Current Controversies in the Management of Pediatric Patients with Well-Differentiated Nonmedullary Thyroid Cancer: A Review

Abstract

Current treatment strategies for pediatric patients with nonmedullary, well-differentiated thyroid carcinoma (WDTC) are derived from single-institution clinical cohorts, reports of extensive personal experience, and extrapolation of several common therapeutic practices for this tumor in adults. Because pediatric WDTC is an uncommon malignancy, the issues of its optimal initial and subsequent long-term treatment and follow-up remain controversial. Pediatric patients with WDTC can be divided into two groups: children younger than 10 years of age and teenagers/adolescents between 10 and 18 years of age because these groups have different recurrence and mortality rates. We hereby present our views and interpret them in the light of the pertinent literature. Our recommendations on treatment strategies are more relevant for younger children. After midpuberty, optimal treatment is adequately addressed in the relevant literature on adults. For the majority of patients, total/near-total thyroidectomy is currently recommended as the standard initial therapy for WDTC. This is commonly followed by administration of radioiodine (RAI; (131)I) therapy to destroy residual normal thyroid tissue (remnant). Routine (131)I remnant ablation has been shown to: (1). decrease the risk of local recurrences, (2) increase the sensitivity of subsequent diagnostic RAI whole-body scanning (WBS), and (3) render serum thyroglobulin (Tg) a highly sensitive marker for recurrent/residual disease during long-term follow-up. We recognize that the above practices are not universally adhered to in children and adolescents, because the risk stratification and intensity of applied therapeutic measures are influenced by institutional traditions and personal experience. In our view, aggressive initial management, followed by evaluations at regular intervals after thyroidectomy and (131)I remnant ablation, in conjunction with long-term thyroid hormone suppressive therapy (THST), result in decreased recurrence rates in pediatric patients with WDTC. Follow-up examinations should include a diagnostic RAI ((131)I or (123)I) WBS and measurement of serum Tg, both performed under conditions of TSH stimulation, as well as neck ultrasonography (US). Our strategy is corroborated by data from retrospective clinical cohort studies. In this malignancy, no evidence of disease (NED) status can be defined as the combination of a negative diagnostic WBS and the presence of undetectable or low serum Tg levels, both tested under TSH stimulation. These findings should be accompanied by the absence of anatomically definable disease by standard imaging modalities, e.g., neck US or chest computed tomography (CT). Although the long-term survival rates are good overall in this disease, selected patients may require further surgery or (131)I therapy for the eradication or clinical control of metastases. Finally, and importantly, because the duration of follow-up is lifelong, the care of children with prior diagnosis of WDTC should be transferred to an adult endocrinologist after th...

Pediatric Thyroid Cancers: An Indian Perspective

“…Lymph node involvement at diagnosis is seen in 40-90% of children [2,25,26], compared with 20-50% of adults [27]. Thirdly, distant metastases, usually pulmonary, are commoner (20-30%) in children, whereas they are seen in about 2% adults [2,9,22,26,28]. We found pulmonary metastases in about 20% of patients in our series; these were significantly higher in patients with lymph nodal involvement than in those with solitary thyroid nodule.…”

“…DTC having onset before 10 years tend to be even more aggressive, and may be more widespread, with increased recurrences and mortality [22,33]. Kumar and Bal reported similar aggressive disease in children below 10 years of age [9].…”

“…FTC is usually a unifocal tumor and tends to have initial hematogenous metastases to lungs and bones, while lymph node metastases are uncommon [7,22]. Multifocal disease is more common in children than adults, being seen in about 40% of pediatric DTC cases [6].…”

“…Some surgeons cite the excellent survival in these patients counterbalancing the morbidity of aggressive surgery, and hence recommend conservative surgery [35,36] Most surgeons prefer to perform a total thyroidectomy for pediatric DTCs [6,7,22,25,29,[37][38][39][40], and the arguments in favour of this are multifold: (a) Multifocal disease occurs in 40% of pediatric PTC, and has a greater risk for recurrence; (b) Pediatric DTC commonly has regional lymph node disease and a greater risk for distant metastasis; (c) Total thyroidectomy will facilitate the future use of radioactive iodine (RAI) where indicated; (d) Postoperative RAI scans and thyroglobulin assays can be best used after total thyroidectomy, these are especially useful in picking pulmonary metastases that may be undetected on initial X-ray. We found that an initial X-ray of chest picked only about 31% of pulmonary metastases [3].…”

“…For therapy, usually an empiric dosing is used according to the uptake on diagnostic scan and the site of disease or metastases: 50-100 mCi for remnant and neck residual, 150 mCi for pulmonary metastases, and 200 mCi for bony and other metastases [22]. We practise a similar strategy.…”