Mutation based approaches to the treatment of anaplastic thyroid cancer

[Update on anaplastic thyroid cancer-What is relevant for surgeons?]

Anaplastic thyroid cancer (ATC) is the rarest but also the most aggressive carcinoma entity of the thyroid gland. In recent years, treatment options have evolved and molecular oncological treatment approaches have gained in importance. The neoadjuvant use of these innovative therapies has the potential to convert previously unresectable tumors into a resectable state, thereby expanding surgical options and significantly improving the prognosis of patients. This article provides recommendations relevant for surgery for the diagnostics and treatment of ATC, based on a current literature review and the discussions of the S3 guideline conferences.

Anaplastic thyroid cancer: Genetic roles, targeted therapy, and immunotherapy

Anaplastic thyroid cancer (ATC) stands as the most formidable form of thyroid malignancy, presenting a persistent challenge in clinical management. Recent years have witnessed a gradual unveiling of the intricate genetic underpinnings governing ATC through next-generation sequencing. The emergence of this genetic landscape has paved the way for the exploration of targeted therapies and immunotherapies in clinical trials. Despite these strides, the precise mechanisms governing ATC pathogenesis and the identification of efficacious treatments demand further investigation. Our comprehensive review stems from an extensive literature search focusing on the genetic implications, notably the pivotal MAPK and PI3K-AKT-mTOR signaling pathways, along with targeted therapies and immunotherapies in ATC. Moreover, we screen and summarize the advances and challenges in the current diagnostic approaches for ATC, including the invasive tissue sampling represented by fine needle aspiration and core needle biopsy, immunohistochemistry, and 18F-fluorodeoxyglucose positron emission tomography/computed tomography. We also investigate enormous studies on the prognosis of ATC and outline independent prognostic factors for future clinical assessment and therapy for ATC. By synthesizing this literature, we aim to encapsulate the evolving landscape of ATC oncology, potentially shedding light on novel pathogenic mechanisms and avenues for therapeutic exploration.

The 2024 revised clinical guidelines on the management of thyroid tumors by the Japan Association of Endocrine Surgery

The Japan Association of Endocrine Surgery published the first edition of the "Clinical guidelines on the management of thyroid tumors" in 2010 and the revised edition in 2018. The guideline presented herein is the English translation of the revised third edition, issued in 2024. The aim is to enhance health outcomes for patients suffering from thyroid tumors by facilitating evidence-based shared decision-making between healthcare providers and patients, as well as standardizing the management of thyroid tumors. The focus is on adult patients with thyroid tumors, addressing clinically significant issues categorized into areas such as an overview of the diagnosis and treatment of thyroid nodules, treatment strategies by histological type, radioactive iodine therapy, treatment of advanced differentiated carcinoma, pharmacotherapy, and complications and safety management associated with thyroid surgery. Thirty-two clinical questions were established in these areas. Following a comprehensive search of the literature and systematic review to evaluate the overall evidence, we aimed to present optimal recommendations by considering the balance of benefits and harms from the patient's perspective. We integrated evidence and clinical experience to determine the "Certainty of evidence" and "Strength of recommendations". Based on these, we illustrated overall flows of care as "Clinical algorithms". Necessary background knowledge of diseases and established clinical procedures for understanding the recommendations are presented in "Notes", while information that may be clinically useful but for which evidence remains insufficient is included in "Columns", based on the current state of evidence. Finally, future challenges for the next revision are presented as "Future research questions".

Neoadjuvant systemic therapy for inoperable differentiated thyroid cancers: Impact on tumor resectability

BACKGROUND

Limited treatment options exist for inoperable thyroid cancers. We evaluated whether neoadjuvant use of systemic tyrosine kinase inhibitors facilitates surgery of differentiated thyroid cancers in this challenging context.

METHODS

A single-institution experience of 42 patients receiving tyrosine kinase inhibitors for papillary, follicular and anaplastic thyroid carcinomas between 2018 and 2023 was reviewed to identify differentiated thyroid cancers treated with neoadjuvant tyrosine kinase inhibitors (dabrafenib/trametinib, lenvatinib/pembrolizumab, or lenvatinib alone) via multidisciplinary protocols.

