Management of locally invasive well-differentiated thyroid cancer

Continuous Intraoperative Nerve Monitoring in Thyroid Surgery: Can Amplitude Be a Standardized Parameter?

The objective of this study is to evaluate electromyographic waveforms related to vagus monitoring. We collected data from patients undergoing thyroidectomy with CIONM, regardless of vocal cord response amplitude initially measured. We divided data of 193 nerves into three groups, according to initial amplitude value: ≥500 µV (Group 1,110 pt.), between 100 and 500 µV (Group 2, 79 pt.), and <100 µV (Group 3, 4 pt.). ROC curve showed a high diagnostic accuracy of final amplitude absolute value in vocal cord paralysis detection in both groups (89 and 86%). An increase of vocal cord paralysis risk was associated with progressive amplitude reduction (Group 1: OR=1.05, CI=1.02-1.09, p=0.001; Group 2: OR=1.05, CI=1.02-1.08, p=0.002). Cut-off values for amplitude reduction with optimal sensitivity and specificity were -77% in Group 1 and -15% in Group 2. In Group 3 signals showed an amplitude <100 µV for all monitoring, with no loss of a recognizable signal and normal postoperative cordal functionality. The use of a strict amplitude signal cut-off value ≥500 µV could be too restrictive. Also, signal with baseline amplitude <500 µV may be considered equally adequate. Setting the alarm for a reduction of 77% in patients with initial amplitude ≥500 µV and of 15% for those <500 µV could make monitoring safe and an effective aid for surgeons. In conclusion, there are cases in which initial amplitude is lower than that considered as adequate by current literature but with well recognizable and stable EMG waveforms. How those cases should be approached and what should the surgeon's attitude be are a matter of discussion.

Potential role of sorafenib as neoadjuvant therapy in unresectable papillary thyroid cancer

Total thyroidectomy, radioiodine (RAI) therapy, and TSH suppression are the mainstay treatment for differentiated thyroid carcinomas (DTCs). Treatments for metastatic disease include surgery, external-beam radiotherapy, RAI, and kinase inhibitors for progressive iodine-refractory disease. Unresectable locoregional disease remains a challenge, as standard therapy with RAI becomes unfeasible. We report a case of a young patient who presented with unresectable papillary thyroid carcinoma (PTC), and treatment with sorafenib allowed total thyroidectomy and RAI therapy. A 20-year-old male presented with severe respiratory distress due to an enlarging cervical mass. Imaging studies revealed an enlarged multinodular thyroid gland, extensive cervical adenopathy, severe tracheal stenosis, and pulmonary micronodules. He required an urgent surgical intervention and underwent tracheostomy and partial left neck dissection, as the disease was deemed unresectable; pathology revealed PTC. Treatment with sorafenib was initiated, resulting in significant tumor reduction allowing near total thyroidectomy and bilateral neck dissection. Postoperatively, the patient underwent radiotherapy for residual tracheal lesion, followed by RAI therapy for avid cervical and pulmonary disease. The patient's disease remains stable 4 years after diagnosis. Sorafenib has been approved for progressive RAI-refractory metastatic DTCs. In this case report, we describe a patient with locally advanced PTC in whom treatment with sorafenib provided sufficient tumor reduction to allow thyroidectomy and RAI therapy, suggesting a potential role of sorafenib as an induction therapy of unresectable DTC.

Surgical treatment of locally advanced papillary thyroid carcinoma after response to lenvatinib: A case report

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There is no established neoadjuvant therapy for advanced DTC.

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We report the case of a locally advanced DTC that was invaded the trachea, the muscular layer of the esophagus, and the right internal jugular vein.

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After response to lenvatinib, the tumor was resected.

Introduction

Differentiated thyroid carcinomas (DTC) have good prognoses after complete resection. Nevertheless, when DTC is associated with an aerodigestive invasion, curative surgery is difficult to perform. However, there is no established neoadjuvant therapy for advanced DTC.

Presentation of case

A 73-year-old man with thyroid papillary carcinoma was referred to our hospital. A computed tomography examination revealed a tumor in the upper right lobe of the thyroid, and multiple bilateral enlarged lymph nodes in the neck, involving the surrounding structures. The enlarged lymph node at the right upper neck was suspected to have invaded the right internal jugular vein, and the left paratracheal lymph node was suspected to have invaded the cervical esophagus and trachea. The tumor was considered resectable; however, surgery would have been highly invasive. Therefore, we initiated neoadjuvant therapy with lenvatinib. After administration of lenvatinib, the tumor decreased in size by 84.3% and the cervical lymph nodes by 56.0%. The patient underwent a total thyroidectomy, modified neck dissection, a resection of the muscular layer of the esophagus, and a tracheal sleeve resection and reconstruction.

