Greater negative lymph node count predicts favorable survival of patients with breast cancer in the setting of neoadjuvant chemotherapy and mastectomy.

Adequate lymph node evaluation is recommended in patients with malignant tumors. However, the role of negative lymph nodes (NLNs) remains unclear in breast cancer (BC), especially in patients who have received neoadjuvant chemotherapy and mastectomy. A total of 435 patients were included in the analysis. On multivariate analysis, NLN count was an independent predictor of 5 year disease-free survival and 5 year overall survival. Patients with NLN count <10 showed significantly worse 5 year disease-free survival than those with NLN count ≥10 (34.8 and 78.2%; p = 0.000); the corresponding 5 year overall survival rates were also significantly different (52.0 and 82.7%; p = 0.000). This is the first study that confirms the relationship between NLN count and prognosis of patients in the setting of neoadjuvant chemotherapy and mastectomy. More NLNs imply better prognosis.