title: Risk of recurrent gastric cancer after endoscopic resection with a positive lateral margin.
abstract: OBJECTIVE
  After noncurative endoscopic submucosal dissection (ESD) for differentiated-type early gastric cancer (EGC), close observation is often preferred when a cancer-positive lateral margin is the only noncurative factor. However, sometimes recurrence is found during the observation period. This study aimed to examine risk factors for recurrent cancer based on the long-term clinical outcomes after noncurative ESD in which the only noncurative factor was a cancer-positive lateral margin.
  
  
  METHODS
  Among 3784 EGCs (3316 patients) treated by ESD between 1997 and 2010, 77 noncurative differentiated-type EGCs (75 patients) were retrospectively analyzed after meeting the following inclusion criteria: 1) the only noncurative factor was a cancer-positive lateral margin; 2) close observation was selected after the ESD; and 3) > 1 year follow-up after ESD.
  
  
  RESULTS
  Locally recurrent cancer was found in 10 lesions within a median follow-up period of 59.8 months; no metastasis or gastric cancer-related death occurred. The cumulative incidence of local recurrence 5 years after ESD was 11.9 %. All locally recurrent cancers were mucosal differentiated-type adenocarcinomas. Multivariate analysis indicated that a cancer-positive lateral margin length of ≥ 6 mm was significantly associated with local recurrence (hazard ratio 20.8; 95 % confidence interval 5.2 % - 82.9 %; P < 0.001). The cut-off value of 6 mm was determined by the receiver operating characteristic curve; the sensitivity and specificity for 5-year risk of developing local recurrence were 66.7 % and 95.6 %, respectively.
  
  
  CONCLUSIONS
  A cancer-positive lateral margin length of ≥ 6 mm was an independent risk factor for local recurrence, and this may be a useful criterion for selecting high-risk cases for stricter management.
authors: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Masau
authors: M
authors: Sekiguchi
authors: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Haruhisa
authors: H
authors: Suzuki
authors: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Ichiro
authors: I
authors: Oda
authors: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Seiichiro
authors: S
authors: Abe
authors: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Satoru
authors: S
authors: Nonaka
authors: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Shigetaka
authors: S
authors: Yoshinaga
authors: Pathology Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Hirokazu
authors: H
authors: Taniguchi
authors: Molecular Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
authors: Shigeki
authors: S
authors: Sekine
authors: Pathology Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Ryoji
authors: R
authors: Kushima
authors: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
authors: Yutaka
authors: Y
authors: Saito
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015331:Cohort Studies; D016001:Confidence Intervals; D018572:Disease-Free Survival; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology / Q000601:surgery*; D005773:Gastroscopy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D015994:Incidence; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016019:Survival Analysis; D016896:Treatment Outcome