Ryder, Mabel M

AbstractBackgroundThe development of systemic treatment options leveraging the molecular landscape of advanced thyroid cancer is a burgeoning field. This is a multidisciplinary evidence‐based statement on the definition of advanced thyroid cancer and its targeted systemic treatment.MethodsAn expert panel was assembled, a literature review was conducted, and best practice statements were developed. The modified Delphi method was applied to assess the degree of consensus for the statements developed by the author panel.ResultsA review of the current understanding of thyroid oncogenesis at a molecular level is presented and characteristics of advanced thyroid cancer are defined. Twenty statements in topics including the multidisciplinary management, molecular evaluation, and targeted systemic treatment of advanced thyroid cancer are provided.ConclusionsWith the growth in targeted treatment options for thyroid cancer, a consensus definition of advanced disease and statements regarding the utility of molecular testing and available targeted systemic therapy is warranted.

Abstract Context Clinical applications of genomic assessment of thyroid cancers are rapidly evolving. Objectives, Design, and Setting We studied tumor samples from patients with imminently threatening and rare thyroid cancers to identify genomic alterations that might correlate with outcomes and/or be productively therapeutically targetable. Patient Context Progressive and metastatic, and/or rare, thyroid cancers were studied, 2012 to 2016, at Mayo Clinic sites. Intervention The intervention was Foundation One tumor interrogation. Main Outcome Measures Main outcome measures included genomic alterations, patient characteristics, and overall survival. Results Samples from 55 patients were evaluated: 20 anaplastic thyroid cancers (ATCs) (36%), 25 radioactive iodine–refractory differentiated thyroid cancers (DTCs)/poorly differentiated thyroid cancers (PDTCs) (45%; 14 papillary thyroid cancer [PTCs], 6 PDTCs, 5 Hürthle cell cancers), 8 medullary thyroid cancers (MTCs) (15%), and 2 others (a spindle epithelial tumor with thymus-like differentiation, and a primary thyroid sarcoma). Overall, 72% of DTCs, 79% of ATCs, and 75% of MTCs were deemed to have potentially productively targetable alterations. The most commonly encountered mutation was of TERT promoter (56% of DTCs, 68% of ATCs)—but this is not presently targetable. Targetable BRAFV600E mutations were found in 40% of DTCs/PDTCs (83% of PTCs) and 32% of ATCs; of MTCs, 75% had targetable RET mutations, and 25% HRAS mutations. Of patient tumors with nonmutated BRAFV600E, 53% of DTC/PDTCs and 69% of ATCs had other potentially productively targetable mutations. Genomic alterations in our series of poor prognosis metastatic DTC/PDTCs also closely resembled those seen in ATC. Conclusions Whereas genomic interrogation of favorable prognosis thyroid cancer seems ill advised, potentially productively targetable mutations were demonstrated in the majority of tumors from patients with metastatic thyroid cancers requiring systemic therapy, suggesting a rationale for the selective application of this technology.

Background: Historical anaplastic thyroid cancer (ATC) outcomes have been terrible, with a median survival of only five months and <20% one-year survival. Improved outcomes are now achieved with aggressive initial therapy in stages IVA and IVB disease, but patients with distant metastatic disease (stage IVC) still do poorly; improved therapies are sorely needed. Kinase inhibitors have emerged as promising agents in the therapy of advanced medullary and differentiated thyroid cancer, but there are limited data regarding the use of lenvatinib in ATC. The aim of this study was to delineate clinical outcomes in a series of patients with advanced ATC in response to lenvatinib therapy. Methods: A retrospective analysis was conducted involving all lenvatinib-treated Mayo Clinic ATC patients in 2015. Results: Of 28 distinct ATC patients seen in 2015, three (11%) with metastatic disease of ECOG performance status 2–3 were treated with lenvatinib. Two patients were male; age range at ATC diagnosis was 57–84 years. All three patients attained successful local control of their disease with surgery and/or combined chemoradiotherapy. Lenvatinib was offered as the second, third, or fourth line of therapy at the time of metastatic disease progression. Two patients incurred minor responses to therapy, with structural regression of distant metastatic tumor disease soon after starting lenvatinib treatment (at one to two months), while one patient achieved stable disease, but no Response Evaluation Criteria In Solid Tumors partial responses resulted. Overall survival after starting lenvatinib was two, six, and seven months. Fatigue and hypertension were prominent, and one patient developed pulmonary emboli while on lenvatinib. Conclusion: This initial single-institution experience suggests that lenvatinib may have some disease-modifying activity in metastatic ATC that is otherwise refractory to cytotoxic chemotherapy. Unfortunately, observed benefits were transient, and toxicities were prominent. Clinical trials are required to ascertain better the utility of lenvatinib in the management of advanced ATC.