Clinical implications of plasma Epstein-Barr virus DNA in early-stage extranodal nasal-type NK/T-cell lymphoma patients receiving primary radiotherapy.

The clinical value of plasma Epstein-Barr virus (EBV) DNA has not been evaluated in patients with early-stage extranodal nasal-type NK/T-cell lymphoma (NKTCL) receiving primary radiotherapy. Fifty-eight patients with stage I disease and 11 with stage II disease were recruited. High pretreatment EBV-DNA concentrations were associated with B-symptoms, elevated lactate dehydrogenase levels, and a high International Prognostic Index score. EBV-DNA levels significantly decreased after treatment. The 3-year overall survival (OS) rate was 82.6% for all patients. Stage I or II patients with a pretreatment EBV-DNA level of ≤ 500 copies/mL had 3-year OS and progression-free survival (PFS) rates of 97.1% and 79.0%, respectively, compared with 66.3% (P = .002) and 52.2% (P = .045) in patients with EBV-DNA levels of > 500 copies/mL. The 3-year OS and PFS rates for patients with undetectable EBV-DNA after treatment was significantly higher than patients with detectable EBV-DNA (OS, 92.0% vs 69.8%, P = .031; PFS, 77.5% vs 50.7%, P = .028). Similar results were observed in stage I patients. EBV-DNA levels correlate with tumor load and a poorer prognosis in early-stage NKTCL. The circulating EBV-DNA level could serve both as a valuable biomarker of tumor load for the accurate classification of early-stage NKTCL and as a prognostic factor.