Autonomic Dysfunction and Cognitive Loss in Female Breast Cancer Survivors: Impact of Physical Activity Level

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All articles of this category (opens in new window) Address for correspondence Patricia C Brum (pcbrum@usp.br) Autonomic dysfunction (AD) and chemotherapy-induced cognitive impairment (CCI) are side effects associated with chemotherapy in the treatment of breast cancer (BC) and can affect the quality and duration of survival. The co-occurrence of AD and CCI and whether higher levels of physical activity (PA) could mitigate these effects, remains unexplored . Objective: To investigate the presence of AD and CICI in female BC survivors undergoing chemotherapy and their associations with PA . Methods: Cross-sectional, single-center, observational study with three groups: control individuals without a history of cancer (CS; n = 29; 50.7 ± 9.0 years; 192.7 ± 117 min PA/week), physically active BC survivors (CA; n = 28; 48.9 ± 7.1 years; 318.6 ± 145.0 min PA/week), and physically inactive BC survivors (CI; n = 25; 50.9 ± 8.5 years; 85.9 ± 37.4 min PA/week). Assessment of heart rate variability (HRV), cardiorespiratory fitness (VO₂peak) and physical functionality tests with and without cognitive tasks, and objective measurement of BP by accelerometry were performed . Results: CA group presented VO2peak higher than the CI and similar to CS (21.2 ± 4.3; 22.1 ± 3.3 vs. 18.9 ± 2.9 mLO2.kg min-1 for the CS, CA and CI groups, p = 0,003). In the temporal domain of HRV, the CA group showed better autonomic modulation, pNN50, compared to CS (23.3±23.8 vs. 10.8±12.0%; p=0.048). In physical functionality with or without cognitive challenge, CI group presented worse performance than the CS group for single task and dual task: Single Task: Steps (7.7 ± 1.20 vs. 8.8 ± 1.19, p = 0.001) and Execution Time (8.0 ± 1.73 vs. 9.6 ± 2.22 s, p = 0.004). Dual Task: Walking with Letters — Steps (8.0 ± 1.39 vs. 9.4 ± 1.22, p < 0.001) and Execution Time (9.9 ± 3.31 vs. 11.7 ± 2.91 s, p = 0.043); Number Subtraction — Steps (8.2 ± 1.2 vs. 9.8 ± 1.4, p < 0.001) and Execution Time (10.1 ± 2.9 vs. 12.9 ± 3.7 s, p = 0.004). CA group showed cognitive impairments when compared to CS: Dual Task — Words Recalled (4.0 ± 1.44 vs. 3.4 ± 1.02, p = 0.033) and Number Subtraction (2.3 ± 1.8 vs. 1.3 ± 1.0, p = 0.050) . Conclusion: Our results indicate that higher PA levels are associated with better autonomic modulation, cardiorespiratory fitness and physical functioning in BC survivors. However, PA alone does not appear to fully mitigate cognitive impairment. These results reinforce the need for combined physical and cognitive training to improve quality of life after BC treatment. Publication History Article published online: 26 June 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution 4.0 International License, permitting copying and reproduction so long as the original work is given appropriate credit (https://creativecommons.org/licenses/by/4.0/) Thieme Revinter Publicações Ltda. Rua Rego Freitas, 175, loja 1, República, São Paulo, SP, CEP 01220-010, Brazil Bibliographical Record Jule P Amaral, Anne CO Souza, Karen M Jircik, Luiz PM Souza, Debora B Silva, Max D Oliveira, Luiz A Riani Costa, Sarah MM Leandrini, Thiago EM Crema, Raquel Marquesini, Jonatas Carvalho, Christina MM Brito, Patricia C Brum. Autonomic Dysfunction and Cognitive Loss in Female Breast Cancer Survivors: Impact of Physical Activity Level. Brazilian Journal of Oncology 2026; 22. DOI: 10.1055/s-0046-1825407