Black patients with multiple myeloma have better survival than white patients when treated equally: a matched cohort study

Abstract

We assessed differences in survival between non-Hispanic black (NHB) and non-Hispanic white (NHW) patients with multiple myeloma (MM), and the sequential effects of patient characteristics, and diagnosis and treatment-related factors on the survival disparity using data from 3319 NHB and 20,831 NHW MM patients in the SEER-Medicare (1999–2017) database. Four sets of 3319 NHWs were matched sequentially to the same set of 3319 NHBs, based on demographics (age, sex, year of diagnosis, marital status, and SEER site), socioeconomic status (SES, demographics plus SES), presentation factors (SES variables plus comorbidity), and treatment factors (presentation variables plus antimyeloma therapies). We found NHBs were less likely to receive treatment than NHWs even among patients matched for demographics, SES, and comorbidities. The absolute difference in 5-year survival between NHBs and NHWs was not significant in the demographics match (0.6%; P = 0.30) and remained non-significant after matching for SES (1.4%, P = 0.17). When matching for presentation, NHBs had significantly longer 5-year survival than NHWs (absolute difference = 3.8%, P = 0.003). Additional matching on treatment-related factors further enlarged the racial difference in 5-year survival to 4.6% (P < 0.001). Our findings reinforce the importance of equitable access to effective treatment modalities to further improve the survival of NHB patients with MM.

Exploring racial disparities in treatment patterns and outcomes for patients with multiple myeloma using real world data

“…These findings are consistent with previous analyses suggesting that younger age at diagnosis and different cytogenetic profile may contribute to similar or more favorable survival outcomes in Black patients. Most recently, results from the CoMMpass registry showed superior survival for White patients when compared to Black patients, a difference seemingly driven, to considerable extent, by different patterns of care (with less utilization of triplet therapy and ASCT in Black patients) [ 15 ], as also suggested by a recent SEER-based report [ 16 ]. Of note, our study was US-based while the CoMMpass registry is worldwide, which may explain the overall differences in care (ASCT being a more common practice outside of the US [ 17 , 18 ]) and diverging outcomes.…”

Socioeconomic disadvantage contributes to ethnic disparities in multiple myeloma survival: a matched cohort study

“…Previous studies applied model-based methods which, when fitted to the entire population, give disproportionate weighting to the majority population (i.e., NHW) [ 9 ]. Using a tapered matching approach, we recently investigated the Surveillance, Epidemiology and End Results (SEER) -Medicare linked database to examine racial disparities in MM survival and associated factors in 3319 NHB and 20,831 NHW patients [ 10 ]. Consistent with previous reports [ 3 , 5 , 11 , 12 ], we found NHBs have a significantly longer overall survival than NHWs when treated similarly [ 10 ].…”

“…Using a tapered matching approach, we recently investigated the Surveillance, Epidemiology and End Results (SEER) -Medicare linked database to examine racial disparities in MM survival and associated factors in 3319 NHB and 20,831 NHW patients [ 10 ]. Consistent with previous reports [ 3 , 5 , 11 , 12 ], we found NHBs have a significantly longer overall survival than NHWs when treated similarly [ 10 ]. However, data on Hispanics, the fastest growing segment of the US population, is limited.…”

“…We identified 1591 Hispanic and 20,831 NHW patients, 65 years or older, diagnosed with MM between 1999 and 2017 and followed up through 2018. Four sets of 1591 NHW patients were matched sequentially, using propensity score matching approach [ 9 , 10 , 13 – 15 ], to the same set of 1591 Hispanic patients based on demographics (age, sex, year of diagnosis, SEER site, and marital status), SES (demographic variables plus SES), presentation (SES variables plus comorbidities) and treatment (presentation variables plus traditional chemotherapy, PIs, IMiDs and ASCT). Details in patient selection and matching process are described elsewhere [ 10 ].…”

“…Intriguingly, although Hispanics and NHBs are both underserved populations, we discovered different survival outcomes compared to NHWs using the same database and matching approach [ 10 ]. To elucidate the underlying reasons for these survival differences, we conducted a subcohort analysis in 1548 Hispanics who had 4 sets of successfully matched NHBs.…”