[Application of serum markers in medullary thyroid carcinoma]

Objective: To discuss the diagnostic value of calcitonin(CT), carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), pro-gastrin releasing peptide (Pro-GRP) and chromogranin A (CgA) in the identification of medullary thyroid carcinoma (MTC). Methods: The CT levels in 105 cases of MTC, 50 cases of papillary thyroid carcinoma, 10 cases of thyroid follicular carcinoma, 5 cases of undifferentiated thyroid carcinoma, 50 cases of benign thyroid diseases, 30 cases of non-thyroid malignant tumors and 50 cases of healthy controls were measured from February 2017 to August 2019 at the Department of Clinical Laboratory, Cancer Hospital affliated to Fudan University. Additionally, 79 cases of MTC, 30 cases of non-MTC thyroid malignant tumors and 30 healthy controls were selected for the measurement of CEA, NSE, Pro-GRP and CgA levels. The receiver operating curve was utilized to clarify the area under the curve (AUC), sensitivity, and specificity of each indicator to distinguish between different groups. Results: The medians of CT concentrations in the group of MTC patients was 607.2 (152.5,2 777.5)pg/ml, which was statistically significantly higher than that of the subjects in the group of papillary thyroid carcinoma 1.48 (0.5,2.91)pg/ml, follicular thyroid carcinoma 1.90 (0.82,2.99)pg/ml, undifferentiated thyroid carcinoma 0.50 (0.50,4.93)pg/ml, benign thyroid disease 1.30 (0.50,2.79)pg/ml, non-thyroid malignancies 1.36 (0.50,2.89)pg/ml and healthy controls 2.05 (0.89,3.18)pg/ml. The sensitivity, specificity and AUC of CT to distinguish MTC vs. non-MTC patients was 96.2%, 99.3% and 0.99, respectively. The maximum diameter (>1 cm, P=0.001, OR=15.74) and number (>1, P=0.04, OR=3.4) of nodules were two independent risk factors for elevated CT. CEA (AUC=0.94), NSE (AUC=0.65), Pro-GRP (AUC=0.94) and CgA (AUC=0.83) could all distinguish MTC vs. non-MTC thyroid malignancies. The AUC, sensitivity and specificity by combining CT, CEA, NSE, Pro-GRP and CgA to differentiate MTC vs. non-MTC thyroid malignancies was 1, 100% and 100%, respectively. Conclusions: CT, CEA, NSE, Pro-GRP and CgA may be helpful for the auxiliary diagnosis of MTC. The combination of these indicators in the diagnosis of MTC has high sensitivity and specificity.