Yoga can help with the side effects of prostate cancer treatment
Katrina Mountfort, Touch Medical Media, Reading, UK

External beam radiation treatment (EBRT) is the mainstay of therapy for patients with localized or locally advanced prostate cancer. However, treatment causes a number of side effects, including sexual dysfunction (mostly, but not exclusively, erectile dysfunction [ED]) in up to 85%, often due to the concurrent use of androgen deprivation therapy (ADT).1,2 Other side effects include fatigue; urinary problems including urinary incontinence, radiation cystitis and urethral stricture; bowel problems such as radiation proctitis; and lymphedema.2,3 Fatigue, increasing over the course of the treatment, has been reported by up to 72% of prostate cancer patients undergoing EBRT.4 This can persist for weeks or months after treatment stops. Cancer-related fatigue is considered by patients to be the most distressing symptom of cancer therapy.5

Recently, a groundbreaking study has shown that relief from some of these symptoms may come from an unexpected source. Men who attended a structured yoga class twice a week while undergoing EBRT experienced less fatigue and better sexual and urinary function than those who did not.6 The classes were Eischens yoga, a high-energy class based on Iyengar yoga, and were led by two instructors, the lead instructor teaching 75% of the classes. Each class lasted 75 minutes, beginning with 5 minutes of breathing techniques and ending with 5 minutes of Savasana, a yoga position that involves relaxing while lying on the back. The sessions also involved sitting, standing, and reclining positions that were modified according to individual patient's needs and restrictions using props such as chairs and belts. The study’s primary outcome measure was fatigue, which was measured using a nine-item questionnaire (the Brief Fatigue Inventory) assessing fatigue severity and impact on daily life. The first questionnaire was completed between 2 and 3 weeks before the start of EBRT, then twice a week while receiving between 6 and 9 weeks of EBRT. The final survey was given within a week of the last yoga class or last radiation treatment, according to the treatment arm.

The study enrolled 68 men, but 18 patients withdrew early, mostly due to unavoidable clashes between yoga classes and radiation therapy, leaving 22 and 28 patients in the yoga and no-yoga groups, respectively. At baseline, both groups were at the lower end of the fatigue scale but as treatment progressed, patients in the yoga arm reported lower fatigue over time whereas those in the control arm reported greater fatigue as treatment progressed. This was a surprising finding; researchers had anticipated that yoga might help men maintain their energy levels but not that they would improve. Levels of fatigue would normally be expected to rise around the fourth or fifth week of a radiotherapy course. The difference between the groups was statistically significant for global fatigue, impact of fatigue, and severity of fatigue subscales (p

Sexual health scores also significantly improved in the yoga group (p=0.0333), according to the International Index of Erectile Function (IIEF) questionnaire, in which scores range from 0-25. Scores greater than 21 are considered normal and scores below 12 indicate moderate to severe ED. At the start of the study, both groups scored around 11. The scores in the yoga group were reported as ‘moderately favourable’, while scores in the non-yoga group declined over the course of treatment. However, the differences between the groups were significant only at 4 weeks (p=0.047) and not at the final follow up at 6 to 9 weeks (p=0.314). Nevertheless, the findings are impressive because a higher percentage of the yoga group received ADT during the study period than controls (60 % versus 53 %, respectively). One reason for the benefits may be the known benefits of yoga on pelvic floor muscle strength,7 which may also explain the improvements in urinary function reported by yoga participants in this study. However, an acknowledged limitation of this study is that the benefits could be at least partly due to non-yoga effects such as focused attention or social interaction.

The results on quality of life measures were largely positive but less conclusive. The patients in the yoga arm showed significant improvements in emotional, physical, and social scores, but not on functional scores.

These findings will add to the growth body of evidence in support of the benefits of yoga, which include physical and mental health.8 Another recent study has found that yoga may help sedentary individuals with arthritis safely increase physical activity, and improve physical and psychological health as well as quality of life.9 This is not the first time yoga has proved beneficial in cancer patients, but these have mostly been women with breast cancer. A recent review of 12 randomised and 13 non-randomised trials concluded that yoga improved quality of life and ameliorated sleep and fatigue.10 However, it has never before been investigated in prostate cancer. The study was initially greeted with cynicism, with doubts that men would sign up for yoga, or take it seriously;11 it has been estimated that less than 7% of the adult who practice yoga are men older than 44 years.12 However, the researchers were staggered by the enthusiasm of the participants, who had a median age of 67.3 years and none of whom had never practiced yoga before.

This study is impressive on several levels. Firstly, it showed a high interest and participation in yoga among men with prostate cancer. Secondly, it demonstrated how complementary therapy can be incorporated within cancer treatment regimens, and finally, it found that two of the most distressing side-effects of EBRT for prostate cancer – fatigue and ED – can be improved by regular yoga practice. An extension study is planned to determine whether these effects will be durable, followed by a randomized controlled study.

References


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