Prevalence of Colorectal Cancer Associated with Streptococcus bovis among Inflammatory Bowel and Chronic Gastrointestinal Tract Disease Patients

Abstract

Colorectal cancer (CRC) is the second most common cause of cancer mortality among men and womenworldwide; the risk of its occurrence has been shown to be increased by chronic bacterial infections. A casecontrol study was therefore carried out at Hospital Universiti Sains Malaysia (HUSM) to determine the incidenceof colorectal cancer associated with S. bovis infection. A total of 166 stool specimens were collected from diseasedpatients and healthy individuals and S. bovis isolates were identified. Suspected colon tumor and cancer caseswere diagnosed and confirmed. It was found that overall prevalence of S. bovis was 41 (24.7%) out of 166 casesstudied. Some 41(48.6%) of these S. bovis isolates was found in patients with colonic polyps, adenocarcinomas,inflammatory bowel disease (IBD) and chronic gastrointestinal tract (GIT). It was also found that colorectalcancer incidence was 24.7%, adenocarinomas accounting for 51% with the highest incidence in the sigmoid partof the colon. Among the IBD and chronic GIT cases, ulcerative colitis featured in the majority of cases (41.4%).In conclusion, there is a high incidence of colorectal cancer associated with S. bovis.