Association of Helicobacter pylori infection with colorectal polyps and malignancy in China

BACKGROUND: Gastric Helicobacter pylori (H. pylori) infection is related to chronic gastritis, gastroduodenal ulcer, and gastric malignancies; whether this infection is related to colorectal polyps and colorectal cancer (CRC), remains debatable. AIM: To investigate the relationship between gastric H. pylori infection and the risk of colorectal polyps and CRC. METHODS: We retrospectively analyzed 3872 patients with colorectal polyps who underwent colonoscopy and pathological diagnosis. We also analyzed 304 patients with primary CRC. The characteristics of these patients were compared with those of the control group, which included 2362 patients with the normal intestinal mucosa. All subjects completed a (14)C-urea breath test, bidirectional gastrointestinal endoscopy, and a biopsy on the same day. Data on the number, size, location, and pathology of the polyps, the location, and pathology of the CRC, the detection of H. pylori, and the incidence of H. pylori-associated atrophic gastritis or intestinal metaplasia were obtained. A logistic regression model was used to analyze the relationship between gastric infection due to H. pylori, and the incidence of colorectal polyps and CRC. RESULTS: The prevalence of H. pylori infection was higher in the multiple polyps group than in the solitary polyp group and the control group [95% confidence interval (CI) = 1.02-1.31, P = 0.03; 95%CI: 2.12-2.74, P < 0.001]. The patients with adenomatous polyps had a higher incidence of H. pylori infection than patients with non-adenomatous polyps [59.95% vs 51.75%, adjusted odds ratio (OR) = 1.41, 95%CI: 1.24-1.60, P < 0.01]. Patients with H. pylori-associated atrophic gastritis or intestinal metaplasia were at high risk of CRC (adjusted OR = 3.46, 95%CI: 2.63-4.55, P < 0.01; adjusted OR = 4.86, 95%CI: 3.22-7.34, P < 0.01, respectively). The size and location of the polyps, the histopathological characteristics and the location of CRC were not related to H. pylori infection. CONCLUSION: Our study demonstrates that the incidence of gastric H. pylori infection and H. pylori-associated atrophic gastritis or intestinal metaplasia elevates the risk of colorectal polyps and CRC.