Several cities have already introduced this system as a mass screening program for gastric cancer [12]. In the ABC system, patients with negative anti-H. pylori Crenolanib nmr antibody titers and high PG levels are classified into “group A,” and are regarded as having a very low risk for gastric cancer [11, 12]. To increase the efficiency of a mass screening system, it is quite important to identify “no risk” subjects and exclude

them from mass screening. However, in clinical practice, gastric neoplasm is occasionally identified in patients in group A. The false-negative evaluation of gastric cancer risk must be prevented. In this study, we aimed to clarify the true risk for gastric epithelial neoplasm in patients classified as group A and retrospectively examined the clinicopathologic features of gastric neoplasms in group A. We also examined advanced methods for identifying the high-risk patients mixed into group A in a mass screening system for gastric cancer. Of 1087 patients with gastric neoplasms (early gastric cancer and adenoma) who were treated with ESD at Hiroshima University

Hospital between April 2002 and May 2010, we analyzed 373 patients with a prior evaluation of serum anti-H. pylori antibody titers and serum PG levels who were followed-up for more than 1 year without recurrence within 1 year in this study. Napabucasin nmr We enrolled patients with gastric adenoma, because they were clinically diagnosed as having potent early gastric cancer with differentiated type, and regarded as an indication for endoscopic resection. We excluded patients with previous gastric surgical history, local recurrence Chloroambucil of gastric neoplasm, gastric mucosa-associated lymphoid tissue lymphoma, Barrett’s adenocarcinoma, severe renal dysfunction, previous H. pylori eradication therapy, and administration of proton pump inhibitor. We defined Barrett’s adenocarcinoma as that endoscopically connected with Barrett’s esophagus. Patients who had undergone additional resection of the stomach or gastric tube construction

after ESD were also excluded. Typical case with EBV-related cancer [13] or hereditary cancer [14] case was not included. Patient with autoimmune gastritis [15] was also excluded. Finally, 271 patients (200 male, 71 female; mean age, 66.9 years) were enrolled in this study. Patients were followed-up by annual endoscopic examination in our hospital, and the average observation period was 40.4 (range 12.2–107) months. We also registered 213 subjects (132 male, 81 female; mean age, 57.1 years) as true H. pylori-negative controls; these subjects had no histologic atrophy of the gastric gland, no histologic inflammation of the gastric mucosa, and no histologic H. pylori infection or had no endoscopic gastric atrophy and negative anti-H. pylori antibody titers. In addition, we used the urea breath test (Otsuka, Tokushima, Japan) and rapid urease test (PyloriTek; Serim Research, IN, USA) for diagnosis of H. pylori infection.