Discussion

The SELECT trial demonstrated that lenvatinib had high response rate with short response time, in patients with radioiodine-refractory DTC. The results suggested that lenvatinib could be effective as neoadjuvant therapy.

Conclusion

For an advanced DTC that requires removal through invasive surgery, preoperative lenvatinib treatment might be one of the options for a less invasive surgery.

Sparing Surgery for the Successful Treatment of Thyroid Papillary Carcinoma Invading the Trachea: A Case Report

Published reports on salvage treatment for trachea reconstruction after total thyroidectomy or partial tracheotomy are available, some of them using structures of the trachea itself, auricular cartilage, a musculocutaneous flap, or other methods. In our report, we emphasize the importance of a search for a new material and approach for sparing surgery. The purpose of this article is to describe a case of a successful sparing surgery in a patient with advanced thyroid papillary carcinoma invading the trachea. After total thyroidectomy in 2012, partial resection of the trachea was performed in 2014. The lesion defect was 5.5 × 2.3 cm in size, located between 4 (2nd–6th) tracheal cartilaginous rings and involving about a semicircumference. It was reconstructed with the aid of the knitted TiNi-based mesh endograft, which has been prefabricated in the sternocleidomastoid muscle and further covered with the skin draped over the wound. The tracheostoma was fully closed 6 weeks after the surgery. There were neither side effects nor complications. This kind of tracheal surgery for extensive lesions demonstrates good functional and cosmetic outcomes.

Neoadjuvant Therapy in Differentiated Thyroid Cancer

Objectives. Invasion of differentiated thyroid cancer (DTC) into surrounding structures can lead to morbid procedures such as laryngectomy and tracheal resection. In these patients, there is a potential role for neoadjuvant therapy. Methods. We identified three studies involving the treatment of DTC with neoadjuvant chemotherapy: two from Slovenia and one from Japan. Results. These studies demonstrate that in selected situations, neoadjuvant chemotherapy can have a good response and allow for a more complete surgical resection, the treatment of DTC. Additionally, the SELECT trial shows that the targeted therapy lenvatinib is effective in the treatment of DTC and could be useful as neoadjuvant therapy for this disease due to its short time to response. Pazopanib has also demonstrated promise in phase II data. Conclusions. Thus, chemotherapy in the neoadjuvant setting could possibly be useful for managing advanced DTC. Additionally, some of the new tyrosine kinase inhibitors (TKIs) hold promise for use in the neoadjuvant setting in DTC.

Overexpression of long non-coding RNA NR_036575.1 contributes to the proliferation and migration of papillary thyroid cancer

Current evidence suggests that the human genome produces a large number of non-coding RNAs, including microRNAs and long non-coding RNAs (lncRNAs). Generally, lncRNAs are defined as RNA transcripts longer than 200 nucleotides that are not transcribed into proteins. In recent years, lncRNAs have been reported to play oncogenic roles in tumourigenesis. However, minimal research has been performed on the expression and clinicopathological significance of lncRNAs in papillary thyroid cancer (PTC). In the present study, we investigated not only the expression and clinicopathological significance of a novel lncRNA, NR_036575.1, in PTC tissues and adjacent non-cancerous tissues but also its potential function in TPC1 cells. The expression levels of the lncRNA NR_036575.1 in 83 pairs of PTC tissues and adjacent non-cancerous tissues were detected via quantitative real-time polymerase chain reaction. The relationships between the expression levels and clinicopathological characteristics of the lncRNA NR_036575.1 were analysed. In addition, we established two receiver operating characteristic (ROC) curves to assess the diagnostic value of NR_036575.1 expression. Cell Counting Kit-8 and transwell assays were used to assess cell proliferation and migration, respectively. The expression levels of the lncRNA NR_036575.1 were significantly higher in PTC tissues than in adjacent non-cancerous tissues. High NR_036575.1 expression was associated with extrathyroidal extension (ETE) (P = 0.011) and tumour size (P = 0.006). The ROC curves indicated that NR_036575.1 could potentially serve as a biomarker for identifying PTC and related, non-cancerous diseases (sensitivity, 80.7 %; specificity, 88 %), as well as for differentiating between PTC with or without ETE (sensitivity, 57.8 %; specificity, 86.7 %). NR_036575.1 knock-down significantly inhibited the proliferation and migration of TPC1 cells. Our findings are the first to describe lncRNA NR_036575.1 overexpression in PTC. NR_036575.1 expression was associated with both ETE and tumour size. In addition, NR_036575.1 modulation could regulate TPC1 cell proliferation and migration. The results of our study suggest that NR_036575.1 could be applied as a potential biomarker and a novel therapeutic target for PTC patients.

