Prognostic relevance of peritumoral vascular invasion in immunohistochemically defined subtypes of node-positive breast cancer

Prognostic factors to better identify subcategories of node-positive breast cancer patients candidate to adjuvant chemotherapy are needed. The prognostic significance of the extent of peritumoral vascular invasion (PVI) in patients with positive axillary nodes is a matter of controversy. No data are available on the role of PVI within immunohistochemically defined subtypes. 3,729 consecutive patients with primary invasive breast cancer and positive axillary nodes were operated and referred for interdisciplinary evaluation from April 1997 to December 2005. Patients were classified as Luminal A, Luminal B(HER2 negative), Luminal B(HER2 positive), Triple Negative and HER-2 positive. The distribution of PVI was as follows: absent 2,010 (54 %), moderate/focal 963 (142 + 821) (26 %), and extensive 756 (20 %). Patients with extensive PVI were more likely to be Luminal B(HER2 negative) (49.3 %), younger (35-50 years), to have larger tumors (≥pT2) with higher grade, a higher extent of node involvement (≥4 nodes) and higher proliferative index, compared with patients with absence or moderate/focal PVI (p < 0.0001). In the multivariate analysis, extensive PVI (vs. absent) was correlated with a significant higher risk of local recurrence (HR 1.42, 95 %CI, 1.03-1.95, p = 0.0301). The immunohistochemically defined Luminal A-like subtype had a significant better outcome in terms of DFS, OS and reduced incidence of distant metastases when compared with the other subtypes. The occurrence of extensive PVI correlates with an increased risk of local recurrence. Luminal A tumors, classified according to the most recent St. Gallen recommendations, had an excellent outcome irrespective to the occurrence of extensive PVI or lymph node metastases and might be a good candidate to personalized adjuvant treatments. © 2014 Springer Science+Business Media.