title: Risk factors for local recurrence after en bloc endoscopic submucosal dissection for early gastric cancer.
abstract: OBJECTIVE
  To investigate factors related to recurrence following en bloc resection using endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC).
  
  
  METHODS
  A total of 1121 patients (1215 lesions) who had undergone ESD for gastric neoplasia between April 2003 and May 2010 were retrospectively reviewed. Data from 401 patients (415 lesions) were analyzed, following the exclusion of those who underwent piecemeal resection, with deep resection margin invasion or lateral margin infiltration, and diagnosed with benign lesions.
  
  
  RESULTS
  Local recurrence after en bloc ESD was found in 36 cases (8.7%). Unclear resection margins, long procedure times, and narrow safety margins were identified as risk factors for recurrence. Lesions located in the upper third of the stomach showed a higher rate of recurrence than those located in the lower third of the stomach (OR = 2.9, P = 0.03). The probability of no recurrence for up to 24 mo was 79.9% in those with a safety resection margin ≤ 1 mm and 89.5% in those with a margin > 1 mm (log-rank test, P = 0.03).
  
  
  CONCLUSIONS
  Even in cases in which en bloc ESD is performed for EGC, local recurrence still occurs. To reduce local recurrences, more careful assessment will be needed prior to the implementation of ESD in cases in which the tumor is located in the upper third of the stomach. In addition, clear identification of tumor boundaries as well as the securing of sufficient safety resection margins will be important.
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Ju Yup
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Kwang Bum
authors.initials: KB
authors.lastname: Cho
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Kyung Sik
authors.initials: KS
authors.lastname: Park
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Yoo Jin
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Yoon Suk
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Byoung Kuk
authors.initials: BK
authors.lastname: Jang
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Chung
authors.affiliation: Ju Yup Lee, Kwang Bum Cho, Eun Soo Kim, Kyung Sik Park, Yoo Jin Lee, Yoon Suk Lee, Byoung Kuk Jang, Woo Jin Chung, Jae Seok Hwang, Department of Internal Medicine, Keimyung University School of Medicine, Daegu 41931, South Korea.
authors.forename: Jae Seok
authors.initials: JS
authors.lastname: Hwang
keywords: Early gastric cancer; En bloc resection; Endoscopic mucosal resection; Endoscopic submucosal dissection; Recurrence