Clinical correlations of alpha 2,6-sialyltransferase expression in colorectal cancer patients

We have previously demonstrated a link between alpha 2,6-Sialyltransferase (alpha 2,6-ST; E.C. 2.4.99.1) expression and differentiation of colon tumor s. So far, information is not available relative to the expression of alpha 2,6-ST in tumors and the survival of patients with colorectal cancer. We h ave examined the expression of alpha 2,6-ST in a variety of colorectal aden ocarcinomas (n = 46) at different stages of differentiation (G(1) to G(3)) by immunoperoxidase assay using monoclonal antibody (MAb) 6B9, Clinical out come of the patients in a 5-year follow-up study has been correlated with t he expression of alpha 2,6-ST in tumors surgically removed from the same pa tients. No significant difference in the alpha 2,6-ST expression was noted when age, sex, and tumor locations (colon, rectum) were included as paramet ers. However, 52% of the moderate (G(2)) and well-differentiated (G(1)) ade nocarcinomas showed stronger alpha 2,6-ST expression compared with poorly d ifferentiated (G(3)) adenocarcinomas, Notably, absence to moderate levels o f tumor alpha 2,6-ST expression was correlated with 100% survival in patien ts with stage I and II tumors compared with 64% survival in patients with s trong tumor alpha 2,6-ST expression (p < 0.01), These studies suggest a neg ative correlation between the expression of alpha 2,6-ST in tumors and a go od clinical outcome in colorectal cancer patients.