A low frequency of losses in 11q chromosome is associated with better outcome and lower rate of genomic mutations in patients with chronic lymphocytic leukemia.

Abstract

To analyze the impact of the 11q deleted (11q-) cells in CLL patients on the time to first therapy (TFT) and overall survival (OS), 2,493 patients with CLL were studied. 242 patients (9.7%) had 11q-. Fluorescence in situ hybridization (FISH) studies showed a threshold of 40% of deleted cells to be optimal for showing that clinical differences in terms of TFT and OS within 11q- CLLs. In patients with ≥40% of losses in 11q (11q-H) (74%), the median TFT was 19 months compared with 44 months in CLL patients with <40% del(11q) (11q-L) (P<0.0001). In the multivariate analysis, only the presence of 11q-L, mutated IGHV status, early Binet stage and absence of extended lymphadenopathy were associated with longer TFT. Patients with 11q-H had an OS of 90 months, while in the 11q-L group the OS was not reached (P = 0.008). The absence of splenomegaly (P = 0.02), low LDH (P = 0.018) or β2M (P = 0.006), and the presence of 11q-L (P = 0.003) were associated with a longer OS. In addition, to detect the presence of mutations in the ATM, TP53, NOTCH1, SF3B1, MYD88, FBXW7, XPO1 and BIRC3 genes, a select cohort of CLL patients with losses in 11q was sequenced by next-generation sequencing of amplicons. Eighty % of CLLs with 11q- showed mutations and fewer patients with low frequencies of 11q- had mutations among genes examined (50% vs 94.1%, P = 0.023). In summary, CLL patients with <40% of 11q- had a long TFT and OS that could be associated with the presence of fewer mutated genes.

This work was supported by grants from the Spanish Fondo de Investigaciones Sanitarias FIS 09/01543, PI12/00281 and PI15/01471, Instituto de Salud Carlos III (ISCIII), European Regional Development Fund (ERDF) "Una manera de hacer Europa", Proyectos de Investigación del SACYL 355/ A/09, GRS/1172/A15, COST Action EuGESMA (BM0801), Fundación Manuel Solórzano, Obra Social Banca Cívica (Caja Burgos), Fundación Española de Hematología y Hemoterapia (FEHH), and by grants (RD12/0036/0069 and RD12/0036/0044) from Red Temática de Investigación Cooperativa en Cáncer (RTICC), Instituto de Salud Carlos III (ISCIII), Spanish Ministry of Economy and Competitiveness and European Regional Development Fund (ERDF) "Una manera de hacer Europa" (CEI 2010-1-0010). The research leading to these results has received funding from the European Union Seventh Framework Programme [FP7/2007-2013] under Grant Agreement n°306242-NGS-PTL. Mutation analyses were performed using oligonucleotide primer plates designed as part of the IRON-II collaborative network of hematological laboratories applying 454 amplicon next-generation deepsequencing. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. María HernándezSánchez is fully supported by an Ayuda Predoctoral de la Junta de Castilla y León from the Fondo Social Europeo (JCYL-EDU/346/2013 Ph.D. scholarship). Vera Grossmann was supported by MLL Munich and Alexander Kohlmann was supported by MLL Munich and AstraZeneca in terms of salary. These funders provided support in the form of salaries for these authors but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the 'author contributions' section.