Infection of the gastric mucosa with Helicobacter pylori (H. pylori) results in a number of disease outcomes including gastritis, which precedes the development of peptic ulcer disease, gastric cancer, and lymphomas of the mucosa associated lymphoid tissue lymphoma. The aim of this study was to assess association of colorectal cancer with H. pylori infection in Guilan province of Iran. Fifty-eight patients with colorectal cancer were enrolled in our study. Specific polymerase chain reaction assays were used for three genes: glmM, vacA and cagA. Of the 20 glmM PCR-positive bacterial colonies, 15 (75%) had the vacA signal sequence genotype s1, and 5 (25%) had subtype s2. The vacA mid- region analysis revealed that 13 (65%) were vacA m1 and 7 (35%) were m2. The cagA gene was present in 13 (60%) of colorectal cancer specimens. These results show that H. pylori can be detected in the tumor tissues specimens of some patients with colorectal cancer by polymerase chain reaction (PCR). vacA s1 is important virulence determinant of H. pylori in patients with colorectal cancer.Further studies are necessary to assess the potential role of H. pylori in the development of colorectal cancer.
