They discarded the obesity epidemic as causal and felt that the relatively slow decline in H. pylori infection and sex differences did not support
the theory that it was a result of the falling prevalence of H. pylori; they concluded that a yet unidentified causal factor—first introduced in the UK in the middle of the 20th century (but at different times in other Selleckchem Stem Cell Compound Library countries) had been responsible. A review paper by Choi [13] from Korea assessed the published studies on H. pylori eradication and gastric cancer prevention. These range from prospective randomized population studies in China to the prevention of metachronous cancer following removal of early gastric cancer (EGC) in Japan and Korea. It also considered publications MI-503 research buy that have looked at the incidence of cancer in treated and untreated peptic ulcer cohorts. The conclusion was that no well-designed study has shown sufficient prevention of gastric cancer by H. pylori eradication in the general population to justify mass eradication policies but that young individuals in high-risk
regions may be the best candidates for eradication therapy. A second article from Korea by Bae et al. [14] was more optimistic. This group retrospectively assessed the outcome of 2089 adults who had undergone endoscopic resection of gastric low-grade neoplasia, high-grade neoplasia, and differentiated invasive neoplasia. The incidence of metachronous gastric cancer was 10.9 cases per 1000 person-years in the H. pylori negative group, 14.7 in the eradicated group, and 29.7 in the noneradicated group. The hazard ratios in the noneradicated group compared with the H. pylori negative and eradicated groups were 2.5 (p < 0.01) and 1.9 (p = .02), respectively. These findings mirror earlier Japanese studies on metachronous cancer. Lee et al. [15] report the 上海皓元 outcome of a population H. pylori eradication study in Taiwan started in 2004. The study group included 5000 residents of Matsu Island (a high-risk population
for gastric cancer.) They were >30 years of age and positive for the 13C-urea breath test. They underwent endoscopic screening and a 1-week clarithromycin-based triple therapy with a 10-day levofloxacin-based triple therapy for those who failed. There was a reduction in H. pylori infection of 79%; re-infection/recrudescence was 1% per person-year. Reduction in gastric atrophy incidence was 77%, but intestinal metaplasia was not significant. Compared with the 5-year period before chemoprevention was instituted, the gastric cancer incidence reduced by 25% and peptic ulcer disease by 67.4%; however, the incidence of esophagitis rose by 6% after treatment and two cases of Barrett’s esophagus were identified. The decline in gastric cancer before the intervention is shown in Fig.