The systemic immune‐inflammation index (SII = N × P/L) based on neutrophil (N), platelet (P) and lymphocyte (L) counts is used to predict the survival of patients with malignant tumours and can fully reflect the balance between host inflammatory and immune status. This study is conducted to explore the potential prognostic significance of SII in patients with breast cancer undergoing neoadjuvant chemotherapy (NACT). A total of 262 patients with breast cancer received NACT were enrolled in this study. According to the receiver operating characteristic curve, the optimal cut‐off value of SII was divided into two groups: low SII group (<602 × 10 ⁹ /L) and high SII group (≥602 × 10 ⁹ /L). The associations between breast cancer and clinicopathological variables by SII were determined by chi‐squared test or Fisher's exact test. The Kaplan‐Meier plots and log‐rank test were used to determine clinical outcomes of disease‐free survival (DFS) and overall survival (OS). The prognostic value of SII was analysed by univariate and multivariate Cox proportional hazards regression models. The toxicity of NACT was accessed by National Cancer Institute Common Toxicity Criteria (NCICTC). According to univariate and multivariate Cox regression survival analyses, the results showed that the value of SII had prognostic significance for DFS and OS. The patients with low SII value had longer DFS and OS than those with high SII value (31.11 vs 40.76 months, HR: 1.075, 95% CI: 0.718‐1.610, P = .006; 44.47 vs 53.68 months, HR: 1.051, 95% CI: 0.707‐1.564, P = .005, respectively). The incidence of DFS and OS in breast cancer patients with low SII value was higher than that in those patients with high SII value in 3‐, 5‐ and 10‐year rates. The common toxicities after NACT were haematological and gastrointestinal reaction, and there were no differences by SII for the assessment of side effects of neoadjuvant chemotherapy. Meanwhile, the results also proved that breast cancer patients with low SII value and high Miller and Payne grade (MPG) survived longer than those breast cancer with high SII value and low MPG grade. In patients without lymph vessel invasion, these breast cancer patients with low SII value had better prognosis and lower recurrence rates than those with high SII value. Pre‐treatment SII with the advantage of reproducible, convenient and non‐invasive was a useful prognostic indicator for breast cancer patients undergoing neoadjuvant chemotherapy and is a promising biomarker for breast cancer on treatment strategy decisions.

Breast carcinoma is one of the most malignant tumors, severely influencing the physical and mental health of people. The latest epidemiological and clinical studies have found that breast tumor and inflammation are determinate relationships with each other. Inflammation is an essential component of the tumor microenvironment, and the change of inflammatory cells might influence tumor progression, such as neoplastic cell proliferation, migration, invasion, the collapse of antitumor immunity, metastasis and so forth. Peripheral blood tests at the time of diagnosis and treatment can reflect inflammatory conditions within the neoplasm. Evaluation of peripheral blood parameters including white blood cell, neutrophil, lymphocyte, monocyte, platelet counts, as well as neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (d-NLR) (neutrophil count divided by the result of white blood cell count minus neutrophil count), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR), which are indicators of systematic inflammatory response, have been widely proposed as prognostic factors for many malignancies. To intensively study the relationship between the common markers in peripheral blood and the treatment or prognosis of breast cancer will have critical clinical significance and application prospect, and can provide useful information for the clinicians. Herein, we review the research progress in the prognostic role of the peripheral blood in breast cancer to provide a new method for the treatment and prognosis of breast cancer.

Background and Objective: Systemic inflammation response index (SIRI=N×M/L), based on neutrophil (N), monocyte (M), and lymphocyte (L) counts, is used to predict the survival of patients with malignant tumors and can fully evaluate the balance between host immune and inflammatory condition. The present study is aimed to evaluate the potential prognostic significance of SIRI in patients with breast cancer undergoing neoadjuvant chemotherapy. Subjects and Methods: A total of 262 breast cancer patients treated with neoadjuvant chemotherapy were enrolled in this retrospective study. The optimal cutoff value of SIRI by receiver operating characteristic curve stratified patients into low SIRI (< 0.85× 10⁹/L) group and high SIRI (≥ 0.85× 10⁹/L) group. The associations between breast cancer and clinicopathological variables by SIRI were determined by chi-square test or Fisher’s exact test. Kaplan–Meier plots and log-rank test were used to evaluate the clinical outcomes of disease-free survival (DFS) and overall survival (OS). Univariate and multivariate Cox proportional hazards regression models were used to analyze the prognostic value of SIRI. The toxicity of neoadjuvant chemotherapy was evaluated by the National Cancer Institute Common Toxicity Criteria (NCICTC). Results: The results were shown that SIRI had prognostic significance by optimal cutoff value of 0.85× 10⁹/L on DFS and OS in univariate and multivariate Cox regression survival analyses. Compared with patients who had high SIRI, patients with low SIRI had longer DFS and OS (41.27 vs 30.45 months, HR: 1.694, 95% CI: 1.128– 2.543, P=0.011; 52.86 vs 45.75 months, HR: 1.288, 95% CI: 0.781– 3.124, P=0.002, respectively). The patients with low SIRI had better 3-, 5-, and 10-year rates of DFS and OS than those with high SIRI. The common toxicities after neoadjuvant chemotherapy were hematologic and gastrointestinal reaction, and the SIRI had no significance on toxicities of all enrolled patients, excepted diarrhea. In patients without neural invasion, those with low SIRI had better prognosis and lower recurrence rates than those with high SIRI. Conclusion: Pretreatment SIRI with the advantage of repeatable, convenient, and non-invasive is a useful prognostic indicator for breast cancer patients who received neoadjuvant chemotherapy and is a promising biomarker for breast cancer on treatment strategy decisions.