@article{Farzaneh Ghazavi_Emmanuelle Clappier_Tim Lammens_Stefan Suciu_Aurélie Caye_Samira Zegrari_Marleen Bakkus_Nathalie Grardel_Yves Benoit_Yves Bertrand_Odile Minckes_Vitor Costa_Alina Ferster_Françoise Mazingue_Geneviève Plat_Emmanuel Plouvier_Marilyne Poirée_Anne Uyttebroeck_Jutte van der Werff-ten Bosch_Karima Yakouben_Hetty Helsmoortel_Magali Meul_Nadine Van Roy_Jan Philippé_Frank Speleman_Hélène Cavé_Pieter Van Vlierberghe_Barbara De Moerloose_2015, place={Pavia, Italy}, title={CD200/BTLA deletions in pediatric precursor B-cell acute lymphoblastic leukemia treated according to the EORTC-CLG 58951 protocol}, volume={100}, url={https://haematologica.org/article/view/7525}, DOI={10.3324/haematol.2015.126953}, abstractNote={DNA copy number analysis has been instrumental for the identification of genetic alterations in B-cell precursor acute lymphoblastic leukemia. Notably, some of these genetic defects have been associated with poor treatment outcome and might be relevant for future risk stratification. In this study, we characterized recurrent deletions of <em>CD200</em> and <em>BTLA</em> genes, mediated by recombination-activating genes, and used breakpoint-specific polymerase chain reaction assay to screen a cohort of 1154 cases of B-cell precursor acute lymphoblastic leukemia uniformly treated according to the EORTC-CLG 58951 protocol. <em>CD200/BTLA</em> deletions were identified in 56 of the patients (4.8%) and were associated with an inferior 8-year event free survival in this treatment protocol [70.2% ± 1.2% for patients with deletions <em>versus</em> 83.5% ± 6.4% for non-deleted cases (hazard ratio 2.02; 95% confidence interval 1.23–3.32; <em>P</em>=0.005)]. Genetically, <em>CD200/BTLA</em> deletions were strongly associated with <em>ETV6-RUNX1</em>-positive leukemias (<em>P</em><0.0001), but were also identified in patients who did not have any genetic abnormality that is currently used for risk stratification. Within the latter population of patients, the presence of <em>CD200/BTLA</em> deletions was associated with inferior event-free survival and overall survival. Moreover, the multivariate Cox model indicated that these deletions had independent prognostic impact on event-free survival when adjusting for conventional risk criteria. All together, these findings further underscore the rationale for copy number profiling as an important tool for risk stratification in human B-cell precursor acute lymphoblastic leukemia. <em>This trial was registered at <a href="http://www.ClinicalTrials.gov">www.ClinicalTrials.gov</a> as #<a class="external-ref external-ref-type-clintrialgov" href="/lookup/external-ref?link_type=CLINTRIALGOV&amp;access_num=NCT00003728&amp;atom=%2Fhaematol%2F100%2F10%2F1311.atom">NCT00003728</a>.</em&gt;}, number={10}, journal={Haematologica}, author={Farzaneh Ghazavi and Emmanuelle Clappier and Tim Lammens and Stefan Suciu and Aurélie Caye and Samira Zegrari and Marleen Bakkus and Nathalie Grardel and Yves Benoit and Yves Bertrand and Odile Minckes and Vitor Costa and Alina Ferster and Françoise Mazingue and Geneviève Plat and Emmanuel Plouvier and Marilyne Poirée and Anne Uyttebroeck and Jutte van der Werff-ten Bosch and Karima Yakouben and Hetty Helsmoortel and Magali Meul and Nadine Van Roy and Jan Philippé and Frank Speleman and Hélène Cavé and Pieter Van Vlierberghe and Barbara De Moerloose}, year={2015}, month={Oct.}, pages={1311-1319} }