Nomograms for Predicting Axillary Response to Neoadjuvant Chemotherapy in Clinically Node-Positive Patients with Breast Cancer

Many patients with clinically node-positive breast cancer receive neoadjuvant chemotherapy (NAC). Recent trials suggest the potential for limiting axillary surgery in patients who convert to pathologically node-negative disease. The authors developed a nomogram to predict axillary response to NAC in patients with cN1 disease that can assist clinicians in treatment planning. Patients with cT1-4N1M0 breast cancer who received NAC and underwent axillary lymph node dissection from 2001 through 2013 were identified (n = 584). Uni- and multivariate logistic regression analyses were performed to determine factors predictive of nodal conversion. A nomogram to predict the likelihood of nodal pathologic complete response (pCR) was constructed based on clinicopathologic variables and validated using an external dataset. Axillary pCR was achieved for 217 patients (37 %). Patients presenting with high nuclear grade [grade 3 vs. 1, odds ratio (OR) 13.4], human epidermal growth factor receptor 2-positive (OR 4.7), estrogen receptor (ER)-negative (OR 3.5), or progesterone receptor-negative (OR 4.3) tumors were more likely to achieve nodal pCR. These factors, together with clinically relevant factors including presence of multifocal/centric disease, clinical T stage, and extent of nodal disease seen on regional nodal ultrasound at diagnosis were used to create nomograms predicting nodal conversion. The discrimination of the nomogram using ER+ status (> 1 % staining) versus ER- status [area under the curve (AUC) 78 %] was improved slightly using the percentage of ER staining (AUC 78.7 %). Both nomograms were validated using an external cohort. Nomograms incorporating routine clinicopathologic parameters can predict axillary pCR in node-positive patients receiving NAC and may help to inform treatment decisions.