Social Determinants of Health Associated with Multiple Myeloma Incidence and Survival among a Low-Income Cohort in the Southeastern U.S.

Objectives: Multiple myeloma (MM) is the second most common hematologic malignancy in the U.S.; however, the etiology is poorly understood. We investigated social determinants of health (SDoH) associated with MM incidence and survival among low-income Black and White participants in the Southern Community Cohort Study (SCCS). Methods: The SCCS enrolled participants aged 40-79 years from 12 Southeastern states. We examined associations between SDoH (residential racial segregation, neighborhood deprivation, population density, persistent poverty, and rurality) geocoded to zip code, with MM incidence and all-cause mortality using multivariable Cox regression analyses. Additional stratified analyses examined MM incidence by obesity status. Results: Among 74,294 participants, there were 162 MM cases, 133 self-identified as Black individuals and 29 self-identified as White individuals. Living in the highest vs. lowest deprivation areas was associated with 2-fold increased MM risk (HR:2.24; 95% CI:1.01-4.95). Among MM cases, those living in the least vs. most residentially segregated areas had 2-fold increased mortality (HR:2.21; 95% CI:1.03-4.74). Among participants who were not obese, those who lived in the most densely populated areas had a reduced risk of MM compared to those who lived in the least densely populated areas (HR:0.31; 95% CI: 0.14-0.67); and those who lived in urban vs. rural areas had a reduced risk (HR:0.52; 95% CI: 0.32-0.85). Discussion: SDoH factors including neighborhood deprivation and residential racial segregation could influence MM risk and survival among low-income populations. Conclusion: SDOH factors should be considered when developing strategies to reduce overall MM burden, and disparities among people with lower socioeconomic backgrounds.