A clinical trial getting underway at OHSU will compare two types of exercise – tai chi versus strength training – as a means to prevent falls and injuries in men who’ve received androgen deprivation therapy, or ADT, for prostate cancer.
Lowering levels of male hormones, called androgens, makes prostate cancers shrink or grow more slowly. It is a mainstay of treatment, but it’s also associated with osteoporosis, muscle wasting and a significantly increased risk of frailty, falls and devastating bone fractures.
“Strength training and tai chi each have been found to reduce falls attributed to age-related risk factors, but not cancer-specific risk factors,” said principal investigator Kerri Winters-Stone, Ph.D.
“We think that one or both might also be effective for men at risks of falls due to prostate cancer therapy. And because such programs are already available in community settings they could translate very quickly to patient care.” Winters-Stone is the Elnora E. Thompson Distinguished Professor in the OHSU School of Nursing and co-leader of the Knight Cancer Institute’s Cancer Prevention and Control Program.
In a 2017 study of men treated for prostate cancer, Winters-Stone and co-authors found that falls were more than twice as common among current and past users of ADT than among never users. Current or past users of ADT had a likelihood of recurrent falls (two or more) that was six times as high as that of never users, the researchers found, after using statistical modeling to adjust for the effect of age, disease severity, and other treatments men received.
The exercise clinical trial, called GET FIT Prostate, will be the first head-to-head comparison of the two exercise modalities and their ability to protect prostate cancer survivors from falls, frailty and functional limitations. The project responds to the National Cancer Institute research priority to expand care to prevent disability in older survivors. A grant from the NCI will provide up to $2.5 million over five years to pay for the direct costs of the randomized, controlled trial.
“The best possible outcome would be that both experimental interventions decrease the risk of falls – that would give men twice as many options to avoid falls and their devastating injuries.”
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The trial will randomly assign prostate cancer survivors to either a tai chi group, a strength training group, or a placebo control group that will practice seated stretching exercises. The subjects in all three groups will take part in supervised exercise programs three times a week for six months. They will be followed for six months after formal training stops to find out if the effects of training persist.
Winters-Stone and colleagues will track the frequency of falls and also record changes in physical functioning and frailty, such as muscle shrinking, weakness, and loss of balance. The researchers will also analyze their findings to see if there are ways to predict who will respond best to either strength training or tai chi.
“To me the best possible outcome would be that both experimental interventions decrease the risk of falls – that would give men twice as many options to avoid falls and their devastating injuries,” Winters-Stone said. Co-investigators are Nathan Dieckmann Ph.D., in the OHSU School of Nursing, and Tom Beer, M.D, Christopher Amling, M.D., Arthur Y. Hung, M.D., and Fay Horak Ph.D., P.T., in the OHSU School of Medicine.
The study will enroll prostate cancer survivors in the Portland metro area, and in Bend, Eugene and Salem. The researchers expect to start enrollment in January 2019.