Impact of lymph node metastases with recurrent laryngeal nerve invasion on patients with papillary thyroid carcinoma

BACKGROUND

Although rare, invasion by papillary thyroid carcinoma (PTC) of the upper aerodigestive tract significantly affects patients' prognosis and quality of life. Within the central compartment, the recurrent laryngeal nerve (RLN) is most frequently invaded by lymph node metastases (LNM). However, such an invasion has not been described in the literature, although reports on RLN invasion by primary tumors have been published. The present study aimed to characterize LNM with RLN invasion in patients with PTC.

METHODS

The participants of this retrospective investigation were selected from 629 PTC patients who received initial surgical treatment at our institution between January 1981 and December 2012. They included 38 (6%) patients with 40 cases of RLN invasion by LNM (LNM invasion group) and 112 (17.8%) patients with 117 cases of RLN invasion by the primary tumor (primary invasion group).

RESULTS

In the LNM invasion group, 70% of the RLN invasion cases occurred on the right side, whereas those in the primary invasion group were almost equally distributed. RLN invasion caused vocal cord paralysis, affecting 13 nerves (32.5%) in the LNM invasion group and 68 nerves (58%) in the primary invasion group. Significant differences in laterality and preoperative vocal cord paralysis were observed between the two groups. In the LNM invasion group, the longest diameter of metastatic lymph nodes (mean±standard deviation) of patients with RLN paralysis was 21±8 mm, whereas it was significantly different at 14±7 mm in those without RLN paralysis.

CONCLUSIONS

Our results indicate that most patients with RLN invasion by LNM did not experience preoperative vocal cord paralysis. LNM invasion of the RLN (70%) more often occurred on the right side as expected given the complexity and three-dimensional anatomy of the RLN in the right paratracheal region compared to the left. RLN invasion by LNM should be considered if preoperative paratracheal nodal disease, especially when bulky, is noted in the right paratracheal region.

Tracheal reconstruction using composite nasal septal graft in patients with invasive thyroid carcinoma

OBJECTIVE

This paper presents a series of three patients who were identified as having partial thickness involvement of the laryngotracheal complex secondary to invasive, well-differentiated thyroid cancer. These patients were managed with full thickness window resection and reconstruction using a composite nasal septal graft.

METHODS

A review of the Princess Alexandra Hospital database (comprising prospectively collated data) was undertaken to identify patients who had undergone full thickness tracheal resection and reconstruction using a composite nasal septal graft; demographic, operative technique and survival outcome data were collated.

RESULTS

Three patients had a composite nasal septal graft performed for reconstruction of full thickness laryngotracheal defects following the excision of well-differentiated thyroid cancer. There were no cases of local recurrence after a minimum of 18 months' follow up.

CONCLUSION

This paper describes our surgical technique for reconstruction of these defects using a composite nasal septal graft. It also presents data on our three cases to date, in which the technique has been used safely. A discussion of the surgical management of locally invasive, well-differentiated thyroid cancer is provided.

Expression of MMP-1 in invasive well-differentiated thyroid carcinoma

The objective of this study is to examine the expression of matrix metalloproteinase 1 (MMP-1) in invasive well-differentiated thyroid carcinoma (WDTC) and its relation to clinicopathological features. This retrospective case study group included 26 patients with invasive WDTC who were treated at our center between January 1985 and May 2007. Clinical data were collected from the medical files. MMP-1 expression was tested in samples from paraffin-embedded tumor by immunohistochemical staining. MMP-1 expression correlated with laryngotracheal invasion (p = 0.032), multifocality of the tumor (p = 0.044), and presence of regional (p = 0.034) and distant metastases (p = 0.048). In conclusion, the expression of MMP-1 in invasive WDTC is consistent with tumor aggressiveness, manifested by laryngotracheal invasion, multifocality, and regional and distant metastases. MMP-1 expression may serve as a prognostic marker and an indicator for the need for more aggressive surgical treatment.