Evidence for the use of exercise in patients with breast cancer to reduce cancer-related fatigue

Background & Purpose: Cancer-related fatigue is the most commonly reported side effect of cancer treatment and affects 70-100% of patients. According to the 2013 National Comprehensive Cancer Network Guidelines on Cancer-Related Fatigue, institutions should assess the quality of fatigue management in their continuous quality improvement projects. In addition, the Guidelines also state that Medicare contracts should reimburse for fatigue management and disability insurance should include coverage for the continuing effects of fatigue. Exercise has been suggested for breast cancer survivors as an intervention to reduce cancer-related fatigue both during and after cancer treatment. However, it has been reported that only 68% of patients receive information about fatigue during their cancer treatment and the information they receive is not specific enough to initiate an exercise program. The objective of this systematic literature review was to summarize the effects of exercise to reduce cancer-related fatigue in patients with breast cancer and discuss the exercise dosage in terms of mode, frequency, duration and intensity. Number of Subjects: Five studies met the inclusion/exclusion criteria for this review. Materials/Methods: The literature search included key word searches in the databases, Medline and CINHAL, and a hand-search of studies included in a Cochrane review. The search was limited to females only, published in 2008-2013 and English language. Of the 23 studies that met the search criteria, five were chosen based on inclusion of an aerobic component, measurement of fatigue levels and high PEDro scores. Types of studies reviewed included clinical trials comparing an exercise intervention group to a control group and one cross sectional survey of an exercise intervention. Outcomes: Four out of five studies showed an improvement in cancer treatment related fatigue in individuals with breast cancer following the exercise intervention. Three different outcome tools were used to measure fatigue. The length of exercise intervention varied among each study and there was inconsistent duration, type of exercise, or supervision reported. The range included 8 weeks aquatic aerobic and resistance exercise, 12 weeks of aerobic, resistance and stretching, a home based walking program of 6 weeks or 14 weeks, in addition to a yearlong combined home-based aerobic exercise program. Intensity was measured using both RPE and/or heart rate. No study reported negative impacts of exercise implementation. General study limitations included group contamination when the control group began an exercise program on their own or there was decreased adherence to the exercise intervention by the study subjects. Systemic bias may have occurred when the control group received little/no attention and the Hawthorne effect of study participants. Discussion: Physical therapists should be aware not only of the important role of exercise intervention for the management of cancer-related fatigue in individuals with breast cancer but the mode, frequency and duration that is most effective. Additional research is needed in this population to clarify optimal exercise dosage and to compare outcomes of total daily physical activity versus only formal exercise. Despite these limitations, the available evidence supports the value of exercise for individuals with breast cancer-related fatigue and the active role physical therapists can play to initiate exercise programs