Aims and background: The carbohydrate chains of malignant cells appear to be related to oncofetal differentiation. The serum levels of CA19-9 have been reported to be evaluated in some patients with lung carcinomas, however, the distribution of carbohydrate antigens were not precisely described. We have investigated in this study the distribution of DU-PAN-2 and CA19-9 antigens in lung tumors.
Methods: Ninety five specimens of lung tumors were selected from surgical specimens. The expression of DU-PAN-2 and CA19-9 were studied by immunohystochemical techniques. The relationship between the expression of these antigens and the classification or the differentiation degree of the tumors were examined.
Results: DU-PAN-2 or CA19-9 antigens were detected in 41 (54%) and 45 (59%) cases of the 76 malignant epithelial tumors investigated. These antigens were detected in all types of malignant epithelial tumors, including squamous cell carcinomas, where they were mainly localized to the entire cell surface of malignant cells. In adenocarcinomas, large cell carcinomas and small cell carcinomas, however, these antigens were commonly detected both on the cell membrane and in the cytoplasm. There was positive correlation between the degree of differentiation and DU-PAN-2, but not CA19-9 expression. Among the non-epithelial tumors investigated, those antigens were detected in pulmonary blastomas but not in mesotheliomas.
Conclusions: Immunohistochemical studies for DU-PAN-2 and CA19-9 are useful for defining characteristics of the lung tumors. DU-PAN-2 could be a marker for differentiating between malignant epithelial tumors and mesotheliomas.