Patients
Potential cases of PTC were identified through review of the Texas Children’s Hospital pathology archives for the years 2005-2016, under a Baylor College of Medicine Institutional Review Board-approved protocol for clinical and genomic analysis of rare tumors. A total of 51 PTC cases were identified for clinical review, with metastatic, relapsed, and treatment-refractory cases prioritized for analysis (Figure 1). Ultimately, 40 cases were selected, all of which were diagnostic (pre-treatment) specimens obtained from either lobectomy or total thyroidectomy. Of note, 14 of the patients included in this cohort were also included in a prior study that included more targeted gene testing (Supplemental Table S1)18. Disease status was classified using the American Joint Committee on Cancer TNM classification system for differentiated thyroid carcinoma, 7th edition, and risk level was assessed as outlined in the American Thyroid Association (ATA) management guidelines for children with differentiated thyroid cancer19.