Efferent Vascular Invasion in the Axillary Nodes in Breast Carcinoma: A Potent Prognostic Factor

Abstract

Tumour cells in the efferent vessels of the axillary nodes in breast cancer (EV status) have been associated with poor prognosis since 1979. A prospective study (1980-1989) of all the nodes from 1037 consecutive female patients with unilateral breast cancer whose treatment included axillary node dissection yielded 471 node-positive cases. Tumour cells were found in the efferent nodal vessels of 210 patients, while 252 were negative. In the remaining 9 patients efferent nodal vessels could not be identified. At follow-up, 62% of the node-positive patients had died of breast carcinoma, in contrast to 32% of node-negative patients. The prognosis in cases with 1-3 versus 4+ tumour-bearing nodes was highly significant, 36% and 64%, respectively having died of breast carcinoma,. Prognosis was not dependent on the number of EV+ nodes in those cases showing efferent vascular invasion, one positive node was enough. Differentiation between these nodal growth forms thus provides a strong prognostic indicator, available to all with access to routine surgical pathology. We confirmed the significance of both variables using Cox's regression analysis and showed that the number of positive nodes adds significant prognostic information to that of EV status, which is the stronger of the two prognostic indicators. EV+ patients with more than three positive nodes have more than a three times higher risk of dying than EV- patients with three or fewer positive nodes.