Study of malignant tumors of the nasopharynx

Incidence : 18% of all malignant neoplasms in Chinaforms over 80 % of all head and neck cancersin china & less than 6% of all head and neckcancers in Europe. Sex ratio is about two mento one woman andrnaximum age incidence is 30-60years.1. Aetiology : not known for certain, but many factorshave been claimed for such as :A. Epstien-Barr virusB. Genetic racial susceptibility.C. Chemicalsand some plant extracts.d. Geographic influence.occupational exposure to carcinogensegwood & plastic products.Many studies had been carried out and supportedmany of these factors, these studies included:Epidemiology and Serology.Virology.Cellular Immunity and genetics.d. Chemical and biological carcinogens andtumor promoters.