The Influence of Radioiodine Therapy on the Number of Circulating Epithelial Cells (CEC) in Patients with Differentiated Thyroid Carcinoma – a Pilot Study

• Published in: Experimental and clinical endocrinology & diabetes Vol. 226; no. 4; pp. 246 - 253
• Main Authors: Winkens, T., Pachmann, K., Freesmeyer, M.
• Format: Journal Article
• Language: English
• Published: Stuttgart · New York J. A. Barth Verlag in Georg Thieme Verlag KG 01.04.2014
• Subjects: Cell Count; Epithelial Cells - radiation effects; Humans; Iodine Radioisotopes - therapeutic use; Microscopy, Fluorescence; Middle Aged; Neoplastic Cells, Circulating - pathology; Neoplastic Cells, Circulating - radiation effects; Pilot Projects; Predictive Value of Tests; Sensitivity and Specificity; Statistics, Nonparametric; Thyroglobulin - blood; Thyroid Neoplasms - blood; Thyroid Neoplasms - pathology; Thyroid Neoplasms - radiotherapy; thyroid cancer; CTC; tumor marker; circulating tumor cells
• DOI: 10.1055/s-0034-1370921
• ISSN: 0947-7349

Abstract Goal: The aim of this pilot study was to investigate the changes of circulating epithelial cells in the blood of patients with differentiated thyroid cancer after radioiodine-therapy with I-131. Methods: The cells were detected by fluorescence-microscopy via the epithelial-cell-adhesion-molecule (EpCAM), a molecule described to be over-expressed in most carcinoma tissues and also present on circulating cells deriving from primary site. Epithelial cells were assessed before radioiodine-therapy, as well as 2 days, 14 days, and 3 months after therapy. 2 patient groups were examined: 1) patients with thyroid cancer receiving a first radioiodine-therapy after thyroidectomy (RIT first , n=13), and 2) patients with thyroid cancer in need of repeated radioiodine-therapy due to local or metastatic recurrences (RIT rep , n=15). Circulating epithelial cell changes were correlated to changes of serum-thyroglobulin and to clinical response evaluated 3 months after therapy. Results: Patients with an early decrease of cells after radioiodine-therapy (RIT first 7/13; RIT rep 2/15) showed an increase of serum-thyroglobulin in most of the cases (RIT first 5/7; RIT rep 2/2). In the RIT rep group, a decrease in cell counts 2 days after radioiodine-therapy indicated a clinical response in 90% of the cases. Conclusion: This study indicates that the number of circulating epithelial cells in differentiated thyroid cancer undergo changes in response to radioiodine-therapy. The destruction of cells through radioiodine-therapy may induce a short-term release of thyroglobulin in the blood. A clear relationship between the clinical outcome and the cell changes could not be found, but early cell decreases may help identifying patients more likely to respond to radioiodine-therapy.