Thyroid carcinoma is the most common endocrine malignancy. Recent advances in molecular profiling identified actionable mutations, leading to the availability of multiple FDA-approved drugs. The current treatments target angiogenesis (sorafenib and lenvatinib) or can be mutation specific (larotrectinib targeting NTRK gene fusion and selpercatinib targeting RET gene fusions).
Anaplastic thyroid carcinoma (ATC) has very poor prognosis, but the clinical outcomes appear to be improving with a multidisciplinary approach utilizing targeted therapy, immunotherapy, radiotherapy, and surgery when feasible.
In cases with suspected parathyroid carcinoma, comprehensive surgery by an experienced team remains the mainstay of therapy, although the role of adjuvant radiation and targeted therapy remains unclear.
Genetic counseling and testing is needed in all cases of pheochromocytoma/paraganglioma, even in the absence of family history of these tumors
The management of metastatic pheochromocytoma/paraganglioma should be in the context of a multidisciplinary and experienced team. Resection of the primary tumor when feasible is associated with improved outcome. Iobenguane I 131 is FDA approved for patients with metastatic pheochromocytoma/paraganglioma that retain meta-iodobenzylguanidine avidity, whereas traditional cytotoxic chemotherapy can be offered to select patients with rapidly progressing disease, especially in the presence of excess catecholamines. The role of targeted therapy is evolving, and extreme care must be exerted when using these drugs in patients with metastatic pheochromocytoma because they could exacerbate preexisting hypertension.
The combined use of mitotane with cytotoxic chemotherapy (etoposide, doxorubicin, cisplatin) is associated with a suboptimal response rate of 23% and represents the first-line systemic therapy in advanced adrenocortical carcinoma. Single-agent immune checkpoint inhibitors are associated with lower response rates based on small clinical trials.
Thyroid cancer is the most common endocrine malignancy. The incidence of thyroid cancer in the United States has slightly declined over the past 5 years and in 2020, approximately 52,890 new cases of thyroid carcinoma were estimated to be diagnosed in the United States, accounting for 3% of all new malignancies, with women accounting for almost 76% of all cases.1 Thyroid cancer occurs less frequently in children compared with adults, with a peak incidence of around 50 years. Despite this, overall long-term survival remains favorable. Histologic types (Table 51–1) include those that derive from the follicular epithelial cells (papillary and follicular), which account for the majority of thyroid cancers, and from the parafollicular C cells (medullary). Other thyroid tumors, including primary lymphomas of the thyroid, which are usually metastases from other primary sites, are also rarely encountered.
Table 51–1 Types of Thyroid Cancer
|Type ||Frequency ||Prognosis (10-year Overall Survival) |
|Originating From Follicular Cells |
|Papillary ||80% ||93% |
|Follicular ||11% ||85% |
|Hürthle cell ||3% ||76% |
|Anaplastic (undifferentiated) ||2% ||14% |
|Originating From C Cells |
|Medullary ||4% ||75% |