Demographic and clinical factors associated with sleep disturbance in breast cancer survivors.

12083 Background: Fatigue and sleep disturbance are prevalent during and after cancer treatment; sleep-related symptoms affect 30-50% of patients with cancer, and sleep-wake disruptions persist beyond the immediate post-surgical period in breast cancer (BC) survivors. Identifying demographic- and treatment-related factors associated with sleep-related symptoms during survivorship is critical to inform interventions for those at highest risk of sleep disturbance. Methods: Patients who were seen at least once at Mayo Clinic Rochester following an initial diagnosis of BC at age 18 or older and provided informed consent were prospectively enrolled in the Mayo Clinic Breast Disease Registry. Surveys mailed to this cohort included two 11-point numeric rating scale questions regarding difficulty falling asleep and staying asleep in the past week, with values for each ranging from 0 (no problem) to 10 (as severe as you can imagine). Participants who provided sleep-related information on the Year 1 survey (answered approximately one year after cancer diagnosis) were included. Participants were excluded if they had clinical or pathologic metastatic disease and/or recurrence prior to the Year 1 survey. Associations of sleep-related symptoms with demographic and clinical characteristics were assessed using multivariate linear regression models, fitting the sleep difficulty rating scale as the outcome and clinical and demographic factors as exposures. Results: In total, 3,354 participants met inclusion criteria. The average age at BC diagnosis was 59, and most participants were female (99.3%), White (95.4%), non-Hispanic (96.2%), married (78.1%), had at least some college education (80.4%), did not report financial insecurity (76.2%), did not consume alcohol (60.6%) or smoke tobacco (93.2%), and reported at least some weekly exercise (76,6%). Sixty-two percent of participants had clinical stage 0 or I disease; 50.3% underwent lumpectomy (not mastectomy), 59.2% received radiotherapy, 34.1% received chemotherapy, and 67.2% received endocrine therapy. Overall, sleep-related symptoms were relatively low (mean rating for falling asleep = 2.1, mean rating for staying asleep = 3.1). In multivariate analyses, more difficulty falling asleep was associated with higher clinical stage (p < 0.001), more cigarettes smoked per day (p = 0.012), less moderate and/or strenuous exercise (p = 0.001), and more financial hardship (p < 0.001). More difficulty staying asleep was associated with higher clinical stage (0.003), older age (p < 0.001), more education (p = 0.011), and more financial hardship (p < 0.001). Conclusions: In our cohort of BC survivors, factors associated with both increased difficulty with falling and staying asleep at one year after diagnosis are higher clinical stage and more financial hardship. Future research should explore the course of these symptoms over time and across varied treatment trajectories.