Labeling index and labeling distribution of cells in esophageal epithelium of individuals at increased risk for esophageal cancer in Huixian, China.

The pattern of proliferation of epithelial cells in esophageal epithelium was studied by means of [3H]deoxythymidine labeling of esophageal epithelium in subjects from Huixian, Henan Province, China, a high-risk geographical region for esophageal cancer. Comparisons were made among patterns of cell proliferation observed in normal esophagus, in hyperplasia, in mild dysplasia, and in moderate dysplasia in a total of 118 subjects. The amount of cell proliferation observed was lowest in normal esophageal epithelium and increased progressively in subjects having hyperplasia, mild dysplasia, and moderate dysplasia. The location of proliferating cells was limited mainly to the base of the esophageal epithelium in normal esophagus, but expanded toward the surface of the esophageal lining in individuals with hyperplasia and dysplasia. The larger total numbers of proliferating cells in the esophageal epithelium and the progressive expansion of the proliferative compartment toward the epithelial surface found in hyperplasia and in dysplasia could both facilitate the screening of subjects for esophageal cancer risk and serve as intermediate biomarkers in prophylactic dietary or pharmacological intervention studies.