Preoperative Immuno-inflammatory Markers as Predictors of Deep Myometrial Invasion in Endometrial Cancer: A Retrospective Study from Southern Thailand.

OBJECTIVES: To evaluate the predictive value of preoperative systemic inflammatory markers neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and systemic immune-inflammation index (SII) for deep myometrial invasion (MI) in patients with endometrial cancer (EC), emphasizing their utility in resource-limited settings. METHODS: This retrospective cohort study included 377 patients with histologically confirmed EC who underwent primary surgery at Hatyai Hospital, Southern Thailand, from October 2016 to September 2024. Preoperative hematologic markers were obtained within two weeks before surgery. Patients with active infection, other inflammatory conditions, or prior neoadjuvant treatment were excluded. Deep MI was defined as ≥50% myometrial invasion on final pathology. Logistic regression was used to identify independent predictors, and diagnostic accuracy was assessed using receiver operating characteristic (ROC) curves. RESULTS: Deep MI was present in 162 patients (42.97%) and was associated with older age, postmenopausal status, advanced FIGO stage, high-grade tumors, larger size, nodal and cervical involvement, and LVSI (all p<0.001). NLR, PLR, MLR, and SII were significantly elevated in this group. Multivariate analysis identified FIGO stage III (OR 7.25; 95% CI, 3.55-14.82), tumor size ≥2 cm (OR 3.85; 95% CI, 1.26-11.77), LVSI (OR 5.01; 95% CI, 2.77-9.08), NLR (OR 1.20; 95% CI, 1.04-1.39), and MLR (OR 57.68; 95% CI, 3.46-960.81) as independent predictors. MLR demonstrated the highest predictive value among biomarkers (AUC 0.612; 95% CI, 0.554-0.670). CONCLUSION: Preoperative immunoinflammatory markers, particularly MLR and NLR, are independently associated with deep MI in EC. MLR, despite variability, may serve as a cost-effective adjunct for risk stratification, especially in resource-limited settings.