MDS-556 Comparison of Demographics, Disease Characteristics and Outcomes Between Black and White Patients With Myelodysplastic Syndrome: A Population-Based Study

Abstract

Myelodysplastic syndrome (MDS) consists of a heterogeneous group of clonal myeloid neoplasms with poor long-term outcomes compared to other cancers. Racial/ethnic disparities in cancer incidence and survival have been reported in many cancers and constitute major health policy and societal issues. Data from US cancer registries indicate that Black patients have the highest mortality rate of any racial and ethnic group for all cancers combined, and for several cancers individually. However, disparities in MDS have been poorly studied. The purpose of our study was to study the relationship between race (Black, White) and baseline characteristics, overall survival, and cause of death in MDS in the United States. We used the Surveillance, Epidemiology, and End Results (SEER) registry of the National Institute of Heath and included 37,562 patients (Black: 8.1%; White: 91.9%) with MDS diagnosed between 2001-2013. Black race was associated with longer overall survival (HR: 0. 79; 95% CI: 0.76- 0.83; p<0.001). Median overall survival (mOS) was 33 months for Black and 26 months for White. This association was maintained in sensitivity analyses (multivariable and matching) adjusting for differences in baseline demographics and disease characteristics. Analysis by histology subset revealed variable levels of association between race and OS with MDS-NOS, a category defined in SEER, representing 52% of cases in our study with the strongest association and contributing largely to the overall result. Black patients had a lower mortality risk due to MDS/leukemia (IRR: 0.79; 95% CI: 0.74-0.84, p<0.001) and a higher risk for cardiovascular death (IRR: 1.12; 95% CI: 1.02-1.23; p=0.02). In this large retrospective study of MDS cases in SEER, we observed differences in patients' demographics, socio-economic factors, disease subtype, mortality rate per COD, and survival outcomes between Black and White patients. The finding of Black having better OS outcomes than White patients was unexpected and needs to be further researched, specifically the contribution of the poorly defined MDS-NOS subset to the overall finding.