Finding targetable gene fusions can expand the limited treatment options in radioactive iodine-refractory (RAI-r) thyroid cancer. To that end, we established a novel cell line ‘JVE404’ derived from an advanced RAI-r papillary thyroid cancer (PTC) patient, harboring an EML4-ALK gene fusion variant 3 (v3). Different EML4-ALK gene fusions can have different clinical repercussions. JVE404 cells were evaluated for cell viability and cell signaling in response to ALK inhibitors crizotinib, ceritinib and lorlatinib, in parallel to the patient’s treatment. He received, after first-line lenvatinib, crizotinib (Drug Rediscovery Protocol (DRUP) trial), and lorlatinib (compassionate use). In vitro treatment with crizotinib or ceritinib decreased viability in JVE404, but most potently and significantly only with lorlatinib. Western blot analysis showed a near total decrease of 99% and 89%, respectively, in pALK and pERK expression levels in JVE404 cells with lorlatinib, in contrast to remaining signal intensities of a half and a third of control, respectively, with crizotinib. The patient had a 6-month lasting stable disease on crizotinib, but progressive disease occurred, including the finding of cerebral metastases, at 8 months. With lorlatinib, partial response, including clinical cerebral activity, was already achieved at 11 weeks’ use and ongoing partial response at 7 months. To our best knowledge, this is the first reported case describing a patient-specific targeted treatment with lorlatinib based on an EML4-ALK gene fusion v3 in a thyroid cancer patient, and own cancer cell line. Tumor-agnostic targeted therapy may provide valuable treatment options in personalized medicine.
Mehtap Derya Aydemirli, Jaap D H van Eendenburg, Tom van Wezel, Jan Oosting, Willem E Corver, Ellen Kapiteijn, and Hans Morreau
Kathleen A. Luckett, Jennifer R. Cracchiolo, Gnana P. Krishnamoorthy, Luis Javier Leandro-Garcia, James Nagarajah, Mahesh Saqcena, Rona Lester, Soo Y. Im, Zhen Zhao, Scott W Lowe, Elisa de Stanchina, Eric J Sherman, Alan L Ho, Steven D Leach, Jeffrey A Knauf, and James A Fagin
Constitutive MAPK activation silences genes required for iodide uptake and thyroid hormone biosynthesis in thyroid follicular cells. Accordingly, most BRAFV600E papillary thyroid cancers (PTC) are refractory to radioiodide (RAI) therapy. MAPK pathway inhibitors rescue thyroid differentiated properties and RAI responsiveness in mice and patient subsets with BRAFV600E-mutant PTC. TGFβ also impairs thyroid differentiation and has been proposed to mediate the effects of mutant BRAF. We generated a mouse model of Braf-PTC with thyroid-specific knockout of the TgfβR1 gene to investigate the role of TGFβ on thyroid differentiated gene expression and RAI uptake in vivo. Despite appropriate loss of TgfβR1, pSmad levels remained high, indicating that ligands other than TGFβ1 were engaging this pathway. The activin ligand subunits Inhba and Inhbb were found to be overexpressed in BrafV600E mutant thyroid cancers. Treatment with follistatin, a potent inhibitor of activin, or vactosertib, which inhibits both TGFβR1 and the activin type I receptor ALK4, induced a profound inhibition of pSMAD in BrafV600E-PTCs. Blocking SMAD signaling alone was insufficient to enhance iodide uptake in the setting of constitutive MAPK activation. However, combination treatment with either follistatin or vactosertib and the MEK inhibitor CKI increased 124I uptake compared to CKI alone. In summary, activin family ligands converge to induce pSMAD in Braf-mutant PTCs. Dedifferentiation of BrafV600E-PTCs cannot be ascribed primarily to activation of SMAD. However, targeting Tgfβ/activin-induced pSMAD augmented MAPK inhibitor effects on iodine incorporation into BRAF tumor cells, indicating that these two pathways exert interdependent effects on the differentiation state of thyroid cancer cells.
Georgios Kostopoulos, Ioannis Doundoulakis, Christina Antza, Emmanouil Bouras, Krishnarajah Nirantharakumar, Dimitrios Tsiachris, G Neil Thomas, Gregory Y H Lip, and Konstantinos A Toulis
Differentiated thyroid cancer (DTC) represents the most common form of thyroid neoplasms and is becoming increasingly prevalent. Evidence suggests a possible relationship between DTC diagnosis and subsequent atrial fibrillation (AF). If confirmed, this may present an alarming health risk (AF) in an otherwise condition with a relatively good prognosis (DTC). The aim of this systematic review and meta-analysis is to provide for the first time a pooled estimate of AF incidence in DTC patients in comparison to healthy controls. A detailed search in electronic databases, clinical trial registries and grey literature was performed to identify studies reporting the incidence of AF in DTC patients. Newcastle–Ottawa quality assessment scale was used to assess study quality. We used a random effects (RE) generalized linear mixed model (GLMM) in pooling of individual studies and also calculated a prediction interval for the estimate of a new study. Six observational studies met the eligibility criteria, which included totally 187,754 patients with DTC and 199,770 healthy controls. The median follow-up period was 4.3 to 18.8 years; the incidence rate of AF was 4.86 (95% CI, 3.29 to 7.17, I2 = 96%) cases per 1000 person-years, while the incidence rate ratio was 1.54 (95% CI, 1.44 to 1.65, I2 = 0%, 95% PI, 1.33 to 1.78).This is the first meta-analysis to confirm that patients with DTC are at a high risk for developing AF, which may be attributed to a state of iatrogenic hyperthyroidism due to long-term thyrotropin suppression therapy.
