Plasma cell-free DNA is a prognostic biomarker for survival in patients with aggressive non-Hodgkin lymphomas

Cell-free DNA (cfDNA) can be released from tumor cells during proliferation and apoptosis; thus, a fraction of the cfDNA in patients with cancer is tumor-derived. However, the prognostic value of cfDNA in aggressive non-Hodgkin lymphoma (NHL) has not been determined. Between March 2017 and April 2019, plasma cfDNA was obtained from 158 patients with aggressive NHL who were registered in a prospective Samsung Medical Center lymphoma cohort (diffuse large B cell lymphoma (DLBCL), n = 51; T cell lymphoma (TCL), n = 51; NK/T cell lymphoma (NKTCL), n = 56). The concentration of cfDNA was estimated in longitudinal samples collected from patients with NHL before and during various chemotherapy regimens. In pretreatment samples, the median cfDNA concentration of all patients with aggressive lymphoma was 13.7 ng/dl (range 1.7–1792), which was significantly higher than that of healthy volunteers (median 7.4 ng, range 3.7–14.4, p < 0.001), and advanced stages showed a higher cfDNA level than earlier stages. Multivariate analysis identified high cfDNA as an independent factor for event-free survival that predicted poor prognosis in DLBCL (hazard ratio [HR] = 5.33, 95% confidence interval [CI] = 1.72–16.52, p = 0.003) and TCL (HR = 2.82, 95% CI = 1.10–7.20, p = 0.030). NKTCL patients with a high level of cfDNA had worse overall survival (HR = 4.71, 95% CI = 1.09–20.35, p = 0.037) compared with those with a low level of cfDNA. In this study, our results suggest the usefulness of pretreatment cfDNA as a prognostic marker for patients with DLBCL, TCL, and NKTCL.