Palliation of advanced thyroid malignancies

Notch Signaling in Thyroid Cancer

Thyroid cancer is the most common malignancy of the endocrine system with a steadily rising incidence. The term "thyroid cancer" encompasses a spectrum of subtypes, namely papillary thyroid cancer, follicular thyroid cancer, anaplastic thyroid cancer, and medullary thyroid cancer. Each subtype differs histopathologically and in degrees of cellular differentiation, which may be in part due to signaling of the Notch pathway. The Notch pathway is an evolutionarily conserved signal transduction mechanism that regulates cell proliferation, differentiation, survival, stem cell maintenance, embryonic and adult development, epithelial-mesenchymal transition, and angiogenesis. Its role in cancer biology is controversial, as it has been shown to play both an oncogenic and tumor-suppressive role in many different types of cancers. This discordance holds true for each subtype of thyroid cancer, indicating that Notch signaling is likely cell type and context dependent. Whether oncogenic or not, Notch signaling has proven to be significantly involved in the tumorigenesis of thyroid cancer and has thus earned interest as a therapeutic target. Advancement in the understanding of Notch signaling in thyroid cancer holds great promise for the development of novel treatment strategies to benefit patients.

PD-1/PD-L1 expressions in medullary thyroid carcinoma: Clinicopathologic and prognostic analysis of Chinese population

INTRODUCTION

Few studies have focused on PD-L1 expression in medullary thyroid carcinoma (MTC). Expressions of PD-1 and PD-L1 and their clinicopathologic and prognostic relevance were therefore further investigated on a relatively large population of MTC patients.

MATERIALS AND METHODS

Surgical specimens were obtained from 87 MTC patients during a median follow-up of 37.7 months. PD-1 and PD-L1 expressions on tumor and associated immune cells were studied immunohistochemically using >1% positive cells as a threshold for positivity. Their correlations with clinicopathologic and prognostic feature were analyzed.

RESULTS

PD-1 and PD-L1 were positively stained in 22 and 19 MTC patients. Most PD-L1-positive cases (18/19) showed weak to moderate staining intensity. PD-1 and PD-L1 were co-expressed in 11 patients. PD-L1 positivity was significantly correlated with distant metastases at surgery (21.1% vs 1.5%, P = 0.007). Coexpression of PD-1 and PD-L1 in MTC was correlated with advanced pathologic TNM stage III/IV (P = 0.040) and distant metastases at surgery (P = 0.013). However, there was no other clinicopathologic and prognostic relevance regarding to PD-1, PD-L1 or their coexpression in our MTC patients.

CONCLUSION

PD-1/PD-L1 pathway was expressed in MTC patients and was significantly correlated with the distant metastases at surgery, which may shed light on PD-1/PD-L1 as a promising therapeutic target in MTC. Future better understanding of PD-1/PD-L1 expression and their relationship with immunotherapy response may provide direct evidence for management of refractory MTC.

Appraising the holistic value of Lenvatinib for radio-iodine refractory differentiated thyroid cancer: A multi-country study applying pragmatic MCDA

BACKGROUND

The objective of the study was to reveal through pragmatic MCDA (EVIDEM) the contribution of a broad range of criteria to the value of the orphan drug lenvatinib for radioiodine refractory differentiated thyroid cancer (RR-DTC) in country-specific contexts.

METHODS

The study was designed to enable comprehensive appraisal (12 quantitative, 7 qualitative criteria) in the current disease context (watchful waiting, sorafenib) of France, Italy and Spain. Data on the value of lenvatinib was collected from diverse stakeholders during country-specific panels and included: criteria weights (individual and social values); performance scores (judgments on evidence-collected through MCDA systematic review); qualitative impacts of contextual criteria; and verbal and written insights structured by criteria. The value contribution of each criterion was calculated and uncertainty explored.

RESULTS

Comparative effectiveness, Quality of evidence (Spain and Italy) and Disease severity (France) received the greatest weights. Four criteria contributed most to the value of lenvatinib, reflecting its superior Comparative effectiveness (16-22% of value), the severity of RR-DTC (16-22%), significant unmet needs (14-21%) and robust evidence (14-20%). Contributions varied by comparator, country and individuals, highlighting the importance of context and consultation. Results were reproducible at the group level. Impacts of contextual criteria varied across countries reflecting different health systems and cultural backgrounds. The MCDA process promoted sharing stakeholders' knowledge on lenvatinib and insights on context.

