Physical activity and mobility disability in older adult cancer survivors.

Background: Cancer survivors may be more likely to experience accelerated declines in physical function compared to cancer-free controls, but objective data and knowledge of preventive interventions are limited.

Methods: The Lifestyle Interventions and Independence for Elders (LIFE) study was a multicenter, single-blinded, randomized trial conducted at 8 centers across the United States that enrolled 1635 sedentary adults aged 70-89 years and with physical limitations but who could walk 400 m at baseline, of which 371 (22.7%) reported a history of cancer. Participants were randomized in a 1:1 ratio to a health education or physical activity program. The primary endpoint was time to major mobility disability, defined objectively by the inability to walk 400 m in less than 15 minutes.

Results: Cancer history modified the effect of randomized group on major mobility disability (P = .006). Among those randomized to the health education program, participants with a history of cancer were 53% more likely to develop major mobility disability compared with participants who did not have a history of cancer (Hazard Ratio (HR) = 1.53; 95% CI = 1.18 to 1.99; P = .001). Among participants with a history of cancer, those randomized to the physical activity program were 43% less likely to develop major mobility disability compared with the health education program (HR = 0.57; 95% CI = 0.40 to 0.82; P = .003).

Conclusion: In this analysis of a randomized clinical trial, cancer survivors had an increased risk of mobility disability compared with non-cancer controls, and physical activity attenuated this risk.