Heterogeneous prognoses of patients with tumors invaded within muscularis propria according to tumor depth in the layers of the muscularis propria.
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.
Imamura
Yu
Y
Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
Baba
Yoshifumi
Y
Ishikawa
Shinji
S
Hiyoshi
Yukiharu
Y
Nagai
Youhei
Y
Nakamura
Tadahiko
T
Hayashi
Naoko
N
Miyanari
Nobutomo
N
Iyama
Kenichi
K
Baba
Hideo
H
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*