IN CHRONIC LYMPHOCYTIC LEUKAEMIA WITH COMPLEX KARYOTYPE, MAJOR STRUCTURAL ABNORMALITIES IDENTIFY A SUBSET OF PATIENTS WITH INFERIOR OUTCOME AND DISTINCT BIOLOGIC CHARACTERISTICS

Complex karyotype (CK) is a negative prognostic factor in chronic lymphocytic leukaemia (CLL). However, CK is a heterogeneous cytogenetic category. Unbalanced rearrangements were present in 733% of 90 CLL patients with CK (i.e. 3 chromosome aberrations in the same clone), and were associated with a shorter overall survival (P=0025) and a shorter time to first treatment (P=0043) by multivariate analysis. Patients with unbalanced rearrangements presented a distinct mRNA expression profile. In conclusion, CLL patients with unbalanced rearrangements might represent a subset of very high-risk CLL patients with distinct clinical and biological characteristics.