Prognostic value of the preoperative prognostic nutritional index and systemic immuno‐inflammatory index in Chinese breast cancer patients: A clinical retrospective cohort study

Abstract Background It has been shown that peripheral blood inflammatory factor ratios correlate with the prognosis of various malignancies. Although indicative of prognosis in some tumors, its value for prognosis in breast cancer patients is unclear. Methods The clinical data of breast cancer patients diagnosed with breast cancer in the Second Hospital of Jilin University from January 1, 2013, to December 31, 2017, were retrospectively analyzed. The prognostic nutritional index (PNI) optimal cutoff values of the subjects' operating characteristic curves divided the patients into a low PNI group (≤51.05) and a high PNI group (>51.05). Correlations between breast cancer and PNI clinicopathological variables were determined by the χ 2 test or Fisher exact test. Kaplan–Meier plots and log‐rank tests were used to assess clinical outcomes in terms of disease‐free survival (DFS). The prognostic value of PNI was analyzed by univariate and multivariate Cox proportional risk regression models. Results The best cutoff value for predicting DFS by pretreatment PNI was 51.05 and the Youden index when was 0.416, with a sensitivity of 71.4% and specificity of 70.2%. Univariate analysis showed that PNI ≤ 51.05, human epidermal growth factor receptor‐2 (HER‐2) positivity, and the number of lymph node metastases >4 were risk factors affecting DFS in invasive breast cancer ( p < 0.05). Cox multifactor analysis showed that PNI and lymph node status were the most important factors affecting the prognosis of invasive breast cancer. Neutrophils‐to‐lymphocytes ratio and platelets‐to‐lymphocytes ratio were not significantly correlated with patient prognosis ( p > 0.05). Conclusion Preoperative peripheral blood PNI in patients with invasive breast cancer are independent risk factors affecting patients' prognosis, they are positively correlated with prognosis and can be used as indicators to assess prognosis. PNI, HER‐2, and lymph node status had the best predictive efficacy with the area under the curve = 0.816 (95% confidence interval: 0.680–0.951, p < 0.001).