Clinicopathological and transcriptomic profiles of 101 patients with diffuse large B‐cell lymphoma/high‐grade B‐cell lymphoma with double‐hit MYC and BCL2 or BCL6 and triple hit

AIMS: Diffuse large B-cell lymphoma/high-grade B-cell lymphoma (DLBCL/HGBCL) with MYC and BCL2 rearrangements (double-hit lymphoma with BCL2, DHL-BCL2) is a mature aggressive B-cell lymphoma that also includes concurrent triple hit with BCL6 translocation (TH). DHL with MYC and BCL6 (DH-BCL6) can also occur. The differences among these three DLBCL/HGBCL subtypes have not yet been definitively determined. METHODS AND RESULTS: This study characterized the clinicopathological features and transcriptomic profiles of a series of 101 cases of DLBCL/HGBCL that were subclassified according to MYC, BCL2 and BCL6 FISH data, including cell-of-origin (COO)-like, molecular high-grade (MHG)-like and double-hit/dark-zone (DHIT/DZsig)-like signatures. DLBCL/HGBCL-DH-BCL2 was characterized by higher HGBCL morphology, CD10 positivity, GCB Hans's, GCB COO and MHG molecular subtype. DLBCL/HGBCL-TH had higher LDH levels and worse overall survival. DLBCL/HGBCL-DH-BCL6 had higher MUM1 expression, non-GCB Hans', ABC/Unclassified COO, non-MHG and low DHIT/DZ signatures. Transcriptomic analysis showed that DLBCL/HGBCL-DH-BCL2 and DLBCL/HGBCL-TH were close but separated from DLBCL/HGBCL-DH-BCL6. Gene set enrichment analysis (GSEA) revealed different levels of enrichment between the subtypes. CONCLUSIONS: DLBCL/HGBCL-DH-BCL6 differs from the DLBCL/HGBCL-DH-BCL2, and the DLBCL/HGBCL-TH is associated with the worst survival. Analysis of all three genes of MYC, BCL2 and BCL6 is recommended in the context of DLBCL/HGBCL diagnosis.