An Examination of the Longitudinal Relationship Between Cognitive Function and Physical Activity Among Older Breast Cancer Survivors in the Thinking and Living With Cancer Study.

Physical activity may improve cognitive function for older cancer survivors; however, cognitive function may also affect the ability to organize oneself to be physically active. We examined this potential bidirectional relationship in a sample of 395 women with newly diagnosed, nonmetastatic breast cancer, and 374 noncancer controls. These women completed cognitive tests and surveys yearly for 36 months. Surveys included their subjective cognitive function and physical activity. We examined the relationships between cognitive function (both objective and subjective) and physical activity over time (baseline, 12, 24, and 36 months). We found that when cancer survivors reported higher physical activity, they had better objective cognitive function at 12 months, and they reported better subjective cognitive function at 12 and 24 months. However, physical activity did not predict cognitive function at later time points, and cognitive function did not predict physical activity at later time points. In controls, better subjective cognitive function was related to higher physical activity overall, but there were not relationships over time or at specific time points. This was an observational study; therefore, future research should consider the potential impact of cognitive function when older cancer survivors are attempting to increase their physical activity.