The clinical meaning of mucin phenotype and Epstein-Barr virus infection in gastric cancer.
OBJECTIVE
Differentiated type adenocarcinomas producing gastric type mucin are receiving much attention because of their degree of clinical malignancy. Most Epstein-Barr virus (EBV)-associated gastric cancers are undifferentiated type, and correlate with gastric type mucin. We analyzed the clinical meaning of mucin phenotypes and the detection of EBV in gastric cancers.


METHODS
The objects of study were 120 consecutive gastric cancer lesions, resected endoscopically (EMR group, n=54) or surgically (surgery group, n=66). The mucin phenotypes were determined using immunostaining for human gastric mucin (HGM), MUC2, and CD10. Changes in histological type within the lesions were examined. The presence of EBV was determined using in situ hybridization for EBV-encoded small RNA 1 (EBER-1).


RESULTS
The incomplete intestinal phenotype accounted for 83% of the EMR group, and the gastric phenotype for only 13%. None of the EMR group lesions had changes in the degree of differentiation, and there was no EBER-1-positive lesion. In the surgery group, the gastric phenotype accounted for 29%, significantly more than in the EMR group (p=0.0363). The incomplete intestinal phenotype accounted for 64% of surgically resected lesions. Changes in the degree of differentiation were significantly more common in the surgery group (16/66) than in the EMR group (0/54) (p=0.0001), tending to be more common in the gastric phenotype lesions. There were 3 EBER-1-positive lesions in the surgery group, accounting for 5%, and all were HGM positive.


CONCLUSIONS
There appears to be little need to determine the mucin phenotype or EBV status of endoscopically resected lesions. In cases of gastric cancer where surgical resection is indicated, however, where the preoperative findings indicate a depth of invasion to SM or greater, and/or an undifferentiated lesion, then mucin phenotyping of biopsy specimens may be useful in predicting the predominant histological type of the tumor.
Nakamura
Youhei
Y
Department of Gastroenterology and Hepatology, Yamaguchi University School of Medicine, Ube, Japan.
Yanai
Hideo
H
Kitoh
Tomoko
T
Matsubara
Yoshitaka
Y
Hirano
Atsuyoshi
A
Okamoto
Takeshi
T
Yoshida
Tomoharu
T
Nishikawa
Jun
J
Okita
Kiwamu
K
D000368:Aged; D002454:Cell Differentiation; D020031:Epstein-Barr Virus Infections / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000235:genetics*; D010641:Phenotype; D012367:RNA, Viral / Q000378:metabolism; D013274:Stomach Neoplasms / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000821:virology
C099537:Epstein-Barr virus encoded RNA 1; D009077:Mucins; D012367:RNA, Viral