title: Optimal management for patients not meeting the inclusion criteria after endoscopic submucosal dissection for gastric cancer.
abstract: The necessity of additional gastrectomy for patients not meeting the inclusion criteria after endoscopic submu cosal dissection (ESD) is controversial. The aim of this study was to elucidate the risk factors for lymph node metastasis (LNM) and residual cancer (RC) in patients not meeting the inclusion criteria after ESD and to determine additional treatment strategies.
  
  
  
  Of 1443 gastric cancer patients who underwent ESD between 2004 and 2013, 167 patients diagnosed as having a lesion not meeting the inclusion criteria after ESD were retrospectively analyzed. Of the 167 cases, 100 cases underwent additional gastrectomy, and 67 cases were observed without surgery.
  
  
  
  Overall, 9.0 % (9/100) and 9.0 % (9/100) of patients not meeting the inclusion criteria after ESD presented with LNM and RC, respectively, but neither was observed in 83 patients (83.0 %). Multivariate analysis revealed that lymphovascular involvement (LVI) (OR 38.38; 95 % CI 1.94-761.43, p = 0.017) and undifferentiated type (OR 45.58; 95 % CI 2.88-720.94, p = 0.007) were independent risk factors for LNM, and positive horizontal margin was an independent risk factor for RC (OR 9.48; 95 % CI 1.72-52.13, p = 0.010). In differentiated types without LVI, no cases had LNM (0/38) in the additional gastrectomy group, and there was no lymph node or distant recurrence (0/39) in the observation group.
  
  
  
  Additional treatment is necessary for patients with LVI, undifferentiated type, and positive horizontal margin. Careful follow-up may be acceptable for patients with the differentiated type without LVI, especially for the elderly or patients with severe comorbidities.
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Toyokawa
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan. masaichi@med.osaka-cu.ac.jp.
authors.forename: Masaichi
authors.initials: M
authors.lastname: Ohira
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Minamino
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: Katsunobu
authors.initials: K
authors.lastname: Sakurai
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Nagami
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: Naoshi
authors.initials: N
authors.lastname: Kubo
authors.affiliation: Department of Gastroenterological Surgery, Osaka City General Hospital, Osaka, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Department of Gastroenterology, Osaka City General Hospital, Osaka, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Sano
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Muguruma
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Tominaga
authors.affiliation: Department of Gastroenterology, Osaka City General Hospital, Osaka, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Nebiki
authors.affiliation: Department of Gastroenterological Surgery, Osaka City General Hospital, Osaka, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Arakawa
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000368:Aged; D000369:Aged, 80 and over; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology / Q000601:surgery*; D000069916:Endoscopic Mucosal Resection / Q000379:methods*; D005260:Female; D005743:Gastrectomy / Q000379:methods*; D005753:Gastric Mucosa / Q000601:surgery; D005773:Gastroscopy / Q000379:methods; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D018365:Neoplasm, Residual; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology / Q000601:surgery*
keywords: Endoscopic submucosal dissection; Gastrectomy; Gastric cancer; Lymph node metastasis; Residual cancer; Risk factor