| Objectives: To determine whether eradication therapy for helicobacter pylori prevents gastric cancer among infected individuals with gastric atrophy or intestinal metaplasia.Methods: On the basis of ensuring thorough investigation,a systematic search of the PubMed,Embase,Cochrane central register databases and major Chinese databases was conducted to identify controlled trials published before February 2017 pertaining to Helicobacter pylori and gastric premalignant lesions.There is no restriction on the language of publication.The Risk of Bias table outlined in the Cochrane Reviewers’ Handbook 5.1.0 was used to assess the risk of bias,including the selective bias,implementation bias,blinding,measurement bias,loss of follow-up bias,and publication bias risk assessment.The presence of heterogeneity was tested using the Chi-square test,and inconsistency was used to reflect the size of the heterogeneity.According to the size of the heterogeneity,we use the random effect model or the fixed effect model to make forest plot and analyze the results.Subgroup analysis was performed on each group of follow-up time and lesion sites to eliminate interference factors.We conducted a sensitivity analysis by assessing the impact of individual studies on the amount of consolidation.Relevant outcomes from articles included in the meta-analysis were combined using Review Manager 5.3 software.Results: The search strategy identified 1321 citations,of which ten individual randomized controlled trials were eligible.The pooled weighted mean difference in gastric atrophy between H.pyloriinfected patients treated with eradication therapy and the controls with its 95% confidence interval was-0.20(-0.33,-0.07),which represented a significant overall effect.After 1 year of follow-up,it was found that eradication treatment had no significant effect on improving the pathological score of atrophic gastritis(RR=-0.16,95% CI(-0.34,0.02),P=0.08).After 3 years of follow-up,eradication treatment was found to improve atrophy,and the gastritis pathology score had a significant effect(RR =-0.26,95% CI(-0.42,-0.11),P = 0.0008).The statistics found that the eradication of Helicobacter pylori had no significant effect on the pathological score of atrophic gastritis of the gastric antrum(RR=-0.16,95%CI(-0.33,0.01),P=0.06).But for atrophic gastritis of the stomach body,Eradication therapy had a significant effect on the improvement of pathological scores(RR =-0.59,95% CI(-0.81,-0.38),P < 0.00001).The pooled relative risks and 95% confidence intervals of the regression and progression of gastric atrophy by at least one score at follow up were 1.65(1.35,2.03)and 0.47(0.31,0.71),respectively;both overall effects were significant(P<0.00001 and P=0.002,respectively).The pooled weighted mean difference in intestinal metaplasia between H.pylori-infected patients treated with eradication therapy and the controls with its 95% confidence interval was-0.11(-0.31,0.08),which was not significant(P=0.26).Either one-year or three-year follow-up observations showed that eradication treatment had no significant effect on improving the pathological score of intestinal metaplasia,and the data were(RR=-0.09,95%CI(-0.29,0.11),P=0.40),(RR =-0.20,95% CI(-0.41,0.01),P = 0.06).The eradication of Helicobacter pylori had no significant effect on the pathological score of intestinal metaplasia of the gastric antrum(RR =-0.16,95% CI(-0.35,0.03),P = 0.10),whereas for intestinal metaplasia of the stomach,Eradication therapy had a significant effect on the improvement of pathological scores(RR =-0.33,95% CI(-0.63,-0.03),P = 0.03).The pooled relative risks and 95% confidence intervals of the regression and progression of intestinal metaplasia by at least one score at follow up were 1.14(0.91,1.43)and 0.93(0.69,1.26),respectively;these effects were not significant(P=0.27 and P=0.06,respectively).The pooled analysis of all selected studies comparing H.pylori eradication with a placebo for gastric cancer yielded a relative risk of 0.85(95% CI,0.51 to 1.42).For the analysis of intestinal metaplasia,one of them used a random effect model,and the other used a fixed-effect model.There were 5 articles that counted the number of people with or without gastrointestinal symptoms after intervention.The combined effect was RR = 0.61,95% CI was(0.54,0.68),showing statistically significant(P < 0.00001).There was no significant heterogeneity(χ2 = 3.46,P = 0.48,I2 = 0%),using the fixed effect model.Sensitivity analysis was performed by excluding each article.No literature was excluded.Sensitivity analysis was performed by excluding each article.No literature was excluded.Conclusions: H.pylori eradication improves the histological score of gastric atrophy and halts the progression of atrophic gastritis.However,Helicobacter pylori eradication has no significant overall effect on the reversal or progression of intestinal metaplasia and the detection of gastric atrophy,intestinal metaplasia,and the subsequent occurrence of gastric cancer. |
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