RESULTS

Nine patients with differentiated thyroid cancers (age 49 years, range 19-80, 5 women, 4 men) received neoadjuvant tyrosine kinase inhibitors with intent to improve resectability of primary or recurrent/residual tumors. All had locoregionally advanced disease deemed either unresectable or resectable with unacceptable morbidities. Six exhibited distant metastases (6 lungs, 6 vertebral/axial bones, 1 sternum). Tumors had BRAF V600E (6 papillary thyroid carcinoma) or RAS/TERT (2 follicular thyroid carcinoma) mutations or NCOA4-RET fusion. Most received neoadjuvant tyrosine kinase inhibitors for <6 months with visible results within weeks, radiologically and by examination. All patients completing surgery achieved R0 resection without major surgical complications or aerodigestive structure resection. Neoadjuvant tyrosine kinase inhibitors were generally well-tolerated (4 minor, 1 major toxicity that halted therapy but not surgery). Unique patients with distant metastases continued to receive adjuvant tyrosine kinase inhibitors. At median postoperative follow-up of 2 years, all patients are alive without new locoregional recurrence.

CONCLUSION

Neoadjuvant use of tyrosine kinase inhibitors seems extremely effective in downstaging surgically unresectable differentiated thyroid cancers to achieve R0 resection while avoiding unnecessary surgical morbidities. A multidisciplinary approach with early genomic profiling to guide personalized neoadjuvant use of tyrosine kinase inhibitors is essential. Prospective studies are urgently needed to define the potential role of neoadjuvant tyrosine kinase inhibitors in advanced thyroid cancer management.

Histopathologic and Molecular Insights Following the Management of Ameloblastomas via Targeted Therapies - Pathological and Clinical Perspectives

PURPOSE

Current standard of care for ameloblastoma (conventional/unicystic - mural type) usually mandates extensive bone resection that frequently necessitates immediate reconstruction with serious sequelae, especially among young patients. BRAF-mutated ameloblastomas can be targeted by BRAF inhibitors to markedly reduce their size, enabling conservative removal of residual tumor. We aimed to characterize the effect of post-treatment histomorphologic changes.

METHODS

Study included 14 patients, 11 mandibular and three maxillary tumors. Cases with very minimal residual tumor were defined as near-complete response, while those with mostly vital residual tumor as partial response. The epithelium component was scored for architectural and cellular changes, stroma - for fibrosis, inflammation and new bone formation, on a 3-tired score system: 0-no, 1-focal and 3-frequent changes. The mean scores of each parameter, total epithelium and total stroma were calculated and related to duration of treatment. Differences in the mean scores were investigated for mandibular tumors with near-complete response (n = 3) and partial response (n = 8).

RESULTS

There were no significant differences in mean epithelium or stroma scores between tumors with near-complete and those with partial response (2.22 ± 0.68 versus 2.08 ± 0.43, p = 0.55; 1.41 ± 1.04 versus 1.43 ± 0.44, p = 0.27), suggesting that ameloblastomas have potential to undergo complete response to targeted treatment. This is probably dependent upon tumor/patient/treatment-related factors. Response to treatment appears to be predictable with neoplastic epithelium being first, while the stromal response increases during treatment, the entire process expanding over weeks-to-months.

CONCLUSION

Albeit preliminary, these are the first comprehensive histomorphologic findings on BRAF-treated ameloblastomas. Analyzing the suggested parameters in tumors with partial response, should highlight which tumor component has responded/failed to respond. This could serve as a basis for decision-taking toward subsequent steps in adjuvant treatment (e.g., follow-up, conservative surgery, modifications/changes in treatment regimen, combinations of approaches), with a prime aim of jaw preservation and minimal risk of sequelae.

Neoadjuvant Treatment in Locally Advanced Thyroid Carcinoma

Although the focus in the last decades has been on the overdiagnosis of incidentally detected thyroid carcinomas in early stages, the other extreme of the disease is represented by locally advanced tumors with the invasion of neighboring structures. These are infrequent tumors, but they have a high complexity and a poor prognosis. In the absence of effective therapies allowing preoperative tumor reduction, in order to achieve a more restricted surgery, treatment was limited to aggressive surgery with resection of the aerodigestive tract and major vascular structures or palliative treatment. However, due to the increased knowledge of tumor biology and the results that tyrosine kinase inhibitors have achieved in the treatment of radioactive iodine-refractory tumors, neoadjuvant therapy with a curative intent has emerged as a reality to be taken into account when dealing with these patients. This paper presents a narrative review of the current scientific evidence regarding neoadjuvant treatment in locally advanced thyroid cancer.

