Predictors of Bilateral Disease in Pediatric Differentiated Thyroid Cancer.

Abstract

CONTEXT\nTotal thyroidectomy is recommended for children with papillary thyroid carcinoma, partly because of a high prevalence of bilateral disease. Identifying characteristics that predict bilateral disease might identify candidates for more limited surgery.\n\n\nOBJECTIVES\nInvestigate associations of preoperative or histopathological characteristics with bilateral disease in children with differentiated thyroid cancer.\n\n\nDESIGN\nRetrospective cohort study (1998-2020).\n\n\nSETTING\nTwo academic hospitals.\n\n\nPATIENTS\nPatients <19 years who underwent total thyroidectomy for differentiated thyroid cancer.\n\n\nINTERVENTIONS\nDescription of clinical, sonographic, and histopathological characteristics.\n\n\nMAIN OUTCOME MEASURE\nPresence of bilateral disease on histopathology, assessed by univariable analysis and multivariable logistic regression.\n\n\nRESULTS\n115 subjects were analyzed (90% with papillary carcinoma). Median (range) age at diagnosis was 15.0 (8.1-18.9) years. Bilateral disease was present in 47/115 subjects (41%). Bilateral disease was associated with solid parenchyma, calcifications, irregular margins, and abnormal lymph nodes detected by ultrasound, Bethesda class V/VI cytology, papillary histology, tumor multifocality in the primary lobe, extrathyroidal extension, lymphovascular invasion, and nodal metastases. In multivariable analysis, only multifocality in the primary lobe was independently associated with bilateral disease (OR 7.61, 95% CI 2.44-23.8, p<0.001). Among clinically node-negative subjects with papillary carcinoma who did not have tumor multifocality in the primary lobe, bilateral disease was present in 5/32 (16%).\n\n\nCONCLUSIONS\nIn children with differentiated thyroid cancer, tumor multifocality in the primary lobe is associated with bilateral disease and should prompt consideration of completion thyroidectomy after initial lobectomy. Clinically node-negative children with tumors that are unifocal in the primary lobe have a low likelihood of contralateral disease.