An endoscopic survey was undertaken in Jiaoxian. Peo-these, 252 subjects (152 males and 100 females) ac-Pie's Republic of China, a population at low risk for cepted endoscopic examination and were included in oesophageal cancer, to determine the prevalence of pre-the present study.
cancerous lesions of the oesophagus, and this rate was in previous surveys, examination of each subject compared with the prevalence observed previously in high-risk populations in and Linxian, China. The study included: a questionnaire to obtain demographic inforinvolved 252 subjects whore exposure to suspected risk mation; data on smoking, alcohol, drinking and dietary factors was determined by aquestionnaire and allof whom habits and on upper gastrointestinal symptoms; a PhYsunderwent physical examination and oesophagoscopy, in-ical examination to detect signs of specific vitamin decluding cytology and biopsy. Chronic oesophagitis, with ficiences; and collection of gastric juice from some endoscopic and histologic characteristics similar to those subjects for analysis of total N-nitroso-compounds. Enobserved in the high-risk populations of Iran and Linxian, doscopic examination of oesophagus and stomach was Iran and 65% in Linxian. Oesophagitis accompanied by 10.5 % in lran and 10.8 % in Enxian. No case of dysplasia were taken according to the protocol used in previous was diagnosed in Jiaoxian while this condition was diag- Surveys (CreSpi et d . , 1979; MUfioz et al., 1982). Pornosed in 4 % of the subjects examined in Iran and in 8 % of tions of the biopsy samples from 125 subjects were those in Linxian. The findings suggest that these lesions are processed for studies of cell kinetics, as reported previin fact precancerous. Vitamin analysis showed that ribofla-ously, Criteria previously described were used to evaluvin deficiency was widespread in Jiaoxian, as in Iran and ate endoscopical and histological findings (Crespi etal., Linxian, but was more severe in Linxian than in Jiaoxian. 1979; ~~f i ~~ et al., 1982; crespi et 1984). ~~i ~f l ~,
No significant difference was found in the mean levels of retinal, oesophagitis was classified endoscopically as: mild tions.