Characteristics and treatment outcomes of aggressive high grade b cell lymphoma with myc and bcl 6 rearrangements

According to the International Consensus Classification of Lymphomas (Blood 2022: 140: 1229–53), a new provisional entity high grade B cell lymphoma with MYC and BCL 6 rearrangements (HGBCL-DH-BCL6) was introduced. HGBCL-DH-BCL6 occurred very rare, in less than 10% of patients with HGBCL with rearrangements. Here we assessed clinicopathological features and treatment outcomes of HGBCL-DH-BCL6. We retrospectively collected clinic-pathological data of patients with HGBCL with MYC/BLC6-rearrangements. All cases were evaluated by histopathological/immunohistochemical/flow-cytometry examination (IHC/FCM), with a broad panel of antibodies, including CD10/CD38/ MYC/LMO2/ BCL2/BCL6. Gene status (MYC/BCL2/BCL6) was examined using fluorescence in situ hybridization (FISH), karyotype was successfully achieved in 70% of patients. We identified 18 patients with MYC-rearrangement (median MYC-R: 49% of examined cells; range: 5%–93%), and BCL6-rearrangements (median BCL6-R: 50% of examined cells; range: 5%–93%) with no BCL2- rearrangements was found. Expression of MYC-protein was found only in 22% of patients. Eleven and seven patients, respectively, had DLBCL and BCL-u morphology. Median age at diagnosis was 57 years (range: 18–84). Advanced stage, extranodal disease, increased dehydrogenase lactate were found in 78%, 33%, 83% of patients, respectively. Only 15 patients received immunochemotherapy: 8 were treated with R-CHOP and CNS prophylaxis, other 7 patients had more intensive therapy: GMALL, CODOX/IVAC or DAEPOCH-R. Six patients had consolidative auto-SCT. Morphology of disease, age and intensity of immunochemotherapy had no impact on response and survival. Only 36% of patients achieved complete remission. Median overall survival (OS) and progression free survival (PFS) were 5.6 months and 3.0 months, respectively. OS and PFS for 1 year were 34% and 28% respectively. Actually, 4 patients are alive with no active disease. HGBCL-DH-BCL6 is a rare and aggressive B-cell lymphoma, often without the IHC-protein MYC deletion, with advanced disease presenting at diagnosis. The outcomes is poor and less than 40% of patient are alive from one year from diagnosis. Intensive therapy has not improved treatment results. Keywords: aggressive B-cell non-Hodgkin lymphoma, pathology and classification of lymphomas No conflicts of interests pertinent to the abstract.