Immunological and hormonal effects of exercise: implications for cancer cachexia

There is increasing interest in the use of therapeutic exercise for cancer cachexia. Apart from the directly beneficial effects on muscle, exercise has the potential to attenuate some of the immunological and hormonal abnormalities found in cachexia. This review summarizes the findings of recent studies, which have explored such effects in patients with cancer, and discusses their relevance to patients with cancer cachexia.

Our search identified 11 studies in patients with breast, colorectal, lung, and prostate cancer, predominantly with early stage disease or following primary curative treatment. Overall, exercise was associated with reduced levels of C-reactive protein (CRP), but not other markers of systemic inflammation. There was no consistent impact on levels of glucose, insulin or measures of insulin sensitivity or, in patients with prostate cancer, on levels of testosterone.

There is limited scope to extrapolate these findings to patients with cancer cachexia, who are more likely to have advanced disease, higher levels of systemic inflammation, and greater degrees of metabolic dysfunction. Studies specific to this group are required to explore what, if any, changes exercise can make to levels of CRP and other immune and hormonal biomarkers, along with their potential clinical relevance.