Multicolor FISH in chronic lymphocytic leukemia. An interphase study of patients with early-onset disease

Trisomy 12 and deletions of 13q14.2 and 14q32 are the most common chromosom e abnormalities in patients with B-chronic lymphocytic leukemia (B-CLL), bu t whether specific chromosomal defects influence the course of B-CLL is sti ll a matter of discussion. The aim of our study was to assess the possible correlation between cytogenetic findings and clinical characteristics. Thir ty patients with previously untreated early-onset B-CLL were recruited. The incidence of trisomy 12, and observations of 13q14.2 and 14q32 was analyze d in unstimulated bone marrow cells by means of multicolor interphase FISH. No correlation was found between trisomy 12 and the patients' clinical cha racteristics. The analysis of the patients with trisomy 12 and observations of 13q14.2 and 14q32 revealed heterogeneity of the leukemic cell populatio n, thus indicating that these chromosomal abnormalities are probably a seco ndary event in CLL leukemogenesis. The finding of RB1 gene nullisomy and 14 q32 deletions in patients at an advanced clinical stage suggests a possible correlation between these rearrangements and disease progression. Multicol or FISH analysis in B-CLL provides important diagnostic, clinical, and prog nostic information that may help in assessing prognosis and making treatmen t decisions. (C) 2001 Elsevier Science Inc. All rights reserved.