RESUMO
OBJECTIVE: To evaluate the sensitivities and specificities of Epstein-Barr virus (EBV) DNA in the detection of locally recurrent or persistent nasopharyngeal carcinoma (NPC) through nasopharyngeal (NP) brush biopsy and plasma, respectively, and whether a combination of both would be superior to the individual tests. STUDY DESIGN: A case-control study was conducted from September 2016 to June 2022. SETTING: A multicentre study at 3 tertiary referral centers in Hong Kong was conducted by the Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong. METHODS: Twenty-seven patients with biopsy-confirmed locally recurrent NPC were recruited as study subjects. Magnetic resonance imaging was performed to rule out regional recurrence. The control group consisted of 58 patients with a prior history of NPC who were now disease-free based on endoscopic and imaging findings. Patients underwent both the transoral NP brush (NP Screen®) and blood for plasma Epstein-Barr DNA levels. RESULTS: The sensitivity and specificity of the combined modalities were 84.62% and 85.19%, respectively. The positive predictive value was 73.33% and the negative predictive value was 92.0%. CONCLUSION: The combination of NP brush biopsy and plasma EBV DNA is potentially an additional surveillance modality in detecting the local recurrence of NPC. Further study with a larger sample size would be required to validate the cutoff values.