The Feasibility and Acceptability of a Remotely Delivered, Combined Exercise Intervention on Cognitive Function in Patients With Breast Cancer Following Chemotherapy: Randomized Controlled Trial.

backgroundCognitive impairments, a prevalent quality-of-life concern in breast cancer (BC), are particularly pronounced in women having undergone adjuvant chemotherapy. These impairments-affecting executive function, attention, and processing speed-are often underdiagnosed, with no established treatments. Exercise is a potential intervention to mitigate cancer-related cognitive impairment (CRCI). Since virtual care delivery is feasible, remotely delivered exercise interventions for CRCI management in patients with BC may be explored.

objectiveWe examined the feasibility of an 8-week remotely delivered combined exercise program (aerobic+resistance training) compared to a stretching and toning active control in postchemotherapy patients with BC.

methodsPatients with BC who completed adjuvant chemotherapy within 48 months were recruited across Canada from February to July 2023. The combined exercise group engaged in unsupervised aerobic exercise (30 minutes, thrice per week), supervised group-based resistance training (30 minutes, twice per week via Zoom [Zoom Communications, Inc]), and one recorded class weekly, supplemented with 4 biweekly behavioral counseling sessions. The active control group participated in low-intensity balance and flexibility classes (30 minutes, twice per week live, once per week recorded). Feasibility was assessed via enrollment, adherence, attrition, measurement completion, adverse events, and participant satisfaction; cognitive function, using the National Institutes of Health Toolbox Cognition Battery Remote Administration (V2) at baseline and post intervention.

resultsTwenty-one participants (mean age 51.6, SD 7.2 years; 11.8, SD 12.9 months since treatment) were randomized to the combined exercise (n=10) or the active control (n=11) group. Final analyses included 18 participants (mean age 51.9, SD 7.4 years; mean months since treatment 12.6, SD 13.5) with 9 participants in each group (51.2% enrollment rate; 14.3% attrition; no adverse events). Measurement completion rates were 85.7% and participants reported high satisfaction with the intervention, indicating minimal burden. Adherence rates for exercise classes were 70.8% in both groups. Adherence to behavioral counseling sessions was 77.5% (combined exercise group only). There were no significant differences in objectively measured cognitive function, but small-to-medium effect size improvements were observed in objectively measured episodic memory (mean difference 5.33, 95% CI -12.5 to 23.2; ηp²=0.03), working memory (mean difference 8.17, 95% CI -4.2 to 20.6; ηp²=0.12), executive function updating (mean difference -394.35, 95% CI -1035.67 to 246.96 ms; ηp²=0.07), and immediate memory and verbal learning (mean difference +3.22, 95% CI -2.0 to 8.5; ηp²=0.12), trending toward the multicomponent exercise group vs the active control group. In contrast, small-to-medium effect size improvements were observed in the Oral Reading Recognition Test (mean difference -9.65, 95% CI -22.9 to 3.5; P=.14; ηp²=0.14) and Picture Vocabulary Test (mean difference -2.48, 95% CI -5.2 to 0.3, P=.07; ηp²=0.20), trending toward the active control group.

conclusionsA remotely delivered combined exercise intervention is feasible and may improve CRCI in patients with BC. Larger randomized controlled trials are warranted to confirm its efficacy in enhancing cognitive function and quality of life in this population.

trial registrationClinicalTrials.gov NCT05704855; https://clinicaltrials.gov/study/NCT05704855.