Although H. pylori is the strongest known risk factor for gastric
cancer, most H. pylori-infected persons tolerate the presence of
this organism over an entire lifetime without any adverse effects,
and some persons may even derive health benefits from H. pylori
(9). An important goal is to define the factors that determine
whether gastric cancer will develop, so that the subset of H. pyloriinfected
persons with the highest risk of gastric cancer can be
identified and targeted for therapeutic interventions.