EXPRESSION OF THE CD44 GLYCOPROTEIN (LYMPHOCYTE-HOMING RECEPTOR) IN UNTREATED HUMAN BREAST-CANCER AND ITS RELATIONSHIP TO PROGNOSTIC MARKERS

CD44 is a cell surface glycoprotein which has been suggested to be ass ociated with aggressive histological features in breast cancer (BC). I t has also been implicated in conferring metastatic potential to rat c at-cinema cells. The aim of this study was to deter-mine the potential value prognostic/metastatic marker in BC by means of immunohistochemi stry. The expression of the CD44 glycoprotein was investigated in tumo urs from 52 untreated female patients with BC, using the monoclonal an tibody A3D8. 10 samples of normal breast tissue were randomly obtained and also investigated with respect to CD44 expression. DNA ploidy, th e S-phase function (SPF) and oestrogen-(OR) and progesterone-receptor. (PgR) contents in the tumours were determined and together with the p rognostic markers of age, age tumour size, tumour grade and lymph none status, correlated with CD44 expression in BC. Also, the distribution of CD44 tumour cell expression was compared with expression of the pe rmeability drug resistance glycoprotein (P-gp) in this material. Expre ssion of CD44 on carcinoma cells was observed in 21/52 cases (40%). Ca pillary endothelial reactivity of the tumours occurred in 42 cases (80 %). Non-neoplastic epithelial breast tissue was positive in 2/10 (20%) samples and capillary vessels in 7/10 (70%). Carcinoma CD44 cell expr ession was not associated with age, tumour size, tumour grade, DNA plo idy, SPF, hormone-receptor contents or lymph node metastases. There wa s a statistical correlation between CD44 and P-gp expression in breast carcinoma cells which may suggest a connection between adhesion molec ules and drug resistance. These findings do not support an association between CD44 expression and adverse prognostic features or lymph node metastases in BC. Capillary CD44 staining was a common feature in BC. There appeared to be an upward regulation in CD44 expression in BC co mpared with the normal breast tissue.