title: Incidence of gastric cancer after endoscopic resection of gastric adenoma.
abstract: OBJECTIVE
  The annual incidence of metachronous cancer after endoscopic resection (ER) of early gastric cancer (EGC) is approximately 3%. However, the incidence of gastric cancer after ER of a gastric adenoma is not known. The aim of this study was to determine whether the incidence of gastric cancer after ER of a gastric adenoma was different compared with that of metachronous cancer after ER of EGC.
  
  
  METHODS
  We retrospectively analyzed data from patients who underwent ER for gastric neoplasia from January 2005 to August 2013. Enrolled patients were divided into 2 groups: patients with low-grade dysplasia were included in the adenoma group and patients with high-grade dysplasia or invasive neoplasia were included in the EGC group. The main outcome was the incidence of gastric cancer after ER.
  
  
  RESULTS
  At a median follow-up of 28 months, gastric cancer newly developed in 13 adenoma patients (3.6%) and in 30 EGC patients (5.1%). The incidence rate of gastric cancer after ER was 14.4 cases per 1000 person-years in adenoma patients and 18.4 cases per 1000 person-years in EGC patients (P = .309 by the log-rank test). The hazard ratio of metachronous neoplasia in adenoma patients compared with EGC patients was 0.97 (95% confidence interval, 0.62-1.53). Metachronous tumors with invasion beyond the muscularis mucosa were more frequent in adenoma patients than in EGC patients (7/35 [20.0%] vs 3/63 [4.8%], P = .017).
  
  
  CONCLUSIONS
  The incidence of gastric cancer after ER for gastric adenoma was not significantly different from that of EGC. If further prospective studies confirm these findings, careful endoscopic surveillance with the same level of intensity should be considered for both gastric adenoma and EGC patients after ER.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Seung Bae
authors.initials: SB
authors.lastname: Yoon
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Jae Myung
authors.initials: JM
authors.lastname: Park
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Chul-Hyun
authors.initials: CH
authors.lastname: Lim
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Jin Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Yu Kyung
authors.initials: YK
authors.lastname: Cho
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Bo-In
authors.initials: BI
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: In Seok
authors.initials: IS
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Myung-Gyu
authors.initials: MG
authors.lastname: Choi
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology* / Q000473:pathology; D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000368:Aged; D018279:Carcinoma, Signet Ring Cell / Q000453:epidemiology* / Q000473:pathology; D000069916:Endoscopic Mucosal Resection; D005260:Female; D005753:Gastric Mucosa / Q000601:surgery; D016481:Helicobacter Infections / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*