Abstract: In this research, 106 patients with DTC were selected as the thyroid cancer group, and 106 patients with thyroid adenoma in the same period were selected as the thyroid adenoma group. The ultrasound elastography parameters (elasticity ratio, blue area ratio), serum midkine (MK) and vascular endothelial growth factor (VEGF) levels of patients in two groups were tested and compared. The study found that the elasticity ratio, blue area ratio, serum MK, and VEGF levels were related to lymph node metastasis, capsule invasion and clinical staging in DTC patients (P<0.05). The area under the curve (AUC) for the combined diagnosis of DTC by elasticity ratio, blue area ratio, serum MK and VEGF levels is 0.888. In tissues of DTC patients, elasticity ratio, blue area ratio, serum MK and VEGF levels were positively correlated with the expression of chemokine receptor (CXCR) 4, disaggregated metalloproteinase (ADAM) 9 and targeting Xklp2 target protein (TPX2) gene, while negatively correlated with the expression of programmed cell death factor (PDCD) 4 gene. It was suggested that the up-regulation of ultrasound elastography parameters, serum MK and VEGF levels may evaluate the condition of patients with DTC and the degree of tumor malignancy. The combination of the three has a reliable diagnostic value for DTC and can provide new ideas for clinical diagnosis and treatment.

Key words: ultrasound elastography parameters, midkine, vascular endothelial growth factor, differentiated thyroid cancer, tumor malignancy, receiver operating characteristic curve