, all from the University of Nebraska and Dan Shackleford, Doctorial Graduate Student, Dr. Colin Quinn, PhD and Dr. Carole Schneider, all from the Rocky Mountain Cancer Rehabilitation Institute, had examined T cells in the blood of cancer survivors before and after a twelve week exercise program. Researchers found that a major portion of immune cells changed from a senescent form (no longer capable of dividing yet remain metabolically active) to naïve cells (not having been exposed previously to an antigen) ready to fight cancer and infection.
Other research has suggested that exercise can remodel the immune system making it more effective to fight disease in general. Dr. Bilek, leader of study and colleagues decided to examine how exercise affects the immune system of cancer patients.
Dr. Bilek explains that past research has found a variety of associations between exercise and cancer, particularly that exercise reduces the risk of getting beginning occurrence of several kinds of cancers and exercise can improve the prognosis in cancer patients along with reducing the risk of recurrence and secondary cancers in some survivors.
For the study researchers had worked with a group of 16 cancer survivors who had finished chemotherapy treatment with the exception of one survivor. Researchers concentrated on T cells. T care a type of white blood cells called lymphocytes. They make up part of the immune system. T cells help the body fight infections and cancers. However, rebuilding the T cells is vital in regaining immune function and the ability to fight cancer.
At the start of the study researchers had taken blood samples from all the volunteers in order to examine how many senescent and naïve T cells each had.
Following the blood samples all the volunteers were enrolled at the Rocky Mountain Cancer Rehabilitation Institute for 12 weeks of exercise programs. All programs were geared to each individual and included the elements of cardiovascular exercise, strength and endurance training and exercises for flexibility, posture and balance and placed extra emphasis on the areas where volunteers had weakness.
When the 12 week program ended blood samples were taken again and the same T cell analysis was run.
The results showed that the ratio of senescent to naïve T cells changed favorably in the majority of participants, with most of the study subjects regaining greater numbers of the naïve variety.
Dr. Bilek states "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.”
She explains that the findings highlight the importance of exercise for everyone including those with cancer and cancer survivors. She adds that those with cancer and survivors may especially benefit from the heightened “cancer surveillance”.
In closing Dr. Bilek comments "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."
The presentation of their study titled “Effect of Exercise on T Cells in Cancer Survivors,” will be discussed at The Integrative Biology of Exercise VI meeting being held October 10-13 at the Westin Westminster Hotel in Westminster, Colorado.
This meeting is a collaborative effort between American Physiological Society, the American College of Sports Medicine and the Canadian Society for Exercise Physiology.
According to the American Cancer Society;
Studies show that exercise is safe during cancer treatment, and can improve many aspects of health, including muscle strength, balance, fatigue, and depression.
Physical activity after diagnosis is linked to living longer and a reduced risk of the cancer returning among people living with cancer, including breast, colorectal, prostate, and ovarian cancer.
The updated Nutrition and Physical Activity Guidelines for Cancer Survivors, published April 26, 2012, can be viewed online at CA; A Cancer Journal for Clinicians.