Background: The clinical relevance of the degree of peritumoral vascular invasion (PVI) in patients with no or limited involvement of the axillary nodes is unknown.
Materials and methods: 2606 consecutive patients with pT1-3, pN0 (1586)-1a (1020) and M0, operated and counseled for medical therapy from 1/2000 to 12/2002, were prospectively classified according to the degree of PVI: absent (2017, 77.4%), focal (368, 14.1%), moderate (51, 2.0%) and extensive (170, 6.5%).
Results: Patients with extensive PVI were more likely to be younger, to have larger tumors, high tumor grade, axillary-positive nodes, high Ki-67 expression and HER2/neu over-expression compared with patients having less PVI (P for trend, <0.0001). In patients with node-negative disease a statistically significant difference in disease-free survival (DFS), risk of distant metastases and overall survival (OS) was observed at the multivariate analysis for extensive PVI versus no PVI (hazard ratios: 2.11, 95% CI, 1.02 to 4.34, P = 0.04 for DFS; 4.51, 95% CI, 1.96 to 10.4, P< 0.001 for distant metastases; 3.55, 95% CI, 1.24 to 10.1, P = 0.02 for OS).
Conclusions: The extent of vascular invasion should be considered in the therapeutic algorithm in order to properly select targeted adjuvant treatment.