Preoperative serum levels of sialyl Lewis(a), sialyl Lewis(x), and sialyl Tn antigens as prognostic markers after curative resection for colorectal cancer.

In this study, we examined the preoperative serum levels of sialyl Lewisa, sialyl LewisX, sialyl Tn, and carcinoembryonic antigen in 243 colorectal cancer patients in order to clarify the role of these antigens as prognostic factors after curative surgery. The patients were divided into two groups: low and high antigen groups (lower and higher than a selected diagnostic-based cut-off value). Patients with high serum levels of sialyl Lewisa and carcinoembryonic antigen had shorter disease-free intervals than those with low serum levels of the respective antigen, although sialyl Lewisx and sialyl Tn showed no significant differences. Multivariate analysis revealed that three independent prognostic variables, including depth of tumor invasion, lymph node metastasis, and serum sialyl Lewisa level, did prove to have value in predicting disease-free interval. In conclusion, among the four antigens examined in this study, the preoperative serum level of sialyl Lewisa is the only independent prognostic variable for recurrence after curative resection of colorectal cancer.