Environmental backgrounds of young Chinese nasopharyngeal carcinoma patients.

Twenty-four Chinese NPC patients under 25 years of age at the time of diagnosis were interviewed. The interviews were carried out in the presence of their families in 22 cases and concentrated on the environmental background of the subject's infancy and early childhood. An analysis of the results eliminated household inhalants, aerial contaminants, medicines, food therapy, spices, fresh foods and soya sauce as likely factors in carcinogenesis. The only remaining foods eaten by all subjects and worthy of consideration were laap cheung, salted fish and tau si. Salted fish was the most commonly eaten and the only one fed to babies. In childhood, the subjects had rarely or never been fed vegetables or fruits. Most had, since childhood, been characteristically sickly, inactive, withdrawn and choosy about their food. It would appear that consumption of salted fish and vitamin C-deficiency in early childhood are important environmental factors and that a certain personality type may be associated with an increased risk.