GENETIC SUBGROUPS INFORM ON PATHOBIOLOGY IN ADULT AND PEDIATRIC BURKITT LYMPHOMA

Burkitt lymphoma (BL) accounts for the majority of pediatric non-Hodgkin lymphomas being less common but significantly more lethal when diagnosed in adults. Much of our knowledge of the genetics of BL thus far has originated from the study of pediatric BL (pBL), leaving its relationship to adult (aBL) and other adult lymphomas not fully explored. We sought to more thoroughly identify the somatic changes that underlie lymphomagenesis in aBL and any molecular features that associate with clinical disparities within and between pBL and aBL. Through comprehensive whole-genome sequencing of 230 BL and 295 diffuse large B-cell lymphoma (DLBCL) tumors, we identified additional significantly mutated genes (SMGs) including more genetic features that associate with tumor EBV status, and unraveled new distinct subgroupings within BL and DLBCL with three predominantly comprising BLs: DGG-BL (DDX3X, GNA13 and GNAI2), IC-BL (ID3, CCND3), and Q53-BL (quiet TP53). Each BL subgroup is characterized by combinations of common driver and non-coding mutations caused by aberrant somatic hypermutation (aSHM). The largest subgroups of BL cases, IC-BL and DGG-BL are further characterized by distinct biological and gene expression differences. IC-BL and DGG-BL and their prototypical genetic features (ID3 and TP53) had significant associations with patient outcomes that were different among aBL and pBL cohorts. These findings highlight shared pathogenesis between aBL and pBL, and establish genetic subtypes within BL that serve to delineate tumors with distinct molecular features, providing a new framework for epidemiological, diagnostic, and therapeutic strategies