CONCLUSIONS

The value of lenvatinib was consistently positive across diverse therapeutic contexts. MCDA identified the aspects contributing most to value, revealed rich contextual insights, and helped participants express and explicitly tackle ethical trade-offs inherent to balanced appraisal and decisionmaking.

Determination of the most appropriate method for extrapolating overall survival data from a placebo-controlled clinical trial of lenvatinib for progressive, radioiodine-refractory differentiated thyroid cancer

BACKGROUND

Cost-effectiveness models for the treatment of long-term conditions often require information on survival beyond the period of available data.

OBJECTIVES

This paper aims to identify a robust and reliable method for the extrapolation of overall survival (OS) in patients with radioiodine-refractory differentiated thyroid cancer receiving lenvatinib or placebo.

METHODS

Data from 392 patients (lenvatinib: 261, placebo: 131) from the SELECT trial are used over a 34-month period of follow-up. A previously published criterion-based approach is employed to ascertain credible estimates of OS beyond the trial data. Parametric models with and without a treatment covariate and piecewise models are used to extrapolate OS, and a holistic approach, where a series of statistical and visual tests are considered collectively, is taken in determining the most appropriate extrapolation model.

RESULTS

A piecewise model, in which the Kaplan-Meier survivor function is used over the trial period and an extrapolated tail is based on the Exponential distribution, is identified as the optimal model.

CONCLUSION

In the absence of long-term survival estimates from clinical trials, survival estimates often need to be extrapolated from the available data. The use of a systematic method based on a priori determined selection criteria provides a transparent approach and reduces the risk of bias. The extrapolated OS estimates will be used to investigate the potential long-term benefits of lenvatinib in the treatment of radioiodine-refractory differentiated thyroid cancer patients and populate future cost-effectiveness analyses.

Hereditary medullary thyroid cancer: age-appropriate thyroidectomy improves disease-free survival

BACKGROUND

Twenty-five percent of medullary thyroid cancer (MTC) cases are hereditary. The ideal age for prophylactic thyroidectomy is based on the specific RET mutation involved. The purpose of this study was to determine whether such age-appropriate prophylactic thyroidectomy results in improved disease-free survival.

METHODS

Twenty-eight patients underwent thyroidectomy for hereditary MTC at our institution. Age-appropriate thyroidectomy was defined according to the North American Neuroendocrine Tumor Society (NANETS) guidelines. Patients who had age-appropriate surgery (group 1, n = 9) were compared to those who had thyroidectomy past the recommended age (group 2, n = 19).

RESULTS

The mean age was 13 ± 2 years, and 61 % were female. Patients in group 1 were younger than in group 2 (4 ± 1 vs. 17 ± 2 years, p < 0.01). There were no significant differences in gender or RET mutation types between these two groups. Group 1 patients were cured with no disease recurrence compared with group 2 patients who had a 42 % recurrence rate (p = 0.05). Subanalysis of group 2 identified that patients who underwent surgery without evidence of disease did so at a shorter period following the guidelines compared with those who underwent therapeutic surgery (2 ± 2 vs. 16 ± 2 years, p = 0.01) and had longer disease-free survival (100 vs. 27 %, p = 0.005).

CONCLUSIONS

Patients with hereditary MTC should undergo age-appropriate thyroidectomy based on RET mutational status to avoid recurrence. Patients who are past the recommended age should have surgery as early as possible to improve disease-free survival.

Palliative and end of life care issues of carcinoma thyroid patient

Malignancies of the thyroid gland has steadily increased over the last few decades, out of which mostly are differentiated carcinomas of the papillary or of follicular type, have a good prognosis and highest cure rate if treatment commences early. Here, we report a case of an 18-years-old boy with a huge multinodular goiter, which compromised the airway and lung metastasis, presented at advance stage of disease in tertiary care center. Factors prevent early diagnosis and treatment, distressing symptoms patient can develop, palliation of those symptoms, and effort to be made to prevent the delay are highlighted.

