New perspectives on the treatment of differentiated thyroid cancer

Downregulation of miR-146b-3p Inhibits Proliferation and Migration and Modulates the Expression and Location of Sodium/Iodide Symporter in Dedifferentiated Thyroid Cancer by Potentially Targeting MUC20

The dedifferentiation of differentiated thyroid cancer (DTC) is a challenging problem for radioactive iodine (¹³¹I) treatment, also known as radioiodine refractory differentiated thyroid cancer (RAIR-DTC). The purpose of this study was to further explore the mechanism of the redifferentiation of dedifferentiated thyroid cancer. Ineffective and effective groups of ¹³¹I therapy were analyzed and compared in both our clinical and TCGA samples. Whole-exome sequencing, mutation analysis, transcriptome analysis, and in vitro functional experiments were conducted. FLG, FRG1, MUC6, MUC20, and PRUNE2 were overlapping mutation genes between our clinical cases, and the TCGA cases only appeared in the ineffective group. The expression of miR-146b-3p target MUC20 was explored. The expression levels of miR-146b-3p and MUC20 were significantly increased, and the inhibition of miR-146b-3p expression significantly inhibited proliferation and migration, promoted apoptosis, regulated the expression and location of thyroid differentiation-related genes, and sodium/iodide symporter (NIS) in dedifferentiated thyroid cancer cells (WRO). Thus, miR-146b-3p potentially targets MUC20 participation in the formation of DTC dedifferentiation, resulting in resistance to ¹³¹I and the loss of the iodine uptake ability of DTC cancer foci, promoting refractory differentiated thyroid cancer. miR-146b-3p may be a potentially therapeutic target for the reapplication of ¹³¹I therapy in dedifferentiated thyroid cancer patients.

'I know I'm not invincible': An interpretative phenomenological analysis of thyroid cancer in young people

Objective

Thyroid cancer is one of the most common cancers affecting young people and carries an excellent prognosis. Little is known about the psychosocial issues that face young people diagnosed with a treatable cancer. This study explored how young people experienced diagnosis, treatment, and how they made sense of an experience which challenged their views on what it means to have cancer.

Method

Semi‐structured interviews were conducted with eight young people diagnosed with either papillary or follicular thyroid cancer, and analysed with interpretative phenomenological analysis (IPA).

Results

Two inter‐related aspects of their experience are discussed: (1) the range of feelings and emotions experienced including feeling disregarded, vulnerability, shock and isolation; (2) how they made sense of and ascribed meaning to their experience in the light of the unique nature of their cancer. A thread running throughout the findings highlights that this was a disruptive biographical experience.

Conclusions

Young people experienced a loss of youthful immunity which contrasted with a sense of growth and shift in life perspective. Having a highly treatable cancer was helpful in aiding them to reframe their situation positively but at the same time left them feeling dismissed over a lack of recognition that they had cancer. The young peoples’ experiences point to a need for increased understanding of this rare cancer, more effective communication from health care professionals and a greater understanding of the experiential impact of this disease on young people. Suggestions to improve the service provision to this patient group are provided.

Flavonoids, Thyroid Iodide Uptake and Thyroid Cancer-A Review

Thyroid cancer is the most common malignant tumor of the endocrine system and the incidence has been increasing in recent years. In a great part of the differentiated carcinomas, thyrocytes are capable of uptaking iodide. In these cases, the main therapeutic approach includes thyroidectomy followed by ablative therapy with radioiodine. However, in part of the patients, the capacity to concentrate iodide is lost due to down-regulation of the sodium-iodide symporter (NIS), the protein responsible for transporting iodide into the thyrocytes. Thus, therapy with radioiodide becomes ineffective, limiting therapeutic options and reducing the life expectancy of the patient. Excessive ingestion of some flavonoids has been associated with thyroid dysfunction and goiter. Nevertheless, studies have shown that some flavonoids can be beneficial for thyroid cancer, by reducing cell proliferation and increasing cell death, besides increasing NIS mRNA levels and iodide uptake. Recent data show that the flavonoids apingenin and rutin are capable of increasing NIS function and expression in vivo. Herein we review literature data regarding the effect of flavonoids on thyroid cancer, besides the effect of these compounds on the expression and function of the sodium-iodide symporter. We will also discuss the possibility of using flavonoids as adjuvants for therapy of thyroid cancer.

