"This research represents by far the largest yoga study done in cancer survivors to date," said Luke Peppone, PhD, MPH, a research assistant professor at the University of Rochester in New York. He presented data the annual meeting of the American Society of Clinical Oncology.
The YOCAS (Yoga for Cancer Survivors) regimen was developed in 2007 by Dr. Karen Mustian at the University of Rochester, explained Dr. Peppone, who presented two posters on YOCAS at the ASCO conference. The first represented data from 167 breast cancer survivors, 95 of whom were receiving aromatase inhibitors, and 72 of whom were receiving tamoxifen.
"Aromatase inhibitors are the main treatment in post-menopausal breast cancer patients with hormone-positive breast cancer. They take AIs for five years after chemotherapy and radiation, because that kind of cancer grows off estrogen," explained Dr. Peppone.
"AIs reduce your estrogen level to virtually zero, but one of the things estrogen is good for is keeping your joints healthy. So 50% of these patients get some musculoskeletal and joint pain. In 20%, the effect is so severe that they stop taking the medication," he explained. The yoga program is designed, in part, to ameliorate this adverse effect of AI treatment.
The YOCAS program utilizes breathing exercises, meditation, and 18 Hatha and restorative yoga postures, in some of which, participants support themselves on a yoga mat or blanket. Dr. Peppone described the YOCAS protocol as, "an ideal intervention for someone who has not been exposed to yoga. We did two 75 minute sessions a week."
YOCAS is one of a number of yoga therapy protocols developed at cancer centers with the goal of tailoring this ancient health-maintenance practice to the needs and physical limitations of people with cancer. The current studies add to a large and growing body of data showing how regular yoga practice can improve quality of life (read, Once Considered "Fringe," Yoga Enters Mainstream Cancer Care).
Joint Pain & Muscle Aches
At baseline, patients taking AIs rated their level of general pain as 2.65 on a scale of 1 to 5, compared to 2.17 for those on tamoxifen. Muscle aches were also worse among the women taking AIs (mean joint pain score of 2.14 vs. 1.65) on a scale of 0 to 4). The women on AIs reported their level of total discomfort as 8.03 on a scale of 0 to 24, compared to 5.92 for those on tamoxifen.
Compared with those who did not take the yoga program, the women who participated in YOCAS showed a mean 0.37-point reduction in general pain score, a 0.58-point reduction in muscle aches, and a 2.07 point reduction in total physical discomfort.
The original aim of the trial was to look at the effect of yoga on sleep quality in all cancer survivors, Dr. Peppone said. Originally, it enrolled over 400 participants from 23 sites and sub-sites, including community clinics.
The investigators observed, "a 21% decrease in sleep medication use in the yoga group, while we found a 5% increase in sleep medication increase in the control group," he said, adding that a paper discussing the findings is to be published in the Journal of Clinical Oncology.
Yoga & "Chemo-Brain"
Dr. Peppone's second poster covered a randomized, controlled clinical trial involving 358 cancer survivors, and looking at the impact of YOCAS on another common, sometimes debilitating side effect experienced by cancer survivors: "chemo brain."
"Patients report a decrease in cognitive abilities like memory and problem solving when they undergo chemotherapy, and 30 to 40% of the time, those abilities don't go back to normal for as long as five years or even more," he explained.
The researchers looked at data from 358 patients who had participated in the prior study of yoga and sleep: 96% were female, and 75% had survived breast cancer. The median age was 54.
Between two and 24 months after the completion of adjuvant therapy, the patients were randomized to a YOCAS intervention, or to no intervention at all.
"In this study, we didn't have any objective measures of memory; we just asked them if they have difficulty remembering things or working things out, on a scale of 0 to 10, with 10 being as bad as can imagine, and 0 meaning none at all. Of those who were in the YOCAS arm, more than 25% experienced at least a 30% improvement in (self-reported) memory."
While the exact etiology of 'chemo brain' is unknown, Dr. Peppone speculated that high levels of inflammation play a role. "We know from research into serious cognitive disorders like Alzheimer's that physical activity in general, which reduces inflammation, does a very good job of helping with memory."
According to this theory, inflammatory molecules like interleukin-6 and C-reactive protein make their way into the brain, and alter the way it functions. "When you exercise, your muscles release anti-inflammation molecules like IL-1 receptor antagonist and IL-4," he explained.
The YOCAS researchers are currently planning a pilot study of low-level physical activity, such as walking and using elastic bands for resistance training, in about 20 people, he said. They are also planning another multi-center yoga trial looking more at the mechanisms behind yoga's effect on sleep and fatigue. This larger study would involve as many as 600 patients, who received YOCAS for eight weeks and were followed for up to three months, to see if the benefits are sustained.