We examined 25 cases of colorectal lymphoma with DLBCL-like morphology and classified them into germinal center B-cell like (GCB)/non-GCB subgroups by immunohistochemistry (IHC) for CD10, bcl-6 and MUM1, or into double-expressor (DE)/non-DE subgroups by IHC for bcl-2 and c-myc.
'Double-hit' lymphoma (DHL) and 'double-expression' lymphoma (DEL) involving gene rearrangement and protein expression of MYC and BCL2/BCL6 have recently become the most commonly used terms to describe the poor prognostic types of diffuse large B-cell lymphoma (DLBCL).
High-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements (HGBL-DH/THs) include a group of diffuse large B-cell lymphomas (DLBCLs) with inferior outcomes after standard chemoimmunotherapy.
Our analysis provided a novel look on the transition range between FL and DLBCL, on DLBCL with poor prognosis showing expression patterns resembling that of Burkitt's lymphoma and particularly on 'double-hit' MYC and BCL2 transformed lymphomas.
For these reasons, we evaluated single-agent activity of venetoclax in the DLBCLs and identified a subset with limited sensitivity to BCL-2 blockade despite having genetic bases of BCL-2 dysregulation.
Immunohistochemically detectable co-expression of MYC and BCL2 in the absence of translocations also portends an increased risk of relapse within the central nervous system, particularly in the setting of the activated B-cell-like subtype of diffuse large B-cell lymphoma.
We retrospectively examined 127 cases of newly diagnosed diffuse large B-cell lymphoma (DLBCL), and used fluorescence in situ hybridization (FISH) to detect genetic abnormalities in <i>MYC, BCL2,</i> and <i>BCL6</i>.
Clinical Significance of <i>BCL2</i>, C-<i>MYC</i>, and <i>BCL6</i> Genetic Abnormalities, Epstein-Barr Virus Infection, CD5 Protein Expression, Germinal Center B Cell/Non-Germinal Center B-Cell Subtypes, Co-expression of MYC/BCL2 Proteins and Co-expression of MYC/BCL2/BCL6 Proteins in Diffuse Large B-Cell Lymphoma: A Clinical and Pathological Correlation Study of 120 Patients.
Recently, high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements have been categorized separately from diffuse large B-cell lymphoma or BL.
Anti-apoptotic Bcl-2 proteins are upregulated in different cancers, including diffuse large B-cell lymphoma (DLBCL) and chronic lymphocytic leukemia (CLL), enabling survival by inhibiting pro-apoptotic Bcl-2-family members and inositol 1,4,5-trisphosphate (IP<sub>3</sub>) receptor (IP<sub>3</sub>R)-mediated Ca<sup>2+</sup>-signaling.
We identified 122 patients diagnosed as having large B-cell lymphoma (44, MYC-negative; 29, MYC-EC; 23, MYC rearrangement; 22, MYC and BCL2 rearrangements; 4, MYC, BCL2, and BCL6 rearrangements). p53 expression significantly correlated with DLBCL with abnormal MYC status (MYC-EC, MYC rearrangement, and MYC overexpression), but adverse p53 prognostic effect was only seen with MYC-rearranged lymphoma.
We sought to understand the biologic underpinnings of HGBL-DH/TH with BCL2 rearrangements (HGBL-DH/TH- BCL2) and diffuse large B-cell lymphoma (DLBCL) morphology through examination of gene expression.
Concurrent of MYC and BCL2 and/or BCL6 abnormalities and MYC/BCL2 double-expressor DLBCL occurred in all 3 patients; two patients had MYC/BCL2/BCL6 triple extra copies, and one patient had MYC extra copy and BCL6 translocation.
Immunohistochemical studies of the lymphoma tissues confirmed that overexpression of MYC and BCL2 was observed more frequently in this subtype than in other germinal center B-cell-like diffuse large B-cell lymphomas.
Targeting MYC in the DHL/THL DLBCLs through bromodomain extra-terminal inhibitors (BETi) (JQ1, I-BET, and OTX015) significantly (p < 0.05) reduced proliferation, similar to WT-MYC cells, accompanied by decreased MYC but not BCL2 protein.
Univariate analyses revealed that EZH2/Bcl-2 coexpression correlated to worse objective response rate (ORR), shorter OS and PFS in DLBCL patients treated with RCHOP while multivariate analysis indicated that only elevated LDH level (<i>P</i>=0.001) and presence of B symtom (<i>P</i>=0.008) rather than EZH2/Bcl-2 coexpression were associated with worse OS.
Despite the recent therapeutic progress, the prognoses of diffuse large B-cell lymphomas (DLBCLs) that concomitantly overexpress c-MYC and BCL2, i.e., double hit lymphoma (DHL) and double expressing lymphoma (DEL), remain poor.
Regarding concurrent expression of MYC and BCL2 and/or BCL6 (double expressors (DE) and triple expressors (TE)), more DE and TE cases were found in the HGBL/DLBCL group than in the DLBCL group (25.53% vs 8.47%, p < 0.001, for DE cases and 55.32% vs 6.21%, p < 0.001, for TE cases).