Researchers reviewed new therapies used to treat patients with medullary thyroid carcinoma (MTC), as published in Annales d’Endocrinologie.
“Surgery represents the initial treatment for localized sporadic forms of MTC. Total thyroidectomy must be systematic due to multifocal, small-sized tumors being frequently found, meaning lobectomy is not possible,” Puerto et al wrote.
At 3 months post-surgery, the American Thyroid Association recommends surveillance adapted to the results of calcitonin and carcinoembryonic antigen assays.
MTC is an exceedingly rare cancer, accounting for only approximately 1% of the total number of thyroid cancers. Like other well-differentiated neuroendocrine tumors, the spontaneous evolution of MTC is slow. Prognosis is strongly correlated with the stage of the disease upon diagnosis: in metastatic MTC, the median survival is a mere 3.2 years.
In terms of systemic treatments available for MTC, tyrosine kinase inhibitors first became available in 2012. Puerto and colleagues reviewed the various clinical studies into the efficacy and safety of tyrosine kinase inhibitors.
Read more about MTC etiology
“In summary, multi-kinase inhibitors of tyrosine kinase represent the first revolution in the treatment of MTC due to their efficacy in comparison to the classical chemotherapy treatments that were available up to that time,” the authors said. “However, their tolerance was mediocre, leading to frequent reductions in dose which may compromise their efficacy.”
Selective RET inhibitors are another form of therapy available to treat MTC. They work by targeting the RET pathway, which is implicated in many MTC cases. One drug of this class that has shown significant promise in improving disease parameters is selpercatinib. It has gained FDA and French regulatory authority approval for use in selected patients with MTC carrying a RET mutation.
“The development of new pharmacological agents will be necessary in the future to combat new mutations that confer tumor resistance, but also for the treatment of MTCs not carrying RET mutations,” Puerto et al concluded. The improvements in the therapeutic landscape of MTC are indeed encouraging, however, more needs to be done.
Puerto M, Borson-Chazot F, Tabarin A. Updates on therapy for medullary thyroid cancer in 2021. Ann Endocrinol. Published online December 15, 2021. doi:10.1016/j.ando.2021.12.002