Effect of Epstein-Barr virus infection on predisposition and postradiotherapeutic prognostic value among Libyan patients with nasopharyngeal cancer

Abstract

Abstract Libya is one of the North African countries with an endemic of nasopharyngeal carcinoma, particularly in the northern part of Libya as compared with its southern part. The clinical and histopathological presentation reveals no uniquely specific pattern of appearance; however, there is high deficiency in the data that confirm the possible predisposing factors that may play a role in the development of this common variety of head and neck cancer in this country, and whether these factors affect the patients’ response to treatment. This study was conducted to determine the role of the Epstein-Barr virus (EBV) in the risk for nasopharyngeal cancer in the Libyan population; the results were correlated with radiotherapy response and improvement in the post-therapeutic prognostic value. Sixteen patients aged 9–80 years presented at the ENT Department, Althowra Central Teaching Hospital, Albyda, Libya, from September 2005 to January 2014 with variable patterns of clinical presentation suggestive of nasopharyngeal carcinoma. All patients were evaluated radiologically and endoscopically. The diagnosis was confirmed by biopsy and further histopathological assessment. For all patients, serological elucidation for IgG and IgM anti-EBV antibodies was carried out, and the results were correlated with age at incidence, sex of the patient, pattern of clinical presentation, pattern of histopathological presentation, response to radiotherapy, rate of recurrence, and 5-year survival. In all, 88% of patients showed a significant increase in serum IgG against viral capsid antigen of EBV; 83% of the cases presented with cervical masses and unilateral otitis media with effusion; 86% of cases showed lymphoepithelioma as histopathological pattern. All patients with lymphoepithelioma showed significant response to concomitant radiochemotherapy (100%) with high survival rate exceeding 5 years. The EBV infection can be considered one of the main predisposing factors to nasopharyngeal carcinoma in the Libyan population. It was noted from this study that the induction of cancer by EBV is mainly by chronic infection rather than by acute infection; this was confirmed by significant elevation in serum IgG rather than IgM. In addition, it was postulated that the EBV infection is most likely associated with the lymphoepithelioma variety of histopathology rather than with the well-differentiated type, and as it was elucidated through this study that the association of the cancer with EBV infection increased the sensitivity of the tumor to concomitant radiochemotherpy, thus improving the 5-year survival after treatment.