Tautomycetin and tautomycin suppress the growth of medullary thyroid cancer cells via inhibition of glycogen synthase kinase-3beta

Medullary thyroid cancer (MTC) is a relatively uncommon neuroendocrine tumor that arises from the calcitonin-secreting parafollicular cells of the thyroid gland. Unfortunately, MTC frequently metastasizes, precluding curative surgical resection and causing significant morbidity. Thus, there is an urgent need for new treatment modalities. Tautomycin and tautomycetin are antifungal antibiotics isolated from Streptomyces spiroverticillatus and Streptomyces griseochromogens, respectively. Glycogen synthase kinase-3beta is a serine/threonine protein kinase that regulates multiple cellular processes and is important in various cancers, including MTC. Treatment with tautomycin and tautomycetin decreased neuroendocrine markers, suppressed hormonal secretion, and inhibited growth through apoptosis in MTC cells. Importantly, we describe a novel action of these compounds: inhibition of glycogen synthase kinase-3beta.

Inhibition of growth in medullary thyroid cancer cells with histone deacetylase inhibitors and lithium chloride

BACKGROUND

While representing only 3% of thyroid malignancies, medullary thyroid cancer (MTC) accounts for 14% of thyroid cancer deaths. MTC has a high rate of recurrence and lacks effective treatments. The histone deacetylase (HDAC) inhibitors valproic acid (VPA) and suberoyl bis-hydroxamic acid (SBHA) activate the Notch1 signaling pathway, while lithium chloride inhibits the glycogen synthase kinase-3ss (GSK-3ss) pathway. These compounds have been shown to limit growth and suppress hormonal secretion; thus, targeting different signaling pathways may be an effective treatment.

METHODS

MTC cells were treated with varying combinations of up to 20 mM lithium chloride with either 3 mM VPA or 20 muM SBHA for 48 h. Western analysis was used to measure the effects on Notch1, GSK-3ss, and neuroendocrine (NE) markers. Growth was assessed by a methylthiazolyldiphenyl-tetrazolium (MTT) bromide cellular proliferation assay. Western analysis was used to determine the mechanism of growth regulation.

RESULTS

Combination therapy increased active Notch1, inhibited the GSK-3ss pathway, and decreased NE markers. Additive inhibition of growth was observed with combination therapy. Lower-dose combination therapy achieved greater decreases on NE markers and growth than treatment with any of the drugs alone. Moreover, an increase in the cleavage of the apoptotic markers caspase-3 and PARP was observed.

CONCLUSIONS

Combination therapy with lithium chloride and HDAC inhibitors suppresses NE markers and decreases growth via apoptosis of MTC cells in vitro. With the possibility of increased efficacy and decreased toxicity, combination therapy may represent a new strategy to treat MTC.

Valproic acid activates Notch1 signaling and induces apoptosis in medullary thyroid cancer cells

OBJECTIVE

To examine the effects of valproic acid (VPA) on Notch1 expression and cancer cell proliferation in medullary thyroid cancer (MTC) cells.

BACKGROUND

Other than surgery, there are no effective treatments for MTC, a neuroendocrine malignancy that frequently metastasizes. We have previously shown that over-expression of Notch1 in MTC cells inhibits cell growth and hormone production. VPA, a drug long used for the treatment of epilepsy, has recently been identified as a potential Notch1 activator. We hypothesized that VPA might activate Notch1 signaling in MTC cells, with antiproliferative effects.

METHODS

Human MTC cells were treated with VPA (0-5 mM) and Western blotting was performed to measure levels of Notch1 pathway proteins and neuroendocrine tumor markers. After confirming that VPA is a Notch1 activator in MTC cells, we performed cell proliferation assay. Finally, to determine the mechanism of growth inhibition, we measured protein levels of various markers of apoptosis.

RESULTS

Notch1 was absent in MTC cells at baseline. VPA treatment resulted in an increase in both full-length and active Notch1 protein. Notch1 activation with VPA suppressed 2 neuroendocrine tumor markers, ASCL1 and chromogranin A. Importantly, VPA inhibited the growth of MTC cells in a dose-dependent manner. Immunoblot analysis demonstrated caspase activation and poly(ADP-ribose) polymerase cleavage, indicating the induction of apoptosis.

CONCLUSIONS

VPA activates Notch1 signaling in MTC cells and inhibits their growth by inducing apoptosis. As the safety of VPA in human beings is well established, a clinical trial using this drug to treat patients with advanced MTC could be initiated in the near future.