An 7-year randomized multi-intervention trial with the Beijing Institute for Cancer Research was conducted see if any of three interventions could reduce the progression of precancerous gastric lesions. The primary endopoint was the prevalence of precancerous lesions: severe chronic strophic gastritis, intestinal metaplasia, and dysplasia. The study was designed to detect a stabilizing or mild decrease in the expected age-related progression of precancerous lesions over the course of the trial. Participating in the trial were approximately 3400 adults aged 35-70 who were part of an ongoing survey of precancerous gastric lesions in 13 Linqu villages in Shandong Province. These individuals were be randomly assigned (taking H. pylori positivity into account) into 8 intervention groups according to a 2^3 factorial design. The interventions were: 1) initial treatment of H. pylori infection with omeprazole & amoxicllin followed by 2) daily supplementation with a combination of alpha-tocopherol, vitamin C, & selenium; & 3) daily supplementation with garlic extracts. Gastroscopic exams with biopsies at 7 standard gastric sites were conducted during March to May, 2003 to detect early cancers and to evaluate gastric mucosal status. The subjects were categorized according to the most advanced lesions detected in all biopsies and assigned a severity scores. The three major endpoints for analysis were: 1) prevalence of dysplasia or cancer 2) prevalence of severe chronic atrophic gastritis, intestinal metaplasia, dysplasioa, or cancer; & 3) average severity score. Not only did antibiotic treatment reduce the progression of precancerous gastric lesions after 7 years, but, after 15 years it reduced gastric cancer incidence. Recent work demonstrated that these reductions were found among older subjects and subjects with advanced precancerous gastric lesions at baseline, as well as in the entire population.