# Association Between Therapeutic Interventions and Sleep Disorders in Patients with Breast Cancer: A National Population-Based Cohort Study

## TL;DR

This study found that breast cancer patients receiving endocrine therapy or taxane chemotherapy are at higher risk for sleep disorders, which persist long after treatment.

## Contribution

The study identifies endocrine therapy and taxane chemotherapy as independent risk factors for sleep disorders in breast cancer patients.

## Key findings

- Endocrine therapy increases the risk of sleep disorders by 27.6%.
- Taxane chemotherapy increases sleep disorder risk by 26.8%.
- Sleep disorders peak within two years post-treatment and remain elevated.

## Abstract

This population-based study of 62,714 breast cancer patients identified from the Korean Health Insurance Review and Assessment database revealed that endocrine therapy and taxane chemotherapy independently increased the risk of sleep disorders, while anxiety and depression rates did not differ between treatment groups. Sleep disorders were most frequent within two years after treatment and remained elevated thereafter, highlighting the need for early screening and tailored interventions to improve long-term quality of life among breast cancer survivors.

Background: Breast cancer survivors often experience long-term endocrine- and chemotherapy-related side effects, including sleep disorders, anxiety, and depression. Sleep disorders are particularly prevalent and affect patient adherence and quality of life. This study examined the prevalence and risk factors for sleep disorders in patients with breast cancer based on treatment exposure. Methods: Patients with breast cancer (2009–2015) were identified from the Health Insurance Review and Assessment database. They were categorized by chemotherapy exposure and further by endocrine or taxane use. Sleep disorders, anxiety, and depression were assessed using diagnostic and prescription codes. Propensity score matching and Cox proportional hazard models were applied to adjust confounders and evaluate risk factors. Results: Among the 62,714 patients, those receiving endocrine therapy had a higher risk of sleep disorders (hazard ratio [HR], 1.276; 95% confidence interval [CI], 1.087–1.497; p = 0.003), irrespective of tamoxifen or aromatase inhibitor use. In chemotherapy-treated patients, taxane exposure significantly increased sleep disorder risk (HR, 1.268; 95% CI, 1.159–1.389; p < 0.001). The cumulative incidence of sleep disorders peaked within two years post treatment and remained elevated over time. Anxiety and depression rates did not differ significantly between the treatment groups. Conclusions: Endocrine therapy and taxane chemotherapy are independent risk factors for sleep disorders in patients with breast cancer. Screening and interventions are essential for improving long-term well-being. Future studies should explore personalized approaches for managing treatment-related sleep disturbance.