Juvenile differentiated thyroid carcinoma and the role of radioiodine in its treatment: a qualitative review

Abstract

Well under 15% of differentiated thyroid carcinoma (DTC) is diagnosed at £18 years of age. The population is heterogenous and the differences between prepubertal children and pubertals and adolescents are to be considered. Although very little has been reported on children with sporadic DTC under the age of 10 years, juvenile DTC has at least some undeniable differences with adult DTC: (1) larger primary tumor at diagnosis; (2) metastatic pattern and features, namely: (a) greater prevalence of neck lymph node and distant metastases at diagnosis, (b) lungs almost the sole distant metastatic site, (c) pulmonary metastases nearly always functional; (3) closer-to-normal and more frequent sodium-iodide symporter (NIS) expression; and (4) higher recurrence rate but longer overall survival. These differences are especially distinct in prepubertal children. The goals of primary treatment of juvenile DTC are to eradicate disease and extend not only overall, but recurrence-free survival (RFS). Extending RFS is itself a desirable goal in children because it improves quality-of-life, alleviates anxiety during psychologically formative years, reduces medical resource consumption, and may increase overall survival. Primary treatment of DTC generally comprises a combination of surgery, radioiodine ( 131 I) ablation, and thyroid hormone therapy applied at varying levels of intensity. Therapeutic decision-making must rely on retrospective adult and/or pediatric outcome studies and on treatment guidelines formulated mostly for adults. Differences between juvenile and adult DTC and physiology dictate distinct treatment strategies for children. We, and many others, advocate a routine intensive approach because of the more advanced disease at diagnosis, propensity for recurrence, and greater radioiodine responsiveness in children, as well as published evidence of significant survival benefits, especially regarding RFS. This intensive approach consists of total thyroidectomy and central lymphadenectomy in all cases, completed by modified lateral lymphadenectomy when necessary and followed by radioiodine administration. However, absence of prospective studies and of universal proof of overall causespecific survival benefits of this approach have led some to propose more conservative strategies. Most European centers give radioiodine ablation to the vast majority of juvenile DTC patients. Ablation seeks to destroy any residual cancer, including microfoci, as well as healthy thyroid remnant. Large studies have documented the procedure to decrease cause-specific death rates and, in children, to significantly lessen locoregional recurrence rates (by factors of 2-11) independent of the extent of surgery. There is universal agreement on treating inoperable functional metastases with large radioiodine activities. Treatment is especially effective in small tumor foci up to 1 cm in diameter, and should be administered every 6-12 months until complete response, loss of functionality, or attainment of cumulative activities between 18.5-3...

Thyroid Cancer in the Pediatric Population

“…The latter appearance associated with the presence of suspicious regional lymph nodes increases the risk of malignancy in pediatric thyroid nodules. However, the presence of cystic lesions should not be ignored since 50% of all malignant thyroid lesions have a cystic component and 8% of sonographic cystic lesions represent neoplasia (Niedziela, 2006,Jarzab, 2005,Luster, 2007.…”

“…Together with the tyrosine kinase receptor ligand it is associated to a higher recurrence risk in children. Gupta (2001) et al found that patients with PTC with the greatest number of proliferating lymphocytes in thyroid infiltrates have the longest disease free survival (Jarzab, 2005, Griffith 2006). On the other hand, patients with intense expression of B7-2 antigen had a greater propensity for recurrence (Jarzab, 2005).…”

“…Certain characteristic features, such as firmness of the mass and the degree of fixation to surrounding tissues, as well as lymphadenopathy and/or vocal cord paralysis are associated with an increased probability of malignancy. Pain, tenderness, difficulty swallowing and respiratory problems are not typically reported in the majority of pediatric patients (Jarzab, 2005). Important risk factors for the development of thyroid cancer in children include exposure to external radiation, congenital hypothyroidism and a history of prior malignancies (Parisi, 2007, Niedziela, 2006.…”

“…Unlike adults, pediatric patients often present with extensive regional nodal disease and distant metastasis at diagnosis. Cervical nodal disease ranges from 60-www.intechopen.com 90%; distant metastasis occurs in 13-23%, most commonly to the lung (Parisi, 2007, Jarzab, 2005. Tracheoesophageal nodes are the ones most frequently involved, followed by the mid jugular and the lower deep jugular group.…”

The Radioprotective Effects of Nano-Curcumin Against Genotoxicity Induced by Iodine-131 in Patients with Differentiated Thyroid Carcinoma (DTC) by Micronucleus Assay

“…The therapeutic effect of iodine-131 is the result of beta and gamma radiations, which is damaging to cells with direct or indirect manner (2,3). Most of Iodine-131 concentrates on residual thyroid tissue and kills tumor cells; however, it has several side effects such as radiation thyroiditis, sialadenitis, xerostomia, neck pain and edema, gastrointestinal symptoms (4), pulmonary problems, and defects in hematopoietic systems, nasolacrimal glands, and gonadal dysfunction, as well as second early malignancies (5,6). The late complications like secondary cancers.…”