People infected with H. pylori have an increased risk of stomach cancer, but many of these people will never develop the disease. Past studies have suggested that disease progression depends on a number of factors, including the bacterial strain and genetic variations in the host.
To determine whether certain combinations of bacterial and host genotypes increase the risk of stomach cancer, Cu Figueiredo, Ph.D., of the Institute of Molecular Pathology and Immunology at the University of Porto in Portugal, and colleagues examined 221 people with chronic gastritis and 222 people with stomach cancer.
The authors found that certain combinations of bacterial and host genotypes were strongly associated with the risk of stomach cancer. For example, people carrying a high-activity version of interleukin-1 beta gene who were infected by an H. pylori strain with a particular variant of the vacA vacuolating cytotoxin had a nearly 90-fold increase in the risk of stomach cancer.
"Our findings indicate that H. pylori and host genotyping can be important in better defining disease risk and preferentially targeting H. pylori eradication to high-risk individuals," the authors conclude.
In an accompanying editorial, Martin Blaser, M.D., of the New York University School of Medicine, says that these findings are promising, but he cautions that it still too early to generalize from this work.
"The study needs confirmation, different ethnic groups must be examined, the technique must be simplified for general use, and our understanding of the risks and benefits of H. pylori must grow," he writes. "Nevertheless, assessing risk for gastric disea
Contact: Linda Wang
Journal of the National Cancer Institute