Relationship Between Systemic Inflammatory Markers and Histopathological Parameters in Endometrial Adenocarcinoma

Background/Objectives: This study aimed to investigate the prognostic value of preoperative systemic inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and prognostic nutritional index (PNI), in conjunction with tumor markers and histopathological parameters, on overall survival (OS) and disease-free survival (DFS) in patients with endometrioid adenocarcinoma. Systemic inflammation has been increasingly implicated in tumor progression, and inflammation-based indices derived from routine blood tests offer a practical approach for preoperative risk assessment. Methods: A total of 155 patients diagnosed with endometrioid adenocarcinoma between 2016 and 2025 were retrospectively analyzed. The NLR, PLR, SII, and PNI were calculated from preoperative complete blood count and biochemical data. Associations with histopathological parameters, including FIGO grade, myometrial invasion, cervical stromal involvement, lymphovascular invasion, and lymph node metastasis, were evaluated. Survival analyses were performed using the Kaplan-Meier method and Cox proportional hazards regression models. Results: Patients with cervical stromal involvement had significantly higher NLR values (p = 0.028) and lower lymphocyte counts (p = 0.032). Additionally, lower albumin and PNI levels were observed in patients with cervical stromal involvement (p = 0.034 and p = 0.031, respectively). Multivariate Cox regression analysis identified advanced age (HR: 1.09, p < 0.001), subtotal hysterectomy (HR: 3.76, p = 0.006), lymph node metastasis (HR: 4.78, p = 0.020), elevated CRP levels (HR: 1.05, p = 0.004), high SII (HR: 1.002, p = 0.037), and increased CA 15-3 levels (HR: 1.04, p < 0.001) as independent predictors of poor OS. CA-125 level was an independent risk factor for DFS (p = 0.031). Conclusions: Systemic inflammatory markers, particularly SII and NLR, may serve as useful prognostic indicators for endometrioid adenocarcinoma. Their association with survival outcomes and local tumor extension highlights their potential clinical value in preoperative risk stratification and individualized treatment planning. Future prospective studies integrating these markers with molecular classification data are required.