Impact of exercise on chemotherapy-induced peripheral neuropathy in survivors with post-treatment primary breast cancer

Purpose: Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of neurotoxic chemotherapy. Exercise activates neuromuscular function and may improve CIPN. We examined the association between exercise and CIPN symptoms in breast cancer survivors.

Methods: In a retrospective cross-sectional study, we included patients completing a survey assessing exercise exposure and neuropathy symptoms in a tertiary cancer center survivorship clinic. We evaluated exercise duration and intensity using a standardized questionnaire quantified in metabolic equivalent tasks (MET-h/wk). We defined exercisers as patients meeting the National Physical Activity Guidelines' criteria. We used multivariable logistic regressions to examine the relationship between exercise and CIPN and if this differed as a function of chemotherapy regimen adjusting for age, gender, and race.

Results: We identified 5444 breast cancer survivors post-chemotherapy (median age 62 years (interquartile range [IQR]: 55, 71); median 4.7 years post-chemotherapy (IQR: 3.3, 7.6)) from 2017 to 2022. CIPN overall prevalence was 34% (95% confidence interval [CI]: 33%, 36%), 33% for non-taxane, and 37% for taxane-based chemotherapy. CIPN prevalence was 28% (95% CI: 26%, 30%) among exercisers and 38% (95% CI: 37%, 40%) among non-exercisers (difference 11%; 95% CI: 8%, 13%; p < 0.001). Compared to patients with low (<6 MET-h/wk) levels of exercise (42%), 11% fewer patients with moderate (6-20.24 MET-h/wk) to high (>20.25 MET-h/wk) levels of exercise reported CIPN. Exercise was associated with reduced prevalence of all CIPN symptoms regardless of chemotherapy type.

Conclusion: CIPN may persist several years following chemotherapy among patients with breast cancer but is significantly reduced by exercise in a dose-dependent manner.