Effect of Yoga and Mediational Influence of Fatigue on Walking, Physical Activity, and Quality of Life Among Cancer Survivors.

BACKGROUND: Cancer-related fatigue (CRF) negatively affects survivors' walking, engagement in physical activity (PA), and quality of life (QoL). Yoga is an effective therapy for treating CRF; however, evidence from large clinical trials regarding how reducing CRF through yoga influences CRF's interference with survivors' walking, engagement in PA, and QoL is not available. We examined the effects of yoga and the mediational influence of CRF on CRF's interference with walking, PA, and QoL among cancer survivors in a multicenter phase III randomized controlled trial. PATIENTS AND METHODS: Cancer survivors (n=410) with insomnia 2 to 24 months posttreatment were randomized to a 4-week yoga intervention-Yoga for Cancer Survivors (YOCAS)-or standard care. A symptom inventory was used to assess how much CRF interfered with survivors' walking, PA, and QoL. The Multidimensional Fatigue Symptom Inventory-Short Form was used to assess CRF. Two-tailed t tests and analyses of covariance were used to examine within-group and between-group differences. Path analysis was used to evaluate mediational relationships between CRF and changes in CRF's interference with walking, PA, and QoL among survivors. RESULTS: Compared with standard care controls, YOCAS participants reported significant improvements in CRF's interference with walking, PA, and QoL at postintervention (all effect size = -0.33; all P≤.05). Improvements in CRF resulting from yoga accounted for significant proportions of the improvements in walking (44%), PA (53%), and QoL (45%; all P≤.05). CONCLUSIONS: A significant proportion (44%-53%) of the YOCAS effect on CRF's interference with walking, PA, and QoL was due to improvements in CRF among cancer survivors. Yoga should be introduced and included as a treatment option for survivors experiencing fatigue. By reducing fatigue, survivors further improve their walking, engagement in PA, and QoL.

Influence of Yoga on Cancer-Related Fatigue and on Mediational Relationships Between Changes in Sleep and Cancer-Related Fatigue: A Nationwide, Multicenter Randomized Controlled Trial of Yoga in Cancer Survivors.

BACKGROUND: Cancer-related fatigue (CRF) often co-occurs with sleep disturbance and is one of the most pervasive toxicities resulting from cancer and its treatment. We and other investigators have previously reported that yoga therapy can improve sleep quality in cancer patients and survivors. No nationwide multicenter phase III randomized controlled trial (RCT) has investigated whether yoga therapy improves CRF or whether improvements in sleep mediate the effect of yoga on CRF. We examined the effect of a standardized, 4-week, yoga therapy program (Yoga for Cancer Survivors [YOCAS]) on CRF and whether YOCAS-induced changes in sleep mediated changes in CRF among survivors. STUDY DESIGN AND METHODS: Four hundred ten cancer survivors were recruited to a nationwide multicenter phase III RCT comparing the effect of YOCAS to standard survivorship care on CRF and examining the mediating effects of changes in sleep, stemming from yoga, on changes in CRF. CRF was assessed by the Multidimensional Fatigue Symptom Inventory. Sleep was assessed via the Pittsburgh Sleep Quality Index. Between- and within-group intervention effects on CRF were assessed by analysis of covariance and 2-tailed t test, respectively. Path analysis was used to evaluate mediation. RESULTS: YOCAS participants demonstrated significantly greater improvements in CRF compared with participants in standard survivorship care at post-intervention ( P < .01). Improvements in overall sleep quality and reductions in daytime dysfunction (eg, excessive napping) resulting from yoga significantly mediated the effect of yoga on CRF (22% and 37%, respectively, both P < .01). CONCLUSIONS: YOCAS is effective for treating CRF among cancer survivors; 22% to 37% of the improvements in CRF from yoga therapy result from improvements in sleep quality and daytime dysfunction. Oncologists should consider prescribing yoga to cancer survivors for treating CRF and sleep disturbance.

YOCAS©® Yoga Reduces Self-reported Memory Difficulty in Cancer Survivors in a Nationwide Randomized Clinical Trial: Investigating Relationships Between Memory and Sleep.

UNLABELLED: Background Interventions are needed to alleviate memory difficulty in cancer survivors. We previously showed in a phase III randomized clinical trial that YOCAS©® yoga-a program that consists of breathing exercises, postures, and meditation-significantly improved sleep quality in cancer survivors. This study assessed the effects of YOCAS©® on memory and identified relationships between memory and sleep. STUDY DESIGN AND METHODS: Survivors were randomized to standard care (SC) or SC with YOCAS©® . 328 participants who provided data on the memory difficulty item of the MD Anderson Symptom Inventory are included. Sleep quality was measured using the Pittsburgh Sleep Quality Index. General linear modeling (GLM) determined the group effect of YOCAS©® on memory difficulty compared with SC. GLM also determined moderation of baseline memory difficulty on postintervention sleep and vice versa. Path modeling assessed the mediating effects of changes in memory difficulty on YOCAS©® changes in sleep and vice versa. RESULTS: YOCAS©® significantly reduced memory difficulty at postintervention compared with SC (mean change: yoga=-0.60; SC=-0.16; P<.05). Baseline memory difficulty did not moderate the effects of postintervention sleep quality in YOCAS©® compared with SC. Baseline sleep quality did moderate the effects of postintervention memory difficulty in YOCAS©® compared with SC (P<.05). Changes in sleep quality was a significant mediator of reduced memory difficulty in YOCAS©® compared with SC (P<.05); however, changes in memory difficulty did not significantly mediate improved sleep quality in YOCAS©® compared with SC. CONCLUSIONS: In this large nationwide trial, YOCAS©® yoga significantly reduced patient-reported memory difficulty in cancer survivors.

Feasibility of implementing a community-based randomized trial of yoga for women undergoing chemotherapy for breast cancer.

BACKGROUND: Treatment-related symptoms and decreased health-related quality of life (HRQoL) frequently occur during chemotherapy for breast cancer. Although research findings suggest that yoga can reduce symptoms and Improve HRQoL after treatment, potential benefits of yoga during chemotherapy have received minimal attention. OBJECTIVE: To estimate accrual, adherence, study retention, and preliminary efficacy of a yoga intervention compared with an active control group for breast cancer patients during chemotherapy. METHODS: Women with stage I-III breast cancer were recruited from 3 community cancer clinics and randomized to 10 weeks of gentle yoga or wellness education. Depressive symptoms, fatigue, sleep, and HRQoL were assessed at baseline, mid-intervention (Week 5), and after intervention (Week 10). RESULTS: 40 women aged 29-83 years (median, 48 years; 88% white) were randomized to yoga (n = 22) or wellness education (n = 18). The groups did not differ significantly on baseline characteristics, adherence, or study retention. Participant feedback was positive and comparable between groups. Meaningful within-group differences were identified For sleep adequacy and quantity in yoga participants and for somnolence in wellness-education participants. LIMITATIONS: Small sample size and lack of a usual-care control group. CONCLUSIONS: This study established Feasibility of a community-based randomized trial of yoga and an active comparison group for women undergoing chemotherapy for breast cancer. Preliminary efficacy estimates suggest that yoga improves sleep adequacy Symptom severity and interference remained stable during chemotherapy for the yoga group and snowed a trend toward increasing in the control group. The study highlighted obstacles to multisite yoga research during cancer treatment. FUNDING/SPONSORSHIP: National Cancer Institute (3U10 CA081851, PI; Shaw; R25 CA122061, PI: Avis); Translational Science Institute, Wake Forest School of Medicine.