Waterpipe Tobacco Smoking and Gastric Cancer Risk among Vietnamese Men.

BACKGROUND:The association of waterpipe tobacco (WPT) smoking with gastric cancer (GC) risk was suggested. METHODS:A hospital-based case-control study was conducted to examine the association of WPT with GC risk among Vietnamese men, in Hanoi city, during the period of 2003-2011. Newly-diagnosed GC cases (n = 454) and control patients (n = 628) were matched by age (+/- 5 years) and the year of hospitalization. Information on smoking and alcohol drinking habits and diet including salty food intake and fruits/vegetables consumption were obtained by the interview. Maximum likelihood estimates of odds ratios (ORs) and corresponding 95% confidence intervals (Cis) were obtained using conditional logistic regression models. RESULTS:The group with the highest consumption of citrus fruits showed a significantly low GC risk (OR = 0.6, 95%CI = 0.4-0.8, P for trend = 0.002). However, there was no association of raw vegetable consumption with GC risk. Referring to never smokers, GC risk was significantly higher in current WPT smokers (OR = 1.8, 95%CI = 1.3-2.4), and it was more evident in exclusively WPT smokers (OR = 2.7, 95%CI = 1.2-6.5). GC risk tended to be higher with daily frequency and longer duration of WPT smoking but these trends were not statistically significant (P for trend: 0.144 and 0.154, respectively). GC risk of those who started smoking WPT before the age of 25 was also significantly high (OR = 3.7, 95%CI = 1.2-11.3). Neither cigarette smoking nor alcohol drinking was related to GC risk. CONCLUSION:The present findings revealed that WPT smoking was positively associated with GC risk in Vietnamese men.