Earlier studies have suggested that H. pylori infection may be associated with a reduced risk of esophageal adenocarcinoma (cancer that arises in the tissue at the lower part of the esophagus), perhaps because such an infection may induce gastric atrophy, leading to less acidic stomach fluids that are less harmful to esophageal tissue. In contrast, researchers have speculated that H. pylori infection may increase the risk of squamous-cell carcinoma (cancer that arises in the cells that line the esophagus) by stimulating the production of cancer-causing nitrosamines.
To investigate the relationship among H. pylori infection, gastric atrophy, and three types of cancer--esophageal adenocarcinoma, esophageal squamous-cell carcinoma, and gastric cardia adenocarcinoma--Weimin Ye, M.D. Ph.D., of the Karolinska Institute in Stockholm, Sweden, and colleagues looked at H. pylori infection rates and the presence of gastric atrophy among 133 patients with the three types of cancer and compared them with 499 control patients.
They found that H. pylori infection was associated with a 50% to 80% reduction in risk of esophageal adenocarcinoma, depending on the type of analysis used. However, gastric atrophy was not associated with risk of the disease, which suggests, the authors say, that gastric atrophy does not play a role in the proposed protective effect of the infection. For squamous-cell carcinoma, H. pylori
Contact: Katie Arnold
Journal of the National Cancer Institute