Tumor infiltrating neutrophil might play a major role in predicting the clinical outcome of breast cancer patients treated with neoadjuvant chemotherapy.

In this study, higher TIN after NACT was confirmed to be associated with breast cancer patients' worse chemotherapy efficiency and shorter disease-free survival (DFS). Furthermore, the TIN's dynamic change before and after NACT was firstly proved to be a more accurate predictive marker compared with TIN after NACT.