Meta-Analysis of Smoking and the Risk of Gastric Cancer among the Chinese Population

OBJECTIVE To reevaluate the effect of tobacco smoking on therisk of developing gastric cancer among the Chinese population.METHODS Thirty articles from the literature both in Chineseand English from January,1988 to present were identified andfrom which adjusted odd ratios(ORs)or relative risks(RRs)werecombined by meta-analysis.Generalized least squares(GLS)fortrend estimation of summarized dose-response data was carriedout.All the analyses were performed using software of STATAversion 10.0.RESULTS Comparing current smokers with subjects who havenever smoked,the summary effect values on gastric cancer witha 95% confidence interval(CI)were 1.67(1.43-1.96)for case-control studies and 1.52(1.17-1.96)for cohort studies,respectively.The combined effect values with a 95%CI for the comparison ofsmoking quantity of current smokers with the referent groupwere 1.41(1.15-1.72)for case-control studies and 1.24(1.02-1.52)for cohort studies,respectively.The combined effect values witha 95%CI for the comparison of accumulative years smoked ofcurrent smokers with the referent group were 1.07(0.89-1.28)for case-control studies and 1.28(0.95-1.74)for cohort studies,respectively.Dose-response meta-analysis showed that the gastriccancer risk will increase 50%(OR=1.50,95%CI:1.34-1.67)witheach 20 cigarette per day increment and increase 14%(OR=1.14,95%CI:1.10-1.18)with each 10 year increment of smoking.CONCLUSION The gastric cancer risk among the Chinesepopulation is significantly associated with tobacco smoking andthe smoking quantity per day.Smoking cessation should be morestrongly advocated.