Values of (99m)Tc-methoxyisobutylisonitrile imaging after first-time large-dose (131)I therapy in treating differentiated thyroid cancer

Objective

The aim of this study is to investigate the use of ^99mTc-methoxyisobutylisonitrile (MIBI) imaging for evaluating the treatment response of differentiated thyroid cancer (DTC) after the first administration of a high dose of ¹³¹I.

Methods

Patients with DTC who received ¹³¹I therapy underwent ^99mTc-MIBI imaging after successive increases in the therapeutic dose of ¹³¹I, and the serum levels of thyroglobulin (Tg) were measured.

Results

A total of 191 patients were enrolled in the final analysis, including 65 metastases and/or thyroid remnant-positive patients (22 patients with metastases and 43 patients with thyroid remnants). The sensitivity of ^99mTc-MIBI imaging for detecting positive cases and thyroid remnants was 56.9% and 39.5%, respectively, which was significantly lower than that of ¹³¹I imaging (92.3% and 100%, respectively, P<0.01 for both). The sensitivity of ^99mTc-MIBI imaging for detecting metastases was 90.9%, which was slightly higher than that of ¹³¹I imaging (77.3%, P>0.05). The Tg levels in the positive group were significantly higher than that in the negative group (P<0.01). In addition, the Tg levels in the ^99mTc-MIBI⁺/¹³¹I⁻ group were significantly higher than that in the ¹³¹I⁺/^99mTc-MIBI group (P<0.05).

Conclusion

After the first ¹³¹I therapy, although ^99mTc-MIBI imaging was able to detect the existence of metastatic lesions in patients with DTC better, its assessment for the removal efficiency of thyroid remnants was unsatisfactory. The results of ^99mTc-MIBI imaging showed good correlations with the Tg level.

Carotid artery rupture following radioiodine therapy for differentiated thyroid carcinoma

INTRODUCTION

Radioiodine therapy for patients with differentiated thyroid cancer aims at reducing tumor recurrence by eradicating residual macro- and microscopic foci. Side effects are generally rare, tenuous and transient, with little clinical significance.

OBJECTIVE

To report a rare case of differentiated thyroid carcinoma presenting a large expansive solid mass at the base of the skull, with invasion of the left masticatory muscle and adjacent subcutaneous tissue, and without invasion of the carotid space, which evolved to carotid artery rupture following radioiodine therapy.

DISCUSSION

Side effects are uncommon after radioiodine therapy and when present, have mild intensity. Serious adverse events are very rare, especially those arising from structures not directly invaded by metastatic tissue with radioiodine uptake, as occurred in this case. This occurrence serves to raise awareness of the need for increased care when using radioiodine therapy on high-avidity masses located close to important structures.

Pediatric thyroid cancer

Thyroid cancer is an uncommon childhood malignancy that presents primarily in young children or adolescent females and may be related to radiation exposure or genetic predisposition. Gene alterations, such as RET mutation or RET/PTC rearrangement, are not uncommon. Recent studies have lead to an increased understanding of the role of these particular gene alterations in the diagnosis, prognosis, and treatment of thyroid cancer. Surgery remains the mainstay of treatment for thyroid cancer followed by radioactive iodine when appropriate. In patients with MEN2, prophylactic thyroidectomy is recommended, although a delay in the initial diagnosis is common. With early aggressive treatment and long-term follow-up, these patients generally have excellent outcomes. Recent research suggests potential usefulness of novel therapies directed at oncogenic signaling pathways, modulators of growth, angiogenesis inhibitors, immunomodulators, and gene therapy.

