Psychooncology. 2017 Jan 11;:
BACKGROUND: Change in cognitive ability is a commonly reported side effect by breast cancer survivors (BCS). The underlying etiology of cognitive complaints is unclear and to date there is limited evidence for effective intervention strategies. Exercise has been shown to improve cognitive function in older adults and animal models treated with chemotherapy. This proof-of-concept randomized controlled trial (RCT) tested the effect of aerobic exercise versus usual lifestyle on cognitive function in postmenopausal BCS.
METHODS: Women, age 40-65 years, postmenopausal, stage I-IIIA breast cancer, and who self-reported cognitive dysfunction following chemotherapy treatment were recruited and randomized to a 24-week aerobic exercise intervention (EX; n = 10) or usual lifestyle control (CON; n = 9). Participants completed self-report measures of the impact of cognitive issues on quality of life (FACT-Cog), objective neuropsychological testing and functional magnetic resonance imaging (fMRI) at baseline and 24-weeks.
RESULTS: Compared to CON, EX had a reduced time to complete a processing speed test (Trail Making Task-A) (-14.2 seconds, p < 0.01; effect size [ES] 0.35). Compared to CON, there was no improvement in self-reported cognitive function and effect sizes were small Interestingly, lack of between-group differences in Stroop behavioral performance were accompanied by functional changes in several brain regions of interest in EX compared to CON at 24-weeks.
CONCLUSION: These findings provide preliminary proof-of-concept results for the potential of aerobic exercise to improve cancer-related cognitive impairment, and will serve to inform the development of future trials.