Differences in prognosis of colorectal cancer patients based on the expression of sialyl Lewisa, sialyl Lewisx and sialyl Tn antigens in serum and tumor tissue.

PURPOSE To clarify the differences in prognosis of colorectal cancer patients based on the expression of sialyl Lewisaa sialyl Lewisx and sialyl Tn antigens in serum and tumor tissue. PATIENTS AND METHODS Preoperative serum levels (by radioimmunoassay) and tumor tissue expression (by immunohistochemistry) of these antigens were simultaneously determined in 52 patients. For each antigen, patients were classified into one of four groups: Group S-/T-, S-/T+, S+/T- and S+/T+. (S denotes serum, T denotes tumor tissue, and negative and positive represent expression). RESULTS For sialyl Lewisa antigen, the survival time of Group S+/T+ was significantly shorter than Group S-/T- or Group S-/T+ (p=0.027 or p=0.032, respectively). For sialyl Lewisx antigen, the survival time of Group S-/T+ was significantly shorter than Group S-/T- (p=0.048). CONCLUSION Increased expressions of sialyl Lewisa antigen in serum and sialyl Lewisx antigen in tumor tissue may be associated with poor prognosis in colorectal cancer patients.