VLA(2) INTEGRIN EXPRESSION IN BREAST CARCINOMAS EVALUATED BY AUTOMATED AND QUANTITATIVE IMMUNOHISTOCHEMISTRY

VLA(2) is thought to be involved in the metastatic process in malignan t tumours, in particular in carcinomatous cell adhesion to vessel base ment membrane. VLA(2) expression was immunohistochemically investigate d in 204 breast carcinomas. Frozen tissue sections were probed with mo noclonal anti-VLA(2) using automated (Ventana ES 320 System) and quant itative (SAMBA 2005 image processor) immunoperoxidase. A positive anti -VLA(2) immunoreaction was observed in 48 rumours (23.5%), within epit helial carcinomatous cells. The VLA(2)-positive surface in rumours var ied from 3% to 20% (mean 8.75, S.D. 7.17) and was correlated with hist oprognostic indicators and tumour expression of various antigens detec ted using the same method as that for VLA(2). The results show that VL A(2) immunoexpression was independent of the tumour size, grade, type and aneuploidy, and of the nodal status. VLA(2) significantly correlat ed with ELAM, VCAM, VLA(2) and P-glycoprotein (P-gp) (P < 0.01) and in versely correlated with cathepsin D (P < 0.001), but was independent o f Ki67/MIB1, p53, bcl-2, c-erbB-2, E cadherin, CD44v, CD31, cestrogen and progesterone receptors' (ER, PR) antigenic sites and pS2, The exac t role, if any, of VLA(2) in tumour cell dissemination remains to be e lucidated and the clinical relevance of VLA(2) immunodetection in brea st carcinomas requires further investigation of the correlation betwee n VLA(2) immunocytochemical expression and patients' outcome and respo nse to chemotherapy.