Identification of Helicobacter pylori in tumor biopsies obtained from patients with colorectal cancer: Indication for a prophylactic vaccine?

The association between H. pylori infection and colorectal cancer (CRC) has been controversial, and despite the undisputed roles of H. pylori in the etiology of gastric cancer, its involvement as a causative agent of CRC is unknown. We aimed to investigate the potential associations between H. pylori infection and CRC in biopsy samples taken from tumors of Iranian patients. Patients (n = 49; aged 38–79 years, mean age = 49) with diagnosed CRC were enrolled. Biopsies from control (n = 10) and suspected CRC patients were collected from March 2017 to 1 August 2019 at the Mehrad Hospital, Tehran, Iran. The diagnosis of CRC was confirmed by pathology and colonoscopic examinations. An expert gastroenterologist performed the colonoscopic surgery and sample collection. DNA was extracted from the samples, and H. pylori infection was detected and confirmed by PCR using the glmM sequence as the species-specific gene. SPSS version 18 was used to determine the significant associations by using the two-tailed Fisher's exact test. Eighteen (46.1%) and 6 (60%) patients were female in the CRC and control groups, respectively. No significant associations were observed between H. pylori infection and family history of cancer, age, or gender. Thirty-one (79%) CRC samples showed severe inflammation. Out of the 31 CRC samples with severe inflammation, 18 (58%) were positive for H. pylori (P < 0.05). We conclude that H. pylori may be involved in the CRC pathogenesis or progression. Our findings suggest that a prophylactic vaccine against H. pylori may be promising in reducing the CRC incidence.