Usefulness of Pre-Thyroidectomy Neutrophil-Lymphocyte, Platelet-Lymphocyte, and Monocyte-Lymphocyte Ratios in Discriminating Lymph Node and Distant Metastases in Differentiated Thyroid Cancer

Abstract Purpose This study aims to show the relationship between neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and monocyte-lymphocyte ratio (MLR), with clinicopathological characteristics in patients with differentiated thyroid cancer (DTC). Methods This is a retrospective study involving 390 DTC patients who had complete blood cell count available at the time of the surgery. NLR, PLR, and MLR were calculated, risk of cancer-related death, structural recurrence, and response to therapy were assessed by the 8th edition of the tumor-node-metastasis (TNM), American Thyroid Association (ATA) Risk Stratification System, and ATA Response to Therapy Reclassification, respectively. Results PLR was higher in distant metastasis (133.15±43.95 vs 119.24±45.69, p = 0.0345), lower in disease-free versus persistent disease or death (117.72±44.70 vs 131.07±47.85, p = 0.0089). In MLR, patients ≥55 had a higher score than < 55 years old (0.26±0.10 vs 0.24±0.12, p = 0.0379). Higher MLR (OR 8.775; 95% CI = 1.532–50.273; p = 0.0147), intermediate (OR 4.892; 95% CI = 2.492–9.605; p ≤ 0.0001) and high ATA risks (OR 5.998; 95% CI = 3.126–11.505; p ≤ 0.0001) were risk factors associated with active disease. NLR was not significant. ROC curve cut-off values for NLR, PLR, and MLR were able to discriminate distant from lymph node metastasis (NLR > 1.93 sensitivity 73.3%, specificity 58.7%; PLR > 124.34 sensitivity 86.7%, specificity 69.2%; MLR > 0.21 sensitivity 80%, specificity 45.2%). Conclusion Cut-off values of NLR, PLR, and MLR discriminated the presence of distant metastasis from lymph node metastasis with good sensitivity and accuracy. PLR was an associated factor with disease-free status and higher in DTC patients with distant metastasis, persistency, and disease-related death. MLR was a risk factor of active disease.