Morning Chronotype Decreases the Risk of Chemotherapy-Induced Peripheral Neuropathy in Women With Breast Cancer

Background: The purpose of this longitudinal prospective cohort study was to investigate the role of chronotype in the incidence of chemotherapy-induced peripheral neuropathy (CIPN) among women with breast cancer. Methods: We recruited women with breast cancer awaiting adjuvant chemotherapy, including four cycles of docetaxel. Participants reported peripheral neuropathy symptoms of numbness/ tingling at the baseline, and at 4weeks after completion of chemotherapy. Candidate psychiatric factors associated with CIPN were assessed at the baseline, using the Composite Scale of Morningness, the Pittsburgh Sleep Quality Index, and the Hospital Anxiety and Depression Scale. To examine the association between chronotype and CIPN, we built logistic regression models, adjusting for demographic, clinical, and other psychiatric variables. Results: Among 48 participants, 29 participants developed CIPN. The morning chronotype was inversely associated with CIPN (odds ratio, 0.06; confidence interval, 0.01-0.74; P = 0.028) after adjusting for age, BMI, education, type of operation, alcohol use, smoking, sleep quality, depression, and anxiety. Conclusion: Our results suggest that the morning chronotype is a protective factor against the development of CIPN in patients with breast cancer who were treated with docetaxel.