Complex karyotype in de novo acute myeloid leukemia: typical and atypical subtypes differ molecularly and clinically.

Mrózek K, Eisfeld AK, Kohlschmidt J, Carroll AJ, Walker CJ, Nicolet D, Blachly JS, Bill M, Papaioannou D, Wang ES, Uy GL, Kolitz JE, Powell BL, Blum W, Stone RM, Byrd JC, Bloomfield CD
Leukemia in press 02/08/2019

Abstract

Complex karyotype (CK) with ≥ 3 abnormalities is detected in 10-12% of patients with acute myeloid leukemia (AML) and associated with poor prognosis. The most common unbalanced abnormalities found in CK result in loss of material from the 5q, 7q, and/or 17p chromosome arms. The presence of 5q, 7q, and/or 17p abnormalities denotes typical CK and their absence denotes atypical CK. Since molecular features of CK-AML are not well characterized, we investigated mutational status of 81 leukemia/cancer-associated genes in 160 clinically well-characterized patients. They included 136 patients with ≥ 3 exclusively unbalanced chromosome abnormalities, 96 of whom had a typical CK and 40 atypical CK, and 24 patients with ≥ 1 balanced abnormality in addition to ≥ 2 unbalanced ones. Patients with atypical CK-AML differed from those with typical CK-AML: they carried TP53 mutations less often (P < 0.001) and more often PHF6 (P = 0.008), FLT3-TKD (P = 0.02), MED12 (P = 0.02), and NPM1 (P = 0.02) mutations. They were younger (P = 0.007), had higher WBC (P = 0.001) and percentages of marrow (P < 0.001) and blood (P = 0.006) blasts, higher complete remission rates (P = 0.02), and longer overall survival (P < 0.001), thus indicating that atypical and typical CK-AMLs constitute distinct disease subtypes. We also identified smaller patient subsets within both typical and atypical CK-AML that differed molecularly and clinically.

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