Study confirms link between inflammation and bowel and stomach cancer
New research has provided evidence for the long-suspected link between chronic inflammation of the intestine or stomach, and cancer.
Two studies published in the Journal of Clinical Investigation show that chronic inflammation accelerated the rate of formation of tumours in a strain of mice that had been bred to have an impaired DNA repair system.
Inflammation is known to produce immune response chemicals called cytokines, which encourage the multiplication of cells and block the natural process of cell death - a key natural defence against cancer.
However, some people appear to be more susceptible to inflammation-induced cancers than others, and this is now thought to be due to genetic variations that govern the effectiveness of their DNA repair systems.
If DNA repair systems do not work effectively, mutations can accumulate as cells multiply naturally, leading to cancer.
Leona Samson, senior author of the study and director of MIT's Centre for Environmental Health Sciences (CEHS), said: "[Genetic] variation could influence the susceptibility of individuals and how they are going to respond to chronic inflammation."
The researchers gave mice a chemical that creates chronic inflammation similar to ulcerative colitis (a form of inflammatory bowel disease) and found that mice which had been bred to have a poor DNA repair system were more likely to develop cancer.
In a second study, these DNA repair-deficient mice infected with Helicobacter pylori - an infectious agent that causes inflammation and increases the risk of stomach cancer - were shown to be more susceptible to pre-cancerous stomach growths.
Lead author Lisiane Meira, a researcher in MIT's Centre for Environmental Health Sciences, commented on the link, saying: "It's something that was expected but it was never formally proven."