Clinical Seminar/114th Congress of the Otorhinolaryngological Society of Japan. Advances in diagnosis and treatment of nasopharyngeal carcinoma. History of a half century from the discovery of EB virus

The title subject is explained about the carcinoma on anatomical characteristics, its diagnosis/relation to Epstein-Barr virus (EBV) infection, EBV gene expression, and treatment. The cancer, because of its location, easily invades the internal carotid artery and parapharyngeal space through Rosenmuller fossa, resulting in the rapid and extensive metastasis. Diagnosis is based on the histological examination and classified in WHO type-I (keratinized), -II (poorly differentiated) and -III (undifferentiated). The stage is decided by CT and MRI. Type I is minor (several %). Type-II and -III express EBERs (EBV-encoded small RNAs) in their nuclei, which is a mean of diagnosis as well as the serum EBV antibody value. Although 50 years have passed since the discovery of the virus, the cause of its dominant carcinogenesis in rather restricted regions of the world and the pathway of its infection in the nasopharyngeal epithelium are not fully elucidated yet. Authors have shown that an oncogene latent membrane protein-1 (LMP1) is important at the latent phase of EBV infection. EBV-positive types are susceptible to both chemo- and radio-therapy, and the linac is generally used for the latter. Machines for intensity modulated radiotherapy (IMRT) and tomotherapy have been introduced recently, of which efficacy is under examination by a multicenter study. The present standard regimen is radiotherapy+cisplatin/booster fluorouracil (5-FU) in Western countries. In Japan, alternating or simultaneous chemoradiotherapy with cisplatin/5-FU (+docetaxel) is spreading with an improved survival rate. Use of cetuximab against this cancer is awaited for examination, and treatment targeting EBV is also promising. (T.T.)