Abstract 4200: Racial differences in multiple myeloma cases with anemia
Authors: Modi Riddhi , Costa Luciano J. , Brown Elizabeth E. 
Published: August 2019

Introduction. Multiple Myeloma (MM) is a hematologic malignancy defined, in part, by prolonged survival and accumulation of clonally expanded plasma cells in the bone marrow microenvironment and extramedullary sites and the presence of hypercalcemia, renal insufficiency, anemia or bone involvement, collectively known as end organ damage. MM is the most common hematologic malignancy affecting Blacks in the US, with standardized incidence rates that are 2 to 3-fold higher than Whites. A rationale for the disparity remains unclear.

Methods. Using participants enrolled in the Molecular And Genetic Epidemiology (iMAGE) study of myeloma (515 MM cases; 54.1%White, 41.9% Black), we examined the clinical and laboratory features associated with the presence of anemia in MM cases at diagnosis and differences by race to provide a rationale for the observed disparity. Risk estimates were calculated using odds ratios and corresponding 95% confidence intervals from logistic regression adjusted for sex, age at diagnosis, presence of other end organ damage and race, where appropriate. Sensitivity analyses were conducted in MM cases with only anemia as the end organ damage.

Results. Overall, anemia was present in 16.7% of MM cases as the only end organ damage at diagnosis and in 56.8% of MM cases as one or more end organ damage. In the combined population, no notable differences by sex or age were observed among MM cases with anemia; however, the presence of anemia was significantly elevated in Blacks compared to Whites (OR=2.11, 95% CI 1.36-3.27; P=0.001) and among Blacks, women were significantly more likely to present with anemia at diagnosis (P=0.002). Overall, compared to MM cases without anemia at diagnosis, significantly more MM cases with anemia exhibited clonal bone marrow plasma cells ≥ 60% (OR=2.43, 1.58-3.76; P&lt;0.0001), high serum lactate dehydrogenase (LDH &gt;300 units/L; OR=5.03, 95% CI 1.47-17.27; P&lt;0.0001), serum total monoclonal protein ≥ 3 g/dL (OR=2.85, 95% CI 1.76-4.62; P&lt;0.0001), involved to uninvolved serum free light chain ratio ≥ 100 (OR=2.20, 95% CI 1.33-3.62; P=0.002) and among chromosomal abnormalities, translocation 4;14 (FGFR3; OR=7.27, 95% CI 1.54-34.28; P=0.012), deletion 13q (OR=1.96, 95% CI 1.14-3.34; P=0.013) and chromosome 1q amplification (OR=2.76, 95% CI 1.31-5.80; P=0.007) after adjusting for confounders. In contrast, MM cases with anemia were significantly less likely to present with serum albumin ≥ 3.5 mg/dL (OR=0.30, 95% CI 0.19-0.47; P&lt;0.0001) and bone involvement (OR=0.23, 95% CI 0.13-0.42; P&lt;0.0001). No notable differences in clinical or laboratory features with the presence of anemia at diagnosis were observed by race. Findings were confirmed in sensitivity analyses.

Conclusions. The excess risk of MM observed in Blacks and the variation in clinical features observed in MM patients according to the presence of anemia at diagnosis may contribute to disparate trends in incidence yet similar overall survival rates.

Citation Format: Riddhi Modi, Luciano J. Costa, Elizabeth E. Brown. Racial differences in multiple myeloma cases with anemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4200.