Predictors of Completion Axillary Lymph Node Dissection in Patients With Immunohistochemical Metastases to the Sentinel Lymph Node in Breast Cancer

Axillary lymph node dissection (ALND) in patients with immunohistochemistry (IHC)-determined metastases to the sentinel lymph node (SLN) is controversial. The goal of this study was to examine factors associated with ALND in IHC-only patients. Retrospective review of an institutional SLN database from July 1997 to July 2003 was performed. We compared sociodemographic, pathologic, and therapeutic variables between IHC-only patients who had SLN biopsy alone and those that had ALND. Our study group consisted of 171 patients with IHC-only metastases to the SLN. Young age, estrogen receptor negative status, high Memorial Sloan-Kettering Cancer Center nomogram score, and chemotherapy were associated with ALND. Among patients who had ALND (n = 95), 18% had a positive non-SLN. Rates of systemic therapy were similar between those with and without positive non-SLNs at ALND. No axillary recurrences were observed in this series with a median follow-up of 6.4 years. The percentage of patients who were recurrence-free after 5 years was 97% (95% confidence interval, 92.1-98.6). On the basis of our findings and the lack of prospective randomized data, the practice of selectively limiting ALND to IHC-only patients thought to be at high risk and to patients for whom the identification of additional positive nodes may change systemic therapy recommendations seems to be a safe and reasonable approach.