title: Lymph node metastasis and preoperative diagnosis of depth of invasion in early gastric cancer.
abstract: BACKGROUND
  No reports have, to date, focused on the relationship between preoperative determination of the depth of invasion and lymph node metastasis. The present study, under the leadership of the Japanese Gastric Cancer Association, was designed to form a basis for decision making in limited treatment for early gastric cancer (EGC).
  
  
  METHODS
  From eight major hospitals in Japan, 2672 gastric cancers whose preoperative depth of invasion was mucosal(M-cancer), and 6209 EGCs, consisting of 3584 mucosal(m-) and 2625 submucosal(sm-) cancers, were collected by questionnaire. All registered patients underwent gastrectomy with D1 or more extensive lymphadenectomy between 1985 and 1998.
  
  
  RESULTS
  The accuracy of preoperative diagnosis of depth of invasion of M-cancers was 80.2% (2144/2672). However, of the total of 2432 M-cancers in which no nodal involvement was observed intraoperatively (N0), histological examination of the resected specimens confirmed that lymph node metastasis was absent in 2353 (96.8%). The frequencies of lymph node metastasis in early gastric, m-, and sm-cancers were 8.9%, 2.5%, and 17.6%, respectively. Node involvement was associated with a higher frequency of undifferentiated than differentiated histology, as well as with greater tumor size. The incidences of lymph node metastasis in m-cancers with a diameter of less than 4 cm, and in sm-cancers with a diameter below 1 cm were 1.3% (37/2837) and 4.9% (4/82), respectively. These metastases rarely extended beyond the first tier.
  
  
  CONCLUSIONS
  N0 and M-cancers, m-cancers less than 4 cm in diameter, and sm-cancers no larger than 1 cm in diameter may be appropriate indications for limited surgery.
authors.affiliation: Department of Gastrointestinal Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Seto
authors.forename: S
authors.initials: S
authors.lastname: Shimoyama
authors.forename: J
authors.initials: J
authors.lastname: Kitayama
authors.forename: K
authors.initials: K
authors.lastname: Mafune
authors.forename: M
authors.initials: M
authors.lastname: Kaminishi
authors.forename: T
authors.initials: T
authors.lastname: Aikou
authors.forename: K
authors.initials: K
authors.lastname: Arai
authors.forename: K
authors.initials: K
authors.lastname: Ohta
authors.forename: A
authors.initials: A
authors.lastname: Nashimoto
authors.forename: I
authors.initials: I
authors.lastname: Honda
authors.forename: H
authors.initials: H
authors.lastname: Yamagishi
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamura
mesh_terms: D016009:Chi-Square Distribution; D006801:Humans; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery