title: Risk factors for local recurrence in patients with positive lateral resection margins after endoscopic submucosal dissection for early gastric cancer.
abstract: With the widespread use of endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC), the number of cases with incomplete resection due to positive lateral resection margins (LM+) is increasing. Local recurrence, which occurs frequently in LM+ cases, is an important issue. This study aimed to clarify the clinicopathological factors related to tumor recurrence in LM+ cases after ESD for EGC.
  
  
  
  From January 2005 to December 2012, a total of 1,083 patients with EGC underwent ESD at our hospital. Of these, cases with a pathological diagnosis of LM+ were included in this study. Patients with positive vertical resection margins, those who underwent surgical resection immediately or were followed up for less than 6 months after ESD, were excluded.
  
  
  
  A total of 55 LM+ cases after ESD for EGC were enrolled. Incorrect delineation of a lesion that extended pathologically beyond the ESD marking dots was the main cause of LM+. Local recurrence was found in 20 (36.4 %) patients (median follow-up period, 23 months). Local recurrence rates related to LM+ length were as follows: 7/29 (24.1 %) in 2 mm, 6/16 (37.5 %) in 4 mm, 1/3 (33.3 %) in 6 mm, 4/5 (80 %) in 8 mm, and 2/2 (100 %) in ≥ 10 mm. In multivariate analysis, tumor size > 2 cm (OR 4.48, 95 % CI 1.18-16.99, p = 0.027), and LM+ length > 6 mm (OR 7.65, 95 % CI 1.15-50.70, p = 0.035) were independent risk factors for tumor recurrence.
  
  
  
  To decrease the risk of LM+, it is highly important to accurately delineate the lateral margins during ESD; when the final histopathological result is LM+, cases with LM+ length >6 mm or tumor size > 2 cm should be considered for additional surgical resection or re-ESD because of a high risk of tumor recurrence.
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, 179, Gudeok-ro, Seo-gu, Busan, 602-739, Korea.
authors.forename: Tae Kyun
authors.initials: TK
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179, Gudeok-ro, Seo-Gu, Busan, 602-739, Korea. doc0224@pusan.ac.kr.
authors.forename: Gwang Ha
authors.initials: GH
authors.lastname: Kim
authors.affiliation: Department of Pathology, Pusan National University School of Medicine, 179, Gudeok-ro, Seo-gu, Busan, 602-739, Korea.
authors.forename: Do Youn
authors.initials: DY
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, 179, Gudeok-ro, Seo-gu, Busan, 602-739, Korea.
authors.forename: Bong Eun
authors.initials: BE
authors.lastname: Lee
authors.affiliation: Department of Surgery, Pusan National University School of Medicine, 179, Gudeok-ro, Seo-gu, Busan, 602-739, Korea.
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Jeon
authors.affiliation: Department of Surgery, Pusan National University School of Medicine, 179, Gudeok-ro, Seo-gu, Busan, 602-739, Korea.
authors.forename: Dae Hwan
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Surgery, Pusan National University School of Medicine, 179, Gudeok-ro, Seo-gu, Busan, 602-739, Korea.
authors.forename: Hong Jae
authors.initials: HJ
authors.lastname: Jo
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, 179, Gudeok-ro, Seo-gu, Busan, 602-739, Korea.
authors.forename: Geun Am
authors.initials: GA
authors.lastname: Song
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000473:pathology* / Q000601:surgery*; D005773:Gastroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery*
keywords: Early gastric cancer; Endoscopic submucosal dissection; Incomplete resection; Recurrence