Increased Expression of Sialyl-Lewis A Correlates with Poor Survival in Upper Urinary Tract Urothelial Cancer Patients

Background: We have previously shown that both sialyl-Lewis A (sLe(a)) and sialyl-Lewis X (sLe(x)) antigens are involved in E-selectin-mediated adhesion of some urothelial cancer cells to the endothelium in vitro. The present study was undertaken to determine whether these antigens could serve as prognostic parameters.

Materials And Methods: We immunohistochemically examined the expression of sLe(a) and sLe(x) in 90 human upper urinary tract urothelial tumours.

Results: Fifty-eight (64%) tumours were found to express sLe(a), while sixty-one (68%) expressed sLe(x). The expression between sLe(a) and sLe(x) was correlated positively (p < 0.0001). Neither sLe(a) nor sLe(x) expression was correlated with any other pathological parameter. The cause-specific survival rate was significantly worse in sLe(a)-positive patients than in sLe(a)-negative patients (5-year survival rates 64% and 93%, respectively: p = 0.023), while the survival rates were not statistically different between sLe(x)-positive and sLe(x)-negative patients. By Cox's multivariate analysis, sLe(a) expression as well as lymph node involvement and venous invasion was an independent risk value to predict survival (p < 0.05). In 24 high-risk patients having lymph node metastasis or having both venous invasion and sLe(a) expression, the 5-year survival rate was 29%, while it was 93% in the other 66 patients (p < 0.0001).

Conclusion: These results indicate that increased expression of sLe(a) antigen as well as lymph node metastasis and venous invasion may be associated with shorter cause-specific survival in upper urinary tract urothelial cancer. The combination of these factors offers a better prediction of prognosis.