A Randomized Multi-Intervention Trial to Inhibit Precancerous Gastric Lesions in Lingu, Shandong Province

The Division of Cancer Epidemiology and Genetics is conducting a collaborative randomized multi-intervention trial with the Beijing Institute for Cancer Research to evaluate the etiologic role of Helicobacter pylori, garlic, and certain micronutrients in the multi-step process of gastric carcinogenesis. The primary endpoint will not be cancer, but rather the precancerous lesions severe chronic atrophic gastritis, intestinal metaplasia, and dysplasia. The study is designed to detect a stabilizing or mild decrease in the expected age-related progression of precancerous lesions over the course of the trial. Thus the trial can be considered a study of the potential inhibitors of the process of gastric carcinogenesis. The trial will also provide an evaluation of therapy for H. pylori, including an assessment of reinfection rates, a critical need for formulating strategies for infection control in China and other developing countries. Participating in the trial are approximately 3400 adults aged 35-70 who were part of an ongoing survey of precancerous gastric lesions in 13 Linqu villages in Shandong Province. Linqu appears to be an ideal setting for the trial since stomach cancer rates are among the highes in the world, precancerous gastric lesions are prevalent, and the population is stable and well characterized. These individuals will be randomly assigned (taking H. pylori positivity into account) into 8 intervention groups according to a 2(3) factorial design. The interventions are: 1) initial treatment of H. pylori infection with ameprazole and amoxicillin followed by 2) daily supplementation with a combination of alpha-tocopherol, vitamin C, and selenium; and 3) daily supplementation with garlic extracts. No serious side effects have been seen from any of the interventions to date. The study staff will continue to monitor for possible adverse reactions and the population will receive routine medical care follow-up throughout the course of the trial. As part of the ongoing study in Linqu, all participants received an endoscopic exam in the fall of 1994. Repeat gastroscopic exams with biopsies at 7 standard gastric sites will be conducted during March to May, 1999 and March to May, 2003 to detect early cancers and to evaluate gasatric mucosal status. The subjects will be categorized according to the most advanced lesions detected in all biopsies and assigned a severity score. The three major endpoints for analysis will be: 1) prevalence of dysplasia or cancer 2) prevalence of sever chronic atrophic gastritis, intestinal metaplasia, dysplasia, or cancer; and 3) average severity score.

Sex

All

Minimum age

35 Years

Maximum age

65 Years

* INCLUSION CRITERIA:

Ages 35-670 in the 14 Linqu villages who received endoscopy examinations in the fall of 1994.

Both men and women will be included.

Patients must sign an informed consent form indicating a willingness to participate in the 42-month trial.

Must be free of debilitating chronic disease.

Must not report allergies to penicillin or similar medications.

Must not have had previous treatment for H. pylori.

Must not have a history of bleeding disorder.

Must not be taking vitamin/mineral supplements on a regular basis.

EXCLUSION CRITERIA:

Persons with cancer (except resected non-melanotic skin cancer), heart failure, emphysema, and other life-threatening illness will be excluded.

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