title: Heterogeneous prognoses of patients with tumors invaded within muscularis propria according to tumor depth in the layers of the muscularis propria.
abstract: BACKGROUND
  The muscularis propria of the stomach is histologically divided into three layers; namely, the innermost oblique, the inner circular, and the outer longitudinal layers. In patients with gastric cancer the depth of tumor invasion has been reported to correlate with lymph node metastasis and prognosis. However, it is unclear whether the depth of tumor invasion in the muscularis propria has an effect on lymph node metastasis and prognosis.
  
  
  METHODS
  Fifty-nine gastric cancer patients with muscularis propria invasion were analyzed retrospectively. These patients were divided into two groups, the inner group, with invasion up to the inner circular layer; and the outer group, with invasion beyond the inner circular layer. The relationships between tumor invasion and clinicopathological factors and survival were evaluated.
  
  
  RESULTS
  Of the 59 patients, 34 were classified as the inner group, and 25 were classified as the outer group. The inner group had a significantly lower probability of lymph node metastasis (P = 0.0053) and a significantly better overall cancer-specific survival (P = 0.017) than the outer group.
  
  
  CONCLUSIONS
  Gastric cancers with muscularis propria invasion had heterogeneous prognoses according to the tumor depth in the muscularis propria layers.
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Imamura
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Baba
authors.forename: Shinji
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Yukiharu
authors.initials: Y
authors.lastname: Hiyoshi
authors.forename: Youhei
authors.initials: Y
authors.lastname: Nagai
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Nakamura
authors.forename: Naoko
authors.initials: N
authors.lastname: Hayashi
authors.forename: Nobutomo
authors.initials: N
authors.lastname: Miyanari
authors.forename: Kenichi
authors.initials: K
authors.lastname: Iyama
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
mesh_terms: D000368:Aged; D017024:Chemotherapy, Adjuvant; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating; D011379:Prognosis; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology*