A retrospective study of MYC rearranged diffuse large B-cell lymphoma in the context of the new WHO and ICC classifications

Fifth Edition of the World Health Classification of Tumors of the Hematopoietic and Lymphoid Tissues: B-cell Neoplasms

We review B-cell neoplasms in the 5th edition of the World Health Organization classification of hematolymphoid tumors (WHO-HEM5). The revised classification is based on a multidisciplinary approach including input from pathologists, clinicians, and other experts. The WHO-HEM5 follows a hierarchical structure allowing the use of family (class)-level definitions when defining diagnostic criteria are partially met or a complete investigational workup is not possible. Disease types and subtypes have expanded compared with the WHO revised 4th edition (WHO-HEM4R), mainly because of the expansion in genomic knowledge of these diseases. In this review, we focus on highlighting changes and updates in the classification of B-cell lymphomas, providing a comparison with WHO-HEM4R, and offering guidance on how the new classification can be applied to the diagnosis of B-cell lymphomas in routine practice.

A MYC-rearrangement is a negative prognostic factor in stage II, but not in stage I diffuse large B-cell lymphoma

MYC oncogene rearrangements (MYC-R) negatively affect survival in patients with Ann Arbor stage III-IV diffuse large B-cell lymphoma (DLBCL), but their impact in limited stage (LS) I-II is unclear. Therefore, we assessed the impact of MYC-R on progression-free survival (PFS) and overall survival (OS) in LS DLBCL patients at the population level. We identified 1,434 LS DLBCL patients with known MYC-R status diagnosed between 2014 and 2020, who received R-CHOP(-like) regimens using the Netherlands Cancer Registry, with survival follow-up until February 2022. Stage I patients with (n = 83, 11%) and without (n = 650, 89%) a MYC-R had similar 2-years PFS (89% and 93%, p = 0.63) and OS (both 95%, p = 0.22). Conversely, stage II DLBCL patients with a MYC-R (n = 90, 13%) had inferior survival outcomes compared to stage II patients without a MYC-R (n = 611, 87%) (PFS 70% vs. 89%, p = 0.001; OS 79% vs. 94%, p < 0.0001). Both single MYC-R (single hit, n = 36) and concurrent BCL2 and/or BCL6 rearrangements (double/triple hit, n = 39) were associated with increased mortality and relapse risk. In conclusion, in stage II DLBCL a MYC-R is negatively associated with survival. In stage I DLBCL, however, survival outcomes are excellent irrespective of MYC-R status. This challenges the diagnostic assessment of MYC-R in stage I DLBCL patients.

2024 Update: Advances in the risk stratification and management of large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with varying clinical outcomes. Our understanding of its molecular makeup continues to improve risk stratification, and artificial-intelligence and ctDNA-based analyses have the potential to enhance risk assessment and disease monitoring. R-CHOP and Pola-R-CHP are used in the frontline setting; chimeric antigen receptor therapy (CART) is now the new standard-of-care for most with primary refractory disease; both CART and autologous stem cell transplantation are utilized in the relapsed and refractory setting. In this review, we summarize the classification and management of DLBCL with an emphasis on recent advances in the field.