Association between pre-treatment sleep disturbance and radiation therapy-induced pain in 573 women with breast cancer.

Abstract Context Pain can be a debilitating side effect of radiation therapy (RT). Data from the general population has shown that sleep disturbance can influence pain incidence and severity; however, less is known about this relationship in breast cancer patients receiving RT. Objectives This secondary analysis examined the association of pre-treatment moderate/severe levels of sleep disturbance with subsequent RT-induced pain after adjusting for pre-RT pain. Methods We report on 573 female breast cancer patients undergoing RT from a previously completed phase II clinical trial for radiation dermatitis. Sleep disturbance, total pain, and pain subdomains – sensory pain, affective pain, and perceived pain intensity were assessed at pre- and post-RT. At pre-RT, patients were dichotomized into 2 groups: those with moderate/severe sleep disturbance (N=85) vs. those with no/mild sleep disturbance (control; N=488). Results: At pre-RT, women with moderate/severe sleep disturbance were younger, less likely to be married, more likely to have had mastectomy and chemotherapy, and more likely to have depression/anxiety disorder and fatigue than the control group (all p’s Conclusion These findings suggest that moderate/severe disturbed sleep prior to RT is associated with increased pain from pre-to-post-RT in breast cancer patients.