P-143: Treatment access among Black and White older adults with multiple myeloma: A SEER-Medicare analysis

Introduction: Multiple myeloma (MM) is an incurable cancer of the plasma cells that has seen incredible treatment innovation over the past two decades though not all groups have benefited equally from these improvements. This study explores trends in MM treatment access among Black and White older adults in the United States.

Methods: Black and White older adults diagnosed with MM (2007-2017) were identified in the SEER-Medicare database. Individuals were required to have continuous Medicare Parts A and B coverage 12 months prior to and following diagnosis (or until death), and Part D coverage 12 months following diagnosis (or until death).
Primary outcomes were receipt of any MM treatment (TX) within 12 months of diagnosis, and receipt of any MM care at an NCI cancer center (NCI CC) within 12 months of diagnosis (a proxy for early access to MM specialists). Patients were categorized by year of diagnosis into 3 roughly equal time periods; 2007-10, 2011-14, 2015-17. We used standardized mortality ratio weighting to standardize the distribution of age, sex, and pre-diagnosis Charlson comorbidity score across racial groups with White race as reference. Modified Poisson regression was used to estimate change (risk difference) across time periods stratified by race, and differences by race within time periods.

Results: Our cohort consisted of 1,649 Black and 9,017 White older adults with MM. The percentage of White individuals receiving any TX increased from 62.8 to 71.0% (2011-14 vs 2007-10, RD = 8.3, [95% CI: 5.9, 10.6]) to 73.4% (2015-17 vs 2011-14, RD = 2.4 [0.2, 4.6]). The percentage of Black individuals receiving any TX increased from 56.9 to 59.4%, (2011-14 vs 2007-10, RD= 2.5, [-4.4, 9.4]) to 64.7%, (2015-17 vs 2011-14, RD = 5.3, [-1.4, 1.2]). A lower percentage of Black individuals received treatment compared with White individuals in all time periods; 2007-10: RD = 5.9 (0.3, 11.5), 2011-14: RD = 11.6 (6.9, 16.4), 2015-17: RD 8.8 (3.7, 13.9).
The percentage of White individuals receiving any care at an NCI CC increased from 21.5 to 28.1% (2011-14 vs 2007-10, RD = 6.6, [4.4, 8.8]) to 34.9% (2015-17 vs 2011-14, RD = 6.8 [4.6, 9.1]). The percentage of Black individuals receiving any care at an NCI CC increased from 16.4 to 19.2%, (2011-14 vs 2007-10, RD= 2.8, [-2.3, 7.9]) to 22.1%, (2015-17 vs 2011-14, RD = 3.0, [-2.5, 8.4]). A lower percentage of Black individuals received care at NCI CC compared with White individuals in all time periods; 2007-10: RD = 5.0 (0.9, 9.1), 2011-14: RD = 8.8 (5.0, 12.6), 2015-17: RD 12.7 (8.2, 17.2).

Conclusions: Overtime more people are enjoying access to MM TX and care at NCI CC, but these increases have not been experienced by all race groups equally. Black/White disparities were noted at each time period and while the percentage of White individuals receiving TX and care at an NCI CC saw significant increases over time, Black individuals, already disadvantaged compared to White individuals, have seen more modest nonsignificant increases over time.