Accelerated sarcopenia and outcomes in older adults with cancer: The Health ABC Study.

Abstract

11526 Background: Progressive loss of muscle mass and strength (sarcopenia) is a well-known phenomenon of aging; however, little is known about the contribution of a cancer diagnosis to sarcopenia and its subsequent impact on disability. Using a prospective cohort of older adults from pre- to post-cancer diagnosis and a similarly-followed non-cancer cohort, we examined the trajectory of sarcopenia measures and their association with overall survival (OS) and major disability among those with cancer. Methods: The Health, Aging, and Body Composition (Health ABC) Study is a prospective longitudinal study where 3,075 community-dwelling older adults (70-79y) underwent 6 annual assessments of body composition and were followed for development of sentinel events (cancer, disability, death). Appendicular lean mass (ALM [kg]) was a sum of DXA-based lean tissue of all extremities. Hand grip strength (HGS [kg]) was averaged from 2 trials per hand. Gait speed (GS) was evaluated over a 20m course. We used linear mixed effect models to compare the change in ALM, HGS, and GS between individuals who subsequently developed cancer and those who did not, adjusting for age, race, gender, enrollment site. Among patients with cancer, we used multivariable cox regression for time from cancer diagnosis to mortality and major disability (cane/walker, inability to walk 0.25 mile/climb 10 steps, assistance with activities of daily living) treating sarcopenia measures as time-varying covariates. Results: Mean age at enrollment was 75y; 52% female; 42% black; 515 new cancers (prostate: 23%, colorectal: 15%, lung: 13%, breast: 11%). Compared with non-cancer controls, we found significantly steeper declines in HGS ( p= 0.03) and GS ( p< 0.001), and a trend in ALM ( p= 0.07) prior to cancer diagnosis; and a significantly steeper decline in ALM ( p< 0.001), but no difference in HGS ( p= 0.6) or GS ( p= 0.4) after cancer diagnosis. Slow GS was associated with a 44% increase in mortality ( p= 0.02) and a 70% increase in disability ( p= 0.02), but not ALM or HGS. Conclusions: Accelerated loss in sarcopenia measures both prior to and after a cancer diagnosis, and association with disability and mortality in older adults with cancer, present opportunities for targeted interventions.