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document
Chemoprevention of gastric dysplasia : randomized trial of antioxidant supplements and anti-helicobacter pylori therapy . BACKGROUND Previous research has identified a high risk of gastric carcinoma as well as a high prevalence of cancer precursor lesions in rural populations living in the province of Nariño , Colombia , in the Andes Mountains . METHODS A randomized , controlled chemoprevention trial was conducted in subjects with confirmed histologic diagnoses of multifocal nonmetaplastic atrophy and/or intestinal metaplasia , two precancerous lesions . Individuals were assigned to receive anti-Helicobacter pylori triple therapy and/or dietary supplementation with ascorbic acid , beta-carotene , or their corresponding placebos . Gastric biopsy specimens taken at baseline were compared with those taken at 72 months . Relative risks of progression , no change , and regression from multifocal nonmetaplastic atrophy and intestinal metaplasia were analyzed with multivariate polytomous logistic regression models to estimate treatment effects . All statistical tests were two-sided . RESULTS All three basic interventions resulted in statistically significant increases in the rates of regression : Relative risks were 4.8 ( 95 % confidence interval [ CI ] = 1.6-14.2 ) for anti-H. pylori treatment , 5 . 1 ( 95 % CI = 1.7-15.0 ) for beta-carotene treatment , and 5.0 ( 95 % CI = 1.7-14.4 ) for ascorbic acid treatment in subjects with atrophy . Corresponding relative risks of regression in subjects with intestinal metaplasia were 3.1 ( 95 % CI = 1.0-9.3 ) , 3.4 ( 95 % CI = 1.1-9.8 ) , and 3.3 ( 95 % CI = 1.1-9.5 ) . Combinations of treatments did not statistically significantly increase the regression rates . Curing the H. pylori infection ( which occurred in 74 % of the treated subjects ) produced a marked and statistically significant increase in the rate of regression of the precursor lesions ( relative risks = 8.7 [ 95 % CI = 2.7-28.2 ] for subjects with atrophy and 5.4 [ 95 % CI = 1.7-17.6 ] for subjects with intestinal metaplasia ) . CONCLUSIONS In the very high-risk population studied , effective anti-H. pylori treatment and dietary supplementation with antioxidant micronutrients may interfere with the precancerous process , mostly by increasing the rate of regression of cancer precursor lesions , and may be an effective strategy to prevent gastric carcinoma .
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Intervention_Pharmacological
antioxidant supplements and anti-helicobacter pylori therapy .
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Participant_Condition
rural populations living in the province of Nariño , Colombia , in the Andes Mountains
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Participant_Condition
subjects with confirmed histologic diagnoses of multifocal nonmetaplastic atrophy and/or intestinal metaplasia , two precancerous lesions
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Participant_Condition
for subjects with atrophy
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Participant_Condition
subjects with intestinal metaplasia
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Participant_Condition
the very high-risk population