Longitudinal prospective assessment of sleep disturbance in breast cancer.

Abstract

9101 Background: Cross-sectional data suggest that individuals with breast cancer experience significant sleep disturbance pre-, during, and post-chemotherapy and/or radiation therapy. To date, longitudinal data indicate sleep disturbances cumulatively worsen over the course of chemotherapy. The objectives of this study were to prospectively examine the longitudinal trajectory of sleep quality in breast cancer patients before, during, and after adjuvant chemotherapy and to evaluate the relationship between sleep quality and health-related quality of life. Methods: Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) and quality of life was assessed with the Functional Assessment of Cancer Therapy (FACT-G). Assessments were completed at baseline immediately prior to chemotherapy, cycle 4 day 1, and 6 months after baseline. Results: Participants (N=80) were primarily women (97.5%) with Stage II (69.0%) breast cancer. Age ranged from 29 to 71 years (M=49.7; SD=9.2). In our sample, 65.8% of patients reported significantly impaired sleep pre- treatment, 60.5% at cycle 4 day 1, and 48.5% at 6 months using the PSQI total score. Most patients either experience impaired sleep (37.5%) or normal sleep (21.9%) throughout the course of the study. A mixed effects model revealed no significant differences in PSQI total score or subscale scores across time points with one exception. The daytime functioning subscale scores were significantly worse during treatment compared to before and after chemotherapy (p<0.01). FACT-G scores were negatively correlated with PSQI total scores across all time points (rho = −0.46; −0.41; −0.45; p<0.001). Conclusions: Results suggest that sleep disturbances were highly prevalent across the continuum of care for persons with breast cancer. Daytime dysfunction increased during chemotherapy and poorer sleep quality was highly correlated with lower health-related quality of life. Most individuals demonstrating sleep problems pre-chemotherapy continue to do so after completion of treatment. Early identification and treatment of sleep disturbances and daytime impairment may minimize disruption to health-related quality of life and lessen symptom burden associated with chemotherapy. No significant financial relationships to disclose.