BackgroundAmong patients with B-cell chronic lymphoid leukemia, those with 13q14 deletion have a favorable outcome. However, whether the percentage of cells with 13q-influences the prognosis or the biological characteristics of this disease is unknown. We analyzed the clinico-biological characteristics and outcome of patients with B-cell chronic lymphoid leukemia with loss of 13q as the sole cytogenetic aberration.
Design and MethodsThree hundred and fifty patients with B-cell chronic lymphoid leukemia were studied. Clinical data were collected and fluorescence in situ hybridization and molecular studies were carried out. In addition, a gene expression profile was obtained by microarray-based analysis.
ResultsIn 109 out of the 350 cases (31.1%) loss of 13q was the sole cytogenetic aberration at diagnosis. In the subgroup of patients with 80% or more of cells with loss of 13q (18 cases), the overall survival was 56 months compared with not reached in the 91 cases in whom less than 80% of cells had loss of 13q (p< 0.0001). The variables included in the multivariate analysis for overall survival were the percentage of losses of 13q14 (p=0.001) and B symptoms (p=0.007). The time to first therapy in the group with 80% or more vs. less than 80% of losses was 38 months vs. 87 months, respectively (p=0.05). In the multivariate analysis the variables selected were unmutated status of IgVH (p=0.001) and a high level of β2microglobulin (p=0.003). Interestingly, these differences regarding overall survival and time to first therapy were also present when other cut-offs were considered. The gene expression profile of patients with a high number of losses in 13q14 showed a high proliferation rate, downregulation of apoptosis-related genes, and dysregulation of genes related to mitochondrial functions.
ConclusionsPatients with B-cell chronic lymphoid leukemia with a high number of losses in 13q14 as the sole cytogenetic aberration at diagnosis display different clinical and biological features: short overall survival and time to first therapy as well as more proliferation and less apoptosis. A quantification of the number of cells showing a genetic abnormality should, therefore, be included in the study of the prognostic factors of B-cell chronic lymphoid leukemia.Key words: B chronic lymphoid leukemia, 13q14 deletion, outcome, proliferation, apoptosis.Citation: Hernández JA, Rodríguez AE, González M, Benito R, Fontanillo C, Sandoval V, Romero M, Martín-Núñez G, de Coca AG, Fisac R, Galende J, Recio I, Ortuño F, García JL, de las Rivas J, Gutiérrez NC, San Miguel JF, and Hernández JM. A high number of losses in 13q14 chromosome band is associated with a worse outcome and biological differences in patients with B chronic lymphoid leukemia. Haematologica 2009; 94:364-371. doi:10.3324/haematol.13862
©2009 Ferrata Storti Foundation. This is an open-access paper.A high number of losses in 13q14 chromosome band is associated with a worse outcome and biological differences in patients with B-cell chronic lymphoid leukemia