Association of the Preoperative Neutrophil-to-ymphocyte Count Ratio and Platelet-to-Lymphocyte Count Ratio with Clinicopathological Characteristics in Patients with Papillary Thyroid Cancer.

Background: Several inflammatory biomarkers, especially a high preoperative neutrophil-to-lymphocyte count ratio (NLR) and platelet-to-lymphocyte count ratio (PLR), are known to be indicator of poor prognosis in several cancers. However, very few studies have evaluated the significance of the NLR and PLR in papillary thyroid cancer (PTC). We evaluated the association of the preoperative NLR and PLR with clinicopathological characteristics in patients with PTC.

Methods: This study included 1,066 female patients who underwent total thyroidectomy for PTC. Patients were stratified into 4 quartiles by preoperative NLR and PLR. And the combination of preoperative NLR and PLR was calculated on the basis of data obtained value of tertile as follows: patients with both an elevated PLR and an elevated NLR were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively.

Results: The preoperative NLR and PLR were significantly lower in patients aged ≥45 years and in patients with Hashimoto's thyroiditis. The PLR was significantly higher in patients with tumor size >1 cm (P=0.021).When the patients were categorized into the aforementioned four groups, the group with the higher preoperative PLR was found to have a significantly increased incidence of lateral lymph node metastasis (LNM) (P=0.018). However, there are no significant association between the combination of preoperative NLR and PLR and prognostic factors in PTC patients.

Conclusion: These results suggest that a preoperative high PLR were significant associated with lateral LNM in female patients with PTC.