title: Lymph node metastasis risk according to the depth of invasion in early gastric cancers confined to the mucosal layer.
abstract: BACKGROUND
  Early gastric cancers (EGCs) within the mucosal layer of the gastric wall have a small risk of lymph node (LN) metastasis.
  
  
  METHODS
  We reviewed clinicopathology data for patients who underwent surgery for EGC between 2001 and 2013 at the National Cancer Center, Korea. Poisson regression analyses were performed to compare the risk of LN metastasis according to the depth of tumor invasion in patients with mucosal EGCs.
  
  
  RESULTS
  Among the 1776 EGC patients included, 580 (32.7 %) had tumors confined to the lamina propria (LP; LP group) and 1196 (67.3 %) had tumors invading the muscularis mucosae (MM; MM group). Seventy-one patients (4.0 %) had LN metastasis, and the MM group had a significantly higher rate of LN metastasis (59 patients, 4.9 %) than the LP group (12 patients, 2.1 %; P = 0.004). A multivariate analysis showed that tumors invading the MM (adjusted risk ratio 1.95; P = 0.045) were significantly associated with LN metastasis in addition to well-known risk factors, including tumor size greater than 3 cm, presence of ulceration, undifferentiated histologic type, and lymphovascular invasion. The incidence of LN metastasis was 1.87 % (95 % confidence interval 0.23-6.59 %) within tumors invading the MM that met the expanded criterion for endoscopic resection of differentiated histologic type of size 3 cm or smaller with ulceration. LN metastasis was not found in tumors meeting the absolute criteria for endoscopic resection.
  
  
  CONCLUSIONS
  EGCs invading the MM had a higher rate of lymph node metastasis than those confined to the LP. Further study is needed to evaluate whether different curative treatment criteria are needed for LP-confined and MM-invading EGCs.
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea.
authors: Young-Il
authors: YI
authors: Kim
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea.|Department of Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea.
authors: Jun Ho
authors: JH
authors: Lee
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea.
authors: Myeong-Cherl
authors: MC
authors: Kook
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea.
authors: Jong Yeul
authors: JY
authors: Lee
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea.
authors: Chan Gyoo
authors: CG
authors: Kim
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea.
authors: Keun Won
authors: KW
authors: Ryu
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea.
authors: Young-Woo
authors: YW
authors: Kim
authors: Center for Gastric Cancer, National Cancer Center, 323 Ilsan-ro Ilsandong-gu, Goyang, Gyeonggi, 410-769, Korea. cij1224@ncc.re.kr.
authors: Il Ju
authors: IJ
authors: Choi
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery; D000368:Aged; D018279:Carcinoma, Signet Ring Cell / Q000556:secondary* / Q000601:surgery; D004724:Endoscopy; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000473:pathology*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery
keywords: Early gastric cancer; Lamina propria; Lymph node metastasis; Muscularis mucosae; Risk