Abstract 1599: Potential values of circulating tumor cell enumeration for clinical management of patients with papillary thyroid carcinoma
Authors: Lin Hung-Chih , Lin Jen-Der , Tseng Ching-Ping 
Published: August 2015

Abstract
Thyroid cancer is one of the most rapidly increasing malignancies, It is the most common endocrine cancer and the fifth most common cancer in women. Moreover, the improved examination technologies of ultrasonographic and thyroglobulin even 18F-fluorodeoxyglucose positron emission tomography and nodule biopsy were insufficient to real-time reflect the patients prognosis. For the prognostic and predictive purpose to improve the diagnostics of thyroid cancer, circulating tumor cells (CTCs) have been developed.Previous studies have shown that CTCs can serve as liquid biopsies to monitoring treatment response and prognosis, but only few articles discussed in papillary thyroid carcinoma (PTC) which composed around 80% of thyroid cancer.In this study, a total of 41 cases were enrolled.In the group I (G1), we included 12 control subjects without clinical significant thyroid disorder like thyroid nodule or autoimmune thyroid disease or any cancer history. In the group II (G2), 11 disease free thyroid cancer patients were enrolled. In the group III (G3), we enrolled 18 PTC patients with distant metastasis that were confirmed by 131I whole-body scintigraphy (WBS) or other imaging methods. The peripheral blood of control subjects and cancer patients were analyzed by a negative selection method PowerMag system. The number of cells with the epithelial cell adhesion molecular (EpCAM) or thyroid stimulating hormone receptor (TSHR)expression was counted. In ROC analysis, EpCAM+ counts showed no significantly difference between G1 and G2 (p = 0.0728). Between G1 and G3 (p&lt;0.0001), we had asensitivity of 100% and a specificity of 66.9%when 5.0CTCs/ml was used as the cutoff, thearea under curve (AUC) equivalent to 0.979. To further distinguishbetween G2 and G3(p = 0.0001), we had asensitivity of 88.9% and a specificity of 81.8%when 16.0CTCs/ml was used as the cutoff; the AUC was equivalent to 0.934.Moreover, by using PowerMag system we could isolate TSHR+/EpCAM- CTCs and identify the potentialmalignancy in disease free group from control subjects. TSHR+-CTCscountsshowedthat, between G2 and G3 (p&lt;0.0001),we had asensitivity of 83.3% and the specificity was 90.9%when 30.7CTCs/ml was used as the cutoff; theAUC was equivalent to 0.854.Remarkably, between G1 and G2 (p = 0.0013), we had asensitivity of 90.9% and a specificity of 70.6%when 7.5 CTCs/ml was used as the cutoff;the AUC equivalent to 0.869. By counting the number of CTCs which expressed EpCAM or TSHR could monitor the progression for the patients with thyroid cancer. CTCs enumeration thereby has the value for clinical diagnosis in PTC and compromises the inefficiency of the current examinations for thyroid cancer.
Citation Format: Hung-Chih Lin, Jen-Der Lin, Ching-Ping Tseng. Potential values of circulating tumor cell enumeration for clinical management of patients with papillary thyroid carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1599. doi:10.1158/1538-7445.AM2015-1599