THE LECTIN-BINDING SITES FOR PEANUT AGGLUTININ IN INVASIVE BREAST DUCTAL CARCINOMAS AND THEIR ROLE AS A PROGNOSTIC FACTOR

The present study was designed to analyze the expression of lectin-bin ding sites for peanut agglutinin (PNA) in paraffin sections of primary invasive ductal carcinoma not otherwise specified and to consider PNA lectin histochemistry as a further aid in the prognostic evaluation o f breast cancer. The expression of lectin-binding sites was studied us ing the avidin-biotin complex/immunoperoxidase technique, and analyzed in relation to the different clinical, pathological, and biological p arameters of the primary disease, i.e. the presence or absence of noda l metastases, pre- or post-menopausal age, size of the tumor, mitotic activity index, morphometric prognostic index, DNA content, S-phase fr action, and steroid receptor status. The results show significant diff erences in PNA binding patterns among malignant epithelial breast cell s. There was no expression of PNA-binding sites in 14 out of 157 tumor s, while 64 showed mostly apical (membrane) staining and 124 non-apica l (membrane and/or cytoplasmic) staining. Apical staining was mostly o bserved in patients without lymph node metastasis, with positive stero id receptor status, and those who were postmenopausal diagnosis; non-a pical staining was mostly observed in lymph-node-positive premenopausa l patients negative for steroid receptors and with aneuploid tumor cel ls. Our results indicate that, in malignant breast cells, there is an alteration of cell-surface glycoconjugates, shown by hetero-geneity wi thin a histopathologically defined group, which is related to differen t properties of tumor cells. The apical PNA binding pattern indicates a better differentiation of tumor cells while non-apical PNA binding s uggests a higher metastatic potential. Specific PNA lectin binding pat terns should be considered as a further reliable prognostic factor in breast cancer.