Cathepsin D in host stromal cells is associated with more highly vascular and aggressive invasive breast carcinoma

Aims: To determinate the relationship between tumoral angiogenesis and cath epsin D (CD) expression in tumour and host stromal cells of invasive breast carcinoma, and to examine its association with classical prognostic factor s such as lymph node status, histological grade, tumour size, mitotic rate, peritumoral lymphovascular invasion and oestrogen receptor (ER) status. Methods and results: Sections from 102 invasive breast carcinoma were cut f rom the archival formalin-fixed, paraffin-embedded tissue blocks and staine d using immunohistochemistry for the endothelial cell adhesion molecule (CD 31) and CD. Microvessel density was assessed by counting vessels in the thr ee most vascular areas at x400 field. The counts were expressed as the high est counts within any x400 field. The evaluation of immunostaining for CD w as performed separately in both the parenchymal and stromal cells. Microves sel density was correlated positively with histological grade and peritumor al lymphovascular invasion, and correlated inversely with ER status. Positi ve CD staining of tumour cells was more frequent in positive ER tumours and was not significantly associated with the other classical prognostic facto rs. However, moderate to strong staining of host cells was correlated with higher histological grade, higher mitotic index and lack of ER protein. The re was a statistically significant association between CD expression of hos t stromal cells and higher vessel count. Conclusions: CD in host stromal cells is associated with more aggressive tu mours and with a higher intratumoral microvessel density. Evaluation of CD in combination with angiogenic activity may be of some help in more accurat ely predicting the biological behaviour of breast carcinoma.