A team from Sweden investigated the role of Helicobacter pylori infection in the development of esophageal malignancies.
Blood samples and a questionnaire on smoking and alcohol habits were collected from a cohort of 32,906 city residents, during a health-screening program between 1974 and 1992.
Some 44 cases of esophageal cancer and 149 matched controls were selected.
The mean interval between screening and cancer diagnosis was 12 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.
H. pylori seropositivity was found to be present in 10 of the cases (23%) and 67 of the controls (45%).
In a multivariate model, with adjustment for occupation, tobacco, and alcohol consumption, the odds ratio for developing an esophageal malignancy, when infected with H. pylori, was 0.29.
|Odds ratio for developing esophageal cancer:|
Current smokers: 17.3
| Helicobacter |
The researchers found that current smokers had an odds ratio of 17.3, and the odds ratio for ex-smokers was 5.9.
High alcohol consumption was no longer significantly associated with esophageal neoplasms after tobacco smoking was included into the model (odds ratio 1.22).
The protective effect of H. pylori was more pronounced for esophageal adenocarcinoma (7 cases, odds ratio 0.16) than for squamous-cell carcinoma (29 cases, odds ratio 0.41).
Author J. Henrik Simán, of the Malmö University Hospital, concluded on behalf of fellow colleagues, "H. pylori infection is associated with a decreased risk of developing an esophageal malignancy.
"However, current smokers and ex-smokers have a definite increased risk of esophageal neoplasms."