Association of Epstein–Barr Virus (EBV) with malignancy of the nasopharynx in Lagos, Nigeria

Background: Nasopharyngeal cancer is a rare cancer worldwide. It is now found to be increasing in incidence in Nigeria, though the incidence is lower when compared to countries in the Mediterranean basin, North Africa and Southeast Asia. This cancer is frequently associated with Epstein-Barr virus (EBV), but no previous study was done in this centre to document the association. Aim and Objectives: To assess the EBV status in Nigerian patients with nasopharyngeal cancer by using Latent membrane protein – 1 immunohistochemistry. ( LMP-1IHC). Materials and Methods: Thirty-five (35) out of Seventy-five (75) histologically-confirmed cases of nasopharyngeal malignancy (NPM) seen in the Department of Anatomic and Molecular Pathology of Lagos University Teaching Hospital, Lagos between January 2003 and December 2012 were available for EBV study using LMP-1 IHC. Results: EBV LMP-1 IHC was positive in thirty (86%) out of the thirty-five cases studied and these consisted of, 14 cases of undifferentiated carcinoma (WHO type 3), 5 cases of non-Hodgkin lymphoma and 2 cases of adenocarcinoma. Also seven out of eleven cases of differentiated non-keratinizing squamous cell carcinoma (WHO type 2) were EBV positive and two of the three cases of keratinizing squamous cell carcinoma (WHO type 1) were EBV positive. Conclusion: This study has shown that nasopharyngeal malignancy in our centre is highly associated with EBV latency as detected by LMP-1 immunohistochemistry.