Circulating thyrotropin receptor messenger RNA for evaluation of thyroid nodules and surveillance of thyroid cancer in children

PurposeThe aim of this study was to determine the role of thyrotropin receptor messenger RNA as a novel blood test for evaluation of thyroid nodules and cancer in children.MethodsWe reviewed thyroid disease management of patients younger than 18 years with thyrotropin receptor messenger RNA measurements identified from a prospective, institutional review board-approved registry during 2008 to 2010.ResultsThirty-nine thyrotropin receptor messenger RNA measurements were made in 21 female patients (12-17 years old; median, 16 years). Four patients with fine-needle aspiration only had benign thyroid cytology, and 3 of 4 had undetectable thyrotropin receptor messenger RNA. Seventeen patients underwent 22 thyroid operations. Preoperative thyrotropin receptor messenger RNA was measured in 9 patients: 3 of 4 with thyroid cancer had elevated levels and 3 of 5 with goiters undetectable. Postthyroidectomy surveillance (median, 16 months; range, 6-24) of 11 thyroid cancer patients (8 papillary, 3 follicular) showed that thyrotropin receptor messenger RNA was concordant with thyroglobulin in 14 (73%) of 19 measurements. In 3 (16%) of 19 measurements, thyrotropin receptor messenger RNA was the only blood test useful for disease assessment because of elevated antithyroglobulin antibodies. Overall, to predict thyroid cancer, thyrotropin receptor messenger RNA demonstrated 73% sensitivity, 82% specificity, 62% positive predictive value, 88% negative predictive value, and 79% accuracy.ConclusionThyrotropin receptor messenger RNA provides complementary evaluation to thyroglobulin and fine-needle aspiration for pediatric thyroid nodule management.