Background: Extracapsular invasion (ECI) of metastatic axillary lymph nodes has been associated with aggressive nodal disease but its prognostic role in breast cancer is unclear. The present study evaluated nodal ECI as a predictor of breast cancer recurrence.
Methods: We evaluated 154 women with histologically proven node-positive breast cancer who were diagnosed with invasive ductal carcinoma, and investigated the relationships between ECI and recurrences and other clinicopathological factors, particularly vascular invasion and the number of lymph node metastases.
Results: The presence of ECI at positive nodes was significantly associated with the number of positive nodes, and with disease recurrence and survival in univariate (but not multivariate) analysis. Interestingly, all ECI(+) patients with distant metastases in our series had peritumoral vascular invasion (PVI), which may have reflected systemic disease; ECI with PVI of the primary tumor strongly predicted recurrent disease and shorter survival.
Conclusion: ECI of axillary metastases combined with PVI indicates high tumor aggressiveness. Patients with ECI and PVI may be considered for stronger adjuvant therapies because of their high risk for distant recurrences.