[Blood group antigen expression in papillary carcinoma of the thyroid gland. An immunohistochemical and clinical study of expression of Lewis, ABO and related antigens].

Nine monoclonal antibodies, lectin from Ulex europaeus and neuraminidase enzyme were employed to demonstrate the occurrence of type 1 and type 2 blood group antigens in 104 cases of papillary carcinoma of the thyroid. The reagents applied, recognize the following blood group related antigens: CA-50 (sialylated type 1 precursor), CA-19-9 (sialylated Le(a)), Le(a), Le(b), A, B, H, Le(x), sialylated Le(x), and Le(y). Immunohistochemical studies revealed that papillary carcinoma of the thyroid, in contrast to histologically normal thyroid tissue, is characterised by a progressive expression of blood group antigens. Most tumours (84%) reacted with C-50 antibody, whereas only a minority of the tissues demonstrated the CA-19-9 antigen (38%). Type 2 structures Le(x) (47%) and Le(y) (13%) were found less often than their corresponding type 1 isomers Le(a) (71%) and Le(b) (62%). Desialylation with neuraminidase increased the Le(a) and Le(x) staining intensity in 27 and 44 case, respectively. Of the A, B, H antigens the A determinants encountered most frequently (24%). Comparative examinations of sequential sections of the same tumour revealed coexpression of type 1 antigens in the same areas. In carcinomas showing type 1 and type 2 antigen reactivity, a complementary distribution of the structures in different tumour areas was often demonstrated. Some tumours presented combined type 1 and type 2 antigen expression in the same cells, however, in distinct areas within the cell. A follow-up examination was carried out in 68 of the 104 cases. The observation time ranged from 12 to 217 months. Thirteen patients suffered from recurrence, of which 7 died. While lymphatic metastases occurred in 39 tumours, distant metastases were detected in 6 patients. Most of the recurrences were found in patients with tumour classification pT4 (n = 19), whereas none of the pT1 carcinomas (n = 20) showed recurrence. The clinical results were compared to the blood group antigen expression results. There was no correlation between antigen expression and differentiation degree of the tumour. The pT4 tumours showed a significant higher expression of the CA-50, CA-19-9, Le(a) and Sialyl Le(x) structures. Carcinomas expressing the Le(y) antigen were associated with a significant higher level of metastasizing capacity. The Le(y), H type 1 and H type 2 antigens occurred more frequently in recurrent tumours (n = 14). In contrast, none of the patients whose carcinomas expressed the A-antigens (n = 14) suffered from a recurrence or hematogenous metastasis. Multiple stepwise regression analysis was carried out to check the importance of each staining and clinical factor. In this analysis, "distant metastasis' was the most important parameter, whereas the staining results were of minor statistical importance.