Clinicopathological significance of sialyl Lex expression in human gallbladder carcinoma

Sialyl Lex antigen, a member of a family of high molecular weight glycoproteins, is a ligand for E-selectin and may play an important role in tumor metastasis. However, expression patterns of sialyl Lex have not yet been established in human gallbladder carcinomas. In this study, we analyzed the clinicopathological significance of sialyl Lex expression and patients' prognosis in cases of human gallbladder adenocarcinoma. Sialyl Lex immunoreactivity was detected not only in cancer cells (cytoplasmic type; 51.9%, 28/54) but also in cancer stroma (stromal type; 38.9%, 21/54). Stromal sialyl Lex expression was detected in 50.0% (20/40) and 7.1% (1/14) of T2-4 and T1 cancers, respectively (p<0.05). Stromal sialyl Lex-positive gallbladder cancers frequently showed lymphatic invasion, venous invasion and lymph node metastasis (54.3, 50.0 and 60.0%, respectively) (p<0.05), and the expression was associated with a poor outcome. Sialyl Lex expression plays important roles in the vascular invasion and metastasis of human gallbladder adenocarcinoma.