Correlation between morphology and blood group-related antigen expression in pancreatic tumors induced in Syrian hamsters.

Expression of blood group-related antigens (BGRAs) A, B, H, Le(b), Le(x) and Le(y) was examined immunohistochemically in neoplastic and hyperplastic lesions induced by N-nitrosobis(2-oxopropyl)amine in Syrian hamsters to determine a relationship between histological and biological patterns of the lesion and expression of BGRAs. With the exception of papillary ductal cell hyperplasia, A-antigen discriminated between the benign and malignant lesions far better than the other antigens, which showed heterogeneity in the expression of benign and malignant tumors. However, production of A-antigen decreased with the degree of tumor dedifferentiation and was absent in anaplastic regions of tumors. Marked differences were found in the expression of A- and B-antigen in tubular complexes, one of the earliest induced changes, in relation to the type of cells populating these lesions. Overall, B-antigen seemed to be associated more with benign cells than malignant cells. On the other hand, Le(x)-antigen was expressed primarily in the invasive portion of some cancers and seemed to reflect active proliferative processes.