Controlling bacteria responsible for typhoid fever could dramatically cut the risk of gall bladder cancer in India and Pakistan, according to scientists including an Indian researcher.
The findings established for the first time the causal link between bacterial infection and gall bladder cancer, explaining why the type of cancer was rare in the west but common in India and Pakistan, where typhoid fever was endemic.
Public policy changes inspired by the research could have an immediate impact on preventing a type of cancer that currently had a very poor prognosis, according to researchers.
According to Jacques Neefjes of the Netherlands Cancer Institute, while viruses were among the established causal factors for particular cancers, bacteria were largely ignored as direct contributors.
According to Neefjes, accepting that bacterial infections could directly contribute to cancer formation made these tumours in principle preventable.
He added if Salmonella Typhi infections were cured immediately with antibiotics and chronic infections prevented, or if vaccination programmes to eradicate S Typhi worked, a major reduction in the incidence of a tumour that represented the third-most common gastro-intestinal tumour in India and Pakistan, could be achieved.
Gall bladder cancer is most difficult to detect in early stages as there are no signs or symptoms. And by the time it was detected it was often too late to save patients.
Given the poor prognosis of gall bladder cancer, Neefjes, Tiziana Scanu of the Netherlands Cancer Institute, and Gopal Nath of Banaras Hindu University set about gaining insight into how to combat this tumour by identifying causal factors underlying its unique global distribution.
The researchers indentified S Typhi, as this typhoid-causing bacterium was endemic in India and had been associated with gallbladder cancer in epidemiological studies.
The proteins that salmonella injected into host cells activated cancer-related signaling pathways called AKT and MAPK, which support not only bacterial infection and survival, but also the proliferation and growth of cancer cells.
According to Tiziana Scanu of the Netherlands Cancer Institute the use of antibiotic treatment to control the infections might come too late for people who had already developed cancer, so rather it was better to prevent the diseases through proper treatment with antibiotics, vaccination programs, or better sanitary conditions.