Abstract:

Objective To investigate the correlation between serum follistatin（FS） and clinicopathological characteristics and prognosis of patients with differentiated thyroid cancer. Methods Totally，78 patients with differentiated thyroid cancer（thyroid cancer group），including 68 cases of papillary thyroid carcinoma（PTC） and 10 cases of follicular thyroid carcinoma（FTC），41 cases of benign thyroid nodules（benign nodule group），and 35 healthy subjects（healthy control group） were enrolled. The patient clinical data were collected，and serum FS levels of patients before and 3 months after operation and healthy subjects were determined. Receiver operating characteristic（ROC） curve was used to evaluate the efficacy of FS in the differential diagnosis of thyroid cancer and cervical lymph node metastasis. Logistic regression analysis was used to evaluate the risk factors for recurrence and metastasis in patients with thyroid cancer. Results The preoperative FS level in thyroid cancer group was higher than those in benign nodule group and healthy control group（P<0.001）. The serum FS level in thyroid cancer group at 3 months after operation was lower than that before operation（P<0.01）. There was no statistical significance in serum FS levels between PTC and FTC patients（P>0.05）. The area under curve（AUC） of FS in the differential diagnosis of benign thyroid nodules and thyroid cancer was 0.78，with an optimal cut-off value of 2.90 ng/mL，the sensitivity of 70.5% and the specificity of 82.9%，respectively. The AUC for cervical lymph node metastasis from thyroid cancer was 0.69，with an optimal cut-off value，sensitivity and specificity of 3.71 ng/mL，58.1% and 77.1%，respectively. The number of cases with lymph node metastasis in high FS（≥2.90 ng/mL） group was larger than that in low FS（<2.90 ng/mL） group（P<0.05）. Multivariate Logistic analysis showed that TNM stage Ⅲ-Ⅳ and serum FS≥4.33 ng/mL were independent risk factors for persistent thyroid cancer [odds ratios（OR） were 8.97 and 7.77，95% confidence intervals（CI） were 2.12-18.33 and 4.54-15.98，respectively]. Conclusions Serum FS level has a certain clinical value in the identification of benign and malignant thyroid nodules and the judgment of cervical lymph node metastasis in thyroid cancer. A high level of FS is a risk factor for thyroid cancer recurrence and metastasis.

Key words: Follistatin, Thyroid cancer, Clinicopathological characteristic, Recurrence, Metastasis