Bacterial bloodstream infections may signal colon cancer, according to a study that found people with the infections are 14 times more likely to be diagnosed with the malignancy a year later than the general population.
The cancer risk varied by type of bacteria, and patients who had germs that didn’t require oxygen to grow -- such as those that inhabit the colon -- faced a 115 times greater chance of cancer diagnosis, the research showed. The study by Canadian researchers was presented today at the Interscience Conference on Antimicrobial Agents and Chemotherapy in Chicago.
Cancers tend to penetrate into blood vessels, which may make it easier for bacteria from the intestinal tract to get into the bloodstream, said Yohei Doi, an infectious disease expert at the University of Pittsburgh who wasn’t involved in the study. Performing a colonoscopy on patients with blood infections may allow for earlier cancer detection, he said.
“When we find something in the blood that should be in the colon, we recommend a colonoscopy,” Doi said in a telephone interview. Today’s study gives a better sense of what kind of risks patients with bloodstream infections face, he said.
About 140,000 people will be diagnosed with colon or rectal cancer in 2011, and 49,000 people will die, according to the National Cancer Institute.
The study was conducted with medical records for bloodstream infections from January 2000 to December 2007 at the Calgary Health Region Area in Canada, a region with a population of about 1.2 million. This was matched with a registry of all new cancer diagnoses in Alberta between 1995 and 2008. Of 10,121 bloodstream infections and 3,859 colon cancers, 71 people had a diagnosis of colon cancer following the bloodstream infection.
Further study of which bacteria increase risk will help identify patients that benefit most from screening, according to study author Sanchia Warren, who was a fellow at the Alberta Health Services’ Department of infectious diseases during the research. She is currently a doctor at St. Vincent’s Hospital in Melbourne, Australia.