Elucidating disparities across racial and ethnic groups in multiple myeloma patients

Genomic analysis of multiple myeloma using targeted capture sequencing in the Japanese cohort

Previous genomic studies have revealed the genomic landscape of myeloma cells. Although some of the genomic abnormalities shown are believed to be correlated to the molecular pathogenesis of multiple myeloma and/or clinical outcome, these correlations are not fully understood. The aim of this study is to elucidate the correlation between genomic abnormalities and clinical characteristics by targeted capture sequencing in the Japanese multiple myeloma cohort. We analysed 154 patients with newly diagnosed multiple myeloma. The analysis revealed that the study cohort consisted of a less frequent hyperdiploid subtype (37·0%) with relatively high frequencies of KRAS mutation (36·4%) and IGH-CCND1 translocation (26·6%) compared with previous reports. Moreover, our targeted capture sequencing strategy was able to detect rare IGH-associated chromosomal translocations, such as IGH-CCND2 and IGH-MAFA. Interestingly, all 10 patients harboured MAX mutations accompanied by 14q23 deletion. The patients with del(17p) exhibited an unfavourable clinical outcome, and the presence of KRAS mutation was associated with shorter survival in patients with multiple myeloma, harbouring IGH-CCND1. Thus, our study provides a detailed landscape of genomic abnormalities, which may have potential clinical application for patients with multiple myeloma.

Molecular underpinnings of clinical disparity patterns in African American vs. Caucasian American multiple myeloma patients

Caucasian Americans (CA) compared with African Americans (AA) have a twofold increased incidence of multiple myeloma (MM) and have an earlier age of diagnosis. However, there is sparse information regarding underlying biological differences across racial/ethnic groups. We characterized genetic alterations using a targeted next-generation sequencing assay called myTYPE, developed at MSKCC, allowing capture of somatic mutations, IgH translocations, gains/losses, and hyperdiploidy. Samples were obtained from the NIH Plasma Cell Dyscrasia Racial Disparity Cohort. In total, 68 patient samples were successfully sequenced and manually curated based on well-established databases. Of the 68 patient samples (47 CA, 21 AA), 84% had at least one type of genomic alteration. Importantly, the IgH translocation, t(11;14), was observed more frequently in the AA group (0 vs. 29%, p = 0.001). Known oncogenic somatic non-synonymous mutations were found in 18 genes and indels in 2 genes. KRAS mutations were the most common mutation found in 16% of patients followed by NRAS and BRAF mutations. TP53 somatic mutations appeared to be more common in CA but lacked significance. This proof-of-principle study indicates the presence of varying underlying tumor biology between racial groups and supports the need of future prospective trials to capture these molecular characteristics.

Israeli-born offspring of Jewish immigrants of Middle Eastern origin have a lower incidence of multiple myeloma than those of European origin: a cohort study of 746 200 Israeli men followed from late adolescence

Differences in the prevalence of multiple myeloma across races have been observed, with a two- to three-fold greater prevalence in African Americans compared with Caucasians. Little is known about the incidence or prevalence of multiple myeloma in other populations. The association between father's country of origin and the incidence of multiple myeloma was examined in a nationwide population-based cohort. Health-related data on 746 200 16-19-year-old Jewish males examined between 1967 and 1998 were linked to the Israel National Cancer Registry to derive multiple myeloma incidence up to 2006. During 17 352 349 person-years of follow-up, 109 examinees developed plasma cell dyscrasias. Middle Eastern origin was protective compared to European origin (hazard ratio [HR] 0.39; 95% confidence interval [CI] 0.22-0.68; p = 0.001, adjusted for year of birth), and also when restricted to Israeli-born males (HR 0.44; 95% CI 0.24-0.82; p = 0.01). In conclusion, second-generation adolescents of Middle Eastern origin are at persistently lower risk of developing multiple myeloma compared to those of European origin, supporting a genetic component in the pathogenesis of multiple myeloma.