Predictors of nodal metastasis in pediatric differentiated thyroid cancer.

Background/purpose: There are limited data identifying risk factors for nodal metastasis in children with differentiated thyroid cancer.

Methods: The 1998-2011 Surveillance, Epidemiology, and End Results Program database was queried for patients ≤18years of age diagnosed with differentiated thyroid cancer who underwent nodal examination. Patients were grouped by absence or presence of nodal metastasis. Multivariable logistic regression methods were used to identify independent risk factors for nodal metastasis.

Results: In total, 1075 children met study criteria: 734 (68%) had nodal metastases, while 341 (32%) did not. After adjustment, risk factors for nodal metastasis included larger tumor size (1.1-2cm: odds ratio [OR] 2.02, 95% confidence interval [CI] 1.22-3.34, p=0.006; 2.1-4cm: OR 3.37, 95% CI 2.03-5.60, p<0.001; > 4cm: OR 3.39, 95% CI 1.69-6.81, p=0.001), extrathyroidal extension (OR 7.28, 95% CI 4.07-13.01, p<0.001), and multifocal disease (OR 1.94, 95% CI 1.33-2.84, p=0.001).

Conclusions: Increasing tumor size, extrathyroidal extension, and multifocal disease are independent factors associated with nodal metastases in pediatric differentiated thyroid cancer. If these risk factors are present, children with differentiated thyroid cancer should undergo careful preoperative evaluation for evidence of lateral cervical lymph node metastases, and the central compartment should be evaluated intraoperatively, with consideration of central lymphadenectomy.

Level Of Evidence: Level III.