Changes in Monocyte Populations Following Acute Aerobic Exercise in Breast Cancer Survivors

Exercise is now strongly recommended for breast cancer patients to improve their overall health and quality of life. Monocytes play an important role in the cancer immune system and a better understanding of how acute exercise alters the monocyte subsets would aid in exercise prescription.

Ten breast cancer survivors (age: 59 ± 7.1) who completed their primary cancer treatment within the previous year were evaluated in this study. Using flow cytometry, monocyte subset percentages were evaluated before, immediately after, and 1 hour after 45 minutes of acute, intermittent exercise. Exercise intensity was 60% of peak wattage obtained from a cardiopulmonary exercise test.

The percentage of CD14 monocytes and CD14࠽ monocyte subsets changed significantly across the trial (p= 0.016 and p = 0.016, respectively), with a small, non-significant increase immediately after exercise (CD14: 9%, p= 0.314; CD14࠽: 5%, p= 0.594) followed by a larger significant decrease 1 hour after exercise relative to baseline (CD14: -26%, p= 0.015; CD14࠽: -28%, p= 0.021). CD14࠽ subpopulation showed a tendency to change across the trial but this did not quite reach significance (p= 0.097).

These findings suggest that acute intermittent exercise mobilizes CD14 monocytes and CD14࠽ monocyte subsets in breast cancer survivors in a manner that is comparable to previous reports in healthy individuals. Further studies are warranted to determine the functionality of the mobilized monocytes and the effects of exercise training.