Yoga is an ancient Eastern science that incorporates stress-reduction techniques such as regulated breathing, visual imagery, and meditation, as well as various postures. Hatha yoga is one type of yoga. Yoga has been examined as an intervention for anxiety, depression, chemotherapy-induced nausea and vomiting, hot flashes, cognitive impairment, sleep-wake disturbances, pain, and fatigue in patients with cancer. It has also been examined as an intervention for caregiver strain and burden.
Chan, R.J., McCarthy, A.L., Devenish, J., Sullivan, K.A., & Chan, A. (2015). Systematic review of pharmacologic and non-pharmacologic interventions to manage cognitive alterations after chemotherapy for breast cancer. European Journal of Cancer, 51, 437–450.
PHASE OF CARE: Late effects and survivorship
Risk of bias was high in 11 studies but unclear in two studies that evaluated psychostimulants.
Pharmacologic interventions: No improvements in cognitive function were found using psychostimulants (four studies) or ginkgo biloba. Patients reported better cognitive function using epoetin alfa with doses titrated for hemoglobin levels (p < 0.05). However, a death caused by a cerebrovascular accident was noted.
Nonpharmacologic interventions: Small-group memory training improved self-reported cognitive function, and both memory and speed of processing after small-group training improved immediate and delayed recall (p < 0.05). Home-based online executive function training improved verbal function and attention (p < 0.05). Speed-feedback therapy during biking improved executive and motor function (p < 0.05). Cognitive behavioral therapy-based interventions (two studies), Tibetan sound meditation, and hatha yoga did not improve cognitive function.
The pharmacologic studies reviewed did not support the use of psychostimulants or ginkgo biloba to improve cognitive function after chemotherapy for breast cancer. Epoetin alfa was not recommended for practice because of safety concerns. The nonpharmacologic studies reviewed provided some evidence that cognitive training and speed-feedback therapy might improve cognitive function for breast cancer survivors.
The risk of bias was high for most studies. Therefore, although positive results were found, well-designed, prospective RCTs need to be completed to confirm these findings. It is unclear how sustainable the positive results of the cognitive training and exercise interventions might be because follow-up was limited to less than three months.
This systematic review provided limited support for cognitive training and structured exercise to improve cognitive function after chemotherapy for breast cancer. Cognitive training is currently categorized as likely to be effective for cognitive impairment.
Derry, H.M., Jaremka, L.M., Bennett, J.M., Peng, J., Andridge, R., Shapiro, C., . . . Kiecolt-Glaser, J.K. (2014). Yoga and self-reported cognitive problems in breast cancer survivors: A randomized controlled trial. Psycho-Oncology. Advance online publication.
To determine the effects of yoga on self-reported cognitive function
Certified yoga instructors led two 90-minute yoga group classes per week for 12 weeks. Each group contained 4–20 participants. Hatha yoga poses targeting relaxation, mindful breathing, chest opening, spinal extension, upper-body strength, and mobility were predetermined for each of the 24 sessions, and protocol drift was monitored. Pamphlets describing the poses from the classes and a yoga DVD were provided for home practice. Participants recorded weekly home and class time to determine dose effects. Participants who missed a class were called to improve adherence. Waitlist control participants continued regular activities and were directed not to begin yoga practice until after their final assessments. Measures were assessed before the behavioral intervention, immediately after the 12-week intervention, and three months after the intervention.
Randomized, waitlist-controlled trial
At baseline, the average self-reported cognitive impairment was slight to moderate and did not differ between groups. Overall group and group-by-time effects were found (p < .05, both). Although no differences were found immediately after the 12-week intervention, the intervention group reported significantly less cognitive impairment than controls three months after the intervention ended (p < .01). However, these effects did not remain after controlling for symptom covariates (e.g., anxiety, depression, fatigue, sleep quality). Participants with more daily yoga practice (mean of 29 minutes) reported less cognitive impairment postintervention through three months (p = .011), and participants with less daily yoga practice (mean of 18 minutes) or no daily yoga practice did not report these changes. This dose response remained when controlling for symptom covariates. At three months, the intervention group reported more physical activity than controls (p = .032). Cytokine levels did not predict changes in self-reported cognitive impairment.
A 12-week, group Hatha yoga intervention provided by a trained instructor may improve self-reported cognitive impairment in breast cancer survivors. This effect may be mediated by improvements in co-occurring symptoms. Practicing yoga for at least 30 minutes per day may be required for a significant improvement over time in cognitive impairment.
A group Hatha yoga class delivered by a trained facilitator may improve cognitive impairment for breast cancer survivors. However, more research with a longer follow-up period is warranted to determine whether the intervention is effective, what component of the intervention is active, and whether yoga is practical for implementation in practice.
Janelsins, M.C., Peppone, L.J., Heckler, C.E., Kesler, S.R., Sprod, L.K., Atkins, J., . . . Mustian, K.M. (2015). YOCAS©® Yoga reduces self-reported memory difficulty in cancer survivors in a nationwide randomized clinical trial: Investigating relationships between memory and sleep. Integrative Cancer Therapies, 15, 263–271.
To investigate the effect of a combined hatha and restorative yoga intervention on memory in cancer survivors and to explore relationships between memory and sleep
YOCAS©® (Yoga for Cancer Survivors) is an instructor-guided standardized program that incorporates movement emphasizing restorative poses, breathing exercises, and mindfulness exercises. The intervention was offered twice a week in the late afternoon or evening over 75 minutes for a total of eight sessions. Although all the group trainers were Registered Yoga Alliance Teachers, they were also required to complete a training session, reviewing a detailed YOCAS©® manual to facilitate standardization across sites.
PHASE OF CARE: Late effects and survivorship
Secondary analysis of a randomized, clinical trial
At baseline, the average score on the MDASI indicated only a mild level of perceived memory problems overall. Although both groups continued to report memory problems as being mild, a significant decrease (p < 0.05) was observed in patients who completed the intervention. This difference continued to be significant when controlling for differences in age, gender, educational level, past treatment regimen, current hormonal therapy, baseline memory, and baseline sleep scores. Of note, those who received the intervention also had improved sleep (p < 0.05), which accounted for approximately 26% of the improvement in memory (p = 0.039).
Although yoga appeared to decrease perceived memory problems, this outcome was based on a single item of the MDASI. Further longitudinal studies designed specifically to measure the effect of yoga on cognitive function as measured by both objective and subjective measures are warranted.
Although this study suggested that yoga may improve patients’ perception of memory problems, some of the benefit was because of better sleep.