JMIR Publications

ABSTRACT

Background:

Background:

More than 75% of breast cancer patients treated with chemotherapy experience cognitive impairments (e.g., memory and attention problems), commonly known as “chemo-brain.” Exercise, especially aerobic high-intensity interval training (HIIT), is associated with better cognitive function in healthy populations; however, clinical trials testing the impact of exercise interventions on chemotherapy-induced cognitive declines in cancer patients are lacking, and the mechanisms through which exercise could improve cognitive function are unclear.

Objective:

The objective of the Improving Cognitive Function through High-Intensity Interval Training in Breast Cancer Patients Undergoing Chemotherapy (CLARITY) Trial is to examine the effects of HIIT on cognitive function in breast cancer patients undergoing chemotherapy.

Methods:

Methods:

This two-arm, single-center, pilot randomized controlled trial will randomize 50 breast cancer patients undergoing chemotherapy to HIIT or attention control (AC). The HIIT group will perform a supervised 16-week, thrice-weekly intervention, with each session including a 5-minute warm-up at 10% maximal power output (POmax), 10 sets of alternating 1-minute high-intensity (90% POmax) and 1-minute recovery (10% POmax) intervals, and 5-minute cool-down (10% POmax). The AC group will receive a stretching program with no exercise components and be asked to maintain their exercise levels for 16 weeks. The primary outcomes of the study are executive function and memory measured by the NIH toolbox, and resting state connectivity and diffusion tensor imaging microstructure evaluated with magnetic resonance imaging. The secondary and tertiary outcomes include cardiorespiratory fitness, body composition, physical fitness, and psychosocial health. The study has been approved by the institutional review board at Dana-Farber Cancer Institute (#20-222).

Results:

Results:

The trial was funded in January/2019 with recruitment started June/2021. As of May 2022, 4 patients have been consented and randomized (N = 2 exercise, N = 1 control, N = 1 non-randomized). Trial completion expected January/2024.

Conclusions:

Conclusions:

This first-of-its-kind study incorporates a novel exercise intervention (i.e., HIIT) and comprehensive cognitive measures. If positive, our findings will establish the pilot efficacy of HIIT on chemotherapy-induced cognitive function in breast cancer patients, providing the foundation of future larger phase II/III trials to confirm the findings and potentially establish HIIT as a standard of care for women undergoing chemotherapy for breast cancer. Clinical Trial: Trial Registration: This study has been registered in ClinicalTrials.gov (NCT04724499).