Extracapsular Invasion of Sentinel Lymph Nodes Is Not Associated With Disease Recurrence in Breast Cancer

The purpose of this study was to evaluate the presence of extracapsular invasion (ECI) in positive sentinel lymph nodes (SLNs) as a predictor of disease recurrence in breast cancer. SLN biopsy was performed on 318 breasts of 316 breast cancer patients, of which 50 (15.7%) had positive SLNs. Six (12.0%) of these 50 cases had disease recurrence. The clinicopathologic features of these cases were reviewed. The ECI at SLNs was not significantly associated with disease recurrence. The recurrence-free interval by Kaplan-Meier curves did not differ significantly among patients with and without ECI at SLNs. On the other hand, metastasis at non-SLNs was observed in 12 cases (24.0%) among the 50 cases with positive SLNs, and in the non-SLN metastasis group there were 7 patients with ECI at non-SLNs. Three of 7 cases with ECI at non-SLNs had disease recurrence and none of those 5 without ECI at non-SLNs had disease recurrence. Our current study suggests that the presence of ECI at metastatic SLNs is not associated with recurrent disease in breast cancer. Our results also imply that patients with ECI at positive non-SLNs have a high risk of disease recurrence.