Tailored Exercise Interventions to Reduce Fatigue in Cancer Survivors

Background and Rationale

Approximately one-third of cancer survivors experience severe and persistent fatigue for a number of years post-treatment, but this distressing symptom is often under-treated by healthcare professionals due to a lack of mechanism-targeted interventions. The assessment of cancer-related fatigue (CRF) is reliant on subjective fatigue measurements such as self-report questionnaires. Less attention has been given to objective physiological measurements. However, there are well-established techniques which allow the assessment of neuromuscular fatigue and its peripheral and central origins which could be utilized in the study of CRF. Very few studies have considered these objective measures alongside self-report scales in the study of CRF and only two have used such techniques in cancer survivors. To date, no studies have investigated neuromuscular fatigue in whole body, dynamic activity as relevant to daily tasks (and involving the lower limb due to its functional relevance to locomotion). Novel testing developed in our laboratory could be used as part of a wider screening to develop individualized interventions to alleviate CRF. It is well accepted in the field that CRF is multidimensional and in addition to a potential neuromuscular component, the role of sleep disturbance may also be implicated. Interventions targeted at improving sleep quality are therefore warranted, and there is sound evidence for the efficacy of exercise interventions in particular for improving CRF in cancer survivors. As a non-pharmacological intervention, physical activity has the strongest evidence base for treating CRF. However, the mechanisms explaining the reduction of CRF with exercise are not understood. Due to the complex and multi-factorial nature of CRF, it would be of benefit to tailor exercise interventions to the specific deficits (in regards to neuromuscular mechanisms) or difficulties (for example sleep disturbance) experienced by the individual. Ultimately, mechanism-targeted exercise interventions could be translated to clinical rehabilitation programs and lead to an improved quality of for cancer survivors.

Research Question & Objectives

The primary aim of this research is to investigate the effect of a traditional vs. tailored 12-week exercise intervention on self-reported CRF severity.

Methods

Fatigued cancer survivors who have completed primary treatment ≥ 3 months and ≤ 5 years from enrollment will be randomly allocated to one of two treatment arms: traditional (active control) and tailored exercise. Participants in the traditional exercise group will engage in aerobic and resistance exercise that is consistent with published recommendations. The tailored exercise group will be prescribed an intervention designed to address individual deficits (identified at baseline) that may be related to CRF. Participants will be assessed before and after the intervention for patient-reported outcomes, neuromuscular function and fatigue in response to whole-body exercise, sleep quantity and quality, physical activity levels, cardiorespiratory fitness and blood biomarkers.

Inclusion criteria

• Aged between 18 and 75 years;
• Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) score ≤ 34;
• Completion of treatment in ≥ 3 months and ≤ 5 years preceding enrollment;
• Approval received from personal physician and/or a Canadian Society for Exercise Physiology-Clinical Exercise Physiologist (CSEP-CEP);
• Command of the English language.

Exclusion criteria

• Contraindication to experimental procedures including transcranial magnetic stimulation (TMS);
• Diagnosed as having obstructive sleep apnea or anemia;
• Currently participating in a structured exercise intervention;
• Participant is pregnant.