Elevated plasma fibrinogen level shows superior prognostic value than Epstein-Barr virus DNA load for stage IVA/B nasopharyngeal carcinoma patients in the intensity-modulated radiotherapy era

Abstract

Purpose: Effective prognostic factors for patients with stage IVA/B nasopharyngeal carcinoma (NPC) who are susceptible to distant metastases are limited. We aim to investigate the prognostic value of pretreatment plasma fibrinogen (FIB) level and Epstein-Barr virus DNA (EBV-DNA) load in these patients in the era of intensity-modulated radiotherapy (IMRT). Results: The 5-year DSS, DFS and DMFS rates of the entire cohort were 72.7%, 66.8%, 80.0%, respectively. High FIB level was identified as a negative prognostic factor for survival: the 5-year DSS, DFS and DMFS rates for patients with high FIB (>4.0 g/L) and normal FIB (≤4.0 g/L) were 60.3% vs. 76.0%, 56.0% vs. 69.9%, and 59.4% vs. 85.5%, respectively (all P < 0.001). Subgroup analysis demonstrated that DSS, DFS and DMFS decreased as FIB gradually increased, even within the normal range. The risk of distant metastasis in patients with high FIB was over 3-fold than patients with normal FIB. EBV-DNA was not an independent prognostic factor for any survival outcomes in multivariate analysis. Conclusion: High pretreatment FIB level shows superior prognostic value than EBV-DNA load for stage IVA/B NPC patients in the era of IMRT. Materials and Methods: A total of 755 patients with newly-diagnosed stage IVA/B NPC treated with definitive IMRT between January 2007 and December 2011 were enrolled. Plasma FIB and EBV-DNA were measured before treatment. Disease-specific survival (DSS), disease-free survival (DFS) and distant metastasis-free survival (DMFS) were calculated using the Kaplan-Meier method; differences were compared using the log-rank test.