Context: Risk stratification for persistent disease is an important step in pediatric differentiated thyroid cancer (DTC) management. The dynamic risk stratification (DRS) is a well validated system for adults, but not yet for children and adolescents.
Objective: To evaluate DRS performance and other prognostic factors in pediatric DTC.
Design: Cohort study.
Setting: Four DTC referral centers at tertiary teaching hospitals.
Patients: Patients aged ≤ 18 years at the time of DTC diagnosis.
Main outcome measures: All patients were classified according to risk stratification system of the 2015 ATA Children DTC guidelines. Patients were also classified according to DRS (excellent, indeterminate, biochemical, or structural incomplete responses). Disease status was evaluated after initial therapy and at last follow-up.
Results: Sixty-six patients were studied: 54 (81.8%) girls, age 14.5±3.0 years, 62(93.9%) papillary thyroid carcinomas. Tumor size was 2.3 cm (P25-75,1.6-3.5), and 41 (63.1%) had cervical and 18 (27.7%) distant metastasis at diagnosis. All patients underwent total thyroidectomy and 63 (95.5%) received radioiodine. Patients were classified according to DRS after initial therapy (n=63) as follows: 21 (33%) excellent, 13 (21%) indeterminate, 6 (9%) biochemical, and 23 (37%) structural incomplete responses. Notably, after 6.0 years (P25-75,2.7-10.0), most patients remained in the same category. Prognostic factors associated with persistent disease in the univariate analysis were TNM, ATA risk, DRS and stimulated postoperative thyroglobulin (sPOTg). Interestingly, the sPOTg cutoff of 37.8 ng/mL displayed 81% sensitivity and 100% specificity to predict excellent response.
Conclusion: DRS after initial therapy and sPOTg are strong predictors of disease status and might be helpful on defining follow-up strategies in pediatric DTC.
19 May 2018 - 22 May 2018