A novel marker in the ovarian preservation approach to endometrial cancer: systemic immune inflammatory index

Abstract Objective: This study aims to to evaluate the frequency of ovarian involvement in endometrial cancer patients aged 50 years and younger, identify associated clinicopathological factors, and uniquely assess the role of the Systemic Immune-Inflammatory Index (SII) in predicting ovarian involvement. Methods: Patients aged 50 years and younger diagnosed with endometrial cancer between 1992 and 2022 were retrospectively analyzed. Two groups were formed based on adnexal involvement: those with (ovarian metastasis or synchronous ovarian cancer) and without adnexal involvement. Clinicopathological predictors of adnexal involvement were evaluated. Preoperative complete blood count values (platelet, leukocyte, lymphocyte, and neutrophil counts) were used to calculate inflammatory indices: PLR (platelet-to-lymphocyte ratio), NLR (neutrophil-to-lymphocyte ratio), and SII (neutrophil × platelet / lymphocyte). A two-group analysis was performed based on the cut-off values of statistically significant parameters. Univariate and multivariate logistic regression analyses were conducted. Results: Among 205 patients, histopathological ovarian metastasis was identified in 5.9% (n=12), and synchronous ovarian tumors in 2.4% (n=5). Significant differences were observed in neutrophil counts, NLR, and SII values between the groups (p<0.05). ROC analysis showed the optimal SII cut-off value as 992.58, with 70% sensitivity and 76% specificity (AUC=0.726). Ovarian involvement was significantly more frequent in patients with SII ≥ 992 (p<0.05). Univariate analysis revealed that myometrial invasion, LVSI, cervical stromal invasion, lymph node metastasis, omental involvement, grade of tumor, NLR and SII were significantly associated with ovarian involvement (p<0.05). Multivariate analysis identified histological grade, myometrial invasion, pelvic lymph node metastasis and SII as independent risk factors (p<0.05). Conclusion: Ovarian involvement is uncommon in patients under 50 years of age with low-grade tumors, absence of myometrial invasion, negative pelvic lymph nodes, and preoperative SII < 992.58. Ovarian-sparing surgery may be a safe option in selected cases, and SII could serve as a valuable index in guiding ovarian preservation decisions.