Racial and Ethnic Variations in Pre-Diagnosis Comorbidity Burden and Health-Related Quality of Life Among Older Women with Breast Cancer.

BACKGROUND: This study examined racial/ethnic differences in comorbidity burden and health-related quality of life (HRQOL) among older women before breast cancer diagnosis. METHODS: From Surveillance, Epidemiology, and End Results-Medicare Health Outcomes Survey (SEER-MHOS) linked data resource, 2513 women diagnosed with breast cancer at ≥ 65 years between 1998 and 2012 were identified and grouped based on comorbidity burden using latent class analysis. Pre-diagnosis HRQOL was measured using SF-36/VR-12 and summarized to physical (PCS) and mental component summary (MCS) scores. The adjusted least-square means and 95% confidence intervals were obtained according to comorbidity burden and race/ethnicity. The interactions were examined with 2-way ANOVA. RESULTS: The latent class analysis revealed four comorbid burden classes, with Class 1 being the most healthy and Class 4 being the least healthy. African American (AA) and Hispanic women were more likely to be in Class 4 than non-Hispanic white (NHW) women (18.6%, 14.8%, and 8.3%, respectively). The mean PCS was 39.3 and differed by comorbidity burden and race/ethnicity (Pinteraction < 0.001). There were no racial/ethnic differences in Classes 1 and 2, while NHW women reported significantly lower PCS scores than AA women in Classes 3 and 4. The mean MCS was 51.4 and differed by comorbidity burden and race/ethnicity (Pinteraction < 0.001). There was no racial/ethnic difference in Class 3; however, AA women reported lower MCS scores than Asian/Pacific Islander women in Class 1, and AA and Hispanic women reported lower MCS scores than NHW women in Classes 2 and 4. CONCLUSION: Comorbidity burden negatively affected HRQOL but differentially for racial/ethnic groups. As the comorbidity burden increases, NHW women are more concerned with physical HRQOL, while AA and Hispanic women are more concerned with mental HRQOL.