Differential clinical significance of pre-, interim-, and post-treatment plasma Epstein-Barr virus DNA load in NK/T-cell lymphoma treated with P-GEMOX protocol.

Circulating EBV-DNA is an accurate biomarker of tumor load in extranodal natural killer (NK)/T cell lymphoma (ENKTL); however, its role in patients treated with P-GEMOX has not been evaluated. In this study, we examined plasma EBV-DNA of 99 patients at different time points by real-time quantitative polymerase chain reaction. Multivariate analysis revealed that ECOG PS score, response rate, and post-treatment EBV-DNA level were independent predictors of progression-free survival (PFS) and overall survival (OS). Positive post-treatment plasma EBV-DNA was associated with poor OS in ENKTL patients. The 3-year OS for patients with positive pre-, interim-, post-treatment EBV-DNA was significantly lower than that for patients with negative EBV-DNA; the values were 70.2% vs. 93.9% (p=.022), 53.8% vs. 99.1% (p<.001), and 40.6% vs. 91.8% (p<.001), respectively. We conclude that monitoring dynamic changes in plasma EBV-DNA in ENKTL patients treated with P-GEMOX could predict important outcomes such as OS.