Physical activity linked to stronger cognitive function among women with breast cancer
High levels of physical activity appeared strongly associated with the ability to maintain cognitive function among women with breast cancer treated with chemotherapy, according to a study published in Journal of Clinical Oncology.
The results of the nationwide, prospective cohort study highlight the importance of promoting physical activity throughout treatment, according to researchers.
“Physical activity is a promising intervention for cancer-related cognitive decline — a growing clinical concern — but research assessing its use during chemotherapy is limited,” Elizabeth A. Salerno, PhD, MPH, assistant professor of surgery in the Mary Culver Department of Surgery at Washington University School of Medicine in St. Louis, told Healio.
“We were interested in exploring patterns of physical activity before, during and after chemotherapy in patients with breast cancer and the association between physical activity and cognitive function,” she added. “Given the detrimental effects of chemotherapy on cognition, understanding the dynamic relationships between physical activity and cognitive function across the entire treatment window could inform early prevention strategies, such as prehabilitation, to promote health in these patients.”
An estimated 75% of patients report cognitive problems during chemotherapy for breast cancer, and such problems may continue for years after treatment completion, according to study background.
The analysis by Salerno and colleagues included 580 women with stage I to stage IIIC breast cancer (median age, 53.4 years; standard deviation [SD], 10.6; 89.1% white) and 363 cancer-free women in an age-matched control cohort (median age, 52.6 years; SD, 10.3; 94.5% white).
Researchers assessed physical activity and perceived and objectively measured cognitive functioning within 7 days before chemotherapy administration, within 1 month after chemotherapy, and 6 months after chemotherapy among women with breast cancer, and at equivalent time points among women in the control cohort. Adjusting for demographic and clinical factors, investigators used longitudinal mixed effects models to characterize physical activity changes over time between the breast cancer and the control group, as well as the role of physical activity before chemotherapy and changes in physical activity during chemotherapy on cognitive changes over time.
Compared with controls, women with breast cancer demonstrated a significant decrease in physical activity from the first to the second time points (P < .001) but a significant increase between the second and third time points across outcomes (all P < .03), with no significant difference at the third time point in exercise levels between groups.
Results among the breast cancer cohort showed meeting physical activity guidelines at baseline correlated with significantly higher scores on the FACT-Cog Perceived Cognitive Impairment (B = 2.7, P =.05), FACT-Cog Total Score (B =4.9, P =.02), and Rapid Visual Processing (B =2.2, P = .01) tests over time, compared with not meeting physical activity guidelines at baseline. Researchers reported similar patterns of objectively-measured cognitive function among inactive controls.
Salerno and colleagues also observed an association of adherence to physical activity guidelines during the course of chemotherapy with better self-reported cognition, and of greater moderate-to-vigorous physical activity at the previous time point with better cognitive trajectories among women with breast cancer.
“[Although] we were not surprised to see that physical activity demonstrated a positive, beneficial association with cognition in these patients, it was encouraging to see how robust this relationship was,” Salerno told Healio. “We were also pleasantly surprised to see that patients recovered to their prechemotherapy physical activity levels 6 months after chemotherapy completion.
“It will be important for us to determine what is driving this recovery, whether it be renewed health status or increased motivation to live a healthy lifestyle, so that we can design interventions during this time that maximize potential health benefits,” she added. “However, we should note that despite this recovery, almost two-thirds of patients remained insufficiently active. This underscores the need to continue promoting physical activity across the cancer continuum.”
Study limitations included the use of self-reported physical activity and that patients with better executive functioning and self-regulation may have been more likely to engage in physical activity. Salerno and colleagues recommended further research on how physical activity before and during chemotherapy may minimize cancer-related cognitive decline, as well as continued promotion of physical activity as early as possible in the cancer treatment timeline.
“Randomized controlled trials are required to confirm if intervening with physical activity during a discrete time window (eg, during chemotherapy) can result in prospective changes in cognitive function, and this is a next step in our program of research,” Salerno told Healio. “Our findings suggest that these interventions are ideally conducted early on in the treatment window, so we’re interested in taking a systematic approach to understanding how to best implement physical activity programs into the standard of cancer care.”
For more information:
Elizabeth A. Salerno, PhD, MPH, can be reached at Washington University School of Medicine in St. Louis, 660 S Euclid Ave., Campus Box 8100, St Louis, MO 63110; e-mail: email@example.com.