Prognostic value of extracapsular extension of axillary lymph node metastases in T1 to T3 breast cancer

Background: The importance of extracapsular extension (ECE) of axillary metastases as a risk factor for either local or distant recurrence and poorer survival in breast cancer has been suggested, but its prognostic value has not been uniformly confirmed. Methods: From a prospective database including 1142 breast cancer patients operated on at the Department of General Surgery and Surgical Oncology of the University of Siena, we selected 376 cases with pT1 to pT3 node-positive breast cancer. The prognostic significance of ECE of axillary metastases was evaluated with respect to disease-free survival, overall survival, and the patterns of disease recurrence. Such prognostic significance was then compared with that of other clinical and pathologic factors. Results: With a median follow-up of 103 months, factors with independent prognostic value for disease-free survival by multivariate analysis included absence of estrogen receptors (P <.0005), pN category (P <.01), presence of lymphovascular invasion (LVI; P <.005), and ECE (P <.0001). An independent negative prognostic effect on overall survival was observed for absence of estrogen and progesterone receptors (P <.05), pN category (P <.05), and presence of LVI (P <.005) and ECE (P <.0001). The presence of ECE was significantly related to an increased risk of regional (13.4% vs. 6.6%; P =.037) and distant (43% vs. 16.2%; P <.001) recurrences. Conclusions: ECE demonstrated a stronger statistical significance in predicting prognosis than the pN category and was also related to an increased risk of distant recurrences. We suggest that the decision on adjuvant therapy should consider the presence of ECE of axillary metastases and peritumoral LVI as indicators of high biological aggressiveness.