[Personalized approach to anaplastic thyroid carcinoma]

BACKGROUND

Anaplastic thyroid carcinoma (ATC) represents the rarest but most aggressive tumor entity of the thyroid gland. In this respect, the treatment of advanced ATC has rapidly evolved in recent years. Recently, new personalized forms of treatment that address the somatic mutational status of the tumor have been increasingly used. The aim of this article is to provide an overview of current molecular-based and personalized treatment options for ATC.

METHODS

A current literature search was performed with a focus on personalized molecular-based treatment options for ATC.

RESULTS

The majority of patients suffering from ATC have an advanced tumor disease at the time of initial diagnosis. Despite multimodal treatment approaches consisting of surgery, external beam radiation therapy (EBRT) and chemotherapy (CTX), the prognosis of ATC is still poor. Accordingly, the focus of innovative treatment approaches is on molecular-based, individualized tumor therapy, including in particular BRAFV600E and multikinase inhibitors. The potential of the latter seems to lie particularly in combination therapy with immune checkpoint inhibitors. These treatment options can be used in both adjuvant and neoadjuvant settings. Neoadjuvant treatment of advanced ATC can achieve a potentially resectable treatment setting and improve the poor prognosis of affected patients; however, larger prospective and randomized studies on these combination therapies are currently pending.

CONCLUSION

The focus of future treatment approaches for ATC will be on individualized, molecular-based tumor therapy. In particular, the neoadjuvant use of these therapies may change the paradigm of ATC surgery as locally advanced as well as metastatic carcinomas can be converted to a potentially resectable status and made amenable to surgery.

Harnessing Immunity to Treat Advanced Thyroid Cancer

The incidence of thyroid cancer (TC) has increased over the past 30 years. Although differentiated thyroid cancer (DTC) has a good prognosis in most patients undergoing total thyroidectomy followed by radioiodine therapy (RAI), 5-10% of patients develop metastasis. Anaplastic thyroid cancer (ATC) has a low survival rate and few effective treatments have been available to date. Recently, tyrosine kinase inhibitors (TKIs) have been successfully applied to RAI-resistant or non-responsive TC to suppress the disease. However, TC eventually develops resistance to TKIs. Immunotherapy is a promising treatment for TC, the majority of which is considered an immune-hot malignancy. Immune suppression by TC cells and immune-suppressing cells, including tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells, is complex and dynamic. Negative immune checkpoints, cytokines, vascular endothelial growth factors (VEGF), and indoleamine 2,3-dioxygenase 1 (IDO1) suppress antitumor T cells. Basic and translational advances in immune checkpoint inhibitors (ICIs), molecule-targeted therapy, tumor-specific immunotherapy, and their combinations have enabled us to overcome immune suppression and activate antitumor immune cells. This review summarizes current findings regarding the immune microenvironment, immunosuppression, immunological targets, and immunotherapy for TC and highlights the potential efficacy of immunotherapy.

The role of surgery for anaplastic thyroid carcinoma in the era of targeted therapeutics: A scoping review

Background

Questions exist regarding patient selection for surgery in anaplastic thyroid carcinoma (ATC), particularly with the advent of neoadjuvant-targeted therapeutics. The present scoping review sought to evaluate what extent of surgical resection should be performed in ATC.

Methods

A scoping review was carried out in accordance with Joanna Briggs Institute and the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) protocols. Included studies were required to provide clear description of the surgery performed for ATC.

Results

The final search identified 6901 articles. Ultimately only 15 articles including 1484 patients met inclusion criteria. A total of 765 patients (51.5%) underwent attempted curative intent surgery. The approach to resection of adjacent tissues varied between studies. Eight studies considered laryngeal ± pharyngeal resection (8/15, 53.3%), eight studies (53.3%) considered tracheal resection and again eight studies (53.3%) considered esophageal resection. More extensive resections increased morbidity without improving overall survival (OS) (<9 months in the 12 studies using a combination of surgery and chemoradiotherapy). In the three studies utilizing targeted therapy in addition to surgery, OS was notably improved while surgical resection following neoadjuvant therapy was less extensive.

