Analysis of EBV DNA in plasma samples was useful in screening for early asymptomatic nasopharyngeal carcinoma. Nasopharyngeal carcinoma was detected significantly earlier and outcomes were better in participants who were identified by screening than in those in a historical cohort. (Funded by the Kadoorie Charitable Foundation and the Research Grants Council of the Hong Kong government; ClinicalTrials.gov number, NCT02063399 .).

Nasopharyngeal carcinoma (NPC) is an aggressive head and neck cancer characterized by Epstein-Barr virus (EBV) infection and dense lymphocyte infiltration. The scarcity of NPC genomic data hinders the understanding of NPC biology, disease progression and rational therapy design. Here we performed whole-exome sequencing (WES) on 111 micro-dissected EBV-positive NPCs, with 15 cases subjected to further whole-genome sequencing (WGS), to determine its mutational landscape. We identified enrichment for genomic aberrations of multiple negative regulators of the NF-kB pathway, including CYLD, TRAF3, NFKBIA and NLRC5, in a total of 41% of cases. Functional analysis confirmed inactivating CYLD mutations as drivers for NPC cell growth. The EBV oncoprotein latent membrane protein 1 (LMP1) functions to constitutively activate NF-kB signalling, and we observed mutual exclusivity among tumours with somatic NF-kB pathway aberrations and LMP1-overexpression, suggesting that NF-kB activation is selected for by both somatic and viral events during NPC pathogenesis.

SignificanceWe identified differentiating molecular characteristics of plasma EBV DNA between nasopharyngeal carcinoma (NPC) patients and non-NPC subjects. Sequencing-based analysis revealed higher amounts of plasma EBV DNA and generally longer fragment lengths of plasma viral molecules in NPC patients than in non-NPC subjects. Based on these findings, we have developed a highly accurate blood-based test for screening of NPC. Such an approach is shown to enhance the positive predictive value and demonstrate a superior performance for NPC screening. It also obviates the need of a follow-up blood sample and therefore allows single time-point testing. We believe that this more clinically practical protocol would facilitate NPC screening on a population scale.