Patients with breast cancer who undertook yoga following radiotherapy derived physical and emotional benefits from the ancient Indian practice, according to research presented at ASCO.
The study randomized 163 stage 0-III breast cancer patients to either yoga (n = 53), stretching (n = 56), or a wait-listed control group (n = 54). The yoga and stretching groups met 3 times a week for 6 weeks during radiotherapy.
Patients self-reported changes in fatigue, physical function, depression, benefit finding, and spirituality. The authors also assessed cortisol slope and heart rate variability (HRV) with saliva tests and 10-minute electrocardiograms that were collected at baseline, end of treatment, and 1, 3, and 6 months’ follow-up.
By the end of radiotherapy, the yoga and stretching groups showed marked improvements in various study endpoints compared with the control group. The results were calculated as change scores:
There were no differences in scores for spirituality and depression.
The authors also found that the cortisol slope at the end of radiotherapy was steepest for the yoga group compared with the stretching and wait-list control arms (-0.12, -0.08, -0.08, respectively; P <.01 for all).
Yoga has been credited with acting as a stress buffer during radiotherapy, and “what we see by the end of radiotherapy is a split, where the yoga group had the steepest cortisol slope. Blunting of the cortisol slope is actually a predictor of mortality in stage IV disease,” said Lorenzo Cohen, PhD, director of the Integrative Medicine Program in the General Oncology Department at the MD Anderson Cancer Center in Houston, Texas.
Finally, there were significant increases in HRV from baseline to post-therapy for the yoga group (64.3 ms; P < .05) but not for the stretching group (5.8 ms) or the wait-list control arm (-8.1 ms).
His group is now recruiting 600 patients for a phase III trial in which patients will be blinded to the opposite study arm (yoga vs another type of stress management). This will address criticism from the cancer community that yoga offers little more than a placebo effect, Cohen said. The followup for this study will be 1 year, and the authors also will assess economic outcomes, he added. Abstract 9009