The metachronous and nonmetachronous groups were matched according to age and sex by using propensity score matching. in the nonmetachronous group (P=0. 002). In addition , open-type atrophy was more frequent in the metachronous group (P=0. 047). In patients with an initial diagnosis of carcinoma, moderate-to-severe IM occurred more frequently in the metachronous group (P=0. 003); however , the eradication failure rate was not Ozarelix significantly different between the two groups. SHH and SOX2 expression was increased, and CDX2 expression was decreased in the nonmetachronous group after eradication (P <0. 05). == Conclusions == Open-type atrophy, moderate-to-severe IM, andH. pylorieradication failure were significantly associated with metachronous lesions. However , eradication failure was significantly associated with dysplasia, but not carcinoma, in the metachronous group. Thus, H. pylorieradication may play an important role in preventing metachronous lesions after ER for precancerous lesions before carcinomatous transformation. Keywords: Helicobacter pylori, Metachronous, Endoscopic resection, Stomach neoplasms == Introduction == Helicobacter pyloriinfection is closely related to gastric atrophy, intestinal metaplasia (IM), and progression to dysplasia or cancer. 1However, the incidence Ozarelix of Ozarelix gastric cancer did not differ between Chinese patients receivingH. pylorieradication treatment and those receiving placebo during 7. 5 years of follow-up. 2Several reports exist on the effect ofH. pylorieradication in patients at a high risk for gastric cancer. Previous studies illustrated that eradication ofH. pyloriafter endoscopic resection (ER) of early gastric cancer (EGC) helped prevent the development of metachronous gastric cancer. 3, 4However, Choi et al. 5revealed thatH. pylorieradication after ER of EGC did not reduce the incidence of Ozarelix metachronous gastric cancer. Therefore , the importance ofH. pylorieradication after ER for gastric neoplasms remains controversial. Defining the subgroup of patients for whomH. pylorieradication after ER for gastric neoplasms is beneficial is important because patients who undergo ER is increasing and the incidence of metachronous lesions is also consequently increasing. Several gastric and intestinal epithelial markers are associated with the progression of IM, a precancerous lesion. 6, 7Sonic hedgehog (SHH) is an essential regulator of developmental and physiological processes. 8, 9, 10In humans, Shh mRNA and SHH protein are expressed in the normal gastric fundus but not in the esophagus and intestine. 11, 12Loss of SHH is an early change associated with the presence of IM. 11, 13CDX proteins (intestine-specific caudal-related homeobox transcription factor) are intestine-specific transcription factors encoded by humanCDX1andCDX2genes. Moreover, Mizoshita et al. 14reported that the expression of CDX1 and CDX2 was found in IM of the human stomach. Shiotani et al. 7demonstrated the reexpression of SHH and reduction of CDX2 levels afterH. pylorieradication. Sox2, a gastric transcription factor, is expressed in the human stomach, and its expression gradually decreases as IM progresses. 15That is, Sox2 expression decreases and Cdx expression increases gradually during the progression of IM. Therefore , these markers might help identify patients for whomH. pylorieradication is advantageous. In this study, we evaluated the clinicopathological factors and gastric and intestinal markers according to the development of metachronous gastric Sdc2 neoplasms after ER, clarified the role ofH. pylorieradication in the development of metachronous lesions, and investigated the patient subgroup for whomH. pylorieradication was beneficial, especially Ozarelix after ER. == Materials and Methods == == 1 . Patients == Between June 2006 and June 2012, gastric neoplasms were diagnosed in 3, 882 patients and treated with ER. Among the patients, we identified those who were infected withH. pyloriand receivedH. pylorieradication treatment; that is, all patients included in this study receivedH. pylorieradication treatment. After theH. pylorieradication treatment, 34 patients with metachronous gastric neoplasms after ER for gastric neoplasms (metachronous group) and 102 age- and sex-matched patients (nonmetachronous) who underwent ER for gastric neoplasms and who did not develop metachronous gastric neoplasms were enrolled on the basis of propensity score matching.