Exercise might boost effectiveness of immunotherapy for chronic lymphocytic leukemia

Image credit – University of Birmingham

CANCER DIGEST – May 25, 2024 – Vigorous exercise could boost the cancer killing effectiveness of immunotherapy aimed at treating a common blood cancer, a new study shows.

Researchers at the Universities of Birmingham and Bath in the UK, compared the effectiveness of anti-cancer immune cells, called natural killer (NK) cells in blood and tissue samples taken from 20 chronic lymphocytic leukemia patients who had not undergone treatment, but vigorously rode an exercise bicycle for 30 minutes. The study appears in the May 2024 edition of the journal Brain, Behavior, and Immunity.

Blood samples were take prior to exercise, immediately after the cycling and again 1 hour after exercise. Advanced blood testing showed that exercise increased the number of natural killer cells by 254 percent and increased the number of cancerous CLL cells in the blood by 67 percent.

Senior author, Dr. John Campbell explained why the number cancer cells increased. 

"Cancer cells often 'hide' in the body but it seems that exercise works to move them out into the blood stream," Campbell said in a press release. "where they are vulnerable to the antibody therapy and the killing capabilities of natural killer cells."

The researchers then isolated the NK cells from the exercise blood samples and put them in close contact with tissue samples that had been treated with the immunotherapy drug Rituximab and samples of tissue that had not been treated with the drug.

What they found was that the NK cells, with the Rituximab present, were slightly more then twice as effective in killing the cancer cells in the tissue samples collected immediately after exercise compared to samples collected before exercise.

One application of this finding might be in followup blood tests for patients after treatment. 

"Monitoring patients after treatment is complicated because if cancer cells remain or reappear, they are sometimes too low to detect," lead author Dr. Harrison Collier-Bain said in a press release. "but a bout of exercise followed by a blood sample immediately afterwards could help to 'find' them if they are 'hiding' in the body."

While the results of the study are encouraging, larger-scale studies will be needed before treatment recommendations can be made.

Sources: University of Birmingham press release and the journal  Brain, Behavior, and Immunity.