Effects of yoga interventions on fatigue in cancer patients and survivors: a systematic review of randomized controlled trials.

BACKGROUND: Fatigue is one of the most frequently reported, distressing side effects reported by cancer survivors and often has significant long-term consequences. Research indicates that yoga can produce invigorating effects on physical and mental energy, and thereby may improve levels of fatigue. The objective of this systematic review was to examine the literature that reports the effects of randomized, controlled yoga interventions on self-reported fatigue in cancer patients and survivors. The online electronic databases, PubMed and PsycINFO, were used to search for peer-reviewed research articles studying the effects of yoga interventions on fatigue in cancer survivors. Combinations of yoga, cancer, and fatigue-related search terms were entered simultaneously to obtain articles that included all three elements. Studies were included if they met the following inclusion criteria: participants were male or female cancer patients or survivors participating in randomized, controlled yoga interventions. The main outcome of interest was change in fatigue from pre- to post-intervention. Interventions of any length were included in the analysis. Risk of bias using the format of the Cochrane Collaboration's tool for assessing risk of bias was also examined across studies.
RESULTS: Ten articles met inclusion criteria and involved a total of 583 participants who were predominantly female, breast cancer survivors. Four studies indicated that the yoga intervention resulted in significant reductions in self-reported fatigue from pre- to post-intervention. Three of the studies reported that there were significant reductions of fatigue among participants who attended a greater number of yoga classes. Risk of bias was high for areas of adequate selection, performance, detection, and patient-reported bias and mixed for attrition and reporting bias. Risk of bias was uniformly low for other forms of bias, including financial conflicts of interest.
CONCLUSIONS: Results of the studies included in this review suggest that yoga interventions may be beneficial for reducing cancer-related fatigue in women with breast cancer; however, conclusions should be interpreted with caution as a result of levels of bias and inconsistent methods used across studies. More well-constructed randomized controlled trials are needed to determine the impact of yoga interventions on fatigue in cancer patients and survivors. Published by Elsevier Inc.