Helicobacter pylori in colorectal neoplasms: is there an aetiological relationship?

Abstract

Background: This pilot study was carried out to determine whether Helicobacter pylori can be detected in normal colon or in association with colorectal neoplasia.

Methods: Paraffin processed colonic tissue blocks of normal colonic mucosa (n = 60), and patients diagnosed as adenoma (n = 60), and adenocarcinoma (n = 60) were retrieved from our archive; the adenoma group included tubular (n = 20), tubulovillous (n = 20) and villous adenomas (n = 20). 4 mum sections were stained by immunohistochemical methods using anti-Helicobacter pylori antibodies (polyclonal NCL-HPp and monoclonal NCL-C-jejuni).

Results: Significant numbers of Helicobacter pylori were identified in tubular adenomas (OR = 11.13; 95%CI = 1.62-76.70), tubulovillous adenomas (OR = 10.45; 95%CI = 1.52-71.52) and adenocarcinomas (OR = 8.13; 95%CI = 1.40-46.99) compared to controls: there was no association in numbers of Helicobacter pylori and villous adenomas (OR = 2.95; 95%CI = 0.29-9.96).

Conclusion: We conclude that although, in this pilot study, there appears to be an association in the prevalence of Helicobacter pylori with some, but not all, colorectal neoplasms, we can not infer causality from these results. These findings need to be further substantiated with a prospective study and the use of molecular biological techniques to determine a causal association.

Figure 1

Positive HP immunohistochemistry (arrowheads) is seen in gastric control material using NCL-HPp (a & b) (internal scale = 50 μm).

Figure 2

Immunopositivity is seen in colorectal neoplasia using a) NCL-HPp and b) NCL-C-Jejuni (internal scale = 50 μm).