Pennsylvania: Men who attended a structured yoga class twice a week during prostate
cancer radiation treatment reported less fatigue and better sexual and
urinary function than those who didn’t, according to a clinical trial
led by the Perelman School of Medicine at the University of Pennsylvania.
It is the first randomized trial to look at the effect of twice-weekly
yoga on the side-effects and quality of life issues caused by prostate
cancer treatment. The results published this week in the International Journal of Radiation Oncology, Biology, and Physics.
All of the patients in the trial underwent between six and nine weeks
of external beam radiation therapy for prostate cancer. The patients
were randomized into two groups: one arm participated in a yoga class
that met twice a week and the other arm served as a control group.
Patients who already practiced yoga on their own were not eligible for
the study, nor were patients with a history of prior radiation therapy
or those with metastatic disease.
Only two instructors led classes for this study, with the lead
instructor teaching 75 percent of the classes. Each session lasted 75
minutes, beginning with five minutes of breathing and centering
techniques and ending with five minutes of Savasana, a common yoga
position. Typical sessions incorporated sitting, standing, and reclining
positions that were modified using props to adapt to each patient’s
needs and restrictions.
Patients were primarily evaluated on their level of fatigue. Each man
filled out a nine-item questionnaire assessing fatigue severity and
impact on daily life. The first questionnaire was given between two and
three weeks before the start of radiotherapy, then twice a week while
receiving radiotherapy, with a final survey filled out within a week of
their last yoga class or last radiation treatment, depending on the
assigned study arm.
“At their baseline, before patients started treatment, patients in
both groups were on the lower end of the scale, meaning they reported
lower amounts of fatigue,” said the trial’s principal investigator Neha Vapiwala, MD, an associate professor of Radiation Oncology. “But as treatment went on, we observed a difference in the two groups.”
Patients in the yoga group reported lower fatigue scores over time,
as they attended more yoga sessions, relative to where they started.
Patients who did not participate in yoga trended in the opposite
direction, reporting greater fatigue as treatment progressed.
“Levels of patient-reported fatigue are expected to increase by
around the fourth or fifth week of a typical treatment course, but that
did not happen in the yoga group,” Vapiwala said. “Both the severity of
the fatigue as well as the patients’ ability to go about their normal
lives appeared to be positively impacted in the yoga group.”
Researchers also evaluated both groups in terms of their sexual
health. Sexual dysfunction – including but not limited to erectile
dysfunction (ED) – is reported by up to 85 percent of radiation therapy
patients during treatment, often due to the concurrent use of androgen
deprivation therapy (ADT). The study utilized 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. Both groups started out with scores of
around 11, and were balanced in terms of ADT exposure; but while the
yoga group’s score ended up largely unchanged from baseline, the
non-yoga group saw a decline over the course of treatment.
“Yoga is known to strengthen pelvic floor muscles, which is one of
several postulated theories that may explain why this group did not
demonstrate declining scores, as seen in the control group,” Vapiwala
said. “That may also explain the yoga patients’ improved urinary
function scores, another finding of this trial.” Vapiwala pointed out
that the findings on improved or stable urinary function are consistent
with other research on the effects of physical therapy on pelvic floor
muscles.
The trial also found that while the emotional well-being of both
groups increased as patients progressed through treatment, the
evaluation scores in the yoga group rose more rapidly than in the
control group. An evaluation of physical well-being showed a similar
pattern.
This study was partially funded through an American Cancer Society
Institutional Grant and a Prostate Cancer Foundation Young Investigator
Award.