Comparison of the prognosis indication of VEGFR-1 and VEGFR-2 and Tie2 receptor expression in breast carcinoma

The degree of angiogenesis in breast cancer has previously been shown to be an indicator of prognosis, and tumor microvasculature is a candidate target for new antiangiogenic therapies. The aim of this study was to investigate the prognostic value of vascular endothelial growth factor (VEGF) receptors, VEGFR-1 (Flt-1) and VEGFR-2 (KDR/Flk-1), and Tie2/tek receptor tyrosine kinase in breast carcinoma. VEGF receptors and Tie2 expression was investigated using immunohistochemical assays with monoclonal antibodies on frozen sections in a series of 918 and 909 patients respectively. VEGFR-1 and VEGFR-2 and Tie2 were correlated with long-term (median, 11.3 years) patients' outcome. Univariate (Kaplan-Meier) analysis showed that VEGFR-1 positive tumor surface (cutoff = 5%) was significantly correlated with high metastasis risk (p=0.03) and relapse (p<0.01) in all patients, and in those with node negative tumors (p<0.001 and p<0.01 respectively), but not with overall survival. In contrast Tie2 positive tumor surface (cutoff = 7%) was significantly correlated with poor overall survival (p=0.025) and also with high metastasis risk particulary among node negative patients (p<0.01). Moreover, Tie2 immunoexpression was significantly predictive of relapse (p=0.003) in the node negative subgroup (p=0.02). In multivariate analysis (Cox model), VEGFR-1 and Tie2 immunoexpressions were identified as independent prognostic indicators. In contrast, univariate analysis showed that VEGFR-2 positive tumor surface (cutoff = 10%) was not correlated with survival or with metastasis and relapse risk. Our results suggest that VEGFR-1 and Tie2 immunohistochemical expression permits the identification of patients with poor outcome, and particulary node negative ones with a high risk for metastasis and relapse. VEGFR-1 and Tie2 immunodetection may also be considered as potential tools for selecting patients who could benefit in the future from specific antiangiogenic therapy interfering with VEGFR-1 and Tie2 activation pathways.