Racial differences in treatment and survival among older patients with multiple myeloma

Abstract

Background: Treatments for multiple myeloma (MM) have evolved over time and improved MM survival. While racial differences in MM treatment and prognosis between non-Hispanic African American (NHAA) and non-Hispanic White (NHW) patients are well-established, it is unclear whether they have persisted after the introduction of novel agents.

Methods: Using the Surveillance, Epidemiology, and End Results-Medicare linked database, our study investigated racial difference in the receipt of treatment within 1 year following diagnosis and assessed survival outcomes among Medicare beneficiaries (≥66 years) diagnosed with MM from 2007 to 2017. We applied multivariable Cox proportional hazards models to estimate the association between race and survival and presented hazard ratios (HRs).

Results: Of 2094 NHAA and 11,983 NHW older patients with MM, 59.5% and 64.8% received treatment during the first year, respectively. Discrepancy in the proportion of patients receiving treatment between the two groups increased from 2.9% in 2007 to 2009 to 6.9% in 2014-2017. After controlling for relevant factors, patients who received treatment within the first year had lower mortality than those who did not (HR = 0.90, 95% confidence interval [CI]: 0.86-0.94). NHAA patients had a lower probability to receive treatments during the first year than NHW patients (HR = 0.91, 95% CI: 0.85-0.97) but had lower mortality (HR = 0.94, 95% CI: 0.88-1.00). The lower mortality was only observed among patients who received no treatment (HR = 0.84, 95% CI: 0.77-0.93); NHAA and NHW patients who received treatment had similar survival (p = 0.63).

Conclusions: The increasing racial disparity in treatment utilization over time is concerning. Efforts are needed to eliminate the barriers of receiving treatment.

Keywords: SEER-Medicare; multiple myeloma; racial disparity; survival; treatment.