Preoperative integrated oxidative stress score as a prognostic factor for predicting clinical outcomes in breast cancer patients received neoadjuvant chemotherapy: a real-world retrospective study

<b>Objective:</b> The current study aims to investigate the prognostic value of breast cancer integrated oxidative stress score (BCIOSS) in patients with breast cancer who received neoadjuvant chemotherapy (NACT). <b>Methods:</b> A retrospective analysis of 104 breast cancer patients who underwent NACT from June 2009 to December 2015 was performed. The differences of BCIOSS of breast cancers in regard to variables were analyzed using Chi-square test and Fisher's exact test. The Kaplan-Meier method was used to evaluate survival curve between low BCIOSS group and high BCIOSS group, and the two groups were compared by Log-rank tests at the individual index level. The univariate and multivariate Cox regression analyses were established by the important predictive factors determined based on univariate analysis. The nomograms were further conducted based on the factors by the multivariate analyses. <b>Results:</b> Patients were assigned to low BCIOSS group (BCIOSS≤2.54) or high BCIOSS group (BCIOSS>2.54) via ROC curve. BCIOSS was a latent prognostic factor for patient survival [DFS; hazard ratio (HR): 0.163, 95%CI: 0.045-0.596, P=0.006; and OS; HR: 0.168, 95%CI: 0.056-0.500, P=0.001]. Patients with a high BCIOSS had longer survival time than those with a low BCIOSS (DFS: χ²=7.317, P=0.0068; and OS: χ²=9.407, P=0.0022). Calibration curves shown that the predicted line conformed well to the reference line for the 5-year survival category. DCA revealed that the nomograms conducted had a better clinical predictive application than only by BCIOSS. <b>Conclusion:</b> BCIOSS is a latent prognostic factor, and patients with high oxidative stress scores have a better prognosis and longer survival time.