Lymph node metastasis-related carbohydrate epitopes of gastric cancer with submucosal invasion

This study was conducted to examine the lymph node metastasis-related carbohydrate epitopes of cancer cells in primary lesions of gastric cancer with submucosal invasion (sm gastric cancer). A total of 118 formalin-fixed and paraffin-embedded surgical specimens were studied. Carbohydrate epitopes were detected histochemically using 17 kinds of biotin-labeled lectins and three kinds of monoclonal antibodies (mAbs) against Thomsen-Friedenreich antigen (HB-T1), Tn (HB-Tn1), and sialyl Tn antigens (HB-STn1). The node-positive group showed significantly lower reactivities with Ricinus communis I (RCA-I), Lotus tetragonolobus (Lotus), Triticum vulgaris (WGA), and Concanavalia ensiformis (ConA), and higher reactivities with HB-STn1. When sm gastric cancer was classified into differentiated and undifferentiated types, lower reactivities with RCA-I and ConA were observed in the differentiated type cancers, whereas lower reactivities with Lotus, WGA, and higher reactivity with HB-STn1 were observed in the undifferentiated type cancers. Nodal status was able to be predicted with high precision by a combination of these carbohydrates and histological subtypes. Since neuraminidase treatment rarely changed the reactivity of cancer cells with these lectins, we conclude that the loss of certain kinds of carbohydrates that are restricted by histological subtypes is related to lymph node metastasis in sm gastric cancer.