Prognostic significance of peritumoral lymphatic and blood vessel invasion in node-negative carcinoma of the breast.

The prognostic significance of intramammary lymphatic and blood vessel invasion was evaluated in a retrospective series of 221 patients with node-negative carcinoma of the breast treated with modified radical mastectomy. To facilitate identification of lymphatic and blood vessel invasion, the tumors were studied with an immunohistochemical technique using antibodies to endothelial markers. Peritumoral lymphatic and blood vessel invasion (PLBI) (encompassing both lymphatic and blood vessel invasion) was an adverse prognostic indicator independent of menopausal status, tumor size, and other histologic variables. Recurrence of disease and death resulting from carcinoma were significantly higher for patients with PLBI-present (+) tumors compared with patients with PLBI-absent (-) tumors (P less than .0001). The risk of recurrence for patients with PLBI+ tumors was 4.7 times that for their PLBI- counterparts. The presence of intratumoral lymphatic and blood vessel invasion (ILBI) is less important because few examples were found without concomitant PLBI. When PLBI was separated into lymphatic invasion and blood vessel invasion individually, the prognostic significance was retained in both groups. The immunohistochemical approach reduced both false-negative and false-positive observations and identified about 40% of PLBI that would have been missed by routine histologic examination alone. The presence of PLBI appears to be a potentially useful discriminant in predicting the outcome of patients with node-negative carcinoma of the breast.