67-kDa laminin-receptor expression adds prognostic information to intra-tumoral microvessel density in node-negative breast cancer.

Experimental studies have shown that the 67-kDa laminin receptor (LRec) is an important molecule for the interaction of tumour cells with the extracellular matrix, and that it plays a role in the early steps of angiogenesis and in tumour invasion and metastasis. We performed a multi-parametric study in 171 node-negative breast cancers, followed for a median time of 6 years, to verify whether determination of the LRec provides prognostic information in addition to intra-tumoral microvessel density (IMD), a measure of tumour angiogenesis, and to other biological and conventional indicators. A positive association between LRec expression and high neovascularization was found, although it did not reach significance. LRec was not associated either with other biological markers (oestrogen receptor, progesterone receptor and p53 expression) or to the conventional prognostic features [menopausal status, tumour size, histological types, grading and peri-tumoral lymphatic vessel invasion (PLVI)]. In univariate analysis, IMD, p53, PgR, PLVI, grading and tumour size were significant prognostic indicators of relapse-free survival (RFS). LRec expression approached significance when considered as a dichotomous variable, after having selected the optimum cutoff of 10% to distinguish high-risk from low-risk patients. For overall survival (OS), tumour size and IMD (continuous variable) were significant prognostic factors, and p53 approached significance. In multivariate analysis for RFS, the joint variable LRec and vascularization was the strongest independent prognostic factor, followed by PgR, PLVI and p53. For OS, tumour size was the only independent prognostic indicator in this series.