Microvessel density and vessel invasion in lymph-node-negative breast cancer: effect on recurrence-free survival

Microvessel density (MVD) and blood and lymphatic vessel invasion (BLVI) were investigated with regard to their influence on the disease-free survival (DFS) in node-negative breast cancer patients. Paraffin embedded microsections of 230 patients with T1,2 N0 breast cancer were immunohistochemically stained for factor VIII-related antigen. Every cluster consisting of more than highlighted endothelial cells was considered a countable microvessel. MVD was counted in 4 fields of 0.25 mm2 each. All MVD values are given as value for the sum of 4 fields of 0.25 mm2 each, that is, I mm2. BLVI was considered positive, when at least one tumor cell could be identified in a stained lumen. Out of 230 patients, 49 experienced local or distant recurrence and had a mean MVD of 72.4/mm2, whereas 181 patients who lived without recurrent disease had a mean MVD of 45.3/mm2. BLVI was negative in 6.2% of the cases with and in 93.8% of the cases without recurrent disease. BLVI was positive in 59.4% of the cases without and 40.6% of the cases with recurrent disease. MVD and BLVI remained the only significant prognostic factors of DFS in the Cox-Model. Tumor size, histological grade, and hormonal-receptor status were not prognostically relevant in the Cox-model. 10-year-DFS was 93.3% in BLVI-negative/MVD < or = 40/mm2 patients, 88.1% when MVD was high or BLVI was positive and 48.9% in BLVI positive/MVD < or = 40/mm2 patients. Our present data indicate that MVD and BLVI identify a very-low risk group among node-negative breast cancer patients, who will not benefit from systemic adjuvant therapy. MVD and BLVI should be used as stratification criteria in clinical trails on node-negative breast cancer patients.