Relationship between exercise behavior, cardiorespiratory fitness, and cognitive function in early breast cancer patients treated with doxorubicin-containing chemotherapy: a pilot study

Abstract

The purpose of this study was to examine the relationship between self-reported exercise behavior, cardiorespiratory fitness (CRF), and cognitive function in early breast cancer patients. Thirty-seven breast cancer patients following completion of chemotherapy (median 16 months) and 14 controls were studied. Cognitive function was assessed using the Central Nervous System (CNS) Vital Signs software (CNS Vital Signs, LLC, Morrisville, N.C., USA), a computerized test battery consisting of 9 cognitive subtests. Exercise behavior was evaluated using the Godin Leisure Time Exercise Questionnaire, and CRF was assessed via a cardiopulmonary exercise test to assess peak oxygen consumption. Patients’ mean total exercise was 184 ± 141 min·week−1 compared with 442 ± 315 min·week−1 in controls (p < 0.001). Significantly fewer patients (32%) were meeting exercise guidelines (i.e., ≥150 min of moderate-intensity or vigorous exercise per week) compared with 57% of controls (p = 0.014). Patients’ peak oxygen consumption averaged 23.5 ± 6.3 mL·kg−1·min−1 compared with 30.6 ± 7.0 mL·kg−1·min−1 in controls (p < 0.01). Scores on the cognitive subdomains were generally lower in patients compared with controls, although only the difference in verbal memory was significant (unadjusted p = 0.041). In patients, weak to moderate correlations were indicated between exercise, peak oxygen consumption, and the majority of cognitive subdomain scores; however, there was a significant positive correlation between exercise and visual memory (r = 0.47, p = 0.004). In conclusion, breast cancer patients following the completion of primary adjuvant chemotherapy exhibit, in general, worse cognitive performance than healthy women from the general population, and such performance may be related to their level of exercise behavior.

Effect of aerobic exercise on cancer‐associated cognitive impairment: A proof‐of‐concept RCT

“…Exercise (approximately 4 km/d) prevented the significant decrease in performance on cognitive tasks and a reduction in hippocampal neurogenesis seen with chemotherapy administration in the nonexercise group. In humans, a recent observational study in early stage BCS treated with chemotherapy found a moderate association ( r = .47, P < .01) between self‐reported physical activity and visual memory abilities, but no association was seen with aerobic fitness …”

Randomized controlled trial of increasing physical activity on objectively measured and self‐reported cognitive functioning among breast cancer survivors: The memory & motion study

“…This recent study in 19 breast cancer survivors enrolled in a 24-week physical activity randomized controlled trial indicated that the exercise arm had greater improvements in a measure of processing speed compared with the control group. 23 Several crosssectional studies in cancer survivors using objective measures of cognition have indicated that greater physical activity is associated with several domains of cognition, including information processing speed, 24 memory, 25 executive functioning, 26 and attention. 26 These studies lend support to the hypothesis that increasing physical activity may be an effective intervention for improving cognition in breast cancer survivors.…”

Potential factors associated with perceived cognitive impairment in breast cancer survivors

“…Exercise is a strategy employed by some breast cancer survivors to attempt to decrease PCI [6], and evidence is building in support of exercise as an intervention for cancer-associated cognitive complaints [25–32]. The NCCN guidelines recommend regular exercise and strength training for cancer survivors and recently added routine exercise as one of the general strategies for management of cancer-associated cognitive dysfunction [33].…”