Treatment outcomes of Epstein-Barr virus-associated nasopharyngeal carcinoma

Abstract

Background: Data on treatment outcomes of Epstein-Barr virus (EBV) associated nasopharyngeal carcinoma (NPC) largely comes from endemic regions. There is limited literature regarding the epidemiology and treatment outcomes of EBV-associated NPC in South Africa.Aim: The aim of the study was to compare overall survival (OS) of EBV positive and EBV negative NPC patients.Setting: Groote Schuur Hospital, South Africa.Methods: Data were collected on all patients with histologically confirmed NPC over an 11-year period, including prevalence of EBV, OS, disease-free survival (DFS), loco-regional control (LRC), and impact of treatment interruptions on OS.Results: There were 53 patients in total. Non-keratinising carcinoma was the primary histological subtype (86.8%). The majority of patients had EBV positive NPC (47.2%). The 2- and 5-year OS of EBV positive patients treated with curative intent were significantly higher than EBV negative patients, 84.0% versus 34.0% and 45.0% versus 17.0%, respectively (hazard ratio [HR] 0.25, 95% confidence interval [CI]: 0.10–0.63, p = 0.002). Two-year DFS was 55.0% versus 43.0% (HR: 0.59, 95% CI: 0.18–1.98, p = 0.38) and 2-year LRC were 76.2% versus 46.2% (HR: 0.40, 95% CI: 0.12–1.36, p = 0.13) for EBV positive and EBV negative patients respectively.Conclusion: Treatment of EBV-associated NPC is associated with superior OS compared to EBV negative tumours.Contribution: Epstein-Barr virus was found to be a significant prognostic factor associated with superior OS compared to EBV negative NPC. These findings correlate with literature from endemic and non-endemic regions.