Randomized controlled trial of increasing physical activity on objectively measured and self-reported cognitive functioning among breast cancer survivors: The Memory & Motion study

Abstract

Background

Increasing physical activity can improve cognition in healthy and cognitively impaired adults; however, the benefits for cancer survivors are unknown. The current study examined a 12-week physical activity intervention, compared to a control condition, on objective and self-reported cognition among breast cancer survivors.

Methods

Sedentary breast cancer survivors were randomized to the Exercise arm (n=43) or Control arm (n=44). At baseline and 12-weeks, objective cognition was measured with the NIH Cognitive Toolbox and self-reported cognition with PROMIS scales. Linear mixed effects regression models tested intervention effects for changes in cognition scores.

Results

Participants’ (n=87) were on average 57 years old (SD=10.4) and 2.5 years (SD=1.3) post-surgery. Oral Symbol Digit (measure of processing speed) evidenced differential improvement in the Exercise vs. Control arms (b=2.01; p<0.05). The between group differences in improvement on self-reported cognition was not statistically significant, but suggestive of potential group differences. Time since surgery moderated the relationship with participants ≤2 years post-surgery having significantly greater improvement in Oral Symbol Digit score, Exercise vs. Control (b=4.00, p<0.01); no significant improvement was observed in patients who were >2 years post-surgery (b=−1.19, p=0.40). A significant dose response was observed with greater increased physical activity associated with objective and self-reported cognition in the Exercise arm.

Conclusions

The exercise intervention significantly improved processing speed, but only among those diagnosed with breast cancer within the past 2 years. Slowed processing speed can have substantial implications for independent functioning supporting the potential importance of early implementation of an exercise intervention among breast cancer patients.