Tobacco smoking is a known cause of gastric cancer, but several aspects of the association
remain imprecisely quantified. We examined the relation between cigarette smoking and the
risk of gastric cancer using a uniquely large dataset of 23 epidemiological studies within the
'Stomach cancer Pooling (StoP) Project', including 10 290 cases and 26 145 controls. We
estimated summary odds ratios (ORs) and the corresponding 95% confidence intervals (CIs)
by pooling study-specific ORs using random-effects models. Compared with never smokers …