The prevalence of Helicobacter pylori infection in hyperplastic polyps, adenomas and cancers of the stomach

Background: Helicobacter pylori (H.p.) gastritis is a risk factor for the development of gastric cancers and there are data on gastric adenomas associated with H.p. infection. Some morphological studies have revealed a strong correlation between gastric adenomas and H.p. persistence and the development of hyperplastic gastric polyps and concomitant H.p. infection.

The aim of our study was to investigate the relationship between H.p. infection, hyperplastic polyps, gastric adenomas, and gastric neoplasms.

Methods: A total of 60 patients with hyperplastic polyp, 31 patients with gastric adenoma, 6 patients with carcinoma in situ, and 43 patients with gastric cancer were examined for H.p. infection. The H.p. status was evaluated by means of the rapid urease test (antrum+corpus) and/or the histology.

Results: The prevalence of H.p. was lower in patients with hyperplastic polyps (6 positive/54 negative; 10%) and adenoma (7/24; 22.6%), carcinoma in situ (1/5; 20%) and carcinoma (4/39;10.2%) than in the Hungarian blood donor controls (age 55–59) (83%). The prevalence of H.p. in these groups of patients did not differ in the two gastroenterological centers. The prevalence of H.p. in hyperplastic polyps and in gastric cancers in this study was much lower than reported in international studies (10% vs. 63–79% and 10.2 vs. 43–75%, respectively).

Conclusion: Our results are in opposite of those suggesting a strong association between H.p. and hyperplastic polyp, gastric adenoma or carcinoma. The prevalence of H.p. infection in gastric cancer is difficult to estimate because the infection may be lost from individuals with cancer from its precursor conditions. The bacterium does not colonize cancerous tissue, and studies using histopathology as a means of assessing infection therefore require gastric biopsy material sampled separately from the tumor itself.