Exercise has been found to potentially aid the efficacy of rituximab, an antibody therapy used to treat chronic lymphocytic leukemia. A study conducted by researchers in England discovered that moderate to intense bursts of exercise can increase the presence of natural killer cells, which when combined with rituximab, can target and attack cancer cells in the blood. However, experts caution that the small sample size of the study makes it difficult to generalize the findings to a larger population.
The study, published in the journal Brain, Behavior, and Immunity, involved 20 participants with CLL who engaged in a 20 to 30 minute round of cycling at moderate to vigorous intensity. The results showed that this type of exercise led to a 254% increase in anti-cancer immune cells, particularly natural killer cells. When combined with rituximab, these cells were found to be twice as effective in killing cancer cells in blood samples taken immediately after exercise.
Catherine S. Diefenbach, MD, director of the Clinical Lymphoma Program at NYU Langone Health, noted that while the study results were interesting, there are still unanswered questions due to the small sample size. She emphasized the need for larger studies with a more diverse patient population to validate the findings and determine the impact on clinical outcomes.
Similarly, Wael Harb, MD, a hematologist and medical oncologist, pointed out the challenges of extrapolating the study’s results to a broader template of treatment due to the feasibility of vigorous exercise and the limitations of the study design. He highlighted the importance of long-term outcomes and the need for structured studies to assess the impact of exercise on response to treatment and disease remission.
Despite the potential benefits of exercise in stimulating immune cells to fight cancer, especially in immune-based therapies, there are practical limitations to consider. Extreme fatigue caused by cancer treatments can hinder physical activity, and vigorous exercise may not be suitable for all patients based on age, comorbidities, and ability to exercise. Therefore, personalized recommendations and structured studies are essential to determine the role of exercise as an adjunct to cancer therapy.
