Environmental Tobacco Smoke and Stomach Cancer Risk

Abstract

P-199 Introduction: Smoking is a risk factor of stomach cancer, although the data on environmental tobacco smoke (ETS) and risk of the disease are not sufficient. Therefore, we tried to assess an association of stomach cancer risk and ETS. The methods: A case-control study included 77 cases aged 25–85 with newly histologically confirmed diagnose of stomach cancer and 181 randomly selected controls that were cancer and stomach diseases free. Cases and controls were matched by gender, age (±5 yr) and residence. A questionnaire made on the basis of Aichi Cancer Center's Questionnaire was used to collect information on ETS at home and workplace as well as on other possible risk factors of stomach cancer. Unconditional logistic regression was used to calculate odds ratios (OR) and corresponding 95% confidence intervals (CI). The results: More than one third (36.5%) of cases and 16.3% of controls were exposed to ETS for half of a workday and longer at workplace (p<0.05), 36.5% of cases and 34.3% of controls experienced exposure to ETS at home (p>0.05). After controlling for age, gender, alcohol use, smoking, family history on cancer and some dietary items (noodles, margarine, butter, beef, pate, salted meat, cabbage, tomato, garlic, onion, yellow and green vegetables, paprika, fruits, pickled vegetables and mushrooms) that were associated with stomach cancer, significant elevation in stomach cancer risk was observed for the subjects exposed to ETS at workplace (OR=5.2, 95% CI=1.95–13.87 sometimes vs. not exposed; OR=7.59, 95% CI=2.58–22.4 half of a workday and longer vs. not exposed). Increased risk of the disease was found for the subjects exposed to ETS at home or at workplace (OR=3.9, 95% CI=1.45–10.47 vs. not exposed), and for those exposed to ETS at both home and workplace settings (OR=3.2, 95% CI=1.04–9.9 vs. not exposed). Duration of exposure to ETS was also associated with higher risk of stomach cancer (OR=9.55, 95% CI=3.39–26.88 less than 20 yrs vs. not exposed; OR=4.01, 95% CI=1.47–10.95 more than 20 yrs vs. not exposed). Conclusion: The findings suggest that environmental tobacco smoke is related to increased risk of stomach cancer.