The Predictive Value Of Neutrophil/Lymphocyte Ratio And Platelet/ Lymphocyte Ratio For Central Lymph Node Metastasis In Patients With Papillary Thyroid Carcinoma

ObjectiveSystemic inflammation has been proved to have an effect on the proliferation,metastasis,and prognosis of many tumor types,including thyroid cancer.However,no consensus has been reached on the extent of central lymph node dissection for papillary thyroid carcinoma（PTC）.This study hopes to evaluate the relationship between neutrophil-to-lymphocyte ratio（NLR）,platelet-to-lymphocyte ratio（PLR）and clinicopathological characteristics,and the predictive value of NLR and PLR combined with related pathological characteristics on central lymph node metastasis.MethodsA retrospective analysis was performed on medical data of patients with thyroid cancer who were admitted to the department of thyroid and breast surgery of Nanjing Medical University Affiliated Suzhou Hospital and underwent surgical resection from June 2016 to December 2019.264 patients diagnosed with PTC were included combined with total thyroidectomy/lobectomy and central lymph node dissection.The optimal threshold values of NLR and PLR were determined by the receiver operating characteristic curve with the risk of recurrence.Based on the threshold,patients were divided into high-NLR or low-NLR group,high-PLR or low-PLR group.Chi-square test was used to analyzed the relationship between the clinical pathological characteristics of PTC patients and NLR and PLR.Single-factor and multi-factor analyses were used to screen the factors affecting lymph node metastasis in the central region of PTC patients and establish a prediction model.The Hosmer-Lemeshow combined with ROC curve was used to test the predictive power of the evaluation model for central neck lymph nodes metastasis.Results1.The preoperative NLR level was correlated with the central lymph node metastasis（P<0.05）.2.The preoperative PLR level was correlated with Hashimoto’s thyroiditis,central lymph node metastasis,number of metastatic lymph nodes,and multifocality（P<0.05）.3.Multivariate logistic regression analysis showed that age,tumor size and PLR level were independent risk factors for lymph node metastasis.4.Prediction model:Logit（P）=In（P/1-P）=-1.896-1.253X₂+1.180X₄+0.792X₁₁,predicting the probability model of uterine prolapse:P=1/(1+Exp(1.896+1.253X₂-1.180X₄-0.792X₁₁)).The correct index of this prediction model was 70.8%,and the sensitivity and specificity were 73.9%和62.2%respectively.ConclusionPreoperative NLR and PLR were related to central lymph node metastasis and a higher risk of recurrence with PTC.NLR>1.91 and PLR>117.00 suggest that patients with PTC have a high risk of recurrence,which should be much attention.Age,tumor size,and PLR were regarded as independent risk factors for central lymph node metastasis.The established prediction model of lymph node metastasis can provide scientific and accurate reference for the evaluation of lymph node metastasis in central region of patients with negative preoperative imaging,avoid unnecessary lymph nodes dissection,reduce surgical trauma,improve patients’quality of life and reduce recurrence.