Family History of Hematologic Malignancies and Risk of Multiple Myeloma in Black Americans

Introduction: Multiple Myeloma (MM) is the most common hematologic malignancy in Black Americans. Standardized incidence rates are increasing, consistent with an aging population, and are 2- to 3- fold higher among Black Americans compared to White Americans for reasons that remain unclear.

Methods: Using participants enrolled in the Integrative Molecular And Genetic Epidemiology (IMAGE) study of myeloma (955 MM cases; 1,316 sex-, race-, age-, geography- matched controls), we investigated the risk of MM associated with family history of cancer and differences by race. We estimated risk using odds ratios and corresponding 95% confidence intervals adjusted for confounders calculated from logistic regression.

Results: Overall, MM risk in cases with a first degree relative affected with any hematologic malignancy was significantly elevated compared to controls (OR=1.36, 95% CI 1.02–1.82; P=0.038). Myeloma risk associated with a family history of MM was higher than the risk associated with any hematologic malignancy (OR=2.13, 95% CI 1.20-3.79; P=0.001), and the magnitude of this effect was greater for Black Americans (OR=4.88, 95% CI 1.90-12.51; P=0.001) than White Americans (OR=1.03, 95% CI 0.45-2.32; P=0.951) with similar relationships observed among first degree relatives with any plasma cell proliferative disorder (OR_Black=5.34, 95% CI 2.11-13.54; P=0.0004 and OR_White=1.18, 95% CI 0.59-2.37;P=0.642) and with increasing numbers of affected relatives (P-trend=0.001).

Conclusions: Findings confirm our previous report that the excess risk of MM observed in Black Americans may be attributed to shared germline and environmental susceptibility. Studies, which include family history of plasma cell proliferative disorders, to determine screening effectiveness in high-risk populations are warranted.