Identifying distinct risks of treatment failure in nasopharyngeal carcinoma: Study based on the dynamic changes in peripheral blood lymphocytes, monocytes, N classification, and plasma Epstein-Barr virus DNA.

Abstract

To evaluate the prognostic value of the dynamic change in absolute lymphocyte counts (ALCs) and absolute monocyte counts (AMCs) and identify patients with N stage and plasma Epstein-Barr virus (EBV) DNA levels in nasopharyngeal carcinoma (NPC) who are at risk of treatment failure. A total of 1124 eligible patients with Stage II-IVb NPC treated with concurrent chemoradiotherapy (CCRT) were enrolled. Percentage changes in the ALC (ΔALC%) and AMC (ΔAMC%) were calculated. Patients with high ΔALC% were correlated with poorer 5-year overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) rates than those with low ΔALC%. Likewise, high ΔAMC% was significantly associated with worse outcome than low ΔAMC% (OS, p=0.001; PFS, p=0.001; DMFS, p=0.034). Multivariate analyses revealed that ΔALC% (p=0.046), ΔAMC% (p=0.019), and EBV DNA level (p < 0.001) were independent prognostic factors for OS. With respect to PFS, ΔALC% (p=0.036), ΔAMC% (p=0.011), N classification (p=0.016), and EBV DNA level (p < 0.001) were also independent prognosticators. Based on the aforementioned independent risk factors (ΔALC% ≥ 83.33%, ΔAMC% ≥ 40.00%, Stage N2-3, EBV DNA ≥ 4000 copies/ml), patients were divided into three different risk groups (low-risk group [with <1 risk factor], intermediate risk group [with 1-3 risk factors], and high-risk group [with 4 risk factors]) that correlated with disparate risks of death (p < 0.001), disease progression (p < 0.001), and distant metastasis (p < 0.001). High ΔALC% and ΔAMC% were correlated with poor prognosis in patients with NPC. Risk stratification based on ΔALC%, ΔAMC%, N classification, and plasma EBV DNA levels could provide potential utility for risk-adapted therapeutic strategies for NPC.