Modern, real-world patterns of care and clinical outcomes among patients with newly diagnosed diffuse large B-cell lymphoma with or without double/triple-hit status in the United States

Modern, real-world patterns of care and clinical outcomes among patients with newly diagnosed diffuse large B-cell lymphoma with or without double/triple-hit status in the United StatesPatients with diffuse large B-cell lymphoma (DLBCL) and double-hit or triple-hit cytogenetics (DHL/THL) historically had a poor prognosis when treated with the standard front-line regimen consisting of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).1,2 Patterns of care and subsequent clinical outcomes of patients with DHL/THL had been largely determined from multiple retrospective studies, most without any direct comparisons to patients without DHL/THL.A single-arm, phase II study utilizing dose-adjusted rituximab, etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (R-EPOCH) in 24 patients with DHL/THL showed a 4-year event-free survival of 73%, which was significantly higher than that of historical controls.3 These data led to the adoption of dose-adjusted R-EPOCH as the preferred treatment for DHL/THL.A recent phase III study comparing R-CHOP versus dose-adjusted R-EPOCH included a small cohort of patients with DHL/THL, which precluded a comparison of efficacy.10 In this study, we aimed to evaluate the patterns of care and clinical outcomes of DLBCL from 2011 to the present day among a contemporary cohort of patients with newly diagnosed DLBCL.We also compared the outcomes of patients with DHL/THL DLBCL morphology treated with R-CHOP and R-EPOCH regimens in this population.This retrospective, observational study utilized the nationwide Flatiron Health electronic health record-derived database.This is a longitudinal database containing de-identified patient-level data, curated via a combination of tech-enabled search engines and abstractors.4 During the study period, data originated from approximately 280 US cancer clinics (~800 sites of care).We included adult patients (>18 years at diagnosis) with a confirmed diagnosis of the following histological subtypes of lymphoma: DLBCL not otherwise specified, DHL, Epstein-Barr viruspositive DLBCL, and T-cell/histiocyte-rich large B-cell lymphoma.We included patients diagnosed on or after January 1, 2011 who had at least two electronic health record-documented visits on or after that date, with at least 6 months of potential follow-up (diagnosis prior to January 31, 2021).Cytogenetic testing groups were defined by the documentation of cytogenetic test results based on fluorescence in situ hybridization (FISH) studies and/or karyotyping be-