Evaluation of sialyl Lewis(a), sialyl Lewis(x), and sialyl Tn antigens expression levels as predictors of recurrence after curative surgery in node-negative colorectal cancer patients.

This study aimed to determine whether sialyl Lewis(a) (Le(a)), sialyl Lewis(x )(Le(x)), or sialyl Tn antigen expression could identify a subset of node-negative colorectal cancer patients that are at high risk for recurrence after curative surgery. Tumor tissue samples from 90 patients with node-negative colorectal cancer, who had undergone surgical resection, were analyzed immunohistochemically for the expression of each antigen. Patients were classified as having low or high antigen expression depending on whether more or less than 40% of the field showed positive staining. The main outcome measure for each variable was disease-free interval. Sialyl Le(a), sialyl Le(x), and sialyl Tn antigens were expressed in 53 (58.9%), 41 (45.6%), and 34 (37.8%) carcinomas, respectively. The median follow-up was 83.5 months. Patients with high sialyl Le(x) expression had shorter disease-free intervals than those with low sialyl Le(x) expression (P = 0.0041); the expression of sialyl Le(a) or sialyl Tn antigens did not show a significant relationship with disease-free survival. Cox's regression analysis revealed that sialyl Le(x) expression was an independent predictor for disease-free survival, separate from T factor or tumor location. High sialyl Le(x) expression may be useful in identifying a subset of node-negative colorectal cancer patients who are at high risk for recurrence.