Ancestry Analysis Identifies Genetic Cause for Increased Multiple Myeloma in African Americans
Three cytogenetic subtypes are particularly responsible for the increased incidence of multiple myeloma in people of African descent, according to the results of a study published in Blood Cancer Journal (https://doi.org/10.1038/s41408-018-0132-1).
Researchers used ancestry analysis based on single-nucelotide polymorphisms to identify the cytogenetic subtypes t(11;14), t(14;16), and t(14;20) in a sample of 881 patients with monoclonal gammopathies, a precurser to multiple myeloma. Previous investigations looking at multiple myeloma’s increased incidence rates in African Americans relied on self-reports of race, which are less accurate.
The likelihood of having the identified subtypes increased with every 10% increase in African ancestry. About 75% of the sample had the t(11;14) subtype, which has a more favorable prognosis than the other two higher-risk subtypes. The researchers hypothesized that the finding may explain that although African Americans have higher multiple myeloma incidence rates, they tend to have better outcomes than European Americans.
Researchers emphasized the importance of testing for the t(11;14) subtype in particular in African Americans; because it is a common subtype, many labs may do so already.
The findings may translate into new targeted treatment options for patients with the cytogenetic subtype. The drug venetoclax targets t(11;14) and is currently approved for patients with chronic lymphocytic leukemia, but preliminary data suggest that patients with t(11;14) mutiple myeloma may respond to it as well.
The researchers called for additional research into treatment options as well as to identify whether their findings apply to European Americans with t(11;14) subtypes.