Prevalence of colorectal cancer associated with Streptococcus bovis among inflammatory bowel and chronic gastrointestinal tract disease patients.

Colorectal cancer (CRC) is the second most common cause of cancer mortality among men and women worldwide; the risk of its occurrence has been shown to be increased by chronic bacterial infections. A case control study was therefore carried out at Hospital Universiti Sains Malaysia (HUSM) to determine the incidence of colorectal cancer associated with S. bovis infection. A total of 166 stool specimens were collected from diseased patients and healthy individuals and S. bovis isolates were identified. Suspected colon tumor and cancer cases were diagnosed and confirmed. It was found that overall prevalence of S. bovis was 41 (24.7%) out of 166 cases studied. 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 colorectal cancer incidence was 24.7%, adenocarinomas accounting for 51% with the highest incidence in the sigmoid part of 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.