The ABO(H) and Y
antigen status of epithelial cells from 45
breast carcinomas, 14 benign breast lesions and 7 normal breasts have been assessed using an indirect immunoperoxidase histochemical assay and a series of
blood group specific
monoclonal antibodies. All 20 A, AB and B group tumours had lost the A and B
isoantigens, 13 of these tumours were however found to express H and Y
antigens. Of 25 group O tumours 17 expressed the expected H and Y
antigens. These findings were not dependent on the histological nature or the invasive characteristics of the tumour. Similar results were obtained when 28
metastases from
breast carcinomas were examined, the H and Y
antigens being identified in the tumour elements in 24 lymph nodes while we failed to identify either the A or B
antigens. The development of breast
malignancy appeared therefore to correlate best with the deletion of A and B glycosyl
transferases. Normal breast tissue consistently expressed the expected
blood group isoantigens. Areas of benign
breast disease showed a more varied pattern of
antigen expression. Seven of 14 lesions lacked ABH
antigens, the loss of
blood group structures could not however be correlated with any specific histological features and was not limited to the loss of A and B substances.