Dimeric sialyl-Le(x) expression in gastric carcinoma correlates with venous invasion and poor outcome.

Background & Aims: High expression of sialyl-Le(x) in tumors of different organs correlates with hematogenous metastasis and adverse outcome. Dimeric sialyl-Le(x) expression in gastric carcinoma was evaluated, and its prognostic significance within this setting was determined.

Methods: Dimeric sialyl-Le(x) immunohistochemical expression in 97 gastric carcinomas was analyzed using the FH6 monoclonal antibody. Scoring was based on the percentage of immunoreactive cells: negative, low expression (< or = 25%), and high expression (> 25%).

Results: Immunoreactivity was observed in 45 cases (46.4%), encompassing 27 and 18 cases with low and high expression, respectively. Significant relationships were found between dimeric sialyl-Le(x) expression and venous invasion (P = 0.0025) and histological classification (P = 0.05). No correlation was observed with other clinicopathologic features. Patients with tumors showing high expression of dimeric sialyl-Le(x) had a significantly shorter survival time than those with low or no expression (P = 0.03). By multivariate analysis, pathological TNM (pTNM) staging and venous invasion emerged as independent prognostic factors in the whole series. Within the group of patients with tumors in pTNM stages II and III, dimeric sialyl-Le(x) was the only independent prognostic factor.

Conclusions: High expression of dimeric sialyl-Le(x) correlates with venous invasion and poor outcome in gastric carcinoma.