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- Simán, Henrik, et al.
(författare)
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Helicobacter pylori infection is associated with a decreased risk of developing oesophageal neoplasms
- 2001
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Ingår i: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 6:4, s. 310-316
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Tidskriftsartikel (refereegranskat)abstract
- Background. The role of Helicobacter pylori infection in the development of oesophageal malignancies was investigated through a multivariate conditional logistic regression analysis in a nested case-control study. Methods. Blood samples and a questionnaire on smoking and alcohol habits were collected from a cohort of 32,906 city residents during a health-screening programme between 1974 and 1992. Forty-four cases of oesophageal cancer and 149 matched controls were selected. The mean interval between screening and cancer diagnosis was 11.9 years. H. pylori seropositivity was determined by an enzyme-linked immunosorbant assay measuring IgG. Occupation was included in the statistical analysis as an indicator of socio-economic status. Results. Helicobacter pylori seropositivity was present in 10 of the cases (22.7%) and 67 of the controls (45.0%). In a multivariate model, vith adjustment for occupation, tobacco and alcohol consumption, the odds ratio for developing in oesophageal malignancy when infected with H. pylori was 0.29 (95% confidence interval (CI): 0.12-0.67). Current smokers had an odds ratio of 17.3 (95% Cl: 3.0-99.4) and the odds ratio for ex-smokers was 5.9 (95% CI: 1.15-29.9). High alcohol consumption was no longer significantly, associated with oesophageal neoplasms after tobacco smoking was included into the model, odds ratio 1.22 (95% CI: 0.46-3.2). The protective effect of H. pylori was more pronounced for oesophageal adenocarcinoma (seven cases, odds ratio 0.16, 95% Cl: 0.00-1.06) than for squamous-cell carcinoma (29 cases, odds ratio 0.41, 95% Cl: 0.14-1.2). Conclusions. Helicobacter pylori infection is associated with a decreased risk of developing an oesophageal malignancy. Current smokers and ex-smokers have instead a definite increased risk of oesophageal neoplasms.
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| 2. |
- Simán, Henrik, et al.
(författare)
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Tobacco smoking increases the risk for gastric adenocarcinoma among Helicobacter pylori-infected individuals
- 2001
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Ingår i: Scandinavian Journal of Gastroenterology. - 1502-7708. ; 36:2, s. 208-213
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The importance of tobacco smoking and Helicobacter pylori infection as risk factors in the development of gastric carcinoma was investigated through multivariate conditional logistic regression analysis in a nested case-control study. METHODS: Blood samples and a questionnaire on smoking habits were collected from a cohort of 32,906 city residents during a health screening programme from 1974 to 1992. Fifty-six cases of gastric cancer and 224 matched controls were selected. The mean interval between screening and cancer diagnosis was 5.7 years. H. pylori infection was determined by IgG-serology. Occupation categorized into blue-collar workers, white-collar workers, self-employed and unknown occupation was included in the statistical analysis as an indicator of socio-economic status. RESULTS: The proportion of current smokers was 61% among gastric cancer cases, versus 41% among controls. H. pylori seropositivity was present in 82% of the cases and 49% of the controls. In a multivariate model current smokers had an odds ratio (OR) of 2.2 (95% confidence interval (CI): 1.2-4.2). With different levels of tobacco consumption, smoking less than 20 g tobacco each day gave the OR of 2.1 (95% CI: 0.98-4.4), and the OR when smoking more than 20 g tobacco per day was 2.5 (95% CI: 1.1-5.6). The OR of H. pylori infection was 5.0 (95% CI: 2.2-11.2). Among H. pylori-seropositive citizens, current smoking was associated with an increased risk of 2.3 (95% CI: 1.1-4.7) compared with non-smoking H. pylori-positive persons. CONCLUSIONS: Tobacco smoking and H. pylori are both risk factors in the development of gastric cancer, and tobacco smoking is still a risk factor among H. pylori-infected individuals. The risk of gastric cancer among H. pylori-infected current smokers is 11 times that of non-infected individuals not currently smoking.
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