Recent advances in the management of anaplastic thyroid cancer

Abstract

Anaplastic thyroid cancer (ATC) is undoubtedly the thyroid cancer histotype with the poorest prognosis. The conventional treatment includes surgery, radiotherapy, and conventional chemotherapy. Surgery should be as complete as possible, securing the airway and ensuring access for nutritional support; the current standard of care of radiotherapy is the intensity-modulated radiation therapy; chemotherapy includes the use of doxorubicin or taxanes (paclitaxel or docetaxel) generally with platin (cisplatin or carboplatin). However, frequently, these treatments are not sufficient and a systemic treatment with kinase inhibitors is necessary. These include multitarget tyrosine kinase inhibitors (Lenvatinib, Sorafenib, Sunitinib, Vandetanib, Axitinib, Pazopanib, Pyrazolo-pyrimidine compounds), single target tyrosine kinase inhibitors (Dabrafenib plus Trametinib and Vemurafenib against BRAF, Gefitinib against EGFR, PPARγ ligands (e.g. Efatutazone), Everolimus against mTOR, vascular disruptors (e.g. Fosbretabulin), and immunotherapy (e.g. Spartalizumab and Pembrolizumab, which are anti PD-1/PD-L1 molecules). Therapy should be tailored to the patients and to the tumor genetic profile. A BRAF mutation analysis is mandatory, but a wider evaluation of tumor mutational status (e.g. by next-generation sequencing) is desirable. When a BRAFV600E mutation is detected, treatment with Dabrafenib and Trametinib should be preferred: this combination has been approved by the Food and Drug Administration for the treatment of patients with locally advanced or metastatic ATC with BRAFV600E mutation and with no satisfactory locoregional treatment options. Alternatively, Lenvatinib, regardless of mutational status, reported good results and was approved in Japan for treating unresectable tumors. Other single target mutation agents with fair results are Everolimus when a mutation involving the PI3K/mTOR pathway is detected, Imatinib in case of PDGF-receptors overexpression, and Spartalizumab in case of PD-L1 positive tumors. Several trials are currently evaluating the possible beneficial role of a combinatorial therapy in ATC. Since in this tumor several genetic alterations are usually found, the aim is to inhibit or disrupt several pathways: these combination strategies use therapy targeting angiogenesis, survival, proliferation, and may act against both MAPK and PI3K pathways. Investigating new treatment options is eagerly awaited since, to date, even the molecules with the best radiological results have not been able to provide a durable disease control.