Management of the child with thyroidal carcinoma

[30 years of prophylactic thyroidectomy for hereditary medullary thyroid cancer : A milestone in translational medicine]

Medullary thyroid cancer (MTC) is the most frequent manifestation of multiple endocrine neoplasia type 2 (MEN2) that determines the oncological outcome. Germline mutations in the rearranged during transfection (RET) protooncogene, a tumor suppressor gene on chromosome 10q11.2, were identified 30 years ago as the genetic basis of MEN2 and published in 1993 and 1994. These seminal findings gave rise to the concept of prophylactic thyroidectomy for asymptomatic gene mutation carriers based on a positive RET gene test, which has become the standard of care ever since. Clinical genetic investigations showed genotype-phenotype correlations with respect to the individual gene mutation regarding the penetrance and onset of MTC and to a lesser extent also with respect to the other components of MEN2, pheochromocytoma and primary hyperparathyroidism. From this a clinically relevant risk stratification could be derived. Initially, the optimal timing of prophylactic thyroidectomy was primarily based on the RET genotype alone, which was not sufficient for a precise age recommendation and subsequently required additional consideration of calcitonin serum levels for fine tuning. Calcitonin levels first show the risk of lymph node metastasis when they exceed the upper normal limit of the assay independent of carrier age and RET mutation. Routine calcitonin screening of patients with nodular thyroid disease, screening of families on identification of MEN2 index patients, and pre-emptive thyroidectomy in carriers of gene mutations with normal calcitonin levels have led to the fact that nowadays, 30 years after the first description of the gene mutations causing the disease, the life-threatening hereditary MTC has become curable: a shining example for the success of translational transnational medical research for the benefit of patients.

Evaluation and management of the pediatric thyroid nodule

Thyroid nodules are commonly diagnosed in adults. Although rare in children, the risk for thyroid cancer is much higher in the pediatric population compared with adults. Presenting as either a solitary nodule or a multinodular goiter, thyroid nodular disease in children requires a thorough workup that includes a detailed clinical examination comprised of prior history of thyroid disease in the patient or in their family, history of radiation exposure, careful palpation of the thyroid and lymph nodes, blood tests, ultrasonography, and cytological assessment. Thyroid surgery is the gold-standard treatment for pediatric thyroid nodules; nonetheless, the extent of surgery remains controversial. Because surgery is not without risk, the decision matrix necessitates focus on the benefits of surgery for the child contingent upon all the preoperative exams. New diagnostic technology such as molecular testing with fine needle aspiration biopsy may help distinguish between benign and malignant lesions while potentially decreasing surgery for benign disease. The objective of this review is to summarize new concepts in clinical disease management of nodular thyroid disease in the pediatric population, including patient history, medical examination, and diagnosis workup.

Differentiated thyroid cancer

OBJECTIVE

The retrospective analysis of the case files of children with differentiated thyroid carcinoma (DTC) was performed to define the disease by its presentation, clinical course and outcome of radioiodine therapy.

METHODS

Between 1967 to October 2002, 1754 patients with thyroid cancer were treated in the Dept of Neuclear Medicine, AIIMS, out of which 122 (7%) were < or = 20 years of age (71 girls and 51 boys). The mean age was 15.8 +/- 3.6 years and the mean duration of follow-up was 90 +/- 59.3 months. Mean tumor size was 4.4 cm. Histologically, 85% of the patients had papillary and rest follicular carcinoma. Cervical lymph node involvement was seen in 64%, and distant metastases, mainly pulmonary, in 23% of the patients. The presentation of the disease was very aggressive in the first decade of life with male preponderance. All but one patient in this age group had nodal and/or distant metastases; in 83.3% the disease had spread to the lymph nodes and 67% had metastases to the lungs. The post-surgery 48-hour mean radioiodine neck uptake was 10.5 +/- 7.6%.

RESULTS

94% of the residual thyroid, 88% of nodal metastases and 71% of pulmonary metastases were ablated requiring mean cumulative doses of 2.8 +/- 2.7 GBq, 4.5 +/- 2.7 GBq and 10.4 +/- 7.9 GBq of 131I, respectively. Average number of doses required for remnant, nodal and pulmonary metastases ablation were 1.3, 2.2 and 3.3, respectively. 80% of the patients with only remnant thyroid tissue and 50% with cervical lymph node metastases got ablated with a single dose of 131I. Overall, 87% patients were currently free of disease. While, nine patients had nodal recurrence between surgery and radioiodine treatment, no recurrence was observed thereafter and 3 disease related deaths producing overall mortality of 2.5% (all in children < or =10 years of age) were seen in the mean follow-up of 7.5 years.

CONCLUSION

Differentiated thyroid cancer in children and adolescents is rare but aggressive. The biological behavior differs from that in adults and is related to the age. Younger the age (< or =10 years), more aggressive and widespread is the disease with male preponderance and high mortality. The post-surgical radioiodine ablation/therapy is an important and effective adjuvant in the management of DTC in children and adolescents and even though they present with advance disease, long-term survival and overall prognosis is good.

