Updates in the role of the tumor microenvironment cellular crosstalk and genetic signatures in diffuse large B-cell lymphoma: a narrative review

Background and objective: The tumor microenvironment (TME) is known to exert a significant impact on disease biology and convey prognostic and therapeutic implications in several hematopoietic neoplasms, including diffuse large B-cell lymphoma (DLBCL). Recent discoveries have yielded new information regarding the genetic signatures of the TME. This study aims to review the updates on the cellular markers and genetics of various components of the TME in DLBCL influencing tumor behavior and patients' responses to treatment and discuss the novel treatment modalities available for the patients. Methods: We systematically reviewed the literature in Medline for DLBCL-related articles on gene expression studies of TME. Forty-seven articles were identified and included that were published between Apr 2006 and Apr 2023. Key content and findings: We review the key components of the TME including the endothelial cells, myofibroblasts and mast cells, and discuss their biologic roles, with a particular focus on elements of their crosstalk relevant to DLBCL. We also review the genetic changes in lymphocytes and macrophages in TME of DLBCL. Increased understanding of emergent molecular alterations may hopefully allow improved prognostication and translational discoveries which will benefit patients with aggressive B-cell lymphomas. Conclusions: Combining cell of origin and TME as a risk stratification/prognostication system could provide more effective targeted therapeutic regiments. Identifying TME-targeted therapies will happen after providing the TME markers in the DLBCLs.