All 3 of these malignancies—multiple myeloma, solitary plasmacytoma, and extramedullary plasmacytoma—occur more frequently in blacks compared to whites.
Incidence rates were higher for men than women for all 3 cancers.
The lowest rates for solitary plasmacytoma and multiple myeloma were found in the non-Hispanic Asian/Pacific Islander group, and, for extramedullary plasmacytoma, rates were lowest in the non-Hispanic white group.
A precursor of multiple myeloma monoclonal gammopathy of undetermined significance, also known as MGUS, is found 2 to 3 times as often in blacks compared to whites.