Endoscopic Surveys in High-risk and Low-risk Populations for Esophageal Cancer in China with Special Reference to Precursors of Esophageal Cancer

Endoscopic surveys were carried out of the people in high-risk and low-risk areas of esophageal cancer in Henan Province, China. Chronic esophagitis was observed with endoscopy in 70.67 % of the inhabitants in the high-risk area and in 63.67 % of the individuals in the low-risk area. The prevalence rate of chronic esophagitis diagnosed with histological examination was 78.28 % and 71.33 % in the two groups, respectively. Basal-cell hyperplasia and dysplasia were present in 74 % and 38.28 % of the populations, respectively, in the high-risk area, and in 48 % and 4.78 % of the inhabitants in the low-risk area. A correlation between the incidence of dysplasia and the severity of esophagitis was found in two groups. One-hundred-and-eighty-six cases of chronic esophagitis in high-risk areas were followed-up with endoscopy from 30 to 78 months. Of the 186 cases, in 62 accompanied by dysplasia 21 (33.87 %) developed early stage esophageal carcinoma; and in 124 cases with esophagitis alone or simple hyperplasia cancer was found in 5 (4.03 %). We suggest that chronic esophagitis is the commonest disease of the esophagus due to mechanical irritation, thermal injury and vitamin deficiencies, while the inflammatory injury may increase the sensitivity of the esophageal mucosa to carcinogens. It might be concluded that esophagitis with dysplasia was likely to develop into esophageal carcinoma and that treatment of this disease would be important to decrease the incidence rate of esophageal cancer.