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

Background: 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. Methods: 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. Results: 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. Conclusion: Nomograms incorporating routine clinicopathologic parameters can predict axillary pCR in node-positive patients receiving NAC and may help to inform treatment decisions.