Introduction: Patients with cancer receiving radio- or
chemotherapy undergo many immunological stressors.
Chronic regular exercise has been shown to positively
influence the immune system in several populations,
while exercise overload may have negative effects. Exercise
is currently recommended for all patients with
cancer. However, knowledge regarding the effects of
exercise on immune markers in patients undergoing
chemo- or radiotherapy is limited. The aim of this study is
to systematically review the effects of moderate- and
high-intensity exercise interventions in patients with
cancer during chemotherapy or radiotherapy on immune
markers. Methods: For this review, a search was performed
in PubMed and EMBASE, until March 2023.
Methodological quality was assessed with the PEDro tool
and best-evidence syntheses were performed both per
immune marker and for the inflammatory profile. Results:
Methodological quality of the 15 included articles was
rated fair to good. The majority of markers were unaltered,
but observed effects included a suppressive effect
of exercise during radiotherapy on some proinflammatory
markers, a preserving effect of exercise
during chemotherapy on NK cell degranulation and cytotoxicity,
a protective effect on the decrease in
thrombocytes during chemotherapy, and a positive effect
of exercise during chemotherapy on IgA. Conclusion:
Although exercise only influenced a few markers, the
results are promising. Exercise did not negatively influence
immune markers, and some were positively affected
since suppressed inflammation might have positive
clinical implications. For future research, consensus is
needed regarding a set of markers that are most responsive
to exercise. Next, differential effects of training
types and intensities on these markers should be further
investigated, as well as their clinical implications.