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.

Patient Characteristics Associated With Chemotherapy-Induced Peripheral Neuropathy Severity in a Phase II Clinical Trial: A Retrospective Analysis.

INTRODUCTION: Chemotherapy-induced peripheral neuropathy (CIPN) can lead to chemotherapy dose reduction, delay, and discontinuation, and has limited effective prevention strategies. Our study aimed to identify patient characteristics associated with CIPN severity during weekly paclitaxel chemotherapy in people with early-stage breast cancer. METHODS: We retrospectively collected baseline data including participants' age, gender, race, body mass index (BMI), hemoglobin (regular and A1C), thyroid stimulating hormone, Vitamins (B6, B12, and D), anxiety, and depression up to 4 months prior to their first paclitaxel treatment. We also collected CIPN severity by Common Terminology Criteria for Adverse Events (CTCAE) after chemotherapy, chemotherapy relative dose density (RDI), disease recurrence, and mortality rate at the time of the analysis. Logistic regression was used for statistical analysis. RESULTS: We extracted 105 participants' baseline characteristics from electronic medical records. Baseline BMI was associated with CIPN severity (Odds Ratio [OR] 1.08; 95% CI, 1.01-1.16, P = .024). No significant correlations were observed in other covariates. At median follow-up (61 months), there were 12 (9.5%) breast cancer recurrences and six (5.7%) breast cancer-related deaths. Higher chemotherapy RDI was associated with improved disease-free survival (DFS, OR 1.025; 95% CI, 1.00-1.05; P = .028). CONCLUSIONS AND RELEVANCE: Baseline BMI may be a risk factor for CIPN and suboptimal chemotherapy delivery due to CIPN may negatively impact disease-free survival in patients with breast cancer. Further study is warranted to identify mitigating lifestyle factors to reduce incidences of CIPN during breast cancer treatment.

insomniac links the development and function of a sleep-regulatory circuit.

Although many genes are known to influence sleep, when and how they impact sleep-regulatory circuits remain ill-defined. Here, we show that insomniac (inc), a conserved adaptor for the autism-associated Cul3 ubiquitin ligase, acts in a restricted period of neuronal development to impact sleep in adult Drosophila. The loss of inc causes structural and functional alterations within the mushroom body (MB), a center for sensory integration, associative learning, and sleep regulation. In inc mutants, MB neurons are produced in excess, develop anatomical defects that impede circuit assembly, and are unable to promote sleep when activated in adulthood. Our findings link neurogenesis and postmitotic development of sleep-regulatory neurons to their adult function and suggest that developmental perturbations of circuits that couple sensory inputs and sleep may underlie sleep dysfunction in neurodevelopmental disorders.