Nomogram Predicting Axillary Lymph Node Dissection Omission After Neoadjuvant Chemotherapy for Node-positive Breast Cancer

Background/Aim: To develop an accurate method to predict nodal pathological complete response (ypN0) in patients after neoadjuvant chemotherapy (NAC) for clinically node-positive breast cancer. Patients and Methods: We included 128 patients with clinically nodepositive primary breast cancer who underwent axillary lymph node dissection after NAC. Results: Breast primary tumor clinical complete response (ycT0) was observed in 29.7% and nodal clinical complete response (ycN0) in 44.5% of cases. When ycN0 was predicted as ypN0, the negative predictive value was 77.2%, and the false-negative rate was 19.7%. Estrogen receptor status, ycT0, and ycN0 were independent predictive factors for ypN0 after NAC in patients with clinically node-positive breast cancer. These factors were used to develop a nomogram for ypN0 prediction. The following points were added: 82 in case of estrogen receptor-negative, 56 in case of ycT0, and 100 in case of ycN0. Score summation was used to prognosticate the manifestation of ypN0. Our nomogram predicted ypN0 with a negative predictive value of 92.9% and falsenegative rate of 4.5%, demonstrating an approximate 15% improvement over ypN0 prediction using ycN0 alone. Conclusion: Estrogen receptor-negativity, ycT0, and ycN0 are independent predictive factors for ypN0 after NAC in clinically node-positive breast cancer. The nomogram may improve individualized axillary treatment.