Predictive Utility of Systemic Immune Inflammation Index (SII) in Identifying Endometrial Carcinoma in Premalignant Endometrial Lesions

Introduction: It is important to detect endometrial cancer (EC) in endometrial intraepithelial neoplasia (EIN) patients. It was aimed to determine the role of systemic immune inflammation index (SII) in predicting concurrent EC in women with EIN. Materials and Methos: In this retrospective study, 429 women with EIN divided into three groups according to final histopathologic results: benign(n=151), EIN(n=152), and EC(n=126). Demographic and clinical data, pathologic and laboratory result were collected. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and SII index were calculated and compared among groups. Results: The SII, PLR and NLR values of benign, EIN and EC groups were compared and all values of EC group were the highest (p<0.001). The ROC analysis showed that although all markers had statistical significance, the AUC of SII was the highest. The SII score>0.67 (95%CI:7.17-37.3, p<0.001) had a 16.35-fold, preoperative platelet count > 287 (95%CI:1.91-6.2, p<0.001) had a 3.45-fold and age >49 years (95%CI:1.97-5.92, p<0.001) had 3.42-fold increased risk for EC. Conclusion: Although age and preoperative platelet count were found independent risk factors, SII was the strongest predictor for EC in women with EIN. SII can be used as a predictive marker for identifying concurrent EC or having risk for developing EC in women with EIN.