Expression of SLC5A5 in Circulating Tumor Cells May Distinguish Follicular Thyroid Carcinomas from Adenomas: Implications for Blood-Based Preoperative Diagnosis

Abstract

Preoperative diagnosis of thyroid nodules reduces unnecessary surgery. Circulating tumor cells (CTCs) may contain information of primary tumor(s). We asked whether the peripheral blood expression of genes specific for circulating tumor cells (CTCs) differentiates benign thyroid nodules from malignant nodules. Peripheral blood mononuclear cells from thyroid nodule patients (n = 20) were isolated preoperatively and the expression of seven CTC-associated genes was measured in patients with thyroid nodule(s) (n = 20). Among the tested genes, the expression of SLC5A5 and LGALS3 were validated in a larger number of patients (n = 64) and our results show that SLC5A5 expression differentiated follicular adenomas from follicular carcinomas (area under the curve (AUC) = 0.831). The expression of SLC5A5 in CTCs may preoperatively distinguish thyroid follicular adenomas from follicular carcinomas.

Opportunities and Challenges of Liquid Biopsy in Thyroid Cancer

“…In the pre-operatory setting, the expression of genes associated with CTCs can help distinguish benign from malignant thyroid nodules with the follicular feature. For example, the expression of the CTC-associated gene SLC5A5 is lower in liquid biopsies of patients with FTC compared to patients with follicular adenoma (FA), while LGALS3 expression is higher in PTC than in FTC patients [ 34 ]. In the follow-up of surgically removed PTCs, serum levels of circulating epithelial cells (CECs) expressing epithelial cell adhesion molecule (EpCAM) and thyroid-stimulating hormone receptor (TSHR) are significantly higher in patients with disease recurrence and undetectable serum Tg due to TgAb [ 35 ].…”

The Role of Exosomes in Thyroid Cancer and Their Potential Clinical Application

“…Although most PTC patients have a good prognosis, LNM often occurs in the early stage, and predicting and diagnosing LNM in advance can prevent patients from experiencing unnecessary pain. The discrimination of follicular lesions is another difficulty in TC, and the current traditional diagnostic methods are often inadequate (52,59). Samsonov et al compared patients with benign thyroid nodules, and found that miR-31 in the serum exosomes of PTC patients was significantly upregulated.…”

Clinical Significance of Circulating Tumor Cells (CTCs) and Survivin on Predicting Prognosis in Thyroid Cancer Patients

“…The differentiation between benign and malignant thyroid nodules is still determined by histological examination from the excised thyroid tumor via nodule biopsy or FNAB [ 4 ]. Therefore, a few methods, including specific gene detection by polymerase chain reaction (PCR) technique, have been developed for differentiating from benign and malignant thyroid nodules preoperatively [ 5 ]. According to the World Health Organization (WHO) on the latest classification of thyroid cancer in 2017 [ 6 ], thyroid cancer is mainly classified into papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), Hürthle (oncocytic) cell carcinoma (HCC), medullary thyroid carcinoma (MTC), poorly differentiated thyroid carcinoma (PDTC), and anaplastic thyroid carcinoma based on their histopathological characteristics [ 7 , 8 ].…”

“…CTCs are classified into epithelial type, mesenchymal CTC (MCTC) type, and both mixed types according to their surface markers [ 23 ]. So far, CTC evaluation for thyroid cancer mostly has only a few available data, and the results revealed a little correlation with CTC number [ 5 , 23 , 24 ]. Here, as in the previous description, PTC and FTC have good 5-year OS.…”