Slow Walking Pace May Be Cause for Alarm in Cancer Survivors

Survivors of cancer are 42% more likely to walk at a slower pace and experience mobility disability compared with healthy peers, which may be associated with a higher mortality rate for up to five years after treatment, according to data published in the American Association for Cancer Research.

Results of this study demonstrated that a cancer diagnosis was associated with poor ambulatory function, or a slower walking pace. A significant association with slow walking was seen in those with a previous diagnosis of breast, colon, oral, prostate, rectal, respiratory, soft tissue, stomach and urinary cancers. The same diagnoses, as well as endometrial, were also associated with a greater risk of being disabled compared with cancer-free, age-matched peers.

A slower walking pace was associated with a higher risk of all-cause and cancer-specific mortality. When comparing survivors with slow and fast walking paces, those with a slower pace had more than double the risk for all-cause mortality. A similar association was also seen in mobility disability and all-cause mortality.

In an interview with Heal®, lead author of the study Elizabeth Salerno, assistant professor of surgery at Washington University School of Medicine in St. Louis, discussed the study and what it means for survivors.

Heal®: What are some key highlights and takeaways from the study for survivors in particular?

Salerno: We really had two key takeaways and findings. We found that the risk for poor ambulatory function as we measure it — so, slower walking pace or having mobility disability — was higher in cancer survivors compared with cancer-free, age-matched controls. And then we also found that survivors who reported slower walking or having mobility disability were at a higher risk for all-cause mortality. And I think one of the big takeaways here is that these findings were consistent across several different types of cancer.

What does “poor ambulatory function” mean?

In our study, poor ambulatory function was indicated by self-reporting a slow walking pace (less than 2 mph) or being unable to walk.

Why was this study conducted?

So, it’s likely no surprise to you and many others that cancer survivors are now living longer than ever before, which is exciting, and we love to see that.

But understanding how the diagnosis of all these different types of cancers can affect ambulatory function — which is potentially modifiable — could lead to new treatment strategies, new rehabilitation strategies and, ultimately, improve the health and longevity of survivors. And so that really was the impetus for us studying this particular ambulatory function.

What do the implications of this study mean for survivors?

I think this study, hopefully, lays a foundation for future work to better understand some of these associations. So, with this, one of the first questions on the questionnaire asked survivors to report their normal walking pace. (We) really need to better understand if we can intervene with targeted interventions like physical activity (to) actually increase walking speed or improve mobility so that we can ultimately improve the lives of cancer survivors. There’s a lot more to be done, but this lays us a nice foundation, particularly for wide surveillance of cancer survivors.

Why are we seeing people have poor ambulatory function after surviving cancer?

That’s a great question and something that I wish we knew more about in the research community. Poor ambulatory function after receiving a diagnosis of cancer and the cause of that is certainly thought to be multifactorial. And we certainly weren’t able to analyze that in this study, and we don’t necessarily demonstrate a causal relationship. But there is a lot of thought about accelerated or accentuated aging that we often see after a diagnosis of cancer. So reduced functional levels certainly could be a part of that.

It could be due to the cancer itself or to changing behavioral factors after a receiving diagnosis of cancer or before that, (which) may predispose an individual to develop cancer in the first place. Or (it could be due) to treatment-related factors. So, all of that is something that we (should) certainly do more research on.

Could something be done during cancer treatment to help prevent this?

Something that we always think about is: When is the optimal time for us to intervene? When is the optimal time for us to be assessing a lot of these different indicators? I don’t know what this study necessarily tells us about when we need to intervene or when we need to monitor, but it definitely tells us that ambulatory function is important, at least in this context. So (do) we need to be monitoring this earlier — during active treatment, right after active treatment? It’s definitely worth further study.

Should this and will this change survivorship care?

I think the monitoring is something of utmost importance for providers and for clinicians, making sure we have continuity of care — and so really thinking about this indicator, function and walking speed because they are potentially modifiable. So, I think if we do some research to better understand the mechanisms of why certain cancers have stronger associations, then absolutely, I can certainly see targeted interventions being developed and then, of course, delivered at appropriate times.

What does this study mean for survivors right now? Is there anything they can do to help themselves if they do experience poor ambulatory function?

Our findings suggest that survivors would do well to watch for poor ambulatory function after a diagnosis and to reach out to their physicians if they are concerned about a loss in mobility or slowed walking pace. Research from other studies suggests that physical activity may improve function during survivorship, and a necessary next step is identifying the extent to which targeted physical activity interventions may improve self-reported ambulatory function after cancer.

What further research should be done?

Certainly more immediate steps would be understanding why certain cancers have those stronger associations with (ambulatory) function and then, of course, (ambulatory) function (association) with mortality than others.

To our understanding, this was the first study to do this analysis in 15 different cancer types. So now we really need to dig further into why we see some of these associations. That may include looking at behavioral factors, biological factors and cancer-specific factors that may be changing from diagnosis all the way well into survivorship. And it’ll really be important for us to better characterize these associations within unique, specific cancer types.

Then, of course, maybe long-term steps would be including measured and self-reported ambulatory function like walking pace or mobility disability, as well as objective measures (for which) we have people come into the clinic and actually time how quickly they walk.

So these results provide a nice signal for the cancer-function mortality relationship in a larger population that we really need to (examine) a bit further. Because again, this would allow us to determine how we need to be targeting ambulatory function so that we can have a lasting impact on survival.

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