Lymphovascular invasion in breast cancer: improved methods of detection and clinical significance

Background

The presence of vascular invasion (VI), encompassing both lymphovascular invasion (LVI) and blood vascular invasion (BVI), in breast cancer has been found to be a poor prognostic factor. It is not clear, however, which type plays the major role in metastasis.

Methods

To distinguish between LVI and BVI, sections from 177 consecutive paraffin-embedded specimens of primary breast cancers, with known long-term follow-up, were immunohistochemically stained with two blood vascular markers (CD34 and CD31) and with a lymphatic marker (podoplanin/D2-40). BVI and LVI were identified and the results correlated with clinicopathological criteria and patient survival.

Results

VI was detected in 56/177 specimens (32%); 54 (96%) were LVI and two (4%) were BVI. The presence of LVI was significantly associated with the presence of LN metastasis, development of distant metastasis, regional recurrence, and a worse disease-free interval and overall survival. In multivariate analysis, LVI retained a significant association with decreased disease-free interval and overall survival. When assessment of LVI using H&E was compared using the lymphatic marker, VI was missed in 30/177 (16.9%) and was falsely positive in 12/177 (6.8%) using H&E.

Conclusion

VI in breast cancer is predominantly of lymph vessels and is a powerful independent prognostic factor. The use of immunohistochemical staining with podoplanin/D2-40 increases the accuracy of identification.