Clinicopathological characteristics, genetic aberrations, and optimized treatment strategies in double-hit and triple-hit lymphoma: a multi-center cohort study.

High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements constitutes a distinct clinicopathological entity characterized by aggressive behavior, inherent resistance to conventional immunochemotherapy, and suboptimal clinical outcomes. Within our cohort, MYC/BCL2 rearrangements defined double-hit lymphoma (DHL), MYC/BCL6 as DHL-BCL6, and concurrent MYC/BCL2/BCL6 as triple-hit lymphoma (THL). Here, we delineated the clinical characteristics and genetic aberrations of 112 DHL/THL patients to investigate the factors influencing lymphoma relapse and optimize treatment strategies. Compared to 80 DHL-BCL6 patients, DHL/THL manifested distinct features, including an increased prevalence of the germinal center B-cell-like subtype and co-expression of MYC/BCL2, and demonstrated significant associations with abbreviated progression-free and overall survival. Univariate and multivariate analyses identified Ann Arbor stage and serum lactate dehydrogenase elevation as independent prognostic determinants. Therapeutic intensification employing R-DA-EDOCH was correlated with enhanced survival outcomes, while consolidative autologous stem cell transplantation significantly improved prognosis in patients who achieved remission after first-line immunochemotherapy. Regarding genetic aberrations, oncogenic mutations were detected in 102 evaluable patients. EZH2 mutation occurred more frequently in DHL/THL, while TNFRSF14 mutation exhibited greater prevalence in THL. The EZB genotype was predominantly observed in DHL/THL patients, and those with TP53 abnormalities exhibited a further diminished prognosis. In terms of the immune microenvironment, the depleted lymphoma microenvironment (LME-DP) subtype, characterized by diminished immune cell infiltration, demonstrated a propensity for increased frequency in DHL/THL patients. Collectively, these findings advance the comprehensive understanding of DHL/THL pathobiology, underscoring the imperative for novel targeted agents and therapeutic approaches.