Low but measurable stimulated serum thyroglobulin levels <2 µg/L frequently predict incomplete response in differentiated thyroid cancer patients. (November 2014)

• Record Type: Journal Article
• Authors: Aldawish, Mohammed; Jha, Naresh; McEwan, Alexander J. B.; Severin, Diane; Ghosh, Sunita; Morrish, Donald W.
• Is Part Of: Endocrine research. Volume 39:Number 4(2014:Nov.)
• Page Start: 157
• Page End: 163
• Publication Date: 2014-11
• Subjects: Endocrinology, Experimental -- Periodicals; Endocrinology -- Periodicals; Endocrinology -- Periodicals; Research -- Periodicals; 616.4
• DOI: 10.3109/07435800.2013.865211
• Languages: English
• ISSNs: 0743-5800

Abstract

&lt;abstract&gt; &lt;title&gt;Abstract&lt;/title&gt; &lt;p&gt; &lt;italic&gt;Introduction&lt;/italic&gt;: The study was aimed to determine the response and predictive risk factors of differentiated thyroid cancer (DTC) with measurable (0.4–2.0 µg/L) stimulated serum thyroglobulin (sTg) during the 10–24 months after radioiodine remnant ablation (RRA) and their long-term outcomes. &lt;italic&gt;Methods&lt;/italic&gt;: Out of 839 retrospectively reviewed patients, 95 eligible DTC patients were included. Patients were classified as having incomplete response or no evidence of disease (NED). The sTg cut-off values with highest predicted accuracy for incomplete response at 10–24 months were calculated with receiver operator characteristics curve analysis. &lt;italic&gt;Results and Conclusion&lt;/italic&gt;: At 10–24 months after RRA, incomplete response was identified in 54 patients (57%) and 38/54 (70.4%) patients were found with structural evidence of disease. The remaining 16 patients (29.6%) had biochemical evidence of disease without structural evidence of disease. Forty-one patients (43%) were classified as having NED at 10–24 months after RRA and 27 patients (66%) did not receive further radioactive iodine (RAI) therapy and remained disease free at median follow-up of 6.5 years. Fourteen patients received second RAI treatment after 6 months and before the 10–24 months assessment time point. Of these, 2 had persistent tumor 6 years later. The sTg &amp;gt;0.6 µg/L at 6–10 months after RRA had optimal sensitivity (83.3%), specificity (56%) and negative predictive value (72%) of detecting incomplete response at 10–24 months after RRA. A total of 23/43 patients in the American Thyroid Association low-risk category had incomplete response after first RRA and 5/23 (21.7%) had recurrent/persistent disease at long-term follow-up.&lt;/p&gt; &lt;/abstract&gt;