title: Clinicopathological factors of multiple lateral margin involvement after endoscopic submucosal dissection for early gastric cancer.
abstract: OBJECTIVE
  In some ESD specimens of EGC, tumors involve multiple lateral margins. However, the factors related to the number of lateral margins involved are unclear. We evaluated the factors related to the multiplicity of lateral margin involvement in specimens of ESD for EGC.
  
  
  METHODS
  The study included 1,358 patients treated with ESD for EGC between March 2004 and September 2011 at a single tertiary hospital. Of those, 71 patients (5.2%) were found to have lateral margin-positive specimens. The demographic, endoscopic, and pathological features between the single lateral margin-positive lesions (SLM+ group) and the multiple lateral margin-positive lesions (MLM+ group) were compared retrospectively.
  
  
  RESULTS
  Single lateral margin involvement was noted in 43 lesions (60.6%), and multiple lateral margin involvement was seen in 28 lesions (39.4%). Extremely well-differentiated adenocarcinoma (EWDA) and histological heterogeneity were more common in the MLM+ group (p = 0.043 and p = 0.070, respectively). In multivariate analysis, EWDA was the only significant risk factor for multiple lateral margin involvement (OR 4.453 [1.011-19.624, 95% CI], p = 0.048). Surgery was performed in 65% (46/71) of the patients as an additional treatment for positive lateral margin, while 20% (14/71) of the patients underwent an additional ESD. After additional treatment, residual tumors were observed in 65% (39/60) of the specimens. There was no local recurrence among the patients treated with either type of additional treatment.
  
  
  CONCLUSIONS
  In ESD for EGC, multiple lateral margin involvement was related to the histological characteristics of the tumor, such as extremely well-differentiated adenocarcinoma and histological heterogeneity.
authors: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710, Korea.
authors: Jun Hee
authors: JH
authors: Lee
authors: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710, Korea. stomachlee@gmail.com.
authors: Jun Haeng
authors: JH
authors: Lee
authors: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Kyoung-Mee
authors: KM
authors: Kim
authors: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710, Korea.
authors: Ki Joo
authors: KJ
authors: Kang
authors: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710, Korea.
authors: Byung-Hoon
authors: BH
authors: Min
authors: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710, Korea.
authors: Jae J
authors: JJ
authors: Kim
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004210:Dissection / Q000379:methods; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000601:surgery; D018365:Neoplasm, Residual / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery
keywords: Endoscopic submucosal dissection; Lateral margin positivity; Stomach neoplasms