Factors predicting the non-sentinel lymph node involvement in breast cancer patients with sentinel lymph node metastases

Abstract

Objective: In a significant proportion of patients, the sentinel lymph node (SLN) is the only involved axillary node. The goal of the present study was to identify predictive factors associated with a positive SLN and with a positive non-SLN in patients in whom axillary lymph node dissection (ALND) was performed. Methods: Data was reviewed for patients with T1-2 invasive breast cancer who underwent SLN biopsy with or without axillary dissection in a single institution between July 2000 and May 2010. The SLNs were examined by serial sectioning and H\&E staining, and by cytokeratin immunostaining in suspicious cases. Results: Of 332 patients with SLNB, 134 had SLN positivity, and 116 of them further underwent completion axillary dissection. Patients with T2 tumors (OR = 3.295\% CI, 1.74-5.58), or tumors with lymphovascular invasion (OR = 8.095\% CI, 4.44-14.27), or invasive ductal cancer (OR = 2.9295\% Cl, 1.1-8.0) were more likely to have a positive SLN. In patients with ALND, the non-SLN involvement rates were 10\%, 11.5\% and 50\% in patients with isolated tumor cells (ITC), micrometastasis and macrometastasis, respectively. Finding of ITC or micrometastasis in SLNs (OR = 0.2895\% CI, 0.08-0.99) or presence of extracapsular invasion (ECI) in SLN (OR = 0.2495\% CI, 0.09-0.67) were the predictive factors of not having a non-SLN metastasis in logistic regression analysis. Conclusions: These findings suggest further axillary surgery can be best omitted in patients with micrometastasis while validation of nomograms including factors such as ECI are still needed to be studied in patients with macrometastasis. (c) 2012 Elsevier Ltd. All rights reserved.