Supplementary Figures 1-10 Figure S1. MYD88 mutation VAF according to L265P or non-L265P variants. Figure S2. Age according to MYD88 mutation status and variant among ABC patients. Figure S3. Genomic profiles of DLBCL according to the presence of MYD88 L265P or non-L265P variants. Figure S4. Relative L265P allele expression level according to L265P VAF. Figure S5. Gene expression according to MYD88 status. Figure S6. NFkB pathway gene expression according to MYD88 mutational status. Figure S7. LPS score according to subtype and downstream NFkB alterations. Figure S8. Clustering according to expression levels of 27 genes involved in LPS response and differentially expressed according to MYD88 L265P. Figure S9. TNFAIP3 and CARD11 expression according to their copy number status. Figure S10. Additional survival analyses.
ARTICLE ABSTRACT
Purpose: MYD88 mutations, notably the recurrent gain-of-function L265P variant, are a distinguishing feature of activated B-cell like (ABC) diffuse large B-cell lymphoma (DLBCL), leading to constitutive NFκB pathway activation. The aim of this study was to examine the distinct genomic profiles of MYD88-mutant DLBCL, notably according to the presence of the L265P or other non-L265P MYD88 variants.Experimental Design: A cohort of 361 DLBCL cases (94 MYD88 mutant and 267 MYD88 wild-type) was submitted to next-generation sequencing (NGS) focusing on 34 genes to analyze associated mutations and copy number variations, as well as gene expression profiling, and clinical and prognostic analyses.Results: Importantly, we highlighted different genomic profiles for MYD88 L265P and MYD88 non-L265P–mutant DLBCL, shedding light on their divergent backgrounds. Clustering analysis also segregated subgroups according to associated genetic alterations among patients with the same MYD88 mutation. We showed that associated CD79B and MYD88 L265P mutations act synergistically to increase NFκB pathway activation, although the majority of MYD88 L265P–mutant cases harbors downstream NFκB alterations, which can predict BTK inhibitor resistance. Finally, although the MYD88 L265P variant was not an independent prognostic factor in ABC DLBCL, associated CD79B mutations significantly improved the survival of MYD88 L265P–mutant ABC DLBCL in our cohort.Conclusions: This study highlights the relative heterogeneity of MYD88-mutant DLBCL, adding to the field's knowledge of the theranostic importance of MYD88 mutations, but also of associated alterations, emphasizing the usefulness of genomic profiling to best stratify patients for targeted therapy. Clin Cancer Res; 23(9); 2232–44. ©2016 AACR.
