Expression of MAGE tumor-associated antigen in thyroid carcinomas.

The 12 members of the MAGE gene family encode tumor-specific antigens that are recognized by autologous cytotoxic T lymphocytes. The MAGE genes are expressed not only in melanoma but in other malignant tumors as well. There is, however, little information on their expression in thyroid carcinomas. We studied the expression of the MAGE-3 antigen in human thyroid carcinomas to explore the possibility of specific immunotherapy using MAGE peptides. Tumor tissue samples of thyroid carcinomas were obtained from 60 patients. Standard pathohistologic analysis followed by immunohistochemistry analysis of MAGE-3 expression was performed in all patients. The overall expression rate of MAGE-3 antigen in thyroid carcinomas was 65%. According to histological types of thyroid carcinomas, expression rate of MAGE-3 antigen was as follows: 0% in anaplastic, 20% in medullary, 29% in follicular, and 80% in papillary thyroid carcinomas (p < 0.01). On the other hand, significantly higher expression of MAGE-3 antigen was observed in classical subtypes of papillary thyroid carcinomas and in small papillary tumors sized to 1 cm in diameter. These findings demonstrated that MAGE-3 antigen expression seems to be particularly high in the small, typical papillary carcinomas, thus suggesting that MAGE-3 gene abnormality is an early step in thyroid cancer progression.