Evaluation of neutrophil-to-lymphocyte ratio and calcitonin concentration for predicting lymph node metastasis and distant metastasis in patients with medullary thyroid cancer.

The aim of the present study was to investigate potential predictive factors of lymph node metastasis (LNM) and distant metastasis (DM) of medullary thyroid cancer (MTC). A total of 61 patients newly diagnosed with MTC at the General Hospital of the Chinese People's Liberation Army between January 2001 and January 2016 were enrolled and divided into two groups according to the results of preoperative examinations and surgical histopathology as follows: Group NM (without metastases), and group M (with metastases). Univariate logistic regression analysis demonstrated that sex, tumor size, preoperative peripheral blood neutrophil-to-lymphocyte ratio (NLR), and concentration of carcinoembryonic antigen (CEA) and calcitonin (Ctn), were significantly associated with LNM and DM. The multivariate analysis revealed that a Ctn concentration of >500 pg/ml [odds ratio (OR)=21.422; 95% confidence interval (CI): 2.611-175.731] and the NLR (OR=5.918; 95% CI: 1.147-30.541) were positively correlated with LNM and DM. The optimal cut-off value of the NLR for predicting LNM and DM obtained from receiver operating characteristic curve analysis was 1.784 (sensitivity 68.3% and specificity 80%), and the area under the curve was 0.717. In conclusion, the findings of the present study strongly suggest that inflammation and immune activation of MTC cells promote LNM and DM, and that higher values of NLR and Ctn concentration confer a high risk of metastasis.