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

OBJECTIVE To reevaluate the eff ect of tobacco smoking on the risk of developing gastric cancer among the Chinese population. METHODS Thirty articles from the literature both in Chinese and English from January, 1988 to present were identified and from which adjusted odd ratios (ORs) or relative risks (RRs) were combined by meta-analysis. Generalized least squares (GLS) for trend estimation of summarized dose-response data was carried out. All the analyses were performed using software of STATA version 10.0.RESULTS Comparing current smokers with subjects who have never smoked, the summary effect values on gastric cancer with a 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 of smoking quantity of current smokers with the referent group were 1.41 (1.15-1.72) for case-control studies and 1.24 (1.02-1.52) for cohort studies, respectively. The combined eff ect values with a 95%CI for the comparison of accumulative years smoked of current 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 gastric cancer risk will increase 50% (OR = 1.50, 95%CI: 1.34-1.67) with each 20 cigaret e 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 Chinese population is significantly associated with tobacco smoking and the smoking quantity per day. Smoking cessation should be more strongly advocated