Luminal membrane expression of mesothelin is a prominent poor prognostic factor for gastric cancer.
BACKGROUND
Mesothelin is expressed in various types of malignant tumour, and we recently reported that expression of mesothelin was related to an unfavourable patient outcome in pancreatic ductal adenocarcinoma. In this study, we examined the clinicopathological significance of the mesothelin expression in gastric cancer, especially in terms of its association with the staining pattern.


METHODS
Tissue specimens from 110 gastric cancer patients were immunohistochemically examined. The staining proportion and intensity of mesothelin expression in tumour cells were analysed, and the localisation of mesothelin was classified into luminal membrane and/or cytoplasmic expression.


RESULTS
Mesothelin was positive in 49 cases, and the incidence of mesothelin expression was correlated with lymph-node metastasis. Furthermore, luminal membrane staining of mesothelin was identified in 16 cases, and the incidence of luminal membrane expression was also correlated with pT factor, pStage, lymphatic permeation, blood vessel permeation, recurrence, and poor patient outcome. Multivariate analysis showed that luminal membrane expression of mesothelin was an independent predictor of overall patient survival.


CONCLUSIONS
We described that the luminal membrane expression of mesothelin was a reliable prognostic factor in gastric cancer, suggesting the functional significance of membrane-localised mesothelin in the aggressive behaviour of gastric cancer cells.
Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
T
T
Einama
S
S
Homma
H
H
Kamachi
F
F
Kawamata
K
K
Takahashi
N
N
Takahashi
M
M
Taniguchi
T
T
Kamiyama
H
H
Furukawa
Y
Y
Matsuno
S
S
Tanaka
H
H
Nishihara
A
A
Taketomi
S
S
Todo
D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D058851:GPI-Linked Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000378:metabolism; D008207:Lymphatic Metastasis; D008297:Male; D000090204:Mesothelin; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D016019:Survival Analysis
D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; D000090204:Mesothelin