Endocrine Abstracts

Objectives: Childhood papillary thyroid cancer (CPTC) often presents with advanced disease but rarely results in cause-specific mortality (CSM). Controversy remains regarding optimal management and association with non-thyroid second primary malignancies (NSPM). We analyzed outcome in 189 CPTC patients and assessed the influence of radioiodine remnant ablation (RRA) and the utility of the American Thyroid Association risk-groups (ATA-R) in predicting tumor recurrence (TR).

Methods: All patients were operated by specialist surgeons. 88% had bilateral thyroidectomy (BT); at first surgery 86% had neck nodes removed, 17% had pT4a tumors and 78% were pN1, 58% with 5 or more regional metastases (RM). During 1951-2020 RRA was given to 43% of TNM stage I patients having BT with curative intent. Mean follow-up was 29 yr (range 1-71). TR and CSM details were derived from a computerized database and analyzed as previously described (WJS 43: 329, 2018).

Results: During 1936-50, 9/19 died from cancer; one from PTC and 8 from NSPM (7 having received radiation therapy); 15 died from all causes, as compared to expected 6 (P<.001). During 1951-2020 none of 170 patients died of PTC but 3 died from NSPM.;13 died from all causes, as compared to 13 expected (P=.97). In 169 patients operated with curative intent 25-yr TR rate was 37%; 57 patients (34%) had recurrence:81% RM and 19% distant metastases (DM). Patient ages <11 and pT4a tumors were significantly (P<.05) associated with postop RM; tumor size >4 cm and pT4a tumors with postop DM (P<.002). BT+RRA did not significantly improve the 20-yr TR rates of 28% and 3% seen with BT alone for RM (P=.75) and DM (P=.99). We applied the ATA-R to 167 patients who had no DM at presentation and had complete tumor excision. 61 were classed as ATA-low risk, 49 as intermediate and 57 as ATA high-risk. 25-yr TR rates for low, intermediate, and high-risk groups were 24%, 34% and 53% (P=0.0015). 25-yr rates for RNM and DM for the 3 risk groups were 19, 34 and 40% (P=0.05) and 0, 4 and 19% (P<.001).

Conclusions: During the I¹³¹ era (1951-2020), we have noted no excess all-causes mortality in CPTC but we have not found that RA reduces postop TR after BT. Given that 78% present with pN1 disease, persistent/recurrent disease within RNM may be expected. The ATA-R high-risk group seems capable of predicting DM; perhaps in future years many CPTC patients classed as low-risk may require less than BT.