PRE-ABLATION THYROGLOBULIN AND THYROGLOBULIN TO THYROID-STIMULATING HORMONE RATIO MAY BE ASSOCIATED WITH PULMONARY METASTASES IN CHILDREN WITH DIFFERENTIATED THYROID CANCER

Objective: Pediatric differentiated thyroid cancer (DTC) frequently presents with extensive disease. We studied the value of pre-ablation thyroglobulin (Tg) and Tg normalized to thyroid-stimulating hormone (TSH) levels in predicting distant metastases in pediatric patients with DTC. Methods: This is a retrospective cohort study of patients <21 years old who underwent thyroidectomy followed by 131I ablation for DTC at 3 university hospitals over 20 years. Tg levels and the Tg/TSH ratio following surgery but prior to 131I ablation were assessed. The presence of distant metastatic disease was determined from the postablation whole-body scan. Results: We studied 44 patients with a mean age of 15.2 years (range 7 to 21 years) and mean tumor size of 2.8 cm. Eight patients had distant metastases and had a higher mean pre-ablation Tg value compared to patients without distant metastases (1,037 μg/L versus 93.5 μg/L, P<.01). The pre-ablation Tg/TSH ratio was also associated with the presence of distant metastases:...