Effect of Exercise on Immune System Markers in Cancer Patients and Survivors: A Systematic Review.

This systematic review aimed to analyze the impact of aerobic, resistance, combined, and mind-body exercise on the cellular markers of the immune system in cancer patients and survivors. Pubmed, Web of Science, the Cochrane Library, and Scopus databases were searched to identify pertinent randomized controlled trials that looked at the effect of exercise interventions on cellular markers of immune system. Risk of Bias 2 (RoB2) Tool was used to evaluate the methodological quality of each study. Of the 20 investigations included, 8 observed beneficial results on the effect of aerobic, resistance, combined, and mind-body exercise on immune cells in cancer patients and survivors when compared to control groups. Observed changes included increases in natural killer (NK) cells, peripheral blood mononuclear cells (PBMCs) and dendritic cell marker DC11c⁺ cytotoxicity, immunoglobulin A, total white blood cells, lymphocytes, NK cell percentages, and NK cell receptor expression (NKG2D⁺ and KIR2DL3⁺). Additionally, NK cell infiltration into healthy prostatic tissue and platelet counts were modulated in some studies. Risk of bias was rated as low in 35% of studies, with 45% classified as high risk, mainly due to randomization and intervention deviations. Exercise, particularly aerobic and mind-body modalities, may improve innate and adaptive immune responses in cancer patients and survivors, although effects were not consistent across all interventions or immune outcomes. More high-quality studies involving diverse types, intensities, and durations of physical exercise are needed during different cancer phases and stages of treatment. Registration Number: CRD42022370010.