The expression of Lewis
x and sialyl-Lewis
x antigens was investigated immunohistochemically in 24 patients with intrahepatic cholangiocarcinoma. Seventeen cholangiocarcinomas of the hepatic hilum (hilar tumors) and 7 peripheral cholangiocellular carcinomas (peripheral tumors) were studied, as well as 9 normal livers obtained at autopsy.
Staining of cancer cells for Lewis
x and sialyl-Lewis
x antigens was classified into 4 categories: negative [type N], membranous or cytoplasmic with polarity [type P(+)], membranous or cytoplasmic without polarity [type P(-)], and stromal [type S]. The 24 cancers were also divided into HLA-DR-positive and -negative lesions. In the 9 normal livers, Lewis
x was expressed by the peribiliary glands in 6 cases, but was not expressed by the bile duct epithelium in any case. Type N staining for Lewis
x was prevalent in hilar intrahepatic cholangiocarcinoma, while HLA-DR-negative tumors were more often type N or P(+) than HLA-DR-positive tumors.
Among the patients with hilar tumors, those with type P(-) or S staining had a better 5-year survival rate than those with type N or P(+) staining, although the difference was not statistically significant. In contrast, there was no difference in sialyl-Lewis
x expression between the peribiliary glands and the bile duct epithelium. No trend in the distribution of sialyl-Lewis
x staining was found, and patients with type P(-) and S hilar tumors had a similar 5-year survival rate to those with type N and P(+) staining.
These results suggest that the Lewis
x staining pattern of tumor cells may contribute to determination of the origin of intrahepatic cholangiocarcinoma.
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