PEOPLE infected with a common bacterium of the stomach known as helicobacter pylori are six times more likely to develop gastric cancer than those who are uninfected, according to a major study by researchers in Europe, the United States and Japan.

Dr David Forman, of the Imperial Cancer Research Fund, who led the team of researchers, says that most people with the bacterium will not go on to develop stomach cancer. But he suggests that those with a family history of gastric cancer should be tested and treated for the infection.