Thyroid cancer: a review of treatment and follow-up

The importance of thyroid cancers far exceeds their frequency, since they are uncommon tumours accounting for only 1% of all malignancies and for even smaller proportion of cancer deaths (0.2%). A variety of distinct tumour types arise in the thyroid gland, with variable natural histories resulting from different rates of growth and biological aggressiveness. The long natural history of the majority of thyroid neoplasms imposes a commitment for long-term follow-up and stresses the importance of planning treatment so as to avoid delayed complications that impair the quality of life of patients. The management of thyroid cancer is multidisciplinary, requiring consultation and active intervention by surgeons, endocrinologists and radiotherapists. Surgery is of paramount importance in the successful eradication of the tumours while radioiodine offers a unique therapeutic approach. Treatment must be strongly influenced by consideration of prognostic variables.

Lymph node metastasis from papillary-follicular thyroid carcinoma in young patients

A total of 117 patients under 20 years of age with papillary and/or follicular thyroid cancer presented to the M. D. Anderson Cancer Center between 1949 and 1987. The most common presenting symptom was a cervical mass. Twenty percent of the patients had a history of prior irradiation. Sixty percent initially had palpable lymph nodes, while 26% who had clinically negative examinations had pathologically positive lymph nodes. Recurrence was highest in regional lymph nodes at 24%, with only a 4% recurrence rate at the primary site and a 3% recurrence rate at distant sites. There were no deaths due to the thyroid cancer. To maintain a low rate of recurrence, near-total thyroidectomy with neck dissection followed by iodine 131 treatment should be considered in these young patients.

Differentiated thyroid cancer in children

Differentiated thyroid cancer in children remains a controversial disease entity. Its incidence has markedly declined over the last decade since the use of radiotherapy in the treatment of benign conditions of the head, neck, and thorax was abandoned. Other etiologic factors have become relatively more important. The clinical presentation of childhood thyroid cancer is similar to that found in adults, except for a higher frequency of local and distant metastases at the time of initial diagnosis. The specificity and sensitivity of diagnostic tests are limited; however, like in adults, fine-needle aspiration compares favorably with other available diagnostic methods. The therapeutic approach to a child with thyroid cancer represents the most controversial issue associated with the disease. This review provides a discussion of the rationale for the different therapeutic options and emphasizes the excellent prognosis and survival rates, especially when patients are subjected to aggressive treatment with total thyroidectomy followed by the administration of radioactive iodine.

Management of thyroid nodules. I: History and physical examination, blood tests, X-ray tests, and ultrasonography

The approach to the management of the thyroid nodule remains controversial. Confusion exists because virtually any thyroidal disease can present as a clinically solitary nodule which means there is no uniformity regarding natural history, incidence, prevalence, epidemiology, and pathophysiology.. The variety of definitions of thyroid nodules and thyroid carcinoma and the different modes of study selection and individual bias add to the confusion. Diagnostic approaches have not yielded a completely reliable technique to differentiate benign from malignant thyroidal disease. A history of neck irradiation of cervical lymphadenopathy significantly increases the chance of thyroid malignancy, but other parameters of the history or physical examination as well as blood tests are unreliable. Ultrasound displays anatomic but not histologic features. X-ray techniques (plain films, computed tomographic scans, xeroradiography, chest x-ray, barium swallow, lymphography, and angiography) have been used to visualize thyroid nodules, with some techniques proving more useful than others.

Thyroid cancer in childhood

Thyroid cancer in childhood is a relatively rare condition. Often it shows biological characteristics different from those seen in adults. Based upon 10 cases in our clinic and 57 cases collected from the Japanese literatures, clinical features, pathology, treatment and prognosis of thyroid cancer in childhood are discussed. Pathogenesis is most likely to be related to hormonal changes during adolescence and previous radiation of the neck region. Cervical lymph nodes swelling was the chief complaint in 84.6 per cent of the cases. On the other hand, pulmonary metastases were recognized in the early stages in 33.5 per cent of the cases. Radical excision of the tumor with modified radical neck dissection is the treatment most frequently employed even in the presence of lung metastases. However, hypoparathyroidism and recurrent nerve injuries should be avoided at all cost in view of long life expectancy and the difficulty in treating them satisfactorily. Prognosis could be as good for children as it is for adults except in cases with early lung metastases.

Total thyroidectomy for occult familial medullary carcinoma of the thyroid in children

Experience with 17 children in one kindred with familial medullary carcinoma of the thyroid and pheochromocytoma has demonstrated the utility and validity of periodic provocative testing by calcium infusion or pentagastrin injection in the identification of children with early medullary carcinoma of the thyroid or its premalignant precursor, C-cell hyperplasia. In these 17 patients with two consecutive elevations of calcitonin levels greater than 0.55 ng/ml after stimulation all but one have had MTC or CCH at operation. Total thyroidectomy has been well tolerated and can be performed with an acceptably low incidence of complications in this group of patients.

Familial medullary carcinoma of the thyroid

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