Update on recent developments in the therapy of differentiated thyroid cancer

In the past decade, the management of differentiated thyroid carcinoma changed significantly and thus contributed to the improvement of the already favorable prognosis of this malignant disease. Surgical treatment techniques improved and the extent of initial surgery is more individualized. Radioiodine therapy is an essential part of therapeutic regimens in almost all cases, and the use of recombinant human thyroid-stimulating hormone has established for ablation of remnant tissue, treatment of iodine-positive cancer, and sensitive thyroglobulin measurement during follow-up. Risk stratification has become more important to plan treatment and follow-up individually, particularly to evaluate the need for thyroid-stimulating hormone suppression therapy. Especially for inoperable and radioiodine-negative thyroid carcinomas, novel treatment options such as tyrosine kinase inhibitor therapy have emerged. This article deals with the current options of optimal therapy regimens in differentiated thyroid carcinoma.

Papillary thyroid carcinoma with brain metastases: an unusual 10-year-survival case

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy with indolent clinical course and good prognosis. Brain metastases are extremely rare and the average survival time after diagnosis has been reported to be around 12 months.

SUMMARY

We here report a 69-year-old patient who was admitted to the emergency room in January 2000 with progressive dizziness, headache, and vomiting. Five years before admission the patient underwent partial thyroidectomy for goiter. On admission, a diagnostic evaluation that included brain magnetic resonance imaging showed multiple brain lesions, and a stereotactic biopsy demonstrated a metastatic carcinoma from primary PTC, with the neoplastic cells staining for thyroglobulin. Total thyroidectomy was then performed, which showed colloid goiter and a PTC metastasis on a cervical lymph node. The patient received 200 mCi of radioactive iodine ((131)I) with suppressive therapy with l-thyroxine thereafter. Subsequently, serial whole-body scanning and magnetic resonance imaging showed multiple brain metastases and the patient received further (131)I treatment, with a total dose of 1.2 Ci in a 10-year span. She also underwent partial surgical resection of brain metastases because complete resection was not feasible. Thereafter, the patient was subjected to whole-brain body radiotherapy with a dose of 44 Gy, followed by two brain gamma knife radiosurgeries (15 Gy each). To date, biochemical tests are within the normal range and the patient remains asymptomatic.

CONCLUSIONS

To our knowledge, this is the first report of a 10-year-survival case of brain metastases from PTC, despite this being a bad prognostic factor. A combined approach of surgical excision, (131)I, whole-brain radiotherapy, and gamma knife radiosurgery was successful to treat metastases derived from primary tumor.

Sodium iodide symporter and the radioiodine treatment of thyroid carcinoma

Since the specific accumulation of iodide in thyroid was found in 1915, radioiodine has been widely applied to diagnose and treat thyroid cancer. Iodide uptake occurs across the membrane of the thyroid follicular cells and cancer cells through an active transporter process mediated by the sodium iodide symporter (NIS). The NIS coding genes were cloned and identified from rat and human in 1996. Evaluation of the NIS gene and protein expression is critical in the management of thyroid cancer, and several approaches have been tried to increase NIS levels. Identification of the NIS gene has provided a means of expanding its role in the radionuclide gene therapy of nonthyroidal cancers as well as thyroid cancer. In this article, we explain the relationship between NIS expression and the treatment of thyroid carcinoma with I-131, and we include a review of the results of our experimental and clinical trials.

Partial remission of metastatic papillary thyroid carcinoma with sunitinib. Report of a case and review of the literature

Tyrosine kinase receptors have been implicated in thyroid cancer. Therefore, tyrosine kinase inhibitors may be used for the treatment of advanced metastatic thyroid carcinoma. The aim is to present a case of metastatic papillary thyroid carcinoma responding to the administration of sunitinib, a multi-targeted protein kinase inhibitor. A patient presented with metastatic papillary thyroid carcinoma and hyperthyroidism. After euthyroidism was achieved the patient was treated by the administration of therapeutic radioiodine (131)I, radiotherapy and sunitinib, a multi-targeted tyrosine kinase inhibitor. Thyroglobulin levels decreased from 9,594 to 6,816 ng/ml after 1 month, 6 months later being 2,776 ng/ml. The lesion in the pelvis was 12.5 × 9 cm before treatment decreasing thereafter and the patient improved clinically. The administration of sunitinib resulted in partial disease response in a patient with progressive metastatic papillary thyroid carcinoma. Protein kinase inhibitors may prove useful in the management of advanced metastatic papillary thyroid carcinoma.