In collaboration with the Cancer Institute of the Chinese Academy of Medical Sciences (CICAMS) in Beijing, NCI scientists conducted studies in Linxian, an area with epidemic rates of esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA). Between 1985 and 1991, two intervention trials – the Nutritional Intervention Trials (NIT) – were conducted in which nutritional supplements or placebos were given to over 33,000 individuals in Linxian. Those studies found that the micronutrient combination of selenium, vitamin E, and beta-carotene reduced total mortality, total cancer mortality, and gastric cancer mortality. Results from the randomized trial are being followed up in long-term observational studies conducted on the same cohort of individuals. Post-intervention follow-up data through 2001 show that the observed benefits for total and cancer mortality are reduced, but that the benefit for gastric cancer remains. Benefits for total cancer, gastric cancer, and esophageal cancer mortalities are most apparent in younger participants and persist for years after cessation of supplementation. Further post-intervention analysis in both trials, including additional sub-group analyses by age, gender, and other factors, is in progress.