Expression of Sialyl-Tn antigens in normal squamous epithelium, dysplasia, and squamous cell carcinoma in the esophagus.

Two monoclonal antibodies, TKH2 and B72.3, directed toward the Sialyl-Tn antigen (SA 2, 6GalNAc alpha-O-Ser/Thr), were examined immunohistochemically to analyze the expression of these antigens in 20 areas of normal squamous epithelium, 12 lesions of dysplasia, and 86 cases of squamous cell carcinoma including 32 with superficial carcinoma in the esophagus. No expression of TKH2 or B72.3 was found in the normal squamous epithelium. Among the 12 lesions of dysplasia only one expressed TKH2. In carcinoma the expression of TKH2 and B72.3 was found in 40 (47%) and 21 (24%) of the 86 carcinomas, respectively; however, the number of positive malignant cells with TKH2 and B72.3 totaled less than half that in the tissue, and no relationship was found between either prognosis or lymph node metastasis and the expression of Sialyl-Tn antigen. These results indicate that Sialyl-Tn antigen appears in the process of malignant transformation or tumor progression in esophageal squamous cell carcinoma; however, the positive expression of Sialyl-Tn antigen was not directly connected to either prognosis or lymph node metastasis.