Association of plasma EBV-DNA copy number and cytokines with B symptoms in patients with extranodal natural killer/T-cell lymphoma, nasal type / 中华放射肿瘤学杂志

ABSTRACT

Objective:To investigate the association of plasma EBV-DNA copy number, serum cytokines and B symptoms in patients with extranodal natural killer/T-cell lymphoma, nasal type (ENKTL), unravel the mechanism and assess the prognostic value of clinical indicators.Methods:Clinical data of 173 newly-diagnosed ENKTL patients (116 male, 57 female; median age 43, 4 to 71 years)were retrospectively analyzed. According to Ann Arbor stage, 126 cases were classified as stage I-II and 47 cases of stage Ⅲ-IV. The primary sites of tumors included nasal cavity (n=100), extranasal upper aerodigestive tract (extranasal UADT, n=34), and extra-upper aerodigestive tract (extra-UADT, n=39). Prior to treatment, 91 patients had B symptoms and 82 cases of without B symptoms. According to plasma EBV-DNA copy levels, all patients were divided into the negative group (n=36), low load group (<10 4 copies/ml, n=73) and high load group (≥10 4 copies/ml, n=64). Serum cytokines including IFN-γ, IL-2, IL-4, IL-6, IL-10 and TNF-α were detected. Correlation analysis was performed by Cochran-Armitage trend test and Spearman correlation analysis. Survival analysis was conducted using univariate and multivariate Cox regression hazard analysis and survival curves were derived from Kaplan-Meier survival analysis. Results:The incidence of B symptoms and fever showed a significant upward trend with the increasing plasma EBV-DNA copy levels. In addition, serum levels of IFN-γ, IL-6 and IL-10 cytokines were higher in patients with B symptoms than those without B symptoms (all P<0.05). Serum IFN-γ, IL-6, and IL-10 levels were also positively correlated with plasma EBV-DNA copy number. The occurrence of B symptoms was associated with high-risk clinical features including advanced stage, primary tumor invasion, regional lymph node involvement, and elevated pre-treatment LDH. Survival analysis showed that stage, B symptoms, plasma EBV-DNA, and the above serum cytokines affected the prognosis of overall survival (OS) and progression-free survival (PFS) (all P<0.05). However, multivariate analysis showed that the occurrence of B symptoms was not an independent prognostic factor of ENKTL patients. Conclusion:This exploratory study suggests that the incidence of B symptoms is associated with increasing levels of EBV-DNA copies and cytokines, and these indicators are also important factors influencing the prognosis of ENKTL patients.