Subtype-specific therapy for DLBCL: Are we there yet?

Abstract

The cell-of-origin (COO), as defined by molecular and immunophenotypic differences, delineates 2 major subtypes of DLBCL, which bear prognostic significance for the patient. Gene expression profiling (GEP) originally identified these subtypes as activated B-cell (ABC) subtype, germinal center (GC) subtype, and a minority of unclassified DLBCL.2 Non-GCB subtypes encompass the ABC and unclassified types. Immunohistochemical means of COO identification remains the standard practice in the clinical setting, and has variable concordance with GEP, as reported in the literature.3 Despite being the gold standard for COO determination, currently GEP is neither widely available nor feasible for COO determination outside of research, even at large centers. In the era of targeted therapies, the molecular differences among the subtypes of DLBCL are particularly relevant, with efforts underway to tailor advantageous therapeutic strategies.