Population differences in the associations between chromosomal abnormalities and overall survival of multiple myeloma

Cytogenetic abnormalities influence the prognosis of multiple myeloma (MM). How these abnormalities associate with overall survival (OS) in European Americans (EAs) and African Americans (AAs) remains unclear. We collected data on fluorescence in situ hybridization targeting 17 cytogenetic abnormalities from 181 patients newly diagnosed with MM between 2010 and 2019. Vital status was ascertained using the National Death Index. Baseline clinical data were retrieved from electronic medical records. Established high-risk cytogenetic abnormalities (HRCAs) include t(4;14), t(14;16), t(14;20), del 17p, and gain/amplification of 1q. In each population, we evaluated the associations between cytogenetic abnormalities and OS. Among 55 AAs and 126 EAs, 65 deaths occurred (median follow-up: 5.8 years). The distribution of the abnormalities was similar between EAs and AAs. High-risk MM, characterized by HRCAs, was associated with worse OS in EAs (hazard ratio [HR], 2.6; 95% confidence interval [CI], 1.3-5.5), but not AAs. Del 13q was associated with worse OS in both populations. Gain/amplification of 1q was associated with poorer OS in EAs (HR, 3.44; 95% CI, 1.3-9.3) but not AAs, whereas t(4;14) was associated with poorer OS in AAs (HR, 14.51; 95% CI, 2.3-92.3) but not EAs. These associations remained after controlling for prognostic factors or other HRCAs, highlighting the potential of population heterogeneity in the prognostic significance of cytogenetic abnormalities.