Exercise Boosts Cancer-Fighting Immune Cells in Breast Cancer Patients, Study Finds

A recent study from the University of Turku has revealed that just 30 minutes of exercise can significantly increase the proportion of tumor-killing white blood cells in the bloodstream of breast cancer patients. This research, published in Frontiers in Immunology, sheds new light on the potential benefits of physical activity in cancer treatment.

The study, led by Tiia Koivula, involved 20 newly diagnosed breast cancer patients who had not yet begun treatment. Participants engaged in a 30-minute bicycle ergometer session, with blood samples taken before, during, and after the exercise.

Results showed a marked increase in cancer-destroying white blood cells, particularly cytotoxic T cells and natural killer cells, during exercise. Conversely, cancer-promoting cells like regulatory T cells and myeloid-derived suppressor cells remained unchanged or decreased in proportion.

While the study demonstrated clear changes in blood cell composition during exercise, the long-term effects and impact on tumor sites remain uncertain. Koivula noted that cell counts returned to baseline levels an hour post-exercise, but previous preclinical studies suggest cancer-destroying cells may migrate to tumor areas.

The research also explored how different breast cancer types might influence exercise responses. Larger tumors were associated with smaller increases in natural killer cells, while hormone receptor-positive cancers showed less increase in cytotoxic T cells compared to hormone receptor-negative cancers.

Despite these variations, Koivula emphasized that exercise appears beneficial for all cancer patients, regardless of cancer type. This study adds to growing evidence supporting the importance of physical activity in cancer care and opens new avenues for research into exercise-based interventions in oncology.