The relationship of pain and sleep disturbances in racially diverse breast cancer survivors – A therapeutic opportunity to improve quality of life in long-term survivorship

Abstract

Breast cancer is the most common cancer in women worldwide. Chronic pain is one of the key negative consequences of surviving cancer reported in breast cancer survivors (BCS) and is associated with increased mortality. Experimental and population-based studies suggest that sleep and pain are reciprocally related. The goal of this study was to assess the relationship of sleep and pain in African-American and Caucasian BCS and to evaluate race as a potential effect modifier. We examined in a post-hoc exploratory analysis the relationship of sleep (PSQI) and pain (SF-36) in BCS (25 African-Americans, 186 Caucasians; Stages 0-IIIA), who had enrolled in the BEAT Cancer study (Rogers LQ et al., 2012). 78% of Caucasian and 72% of African-American BCS reported persistent pain and pain-related disability (44%, 60%). African-American BCS presented with significantly higher pain intensity and more severe pain-related interference than Caucasians (P = .032, P = .002). 92% of Caucasians and 100% of African-American BCS reported sleep disturbances. There was a significant positive correlation between sleep disturbances and pain severity (p = .022), but the factors associated with sleep disturbance severity differed between racial groups. African-Americans reported significantly less sleep-duration than Caucasians (P = .001; 5.98 vs. 6.96 h). Pain interference was significantly associated with sleep-duration for Caucasians (P = .049), but not for African Americans. There is an association of chronic pain and sleep disturbances in BCS, and the relationship of specific sleep disturbances and pain is influenced by race. This correlation might provide an important therapeutic target to improve quality of life in racially diverse populations of BCS.