Physical Activity And Cognition: Longitudinal Findings From The Thinking And Living With Cancer Study

Physical activity engagement reduces treatment-related side effects and improves functional capacity, cognition, and quality of life in cancer survivors. Despite these benefits, physical activity participation is low among breast cancer survivors, and less is known in older survivors. The effect of physical activity on cognition in older survivors and the potential mechanistic role of inflammation have also not been explored. PURPOSE: We evaluated longitudinal physical activity in older breast cancer survivors compared to non-cancer controls, identified if meeting Aerobic Physical Activity Guidelines was related to cognition in survivors, and explored the role of inflammation. METHODS: Older breast cancer survivors (68 ± 5 years, n = 216) and controls (67 ± 5 years, n = 216) were assessed at baseline (post-surgery, pre-systemic therapy) and annual visits for up to five years. Actigraphy assessed weekly minutes of moderate-to-vigorous physical activity (MVPA). Functional Assessment of Cancer Therapy-Cognitive Function perceived cognitive impairment (FACT-Cog PCI) evaluated perceived cognition. Neuropsychological tests measured objective cognition. Plasma levels of C-reactive protein (CRP) and interleukin-6 (IL-6) assessed inflammation. Data were analyzed using linear mixed-effect models, random-effect contemporaneous fluctuation models, and multi-level mediation models. RESULTS: There were no early MVPA differences between survivors and controls, but survivors had significantly less weekly MVPA by 36 (110 ± 21 min vs. 156 ± 21 min), 48 (82 ± 23 min vs. 142 ± 22 min), and 60 (74 ± 26 min vs. 135 ± 22 min) months post baseline. Fewer survivors than controls met Physical Activity Guidelines at 36 months (17.7% vs. 33.0%, p = 0.030). When Guidelines were met (vs. not), FACT-Cog PCI scores were 2.08 ± 0.98 (p = 0.034) points higher. MVPA was inversely associated with CRP and IL-6; inflammation did not mediate MVPA effects on perceived cognition. MVPA was not related to objective cognition. CONCLUSION: Survivors were less physically active than controls, especially farther from diagnosis. Meeting Guidelines was associated with better perceived cognition. Three-to-five years post-surgery may be a critical time for physical activity interventions targeting cognition in older breast cancer survivors. NIH (R01AG068193, R01CA129769, R35CA197289, R35CA283926, R21AG075008, P30CA51008, R56AG068086, R01CA237535, K01AG065485, P30AG028716, K01CA212056, K08CA241337, R01CA172119, U54CA137788, P30CA008748, K99CA270294, R01CA244673, P30AG010133, P30AG072976, R01CA261793, T32AG000029), Cousins Center for PNI