Abstract: This study aimed to clarify the value of ultrasound elastography (UE) combined with S100 calcium binding protein A4 (Mts1/S100A4) protein in the diagnosis of thyroid cancer (TC) and its lymph node metastasis. Patients with thyroid lesions who underwent UE examination in our hospital were selected as the research objects. Among them, 107 patients (107 lesions) diagnosed with TC were included in the TC group, and 101 patients (101 lesions) diagnosed with benign thyroid nodules were included in the benign group. Among 107 patients with TC, 64 patients did not develop lymph node metastasis and 43 patients developed lymph node metastasis. All patients underwent UE examination, and serum Mts1 was detected using human Mts1 enzyme-linked immunosorbent assay (ELISA) kit. The results showed that compared with the benign group, the SR and serum Mts1 in the TC group were increased (P<0.001). Correlation analysis showed that SR and serum Mts1 levels were significantly positively correlated (r=0.463, P<0.001). The area under the curve (AUC) (0.859), the sensitivity (68.18%) and the specificity (97.37%) of SR and serum Mts1 for diagnosing TC were higher than those for single diagnosis. Compared with the non-metastatic group, both SR and serum Mts1 in the metastatic group were increased (P<0.01). The combined AUC (0.817) and specificity (89.06%) of SR and serum Mts1 for the diagnosis of lymph node metastases were higher than those for single diagnosis, but the sensitivity (65.12%) was lower than that of serum Mts1. This study shows that SR combined with serum Mts1 is of high value in the diagnosis of TC and lymph node metastasis, and may be helpful for early diagnosis and prediction of lymph node metastasis in patients with TC.

Key words: ultrasound elastography, Mts1, thyroid cancer, diagnosis, lymph node metastasis