Does yoga decrease cancer-related fatigue in women with breast cancer? Systematic review of randomized controlled trials

Abstract

In its most recent report, the International Agency for Research on Cancer revealed that 1.7 million new cases human beings that year. The International Agency for Research on Cancer reported that 1.7 million new cases of breast cancer were diagnosed worldwide in 2012, which represented almost 12% of all cancer types diagnosed in human beings that year. The purpose of the study was to determine if the practice of yoga allows decreasing cancer-related fatigue in women diagnosed with breast cancer. Methodology of the study was taken from database search on Web of Science, Embase, Pubmed, and Cochrane Library, as well as manual reference registration. The eligibility criteria were: (a) randomized controlled trials; (b) measurement of fatigue as main or secondary outcome; (c) studies published until December 2016; (d) studies published in English, Spanish, French or Portuguese. The guidelines of the PRISMA statement were followed. Methodological quality of randomized controlled trials was evaluated with the PEDro scale. Out of the 255 registers found, 14 randomized controlled trials were included. In half of the studies no statistically significant differences were found between experimental and control groups. Only four studies included had a comparative group besides a control group. All studies included were of moderate or high methodological quality according to PEDro scale. Findings suggest that yoga may not be effective to decrease cancer-related fatigue in women diagnosed with breast cancer.

Cancer-related fatigue: Systematic reviews and meta-analyses of mind–body intervention

“…Two articles were excluded because one of them was not a systematic review (Kwekkeboom et al, 2010), and the other one did not review trials on CRF (Ulrichsen et al, 2016). Finally, a total of 16 studies met inclusion criteria (Santos et al, 2010;Zhang et al, 2012Zhang et al, , 2018Finnegan-John et al, 2013;He et al, 2013;Posadzki et al, 2013;Sadja and Mills, 2013;Lee et al, 2014;Ling et al, 2014;Zeng et al, 2014;Lau et al, 2016;Tao et al, 2016;Duong et al, 2017;Haller et al, 2017;Morgan, 2017;Hilfiker et al, 2018). Figure 1 describes the flowchart of searching for and screening of eligible studies.…”

“…Second, most of the systematic reviews did not search the gray or unpublished literature for eligible studies (AMSTAR, item 4) (Santos et al, 2010;Zhang et al, 2012Zhang et al, , 2018; Finnegan-John Sadja and Mills, 2013;Ling et al, 2014;Zeng et al, 2014;Lau et al, 2016;Tao et al, 2016;Duong et al, 2017;Haller et al, 2017;Morgan, 2017;Hilfiker et al, 2018). In most cases, studies containing significant findings were more likely to be published than were those with non-significant findings, and systematic reviews based mainly on the published literature tended to overestimate the effectiveness of interventions (Sterne et al, 2011;Schmucker et al, 2017).…”

“…The methodological quality of the 16 included reviews was generally moderate (score 4-7) to high (score ≥ 8) on the 11-point AMSTAR scale. Only 4 systematic reviews were found to be high quality (Lee et al, 2014;Zeng et al, 2014;Haller et al, 2017, Hilfiker et al, 2018, whereas 12 systematic reviews were of moderate quality (Santos et al, 2010;Zhang et al, 2012Zhang et al, , 2018Finnegan-John et al, 2013;He et al, 2013;Posadzki et al, 2013;Sadja and Mills, 2013;Ling et al, 2014;Lau et al, 2016;Tao et al, 2016;Duong et al, 2017;Morgan, 2017).…”

“…Overall, the 16 systematic reviews reported results from 202 primary studies (median, 10). Twelve systematic reviews included RCTs only (Zhang et al, 2012(Zhang et al, , 2018He et al, 2013;Posadzki et al, 2013;Sadja and Mills, 2013;Lee et al, 2014;Ling et al, 2014;Zeng et al, 2014;Lau et al, 2016;Tao et al, 2016;Haller et al, 2017;Morgan, 2017). The remaining four systematic reviews included RCTs as well as quasi-RCTs (Santos…”

The Effect of Yoga Interventions on Cancer-Related Fatigue and Quality of Life for Women with Breast Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

“…25 Furthermore, yoga can be adapted specifically for individuals with cancer; yoga postures can help with strength and flexibility, breath control assists with relaxation and focus, while meditation can help to calm the mind. 25 To date, 5 systematic or comparator reviews 16,[25][26][27][28] and 8 meta-analyses have evaluated the effects of yoga on CRF and/or QOL; of these, 3 meta-analyses evaluated the role of yoga interventions on fatigue in multiple populations including BC and 2 on QOL, 27,29,30 4 meta-analyses included yoga interventions within a broader analysis of the relationship of all exercise on CRF only in individuals with cancer (including BC), 5,14,31,32 and 1 meta-analysis included mindfulness stress reduction therapy as a yoga comparator in women with BC on CRF and QOL. 33 The previous systematic reviews and meta-analyses were limited in their elucidation of the role of yoga exclusively to improve CRF and QOL in BC population, as yoga and/or BC were not the only focus of the reviews.…”