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.

Keywords: circulating tumor cell; follicular adenoma; follicular carcinoma; peripheral blood; thyroid nodule.

Figure 1

Differences in expression of seven target genes from circulating tumor cells derived from the peripheral blood of patients with benign and malignant thyroid nodules. Black bars denote lower expression in the malignant groups and white bars the opposite. ND, not detected.

Figure 2

Expression of SLC5A5 and LGALS3 in circulating tumor cells from patients with thyroid nodules. The center bar represents the mean value. For SLC5A5, two normal healthy control samples were below the detection limit. BEN, benign thyroid nodules (follicular adenomas); MAL^papillary, papillary subtype of malignant thyroid nodules (papillary thyroid carcinomas); MAL^follicular, follicular subtype of malignant thyroid nodules (follicular thyroid carcinomas); NL, normal healthy controls.