The Prognostic Power of Preablation Stimulated Thyroglobulin in Children With Differentiated Thyroid Cancer

Abstract

Purpose

To analyze prognostic factors in children with differentiated thyroid carcinoma (DTC) who have been treated in a single center in the last 27 years.

Methods and patients

We studied 126 children (≤18 years old) who have been treated with near-total thyroidectomy followed by radio-iodine therapy and thyroid hormone replacement. Follow-up of the patients was done 2, 6, and 12 months after treatment and then by yearly evaluation. Response to treatment was defined according to the American Thyroid Association (ATA) guideline.

Results

Papillary thyroid cancer was the main pathology (93.7%), and 52.4% of the patients had lymph node metastasis at presentation, which was extensive (>5) in 30% of the patients. Distant metastasis was seen in 8.8%. The mean initial dose of I-131 was 74±42.2 MBq/kg. The median follow-up was 59 months and the median time to achieve an excellent response was 29 months. The pre-ablation stimulated thyroglobulin (psTg) level was 202.4±301.8 ng/ml in patients with first-year incomplete response compared to 11.2±17.5 ng/ml in others (P=0.001). Furthermore, using logistic regression, the psTg level was the only significant predictor of distant metastasis, and a psTg ≥13.75 ng/ml was the most powerful predictor of first-year incomplete response. Additionally, distant metastasis was more common in boys than girls, and it took longer time for boys to achieve an excellent response.

Conclusion

The psTg level was the only significant predictor of distant metastases in children with DTC, and a psTg level of ≥13.75 ng/ml was the most powerful predictor of first-year incomplete response.