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

The potential role of neoadjuvant treatment in thyroid cancers in the era of kinase inhibitors: a narrative review

AIM

To analyse the literature on the potential role of kinase inhibitors (KI) as neoadjuvant treatment (NAT) in all thyroid cancers (TC).

MATERIALS AND METHODS

Online databases were systematically examined, including MEDLINE (via PubMed) Embase, ISI Web of Science, Google Scholar, and Scopus. As many papers were published before the classification of TC was revised, our search was conducted as follows: NAT in TC, NAT in papillary thyroid cancer (PTC), NAT in follicular thyroid cancer (FTC), NAT in anaplastic thyroid cancer (ATC), and NAT in medullary thyroid cancer (MTC).

RESULTS

The search revealed 21 single case reports and three small series on NAT in TC. Overall, 32 cases were found: 24 follicular cell derived cancers (FCDC) of which nine were ATC, eight were MTC. We also found four major retrospective series, in two of which the cohort was divided and analysed into different groups according to the kind of treatment. In these four series, NAT was performed in in a total of 99 patients (32 FCDC, 60 ATC, and 7 MTC).

CONCLUSIONS

While awaiting large-scale clinical trials, the literature highlights that NAT may be an option for locally advanced TC (and above all ATC) when surgery may be too destructive or when the tumour is inoperable. The use of NAT should be discussed with the patient. An R0 or at least an R1 should be the goal of NAT, and the molecular profile should be performed as rapidly as possible.

Exploring the role of immunotherapy in the management of follicular cell-derived thyroid cancer

Anaplastic and poorly differentiated thyroid carcinomas are the two most aggressive forms of thyroid cancers and carry significant morbidity and mortality despite multimodal therapeutic approaches. Anaplastic thyroid carcinoma (ATC) and, to a lesser degree, poorly differentiated thyroid carcinoma (PDTC) have a high tumor mutation burden, and immunologically hot tumor microenvironment when compared to well-differentiated thyroid carcinomas. As such, immunotherapy, and in particular immune checkpoint inhibitors, have been hypothesized to be effective against these cancers. This review aims to explore the biological rationale for immunotherapy in dedifferentiated thyroid carcinomas and to summarize the current evidence underlying this treatment modality.

Combination kinase inhibitors and immunotherapy for unresectable anaplastic thyroid carcinoma: A retrospective single-center study

INTRODUCTION

Anaplastic thyroid carcinoma (ATC) is rare but has a very poor prognosis. New therapeutic options such as multikinase inhibitors and selective tyrosine kinase inhibitors have revolutionized the treatment of ATC, with immunotherapy also showing encouraging effects. This study evaluated the efficacy and safety of kinase inhibitors combined with an anti-PD-1 inhibitor as first-line treatment, as well as in the neoadjuvant setting for patients with unresectable ATC.

MATERIALS & METHODS

This retrospective single-center study recruited consecutive patients with stage IVB and IVC ATC who received first-line kinase inhibitors plus immunotherapy between June 2021 and June 2023. The patients were treated with either selective or multi-kinase inhibitors (dabrafenib/trametinib, lenvatinib, or anlotinib) in combination with one immune checkpoint inhibitor (pembrolizumab, sintilimab, or camrelizumab). The endpoints included overall survival (OS), progression-free survival (PFS), response evaluation, and feasibility of R0/R1 resection.

RESULTS

Eighteen patients were included in this analysis. The median OS (mOS) was 14.0 months and the 12-month survival rate was 55.6 %. The mOS in BRAF V600E mutated ATC was not reached, significantly longer than non-BRAF V600E mutated ATC (4.0 months [95 %CI, 1.1-6.9], p = 0.049). Among evaluable patients, 5 achieved a complete response (CR) and 6 patients achieved partial response (PR). The best ORR was 61.1 %. Surgical resection was feasible in 7/18 (38.9 %) patients. One grade 5 adverse event (AE) occurred. Most AEs were well tolerated.

CONCLUSIONS

Combination kinase inhibitors with immunotherapy as first-line therapy are safe and effective for the treatment of unresectable ATC, especially with BRAF V600E mutation.

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.