Proliferative abnormalities of the oesophageal epithelium of Chinese populations at high and low risk for oesophageal cancer.

Studies on the pattern of proliferation of epithelial cells from the oesophagus of 33 individuals from Linxian, a high-risk area for oesophageal cancer in China, and of 22 subjects from Jiaoxian, a low-risk area for the same cancer in China, were performed using thymidine labelling. Oesophageal biopsies were obtained during endoscopic surveys carried out in these 2 populations. A clear difference was observed between the 2 groups; the high-risk group showed cell proliferation in the upper layers of the epithelium more often than the low-risk group. No difference was found in the cell proliferation patterns of subjects with oesophagitis and those without oesophagitis in the high-risk area. This finding could suggest that the tritiated thymidine assay may be a more sensitive method to characterize the precancerous lesions of the oesophagus in high- and low-risk populations than simple histological evaluation.