[Study on the value of systemic immune inflammation index and nomogram in predicting the prognosis of patients with mucoepidermoid carcinoma].

Purpose: To investigate the relationship between preoperative systemic immune-inflammation index (SII) and relapse-free survival (RFS) after surgical resection of mucoepidermoid carcinoma(MEC).

Methods: The data of 135 patients with MEC who underwent surgical resection in the First Affiliated Hospital of Zhengzhou University from January 2016 to July 2019 were collected, and the receiver operating characteristic(ROC) curve was performed on the SII of patients. The optimal cut-off value was obtained by ROC analysis. Therefore, the patients' SII index was divided into high and low group, and survival analysis was performed by Kaplan-Meier method. Cox proportional regression model and least absolute shrinkage and selection operator (LASSO) were used to analyze the factors influencing prognosis, and a nomogram model was built to predict patients' relapse-free survival(RFS). Area under curve (AUC) and correction curve were used to evaluate the model and verify the consistency.

Results: Survival analysis showed that the RFS rate in low SII group was significantly higher than that in high SII group. Cox proportional hazard regression model showed high SII(HR=2.179, 95%CI: 1.072-4.426, P=0.031) and low tumor differentiation(HR=6.894, 95%CI: 2.770-17.158, P=0.000) and cervical lymph node metastasis (HR=2.091, 95%CI: 1.034-4.230, P=0.040) were significant predictors of poor RFS.

Conclusions: The lower the preoperative SII, the better the prognosis of patients. The nomogram prognosis of MEC based on SII is effective.