Early Mortality in Patients with Newly Diagnosed Multiple Myeloma (NDMM): Sociodemographic and Economic Factors Contributing to the Disparity

Introduction: Overall outcomes have improved significantly for MM with a 5-year relative survival rate currently of >60%. With effective treatments, patients from all clinical strata and age groups are expected to have meaningful benefit, but despite excellent therapeutic advancements, some patients continue to have early mortality. We conducted this study to investigate factors associated with early mortality.

Methods: The National Cancer Database (NCDB) was queried for adult patients with NDMM between 2004 and 2021. We excluded patients with multiple primary malignancies or lost to follow-up (unknown vital status or last contact). Early mortality was defined as death within 6 months from MM diagnosis. Patient demographics and socioeconomic factors available in NCDB were collected. Kaplan-Meier and multivariate Cox regression were used to evaluate the likelihood of early mortality in this large cohort of MM patients using multi-variate analysis.

Results: Out of 255,579 eligible patients with MM, 35,302 (13.8%) died within the first 6 months of diagnosis and 108,534 (42.5%) died after the first 6 months of MM diagnosis. The early mortality cohort had significantly higher mean age at MM diagnosis (73.9 vs. 68.5 years, p<0.001) but no significant differences were noted for gender distribution. There was a statistically significant difference for racial/ethnic distribution (p=0.019), but the percentages were very similar among non-Hispanic White (69% vs 68.1%), non-Hispanic African American (18% vs 18.7%) and Hispanic patients (4.7% vs 4.8%). Patients in the early mortality cohort were less likely to be treated at academic institutions (28.4% vs 37.8%, p<0.001) and have significantly different distribution by insurance type (less likely to have private insurance; 17.3% vs. 30%, more likely to have Medicare; 72.1% vs. 58.7%, p<0.001) although overall insurance access was similar between the two groups (95.3% vs 95.2%, p=0.283). Early mortality was associated with higher morbidity scores as per the Charlson-Comorbidity Index (CCI) (p<0.001) and were more likely to have not received any treatment for MM (53.2% in early mortality group vs. 28.4% in late mortality, p<0.001). Early mortality was also associated with a lower literacy rate (high school graduation rate 21.2% vs. 19.7%, p<0.001) and lower household income (<$46,277; 19.1% vs. 17.7%, p<0.001).

Conclusion: This large real-world analysis shows that despite therapeutic advances in recent years, there is a significant percentage of patients with NDMM in the U.S. who suffer from

early mortality. There are several sociodemographic and economic factors that were found to be associated with early mortality, with some showing clear trends (older age, treatment facility type, insurance type, income, education, CCI), while others like racial differences were significant but somewhat ambiguous. Identifying and addressing these factors at diagnosis will help provide personalized care plans and minimize early mortality.