Effects of aerobic exercise on neurocognitive function in postmenopausal women receiving endocrine therapy for breast cancer: The Exercise Program in Cancer and Cognition randomized controlled trial

Objective The Exercise Program in Cancer and Cognition Study was a randomized controlled trial designed to determine whether 6 months of moderate‐intensity aerobic exercise improves neurocognitive function in women with breast cancer (BC) receiving endocrine therapy (ET). Methods Postmenopausal women with hormone receptor+, early‐stage BC, within two years post‐primary therapy were randomized to the exercise intervention (six months, ≥150 min of moderate‐intensity aerobic exercise/week) or usual care control condition. Outcomes were assessed at pre‐randomization and after intervention completion. Groups were compared using linear mixed‐effects modeling. Results Participants (N = 153) were X‾ $\overline{X}$ = 62.09 ± 8.27 years old, with stage I BC (64.1%) and a median of 4.7 months post‐diagnosis. We found a group‐by‐time interaction (p = 0.041) and a trend for the main effect of time (p = 0.11) for processing speed with improved performance in the exercise group and no change in the controls. Similar main effects of time were observed for learning and memory (p = 0.024) and working memory (p = 0.01). Better intervention adherence was associated with improved processing speed (p = 0.017). Conclusions Six months of moderate‐intensity aerobic exercise improves processing speed in postmenopausal women with BC receiving ET who initiate exercise within 2 years of completing primary therapy (surgery +/− chemotherapy). This is the first large‐scale study to examine the effects of aerobic exercise on neurocognitive function in women with BC. Additional research is needed to address the long‐term effects of aerobic exercise on cognitive function.