Helicobacter Pylori and Gastric Cancer: An Update in the Literature.

Of the chronic bacterial infections that affect humans, Helicobacter pylori (H. pylori) infection is one of the most common. It inhabits the stomachs of half of the adult human population. In Puerto Rico, a US territory, it has an overall prevalence of 33%, similar to the prevalence reported in the population of the US as a whole. Helicobacter pylori infection is responsible for mucosal inflammation that may lead to chronic gastritis, most peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. The International Agency for Research on Cancer identified H. pylori as a definite carcinogen in 1994, the only bacterium to be given such a classification. Its oncogenic effect has been postulated to be caused by different mechanisms, including bacterial characteristics and host factors. Epidemiologic studies have shown that gastric cancer risk differs among regions. One of the top 10 causes of cancer death in Puerto Rico is gastric cancer. Although the eradication of H. pylori has well-known benefits, there are some concerns when considering mass screening and treatment of infected patients. These include the fact that such eradication could provoke an increase in antibiotic resistance rates, the disturbance of the gut microbiota, an increase in body weight, and the aggravation of existing gastroesophageal reflux symptoms. Gastric cancer is a major health concern, and we should understand the role of H. pylori eradication in its prevention. This article is geared to summarize current knowledge and controversies.