Differentiated thyroid cancer in adolescents - does extent of disease at presentation differ with age?

The authors sought to assess whether the age of 18 reflects a true pathological inflection point that justifies transitioning between pediatric and adult paradigms of care with differentiated thyroid cancer (DTC).

A retrospective chart review was conducted for patients aged 12-24 undergoing hemithyroidectomy or total thyroidectomy for papillary or follicular thyroid carcinoma from 2010 to 2020.

A total of 153 patients receiving surgery for DTC were assessed for pathological stage, nodal metastasis, and thyroid neoplasm characteristics. When comparing pathologic tumor staging of patients <18 vs. ≥18 years old, there was a significant relationship between age and pT stage (p=0.009), but not between age and pN stage (p=0.319). However, when comparing patients ≤15 vs. >15 years, there was a significant relationship between age and pT stage (p=0.015) and age and pN stage (p=0.016). Patients ≤15 years of age most commonly had stage pT2 tumors (48.9 %, n=22), whereas most >15 years had stage pT1 tumors (37.9 %, n=41). Of patients whose lymph nodes were analyzed, patients ≤15 years were most likely to have pN1b disease (31.1 %, n=14), while patients >15 years were most likely to have pN0 disease (33.3 %, n=36).

In this sample, separating children and adults at an age of 15, rather than 18, yielded more significant differences in risk of nodal involvement. Markers of invasive histology were more common in patients older than 15, while nodal involvement was more common in patients 15 and under.