ESMO Congress 2024 | OncologyPRO

Abstract 1937P

Background

To clarify the clinicopathological features and clinical outcomes of histological subtypes of papillary thyroid carcinoma (PTC) in the pediatric and adolescent population treated at a single institution.

Methods

A total of 153 PTC patients ≤18 years of age who underwent initial surgery between 1979 and 2019 were investigated. The most common subtypes included classic PTC in 124 (81%), solid variant in 16 (10%), diffuse sclerosing variant in 7 (5%), and follicular variant in 6 (4%). Cause-specific survival (CSS) and disease-free survival (DFS) rates were calculated by the Kaplan–Meier method.

Results

There were 135 female and 18 male patients, with a mean age at the time of surgery of 16 (range, 8-18) years, and 5% (8 patients) were ≤10 years of age at diagnosis. At initial surgery, 49 patients (32%) had lymph node metastases diagnosed preoperatively (cN1), 16 (10%) had gross extrathyroidal extension (ETE), and 18 (12%) had lung metastases. Total thyroidectomy was performed in 55 (36%) patients, and 98 (64%) patients underwent less than total thyroidectomy. During a mean follow-up of 16 years, 3 patients died of their disease, and 34 patients had recurrent disease. The 30-year CSS rate was 97.2%, and the 30-year DFS rate was 65.0%. On univariate analysis, extensive ETE (p=0.001) and cN1 (p=0.003), but not histological subtype (p=0.21), were associated with disease recurrence. Extensive ETE and cN1 were identified as significant factors related to DFS on multivariate analysis (hazard ratio (HR) 5.2, confidence interval (CI) 1.9-12.4, p=0.0028; HR 3.2, CI.6-6.6, p=0.0021).

Conclusions

The prognosis of pediatric patients with PTC was good, but recurrence was common. In pediatric PTC, histological subtype did not affect survival and recurrence.