New pre-treatment eosinophil-related ratios as prognostic biomarkers for survival outcomes in endometrial cancer

Abstract Background Systemic inflammation has long been related with adverse survival outcomes in cancer patients, and its biomarkers, such as the Neutrophil-to-Lymphocyte Ratio (NLR), are recognized as poor prognostic indicators. However, the role of eosinophils in this field has been largely overlooked. Here, we describe two new pre-treatment biomarkers, expressed as Eosinophil-to-Lymphocytes Ratio (ELR) and Eosinophil*Neutrophil-to-Lymphocytes ratio (ENLR), and we analyse their impact on prognosis of endometrial cancer (EC) patients. Methods A total of 163 consecutive patients diagnosed with EC and treated with postoperative radiotherapy +/− chemotherapy in our institution from January 2011 to December 2015 were evaluated. The cohort was divided in two groups applying the cut-off value of 0.1 and 0.5 according to ROC curve for pre-treatment ELR and ENLR, respectively. After patients’ stratification according to the ESMO-ESGO-ESTRO modified risk assessment, subgroup analyses were conducted. Results Higher values of ELR and ENLR were associated with worse OS (p = 0.004 and p = 0.010, respectively). On univariate analysis, the factors associated with shorter OS were ELR ≥ 0.1 (HR = 2.9, p = 0.017), ENLR ≥ 0.5 (HR = 3.0, p = 0.015), advanced FIGO stage (HR = 3.4, p = 0.007), endometrioid histology (HR = 0.26, p = 0.003) and ESMO-ESGO-ESTRO high-risk (HR = 10.2, p = 0.023). On multivariate Cox regression, higher ELR and ENLR were independently associated with a worse outcome adjusted for the standardly applied prognostic factors. Conclusions Increased values of ELR and ENLR portend worse OS in EC, especially in patients classified by the ESMO-ESGO-ESTRO guidelines as a high-risk group. To our best knowledge, this is the first report describing eosinophils-related ratios as prognostic biomarkers in malignant tumours