Effects and potential mechanisms of exercise training on cancer progression: a translational perspective

Abstract

Over the past decade there has been increasing research and clinical interest in the role of exercise therapy/rehabilitation as an adjunct therapy to improve symptom control and management following a cancer diagnosis. More recently, the field of 'exercise - oncology' has broadened in scope to investigate whether the benefits extend beyond symptom control to modulate cancer-specific outcomes (i.e., cancer progression and metastasis). Here we review the extant epidemiological evidence examining the association between exercise behavior, functional capacity/exercise capacity, and cancer-specific recurrence and mortality as well as all-cause mortality individuals following a cancer diagnosis. We also evaluate evidence from clinical studies investigating the effects of structured exercise on blood-based biomarkers associated with cancer progression/metastasis as well findings from preclinical investigations examining the effects and molecular mechanisms of exercise in mouse models of cancer. Current gaps in knowledge are also discussed.

Fig 1

Evidence-based representation of the known effects and mechanisms of exercise on tumor progression adopting a bi-directional translational research or scientific discovery (T0) paradigm. Exercise/fitness and prognosis, evidence supporting association between self-reported exercise behavior, objective measures of exercise capacity or functional capacity, and cancer prognosis; Host-Related Factors, postulated systemic (host-related) pathways mediating the association between exercise behavior and exercise/functional capacity and cancer prognosis; Tumor-Related Factors, intratumoral factors shown to mediate the association between exercise and prognosis or factors shown to be modulated in response to exercise. +++, strong evidence; ++, moderate evidence; +, weak evidence; —, null; ?, unknown at present.