Racial Differences in Abnormalities by FISH in Minorities with Multiple Myeloma: A Single-Center Experience

Conference Correspondent - ASCO 2017

Disparities in fluorescence in situ hybridization (FISH) abnormalities in patients with multiple myeloma (MM) by race have been well-described in whites but have only been partially detailed in minorities (Paulus, et al. ASH 2016). This study aimed to explore race-based differences in FISH abnormalities using the largest cohort of minority patients with MM to date.

A total of 799 consecutive patients underwent CD-138–selected FISH testing. Patients were excluded from this study if they did not have symptomatic MM and biopsy <6 months after diagnosis. The abnormalities evaluated included standard and intermediate risk: IGH rearrangements (IGH r), t(4;14), t(11;14); and high risk: t(14;20), t(14;16), del13q, del 17p, and 1q21. Due to smaller numbers, all minority patients (Hispanic, black, Asian, and others) were included in the same group for analysis in this study.

A total of 482 patients were eligible for study inclusion and randomization. There were 343 (71%) patients identified as white, 52 (10%) as Hispanic, 50 (10%) as black, 19 (3%) as Asian, and 18 (3%) were identified as other. The median age of participants was 65 years, 54% were male, and 26% had International Staging System stage 3 disease. Results showed no statistically significant differences in FISH abnormalities between patients in the minority populations. Overall, the white cohort showed more abnormalities in IGH r, t(4;14), t(11;14), t(14:20), and 1q21 gain compared with the minority group. Racial differences in IGH r (39% vs 28%; P = 0.019) and t(11;14) (20% vs 12%; P = 0.024) were statistically significant. There were no statistically significant differences between the white and minority cohorts in other high-risk FISH abnormalities.

Significant differences in the presence of FISH abnormalities were reported in the white cohort versus the minority cohort. This study confirms the biological racial disparities in minorities with MM, and studies that include a larger minority cohort are necessary to better understand the disparity between groups.

Velez MG, et al. ASCO Abstract 8044.