Baseline Plasma Cell-Free and Circulating Tumor DNA Across Lymphoma Subtypes and its Prognostic Impact in Diffuse Large B-Cell Lymphoma.

BACKGROUND: Circulating tumor DNA (ctDNA) analysis enables real‑time assessment of the tumor burden and genomic complexity in lymphomas. However, real‑world evidence across lymphoma subtypes is limited. METHODS: We analyzed cell‑free DNA (cfDNA) and ctDNA data from 336 consecutive patients with newly diagnosed Hodgkin or non-Hodgkin lymphoma in 2022 and evaluated their prognostic impact in diffuse large B‑cell lymphoma (DLBCL). RESULTS: We detected somatic alterations in 248 of 336 patients (73.8%). DLBCL and follicular lymphoma showed the highest variant prevalences and ctDNA burdens. Epigenetic regulators, including KMT2D, CREBBP, TET2, and HIST1H1E, constituted the dominant class of genes with recurrent alterations. Plasma variant profiles closely mirrored publicly available, tissue‑based next-generation sequencing datasets. The baseline ctDNA burden correlated with adverse clinical features, and ctDNA positivity was associated with failure to achieve complete remission. In DLBCL, elevated cfDNA (top quartile) and a high International Prognostic Index (IPI) were independently associated with shorter overall and progression‑free survival. However, the total variant count per patient was not significantly associated with survival after adjustment. CONCLUSIONS: Baseline plasma cfDNA and ctDNA assessments are feasible in routine practice and recapitulate tissue-variant landscapes. Elevated cfDNA concentrations-but not the total variant count-were independently associated with survival in DLBCL, providing prognostic information beyond the IPI and supporting integration of plasma-based biomarkers into multiparameter risk models. Gene‑level ctDNA associations should be regarded as exploratory and hypothesis‑generating.