Conclusions

There is no clear agreement in the literature regarding the limits of surgical resection in locoregionally advanced ATC. A definition of surgically resectable disease will be required to guide surgical decision making in ATC, particularly with the potential to reduce tumor burden using neoadjuvant targeted treatment in suitable patients.

Level of evidence

III.

TRβ Agonism Induces Tumor Suppression and Enhances Drug Efficacy in Anaplastic Thyroid Cancer in Female Mice

Thyroid hormone receptor beta (TRβ) is a recognized tumor suppressor in numerous solid cancers. The molecular signaling of TRβ has been elucidated in several cancer types through re-expression models. Remarkably, the potential impact of selective activation of endogenous TRβ on tumor progression remains largely unexplored. We used cell-based and in vivo assays to evaluate the effects of the TRβ agonist sobetirome (GC-1) on a particularly aggressive and dedifferentiated cancer, anaplastic thyroid cancer (ATC). Here we report that GC-1 reduced the tumorigenic phenotype, decreased cancer stem-like cell populations, and induced redifferentiation of the ATC cell lines with different mutational backgrounds. Of note, this selective activation of TRβ amplified the effects of therapeutic agents in blunting the aggressive cell phenotype and stem cell growth. In xenograft assays, GC-1 alone inhibited tumor growth and was as effective as the kinase inhibitor, sorafenib. These results indicate that selective activation of TRβ not only induces a tumor suppression program de novo but enhances the effectiveness of anticancer agents, revealing potential novel combination therapies for ATC and other aggressive solid tumors.

Mutation-based, short-term "neoadjuvant" treatment allows resectability in stage IVB and C anaplastic thyroid cancer

INTRODUCTION

Few available data indicate that a mutation-based "neoadjuvant" therapy in advanced anaplastic thyroid carcinoma (ATC) might convert an initially unresectable primary tumor to resectable and optimize local tumor control. We evaluated a preoperative short-term "neoadjuvant" therapy with a BRAF-directed therapy or, in case of BRAF non-mutated tumors, an mKI/checkpoint inhibitor combination in three patients with ATC stage IVB and C.

METHODS

In the context of preoperative diagnostics, immunohistochemistry (IHC) assessment and genetic analysis was started as soon as possible. The antiangiogenetic therapy with lenvatinib was immediately after diagnosis of ATC started as bridging therapy. In case of a BRAF-mutated ATC, a combination therapy of dabrafenib and trametinib, in case of BRAF-wildtype ATC a combination of pembrolizumab and lenvatinib was given for 4 weeks. If re-staging has shown a significant therapy response due to a decrease in size of > 50%, surgical resection was reconsidered. A primary tumor resection was performed first. As a second step, limited distant metastasis have been resected approximately 4 weeks after thyroid surgery. After postoperative recovery, the targeted systemic therapy was continued.

PATIENTS

Two patients presented with BRAF-wildtype ATC stage IVC, one with BRAF-mutated ATC stage IVB. All patients were evaluated by surgery, nuclear medicine and oncology upon diagnosis of ATC.

RESULTS

In all three cases, the "neoadjuvant" therapy induced a dramatic response and led to local resectability in primarily non-resectable ATC stage IVB or C. We have chosen for the first time a short-term "neoadjuvant" treatment period to reduce the risk of bleeding and/or fistula due to potential rapid tumor shrinkage. The results of surgery after only short-term "neoadjuvant" therapy showed two R0 und one R1 resections. Postoperative histopathological findings confirmed an extent of tumor necrosis or regressive fibrotic tissue between 60 and > 95% in our patients.

CONCLUSIONS

A short-term mutation-based "neoadjuvant" therapy can achieve local resectability in initially unresectable ATC stage IVB or C. A neoadjuvant treatment period of about 4 weeks seems to show similar response as a treatment duration of at least 3 months.

