The purpose of this study is to develop clinically useful techniques for early detection and treatment of esophageal cancer. The study has four parts: (1) primary screening studies, to develop accurate, cost-effective and patient-acceptable primary screening tests for esophageal precursor and early invasive lesions; (2) endoscopic localization studies, to endoscopically visualize foci of dysplasia and early cancer; (3) endoscopic therapy studies, to develop focal curative endoscopic therapies for high-grade dysplasias and early invasive cancers; and (4) chemoprevention studies, to evaluate the ability of oral chemopreventive agents to reduce progression or cause regression of low-grade esophageal dysplasias. Most of the study activities are carried out in Linxian, China, a county in north central China which has very high rates of esophageal cancer.
