Dong J, Sun Q, Pan Y, et al. - Among patients with breast cancer undergoing neoadjuvant chemotherapy (NAC), this investigation was carried out to assess the correlation between systemic inflammation response index (SIRI) and pathological complete response (pCR). Convenient and accurate predictive indicators for pCR were also explored in this population. A retrospective analysis of 241 patients with breast cancer who had NAC between June 2015 and June 2020, was conducted. pCR was achieved by 48 (19.92%) of 241 patients. In multivariate analyses, the following were revealed as independent prognostic factors for pCR in breast cancer patients: clinical T and N staging, SIRI, and neutrophil-lymphocyte ratio. A nearly 5-fold higher probability of achieving pCR was observed in patients with SIRI < 0.72 vs those with SIRI ≥0.72. These findings demonstrate that pCR in breast cancer patients receiving NAC can be predicted by pretreatment SIRI, and the index can help clinicians in formulating personalized therapeutic approaches.