Pathologic complete response after neoadjuvant v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibition combined with immunotherapy therapy for anaplastic thyroid carcinoma: a case report and literature review

Anaplastic thyroid carcinoma (ATC) is a highly malignant tumor with invasive nature. Most patients present with locally advanced and/or distant metastatic diseases that are difficult to treat. We report a case of a previously inoperable patient with v-Raf murine sarcoma viral oncogene homolog B (BRAF) mutated ATC. After a trial of neoadjuvant Dabrafenib/Trametinib with immunotherapy, the tumor became operable, and surgical pathology indicated a pathologic complete response (pCR). We also reviewed cases from the literature that utilized neoadjuvant BRAF-directed therapy in ATCs. These cases emphasize that BRAF-and immune-directed therapy is a feasible option in patients with inoperable ATC and may lead to improved outcomes.

Dabrafenib and Trametinib Therapy for Advanced Anaplastic Thyroid Cancer - Real-World Outcomes From UK Centres

AIMS

Anaplastic thyroid cancer (ATC) is a rare but aggressive form of thyroid cancer with a median survival of 4 months. Recent advances in molecular profiling have shown that up to half of ATCs harbour the BRAF-V600E mutation. The aim of this study was to provide real-world data and experience on the use of combination therapy dabrafenib and trametinib in patients with BRAF-V600E-mutated advanced ATC.

MATERIALS AND METHODS

We retrospectively evaluated patients with confirmed BRAF-V600E-mutated ATC, defined as patients with locally advanced or metastatic ATC with no locoregional, radical treatment options. Outcomes measured were overall survival, progression-free survival, response rate, discontinuation rate, dose reduction rate and toxicity data.

RESULTS

Seventeen patients were evaluated and the mean age was 68 years. Ten patients died by the time of censoring. The median duration of follow-up was 12 months (3-43 months). The estimated median overall survival was 6.9 months (95% confidence interval 2.46 months - upper confidence interval not reached) and the median progression-free survival was 4.7 months (95% confidence interval 1.4-7.8 months). Dose interruptions and/or reductions were common, but none of the patients had to permanently discontinue treatment because of toxicities. Severe toxicities (grades 3 and 4) were uncommon.

CONCLUSIONS

This study supports the indication of dabrafenib and trametinib in BRAF-V600E-mutated ATC as an effective and well-tolerated treatment in an historically difficult to treat cancer.

Combination of Novel Therapies and New Attempts in Anaplastic Thyroid Cancer

Anaplastic thyroid cancer (ATC) is one of the most lethal human malignancies, and it is rapidly falling without any effective therapeutic options. Although radical surgery, radiotherapy, and chemotherapy are performed on patients, the curative effect is suboptimal, and the survival rate is still poor. The discovery of altered gene pathways involved in this aggressive disease has advanced, but molecular targeted drugs targeting these pathways are still in clinical trials. To date, there is no effective way to treat this disease, so it is particularly urgent to find new treatments. At present, multimodal therapy is gradually being applied in clinical practice, which provides a new possibility for prolonging the survival time and improving the prognosis of anaplastic thyroid carcinoma. In this study, we retrospectively analyzed the current clinical multimodal therapy for patients with anaplastic thyroid cancer to evaluate its effect on improving the survival of patients with anaplastic thyroid cancer at different stages.

Rationale Efficacy and Safety Evidence of Lenvatinib and Pembrolizumab Association in Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma (ATC) are highly aggressive malignant tumors with poor overall prognosis despite multimodal therapy. As ATC are extremely rare, no randomized controlled study has been published for metastatic disease. Thyrosine kinase inhibitors, especially lenvatinib and immune checkpoint inhibitors such as pembrolizumab, are emerging drugs for ATC. Few studies have reported the efficacity of pembrolizumab and lenvatinib association, resulting in its frequent off-label use. In this review, we discuss rationale efficacy and safety evidence for the association of lenvatinib and pembrolizumab in ATC. First, we discuss preclinical rationale for pembrolizumab monotherapy, lenvatinib monotherapy and synergistic action of pembrolizumab and lenvatinib in the metastatic setting. We also discuss clinical evidence for immunotherapy and pembrolizumab in ATC through the analysis of studies evaluating immunotherapy, lenvatinib and pembrolizumab lenvatinib association in ATC. In addition, we discuss the safety of this association and potential predictive biomarkers of efficiency.