Genome studies of diffuse large B-cell lymphoma (DLBCL) have revealed a large number of somatic mutations and structural alterations. However, the clinical significance of these alterations is still not well defined. In this study, we have integrated the analysis of targeted next-generation sequencing of 106 genes and genomic copy number alterations (CNA) in 150 DLBCL. The clinically significant findings were validated in an independent cohort of 111 patients. Germinal center B-cell and activated B-cell DLBCL had a differential profile of mutations, altered pathogenic pathways and CNA. Mutations in genes of the NOTCH pathway and tumor suppressor genes (TP53/CDKN2A), but not individual genes, conferred an unfavorable prognosis, confirmed in the independent validation cohort. A gene expression profiling analysis showed that tumors with NOTCH pathway mutations had a significant modulation of downstream target genes, emphasizing the relevance of this pathway in DLBCL. An in silico drug discovery analysis recognized 69 (46%) cases carrying at least one genomic alteration considered a potential target of drug response according to early clinical trials or preclinical assays in DLBCL or other lymphomas. In conclusion, this study identifies relevant pathways and mutated genes in DLBCL and recognizes potential targets for new intervention strategies.

This study was supported by the Ministerio de Economía y Competitividad, Grant No. SAF2015-64885- R (to EC), Generalitat de Catalunya Suport Grups de Recerca AGAUR 2014-SGR-795 (to EC), Instituto de Salud Carlos III, Spanish Ministry of Health, PI12/01536 (to AL-G) and PI16/00420 (to AL-G), the Red Temática de Investigación Cooperativa en Cáncer (RTICC) grant RD12/0036/0036 (to EC), RD12/0036/0023 (to AL-G), RD12/0036/0069 (to MA), BIO/SA78/15 (to MA) and the European Regional Development Fund 'Una manera de fer Europa', CERCA Programme/Generalitat de Catalunya. EC is an Academia Researcher of the 'Institució Catalana de Recerca i Estudis Avançats' (ICREA) of the Generalitat de Catalunya. KK has received a research fellowship from the Uehara Memorial Foundation (Japan). DT is supported by the People Programme (Marie Curie Actions) of the Seventh Framework Programme of the European Union (FP7/2007-2013) under REA grant agreement number 600388 and by the Agency of Competitiveness for Companies of the Government of Catalonia, ACCIÓ and SAF2015-74072-JIN. CR-P is supported by an FPI fellowship. ID is supported by 'Josep Font' grant from Hospital Clinic. This work was also supported by La Fundació la Marató de TV3 and EU H2020 Programme 2014-2020 under grant agreements no. 634143 (MedBioinformatics), and the European Research Council (consolidator grant 682398) (to NL-B).