Men with prostate cancer became more vulnerable to falls if they used androgen deprivation therapy, and the heightened risk of falling persisted for more than a year after ending therapy, a study has revealed.
It’s an eye-opening result given that nearly half of all prostate cancer patients receive androgen deprivation therapy at some point. Lowering levels of male hormones, called androgens, makes prostate cancers shrink or grow more slowly for a time. The known side effects include fatigue, osteoporosis, muscle wasting, and fat gain.
“This is not the kind of thing you just rebound from,” said the study’s first author, Kerri Winters-Stone, Ph.D., Elnora E. Thompson Distinguished Professor in the School of Nursing at Oregon Health & Science University and co-leader of the Knight Cancer Institute’s Cancer Prevention and Control Program.
Image: details from “Leaning, Flying and Falling,” an 1829 lithograph by George Scharf in the online collection of the National Gallery of Art.What has remained uncertain is the short and long-term impact of these body changes on men’s vulnerability to falls and falls-related injuries, which are the costliest and most life-threatening injuries in older persons.
Winters-Stone and colleagues analyzed questionnaire responses from 280 men age 49 to 94 diagnosed with prostate cancer within the last ten years. The questionnaires asked about their treatment, falls history, frailty status and other characteristics. The researchers confirmed the use of androgen deprivation therapy, or ADT, in electronic health records. They categorized each participant as a never user, current user (dose received within the past year), or past user (no ADT treatment for a year or more).
Falls were more than twice as common among current and past ADT users than among never users: 37 percent of current users and 34 percent of past users had one or more falls in the past year, compared with 15 percent of never users.
Current or past users of androgen deprivation therapy had a likelihood of recurrent falls that was six times as high as that of 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 received.
The male-hormone suppressing therapies were associated with nearly three times the odds of any frailty, a sign of accelerated aging. The prevalence of frailty did not significantly differ between current and past users. Traditionally defined frailty or a more contemporary definition that includes obesity in the calculation (“obese frailty”) were associated with a three to four-fold greater risk of falling.
“These findings strongly suggest that ADT is not merely a proxy indicator of disease severity or overall health status, but has an independent influence on fall risk, potentially through frailty,” the researchers concluded in their paper in the Journal of the American Geriatrics Society.
The main limitation of the study is its cross-sectional design, which can’t prove cause-and-effect between ADT use and falls. Nevertheless, Winters-Stone said there’s enough evidence for clinicians to pay serious attention to fall prevention in men treated with ADT, for instance by screening for frailty and following guidelines for fall prevention.
Prostate cancer survivors can benefit from exercises that build strength. A referral to a physical therapist could identify gait and balance problems, for which there are prescribed exercises that can improve stability. It’s important to stay up-to-date on vision checkups, and to eliminate home hazards such as broken stairs, poor lighting and uneven or cluttered floors. It may be prudent to have a pharmacist review medications to avoid those that can interfere with balance.
“I think there is a fair amount that can be done just to lower the risk in general,” Winters-Stone said.
An earlier randomized clinical trial led by Winters-Stone showed that targeted exercise can slow bone loss, reverse muscle weakness, and prevent gains in body fat in men with prostate cancer receiving ADT. The exercise program combines functional resistance training with jumping exercises performed wearing a weighted vest.
“We’ve shown that certain kinds of training can reverse a lot of the components that increase risk of falling,” she said. But it remains unknown whether such a program can specifically reduce the risk of falls and injuries. Winters-Stone plans next to pursue trials that will help define the type of exercise training needed to prevent falls and frailty in prostate cancer survivors.
Falls and Frailty in Prostate Cancer Survivors: Current, Past, and Never Users of Androgen Deprivation Therapy by Kerri M. Winters-Stone, Esther Moe, Julie N. Graff, Nathan F. Dieckmann, Sydnee Stoyles, Carolyn Borsch, Joshi J. Alumkal, Christopher L. Amling, and Tomasz M. Beer, Journal of the American Geriatrics Society (March 6, 2017)
Resistance Exercise Reduces Body Fat and Insulin During Androgen-Deprivation Therapy for Prostate Cancer by Kerri Winters-Stone, Nathan F. Dieckmann, Gianni F. Maddalozzo, Jill A. Bennett, Christopher W. Ryan, and Tomasz M. Beer; Oncol Nurs Forum, (July 2015)
Resistance training reduces disability in prostate cancer survivors on androgen deprivation therapy: evidence from a randomized controlled trial by Kerri Winters-Stone, Jessica C. Dobek, Jill A. Bennett, Nathan F. Dieckmann, Gianni F. Maddalozzo, Christopher W. Ryan, and Tomasz M. Beer; Arch Phys Med Rehabil (January 2015)
Skeletal Response to Resistance and Impact Training in Prostate Cancer Survivors by Kerri M. Winters-Stone, Jessica C. Dobek, Jill A. Bennett, Gianni F. Maddalozzo, Christopher W. Ryan, and Tomasz M. Beer; Med Sci Sports Exerc (August 2014)