Patterns of racial/ethnic disparities in baseline health-related quality of life and relationship with overall survival in patients with colorectal cancer.

PURPOSE: Racial disparities are evident in colorectal cancer (CRC) prognosis with black patients experiencing worse outcomes than Hispanics and whites, yet mediators of these disparities are not fully known. The aim of this study is to identify variables that contribute to racial/ethnic disparities in health-related quality of life (HR-QoL) and overall survival in CRC. METHODS: Using SF-12 questionnaires, we assessed HR-QoL in 1132 CRC patients by calculating their physical (PCS) and mental composite summary (MCS) scores. Associations between poor PCS/MCS and sociodemographic factors were estimated and survival differences were identified by race/ethnicity. RESULTS: Hispanic patients who never married were at greater risk of poor PCS (OR 2.69; 95% CI 1.11-6.49; P = 0.028) than were currently married patients. College education was associated with a decreased risk of poor PCS in Hispanic and white, but not black, patients. Gender was significantly associated with poor MCS among white patients only. CRC patients who reported a poor PCS or MCS had poor survival, with differences in median survival times (MSTs) by race. The effect of PCS was strongest in white CRC patients with a difference in overall MST of > 116 months between those with favorable versus poor physical HR-QoL. Black patients who reported poor Physical and Mental HR-QoL showed significant risk of a poor outcome. CONCLUSION: These findings suggest that racial/ethnic disparities in CRC survival may be related to differences in HR-QoL. Identified mediators of HR-QoL could supplement current CRC management strategies to improve patients' survival.