Adam Stenman, Samuel Backman, Klara Johansson, Johan O Paulsson, Peter Stålberg, Jan Zedenius, and C Christofer Juhlin
Pediatric papillary thyroid carcinomas (pPTCs) are often indolent tumors with excellent long-term outcome, although subsets of cases are clinically troublesome and recur. Although it is generally thought to exhibit similar molecular aberrancies as their counterpart tumors in adults, the pan-genomic landscape of clinically aggressive pPTCs has not been previously described. In this study, five pairs of primary and synchronously metastatic pPTC from patients with high-risk phenotypes were characterized using parallel whole-genome and -transcriptome sequencing. Primary tumors and their metastatic components displayed an exceedingly low number of coding somatic mutations and gross chromosomal alterations overall, with surprisingly few shared mutational events. Two cases exhibited one established gene fusion event each (SQSTM1-NTRK3 and NCOA4-RET) in both primary and metastatic tissues, and one case each was positive for a BRAF V600E mutation and a germline truncating CHEK2 mutation, respectively. One single case was without apparent driver events and was considered as a genetic orphan. Non-coding mutations in cancer-associated regions were generally not present. By expressional analyses, fusion-driven primary and metastatic pPTC clustered separately from the mutation-driven cases and the sole genetic orphan. We conclude that pPTCs are genetically indolent tumors with exceedingly stable genomes. Several mutations found exclusively in the metastatic samples which may represent novel genetic events that drive the metastatic behavior, and the differences in mutational compositions suggest early clonal divergence between primary tumors and metastases. Moreover, an overrepresentation of mutational and expressional dysregulation of immune regulatory pathways was noted among fusion-positive pPTC metastases, suggesting that these tumors might facilitate spread through immune evasive mechanisms.
Patricia Borges de Souza and Chris McCabe
Radioiodine (RAI) therapy has been used to treat thyroid diseases for around 80 years, and yet it is only relatively recently that we are beginning to manipulate its use, as we understand more of the cellular complexities which govern its success. From the benign nature of hyperthyroidism to malignant thyroid carcinomas and their metastases, RAI has profoundly changed the management of thyroid disorders. However, the complex journey which has elicited this simple therapy is worth exploring.
Ha Nguyen, Komal Shah, Steven G Waguespack, Mimi I Hu, Mouhammed Amir Habra, Maria E Cabanillas, Naifa L Busaidy, Roland Bassett, Shouhao Zhou, Priyanka C Iyer, Garrett Simmons, Diana Kaya, Marie Pitteloud, Sumit K Subudhi, Adi Diab, and Ramona Dadu
Data on the diagnosis, natural course and management of immune checkpoint inhibitor (ICI) related hypophysitis (irH) are limited. We propose this study to validate the diagnostic criteria, describe characteristics and hormonal recovery and investigate factors associated with occurrence and recovery of irH. A retrospective study including patients with suspected irH at the University of Texas MD Anderson Cancer Center from 5/2003 to 8/2017 was conducted. IrH was defined as: (1) ACTH or TSH deficiency plus MRI changes or (2) ACTH and TSH deficiencies plus headache/fatigue in the absence of MRI findings. We found that of 83 patients followed for a median of 1.75 years (range 0.6-3), the proposed criteria used at initial evaluation accurately identified 61/62 (98%) irH cases. In the irH group (n=62), the most common presentation were headache (60%), fatigue (66%), central hypothyroidism (94%), central adrenal insufficiency (69%) and MRI changes (77%). Compared with non-Ipilimumab (Ipi) regimens, Ipi has a stronger association with irH occurrence (p=0.004) and a shorter time to irH development (p<0.01). Thyroid, gonadal and adrenal axis recovery occurred in 24%, 58% and 0% patients, respectively. High dose steroids (HDS) or ICI discontinuation were not associated with hormonal recovery. In the non-irH group (n=19), one patient had isolated central hypothyroidism and 6 had isolated central adrenal insufficiency. All remained on hormone therapy at last follow up. We propose a strict definition of irH that identifies the vast majority of patients. HDS and ICI discontinuation is not always beneficial. Long term follow up to assess recovery is needed.
