Summary Immunophenotypic studies, fluorescence in situ hybridization (FISH) and conventional karyotyping were used to define the clinicobiological significance of 14q32 translocations involving the immunoglobulin gene locus (14q32/IGH) in 252 chronic lymphocytic leukaemia (CLL) patients. The following regions were studied: 13q14, centromere 12, 6q21; 11q22/ATM; 17p13/TP53, 14q32/IGH. Patients were classified as group 1 (favourable, i.e. 13q‐single or normal), group 2 (intermediate risk, i.e. +12, 6q‐, 1–2 anomalies), group 3 (unfavourable, i.e. 17p‐, 11q‐, complex karyotype), or group 4 (14q32/IGH translocation). Endpoints were treatment‐free survival (TFS) and overall survival (OS). One hundred and ten patients were included in group 1, 99 in group 2, 25 in group 3 and 18 in group 4. 14q32/IGH translocation partners were identified in eight cases (BCL2 in five cases, BCL11A, CCND3 and CDK6 in one case each). group 4 showed shorter TFS versus groups 2 and 1 (25% patients treated at 2 months vs. 12 (P = 0·02) and 20 months (P = 0·002), respectively) and shorter OS (25% patients dead at 18 months versus 50 (P = 0·0003) and >60 months (P < 0·0001) respectively. The 14q32/IGH translocation maintained prognostic significance at multivariate analysis on TFS (P = 0·025) and OS (P < 0·001), along with advanced stage and CD38+. These findings show that the 14q32/IGH translocation predicts for an unfavourable outcome in CLL and that this cytogenetic subset might be included as a separate entity in a hierarchical cytogenetic classification of CLL.

Cytogenetic and fluorescence in situ hybridization studies were successfully performed in 217 chronic lymphocytic leukemia (CLL). In all, 13 patients with 6q21 deletion were identified and characterized in comparison with 92 patients with 'favourable' karyotype (normal or 13qÀ), 69 cases with 'intermediate risk'(1-2 anomalies) and 43 cases with 'unfavourable' karyotype (complex, 11qÀ or 17pÀ). Six out of 13 cases with 6qÀ showed an excess of atypical lymphocytes, a finding confirmed at the histologic level; 420% CD38 þ cells were seen in 5/6 cases. IGVH mutational status revealed 498% homology to the germline sequence in 4/10 cases. When compared with the 'favourable' group, patients with 6qÀ showed a higher white blood cell (WBC) count, frequent splenomegaly, atypical morphology, CD38 þ and short time from diagnosis to first treatment and short survival. A higher median WBC count was found in the 6qÀ group vs the intermediate-risk group; survival was shorter in the unfavourable group. To ascertain if the 6qÀ anomaly was an independent factor predicting for an inferior outcome among those patients with 'favourable' cytogenetics, we performed an analysis of prognostic factors in 105 patients (92 'favourable' plus 13 with 6qÀ), showing that the 6qÀ chromosome maintained its prognostic significance at multivariate analysis (P ¼ 0.02) along with stage (P ¼ 0.01). We conclude that CLL with 6qÀ is characterized by a high incidence of atypical morphology, classical immunophenotype with CD38 positivity and intermediate incidence of IGVH somatic hypermutation. Clinicobiological features and outcome show that this cytogenetic subset of CLL should be allocated in an intermediate-risk category.

At diagnosis, approximately half of myelodysplastic (MDS) patients presents a normal karyotype by conventional cytogenetic analysis (CCA). Fluorescent in situ hybridization (FISH) is more sensitive than CCA allowing for the detection of minor clones and of submicroscopic lesions. We have analyzed by FISH 101 MDS patients with normal karyotype for the occurrence of the abnormalities which are most frequently observed in MDS (ie ؊5/5q؊, ؊7/7q؊, ؉8, 17p؊). In 18 patients, 15 to 32% of interphase cells were found to carry one FISH abnormality. Six patients presented trisomy 8, five had del(5)(q31), five del(7)(q31), one monosomy 7 and one del(17)(p13). FISH abnormalities were more frequently observed among patients with an increased percentage of bone marrow blasts (P ‫؍‬ 0.001). FISH abnormalities were also associated with a higher rate of progression into AML (13/18 vs 12/83, P Ͻ 0.001) and were predictive for a worse prognosis (P Ͻ 0.001). Multivariate analysis indicated that FISH positivity and IPSS risk group were independent predictors for a poor survival (P ‫؍‬ 0.0057 and 0.0123, respectively) and for leukemic transformation (P ‫؍‬

It is unclear whether karyotype aberrations that occur in regions uncovered by the standard fluorescence in situ hybridization (FISH) panel have prognostic relevance in chronic lymphocytic leukemia (CLL). We evaluated the significance of karyotypic aberrations in a learning cohort (LC; n ‫؍‬ 64) and a validation cohort (VC; n ‫؍‬ 84) of patients with chronic lymphocytic leukemia with "normal" FISH.