A study recently published in the Journal of Clinical Oncology compared two exercise-based fall prevention strategies (tai ji quan vs. strength training) for postmenopausal, female cancer survivors who had been treated with chemotherapy and are at higher risk of falls. It concluded that neither intervention found a significant reduction in falls relative to a stretching control group for these individuals (2023; doi: 10.1200/JCO.22.01519). But the researchers say that conclusion isn't the whole story. "Showing that an intervention prevents a single event is a more challenging type of research than studies that measure exercise-induced increases in strength, balance, endurance, and other measures," explained Kerri Winters-Stone, PhD, Professor and Section Head of Cancer Population Science in the Division of Oncological Sciences at the Knight Cancer Institute at Oregon Health & Science University. "I never want to give a message that exercise isn't helpful because we know without a doubt that it is," she told Oncology Times, noting these findings still answer important questions about how to best help this population of cancer survivors.
1 Why compare these two interventions in this population of cancer survivors?
"While we certainly need to understand more about exactly why and how different cancer treatments might increase the risk of falls in persons with cancer, we felt there was an urgent need to test fall prevention strategies that had already been useful in reducing the number of falls that are mostly due to age because they could be more quickly implemented in oncology care than less established programs.
"There have been a few other resistance training and/or balance studies in cancer survivors that have also collected data on falls as secondary or additional endpoints, but these studies were not specifically powered to detect an effect of exercise on falls. So, those results need to be interpreted with caution because they were grossly underpowered."
2 Data showed neither exercise-based fall prevention nor intervention reduced falls. Is the message that these modalities aren't helpful after chemotherapy?
"I'm glad you asked this because I don't think this is the message we want to send. We did find that women could significantly increase their strength and balance by doing specific types of exercise, and both of those attributes are important for daily functioning and long-term fall prevention. These kinds of exercise have many different benefits like improved emotional well-being, weight management, and less fatigue. Our key findings were that tai ji quan exercise and strength training exercise can increase balance and strength in our population of female cancer survivors, respectively, but did not reduce the number of falls.
"When we looked at the data slightly differently, we did detect a positive impact from tai ji quan on fall-related injuries, where injury rates within that group were lower after tai ji quan training than before these women started the study. Although our primary hypotheses weren't fully supported, these findings suggest that, in women who may be at high risk of falls, balance-based exercise could reduce the potential for injurious falls.
"This is highly significant because injuries related to falls can be very costly and deadly. Fall injuries also impact quality of life because people can develop a fear of falling and limit their activities to avoid falls. The latter can lead to a downward spiral of reduced activity that can actually worsen fall risk because of loss of strength and balance from inactivity.
"While it's possible [tai ji quan and strength training] may not be the right fall prevention strategy, there were some methodological limitations to our study that might have affected our findings, too. We may not have recruited a study sample at a high enough risk of falls and thus less responsive to our intervention. In fact, the fall history of women enrolling in our study was lower than we expected. We aren't sure that chemotherapy alone indicates high fall risk. Rather, it might be that having chemotherapy and a history of falls and/or having fall risk factors better identifies the group of cancer survivors who would respond most to exercise-based fall prevention.
"Our interventions may not have been long enough or frequent enough to reduce falls in a short period of time. The trends we observed over time showed the intervention became more effective the longer it went. Since women only exercised twice a week for 6 months and falls are a relatively rare event, if women exercised a little more and we observed them over a longer time period, we might have seen more of an impact.
"I do think that falls in cancer survivors may be more complex than falls due to older age, so more research to identify the major risk factors for falls in different cancer populations may be needed to better inform very specific interventions targeted to the highest risk groups."
3 What's the takeaway message?
"I urge health care providers to ask their patients about whether they have experienced falls or near falls and/or have problems with balance and stability before they start treatment, during treatment, and even in follow-up. A referral to physical therapy could help to identify fall risk factors and address impairments that might increase fall risk. There are no real pharmacologic approaches to reducing fall risk and exercise has known efficacy to reduce falls related to age and possibly cancer treatment, so providers should encourage their patients to engage in balance and strengthening exercises 2-3 days per week.
"[The team is] continuing to better understand falls in different cancer populations and refining our exercise-based approaches. Since COVID we have also had to adapt all of our exercise interventions to online delivery, which has greatly improved the reach and accessibility of our programs. We're very interested now in studying these remote exercise delivery approaches and the potential for them to be rapidly scaled into clinical and community practice."