Collatuzzo G, Pelucchi C, Negri E, et al. - Researchers conducted the study for exploring the interaction between Helicobacter pylori (Hp) infection and other risk factors of gastric cancer, focusing in particular on tobacco smoking, alcohol drinking, low socioeconomic status (SES) and salt consumption. One thousand three hundred seventy-seven cases (885 men and 492 women) and 2,470 controls (1,570 men and 900 women) were analyzed. The study found no consistent association between Hp infection and cigarette smoking, although there was a more than multiplicative interaction between alcohol use and high salt intake. The interaction with SES followed the multiplicative model, resulting in a weakening among infected people of the protective effect of high SES among observed Hp-negative people. In participants who had a history of peptic ulcer, the interactions were more significant. In the case of noncardia cancer, the interactions with Hp infection were stronger for cigarette smoking and dietary salt, and for alcohol and SES in the case of cardia cancer. When stratified by histologic type, no differences were discovered. This large-scale study, which sought to quantify the interaction between Hp infection and other modifiable risk factors for gastric cancer, discovered that the benefit of combined Hp eradication and lifestyle modification on gastric cancer prevention may be greater than previously thought.