Predictive value of preoperative systemic immune-inflammation index and prognostic nutrition index in patients with epithelial ovarian cancer

Background This study aimed to evaluate the predictive value of Prognostic Nutritional Index (PNI), Systemic Immunoinflammatory Index (SII), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) in patients with epithelial ovarian cancer ( EOC). Also, to explore the predictive value of a new scoring system combining PNI and SII (coPNI-SII) in patients with EOC. Methods In this study, 154 patients with EOC were analyzed and classified according to the best cut-off values for SII, PNI, PLR, and NLR. Spearman's rank correlation was used to analyze the correlation of variables. The Kaplan-Meier survival curve and log-rank test were used to investigate the relationship between inflammatory indicators and overall survival (OS), which was then followed by a multivariate Cox proportional hazards model. All patients were categorized into three groups based on PNI-SII scores. The coPNI-SII score ranged from 1 to 3 as follows: score of 1, high PNI (>= 48.98) and low SII(< 998.87); score of 2, high PNI and high SII or low PNI and low SII; score of 3, low PNI and high SII. To assess the prognostic value of coPNI-SII in patients with EOC. Results The areas under the ROC curves for SII, PNI, PLR, NLR, and coPNI-SII were 0.814, 0.814, 0.780, 0.769, and 0.860, respectively. The optimal cut-off values for SII, PNI, PLR, and NLR were 998.87, 48.98, 217.63, and 2.61, respectively. The Kaplan-Meier analysis showed that the OS of the patients in the high PNI group, low SII group, low NLR group, and low PLR group was significantly higher than that of the patients in the low PNI group, high SII group,high NLR group, and high PLR group (p < 0.01). SII (P = 0.034), PNI (P = 0.013), FIGO staging (P = 0.009), ascites (P = 0.003), CA199 (P = 0.003), HE4 (P = 0.028), residual lesions (P = 0.022), and margins of incision (P < 0.001) were found to be significant prognostic indicators of OS by multifactorial Cox regression analysis. There was a significant inverse relationship between the PNI and SII (r = -0.484; P < 0.01). EOC patients with a coPNI-SII score of 1 had a higher 5-year OS rate (P < 0.05) than EOC patients with a coPNI-SII score of 2 or 3. When taking into account both the SII and PNI, the predictive value rose. Conclusion Interestingly, we found that low preoperative PNI and high SII were strong indicators of poor prognosis in patients with EOC. The combination of SII and PNI can enhance the accuracy of prognosis.