Sialyl Le(a)
antigen (CA19-9), a member of a family of high molecular weight
glycoproteins, was originally described as a gastrointestinal- and pancreatic-specific
tumor marker. Recent studies have demonstrated that sialyl Lea is a
ligand for
E-selectin and may play an important role in
tumor metastasis. However, expression patterns of
sialyl Le(a) have not yet been established in human gallbladder
carcinomas. In this study, we examined
sialyl Le(a) expression in human gallbladder
adenocarcinoma and its clinicopathological significance.
Sialyl Le(a) immunoreactivity was detected not only in
cancer cells (cytoplasmic type; 68.5%, 37/54) but also in
cancer stroma (stromal type; 46.3%, 24/54). According to TNM classification, stromal
sialyl Le(a) expression was detected in 60. 0% (24/40) and 7.1% (1/14) of the T2-4 and T1
cancers, respectively (p<0.01). Stromal
sialyl Le(a)-positive
gallbladder cancers frequently showed lymphatic invasion, venous invasion and
lymph node metastasis (62.9%, 62.5% and 70.0%, respectively) (p<0.01). These observations suggested that
sialyl Le(a) expression plays important roles in vascular invasion and
metastasis of human gallbladder
adenocarcinomas.