Genomic aberrations in anaplastic multiple myeloma: high frequency of 1q21(CKS1B) amplifications.

Anaplastic multiple myeloma (AMM) is a rare morphologic variant of MM with adverse prognosis. The underlying molecular cytogenetic abnormalities are poorly understood. We investigated 11 patients with AMM for myeloma associated cytogenetic aberrations and compared with 188 non-anaplastic MM using fluorescent in situ hybridization. Of the 11 AMM patients studied, 10 had CKS1B amplification, 5 hemizygous 17p(p53) deletions, 4 13q14 deletions, 4 t(4:14), and 2 had t(11:14). AMM was associated with significantly higher prevalence of CKS1B amplification (91% vs. 34%, p<0.001), 17p(p53) deletion (45% vs. 11%, p=0.006) and t(4,14) (36% vs. 14%, p=0.015) than non-anaplastic MM, which may have resulted in the genetic instability and more aggressive clinical course.