Trisha Dwight, Edward Kim, Karine Bastard, Diana E Benn, Graeme Eisenhofer, Susan Richter, Massimo Mannelli, Elena Rapizzi, Aleksander Prejbisz, Mariola Pęczkowska, Karel Pacak, and Roderick Clifton-Bligh
Mosaic or somatic EPAS1 mutations are associated with a range of phenotypes including pheochromocytoma and/or paraganglioma (PPGL), polycythemia and somatostatinoma. The pathogenic potential of germline EPAS1 variants however is not well understood. We report a number of germline EPAS1 variants occurring in patients with PPGL, including a novel variant c.739C>A (p.Arg247Ser); a previously described variant c.1121T>A (p.Phe374Tyr); several rare variants, c.581A>G (p.His194Arg), c.2353C>A (p.Pro785Thr) and c.2365A>G (p.Ile789Val); a common variant c.2296A>C (p.Thr766Pro). We performed detailed functional studies to understand their pathogenic role in PPGL. In transient transfection studies, EPAS1/HIF-2α p.Arg247Ser, p.Phe374Tyr and p.Pro785Thr were all stable in normoxia. In co-immunoprecipitation assays, only the novel variant p.Arg247Ser showed diminished interaction with pVHL. A direct interaction between HIF-2α Arg247 and pVHL was confirmed in structural models. Transactivation was assessed by means of a HRE-containing reporter gene in transiently transfected cells, and significantly higher reporter activity was only observed with EPAS1/HIF-2α p.Phe374Tyr and p.Pro785Thr. In conclusion, three germline EPAS1 variants (c.739C>A (p.Arg247Ser), c.1121T>A (p.Phe374Tyr) and c.2353C>A (p.Pro785Thr)) all have some functional features in common with somatic activating mutations. Our findings suggest that these three germline variants are hypermorphic alleles that may act as modifiers to the expression of PPGLs.
Pei-Pei Xu, Su Zeng, Xiao-Tian Xia, Zi-Heng Ye, Mei-Fang Li, Ming-Yun Chen, Tian Xia, Jing-Jing Xu, Qiong Jiao, Liang Liu, Lian-Xi Li, and Ming-Gao Guo
Our aims were to uncover the role of FAM172A (Family with sequence similarity 172 member A) in the pathogenesis of follicular thyroid carcinoma (FTC) and to evaluate its value in the differential diagnosis between malignant and benign thyroid follicular lesions. FAM172A expression was evaluated by q-PCR, immunoblotting and immunohistochemistry (IHC). The ability of proliferation, migration and invasion of cells were assessed by Cell Counting Kit-8 assay (CCK8), clone-formation and Transwell assays. Nude mouse tumorigenicity assays were used to investigate the role of FAM172A in the pathogenesis of FTC in vivo. The value of FAM172A in the differential diagnosis for FTC was assessed using 120 formalin-fixed paraffin-embedded (FFPE) tissues after the operation and 81 fine-needle aspiration biopsy (FNAB) samples before the operation. FAM172A was highly expressed in FTC tissues and FTC cell lines. Downregulation of FAM172A inhibited the proliferation, invasion and migration of FTC cells through Erk1/2 and JNK pathways. Subcutaneous tumorigenesis in nude mice showed that knockdown of FAM172A inhibited tumor growth and progression in vivo. The FAM172A IHC scores of 3.5 had 92% sensitivity and 63% specificity to separate FTC from benign/borderline thyroid follicular lesions, and 92% sensitivity and 80% specificity to discriminate FTC from benign thyroid follicular lesions in postoperative FFPE samples. The corresponding values were 75 and 78%, and 75 and 89% in preoperative FNA samples, respectively. FAM172A plays an important role in the pathogenesis of FTC through Erk1/2 and JNK pathways. FAM172A may be a potential marker for the preoperative diagnosis of FTC based on the IHC results of thyroid FNAB samples.
Jonathan M Fussey, Robin N Beaumont, Andrew R Wood, Bijay Vaidya, Joel Smith, and Jessica Tyrrell
Jonathan M Fussey, Robin N Beaumont, Andrew R Wood, Bijay Vaidya, Joel Smith, and Jessica Tyrrell
Evidence from observational studies suggest a positive association between serum thyroid-stimulating hormone (TSH) levels and differentiated thyroid carcinoma. However, the cause–effect relationship is poorly understood and these studies are susceptible to bias and confounding. This study aimed to investigate the causal role of TSH in both benign thyroid nodules and thyroid cancer in up to 451,025 UK Biobank participants, using a genetic technique, known as Mendelian randomization (MR). Hospital Episode Statistics and Cancer Registry databases were used to identify 462 patients with differentiated thyroid carcinoma and 2031 patients with benign nodular thyroid disease. MR methods using genetic variants associated with serum TSH were used to test causal relationships between TSH and the two disease outcomes. Mendelian randomization provided evidence of a causal link between TSH and both thyroid cancer and benign nodular thyroid disease. Two-sample MR suggested that a 1 s.d. higher genetically instrumented TSH (approximately 0.8 mIU/L) resulted in 4.96-fold higher odds of benign nodular disease (95% CI 2.46–9.99) and 2.00-fold higher odds of thyroid cancer (95% CI 1.09–3.70). Our results thus support a causal role for TSH in both benign nodular thyroid disease and thyroid cancer.