Tracheal Resection in the Management of Thyroid Cancer: An Evidence-Based Approach

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".

Deterioration of Vocal Cord Paralysis after COVID-19 Infection in Multiple System Atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative disease that often causes vocal cord paralysis (VCP), Parkinsonism, cerebellar ataxia, and autonomic dysfunction. VCP is the most fatal symptom that affects the prognosis of patients with MSA. Coronavirus disease 2019 (COVID-19) is often associated with neurological complications and it has recently been reported to induce VCP in patients without neurodegenerative diseases. We herein present two cases of patients with MSA in whom VCP worsened after COVID-19 and this led to the need to perform emergency tracheostomies. As VCP may deteriorate after COVID-19 in patients with MSA, it is important to prevent COVID-19 in these patients and closely monitor such patients for any signs of VCP deterioration post-infection to improve their prognosis.

Comparative long-term outcomes of airway resection and functional reconstruction for papillary thyroid cancer

INTRODUCTION

The surgical management of patients diagnosed with papillary thyroid carcinoma (PTC) and tracheal invasion has been a subject of ongoing discussion, particularly regarding the approach to tracheal functional reconstruction. The objective of this study was to examine the surgical technique and prognosis of PTC patients with tracheal invasion.

MATERIALS AND METHODS

This study employed both univariate and multivariate Cox proportional hazard models to determine predictive factors that affect the progression-free survival (PFS) of PTC patients with tracheal invasion. Cox regression analysis was conducted by using R software version 4.3.1.

RESULTS

In our study, we included 247 patients with T4a PTC. Among them, 146 patients (59.1 %) were classified as Shin I, 57 patients (23.1 %) as Shin II-III, and 44 patients (17.8 %) as Shin IV. Patients in the Shin I group underwent shaving of the tumours in the airway. The preferred surgical methods in the Shin II, III and IV groups were window resection (66.7 %), sleeve resection (34.8 %) and partial tracheal resection and skin fistula (61.8 %), respectively. Multivariate analysis demonstrated that neither tracheal surgery nor reconstruction procedures had an impact on PFS in T4a PTC patients with tracheal invasion. The 5-year DSS rate for patients receiving radioiodine (RAI) therapy was 87.3 % (p = 0.033).

CONCLUSION

This study confirmed that tracheal surgery and reconstruction methods had no impact on PFS in T4a PTC patients with tracheal invasion in different Shin groups. Furthermore, RAI therapy has the potential to increase the survival rate of patients with preoperative distant metastasis of T4a PTC.

BRAF and RET polymorphism association with thyroid cancer risk, a preliminary study from Khyber Pakhtunkhwa population

BACKGROUND

Thyroid cancer, originating in the neck's thyroid gland, encompasses various types. Genetic mutations, particularly in BRAF and RET genes are crucial in its development. This study investigates the association between BRAF (rs113488022) and RET (rs77709286) polymorphisms and thyroid cancer risk in the Khyber Pakhtunkhwa (KP) population.

METHODS

Blood samples from 100 thyroid cancer patients and 100 healthy controls were genotyped using ARMS-PCR followed by gel electrophoresis and statistical analysis.

RESULTS

Analysis revealed a significant association between the minor allele T of BRAF (rs113488022) and thyroid cancer risk (P = 0.0001). Both genotypes of BRAF (rs113488022) showed significant associations with thyroid cancer risk (AT; P = 0.0012 and TT; P = 0.045). Conversely, the minor allele G of RET (rs77709286) exhibited a non-significant association with thyroid cancer risk (P = 0.2614), and neither genotype showed significant associations (CG; P = 0.317, GG; P = 0.651). Demographic and clinical parameters analysis using SPSS showed a non-significant association between BRAF and RET variants and age group (P = 0.878 and P = 0.536), gender (P = 0.587 and P = 0.21), tumor size (P = 0.796 and P = 0.765), or tumor localization (P = 0.689 and P = 0.727).

CONCLUSION

In conclusion, this study emphasizes the significant association between BRAF polymorphism and thyroid cancer risk, while RET polymorphism showed a less pronounced impact. Further validation using larger and specific datasets is essential to establish conclusive results.

A 16-Year Single-Center Series of Trachea Resections for Locally Advanced Thyroid Carcinoma

(1) Background: Infiltration of the aerodigestive tract in advanced thyroid carcinoma determines the prognosis and quality of life. Different stages of tracheal tumor invasion require customization of the surgical concept. (2) Methods: In the period from January 2007 to January 2023, patients who underwent surgery for advanced thyroid carcinomas with trachea resections were included in a retrospective observational study. The surgical resection concepts and operation-associated complications were documented. The overall survival and post-resection survival were analyzed. (3) Results: From 2007 to 2023, at the single-center UMC Mainz, 33 patients (15 female and 18 male) underwent neck surgery with trachea resections for locally advanced thyroid carcinomas. Of these, 14 were treated with non-transmural (trachea shaving) and 19 transmural trachea resections (9 "window" resections, 6 near-circular resections, 3 sleeve resections and 1 total laryngectomy with extramucosal esophageal resection). The two-year postoperative survival rate was 82.0 percent. The two-year recurrence-free survival rate was 75.0 percent (mean follow-up period: 29.2 months). (4) Conclusions: Tracheal resections for locally advanced tumor infiltration are feasible as an element of highly individualized treatment concepts.

"Flap of Hope: a Pectoralis Major Muscle Solution for Tracheal Resection Closure": Case Report

Medullary carcinoma of the thyroid is a rare type of thyroid cancer that arises from the parafollicular cells or C-cells, which produce calcitonin. It accounts for approximately 5-10% of all thyroid cancers (Leboulleux et al. in Clin Endocrinol 61(3):299-310, 2004). The main treatment for medullary thyroid carcinoma is surgery, which involves the removal of the thyroid gland and any affected lymph nodes. In advanced cases where the cancer has spread to nearby structures such as the trachea (Gupta et al. in Indian J Surg Oncol 11(1):75-79, 2020), tracheal resection followed by reconstruction may be necessary to remove the cancer (Chernichenko et al. in Curr Opin Oncol 24(1):29-34, 2012) and restore proper breathing, closure of large tracheal defect can be done with pectoralis major myocutaneous flap (Salmerón-González et al. Plast Surg Nurs 38. 162-165, 2018). In this article, we report a case of recurrent medullary carcinoma thyroid with tracheal infiltration and tracheal resection was done, both of which is extremely rare. A 38-year-old male patient with a history of total thyroidectomy presented with recurrence was referred to our department, his previous biopsy and IHC revealed medullary carcinoma thyroid. Ga-68 DOTA PET CT scan was done which showed PET avid residual mass over right side, multiple bilateral cervical nodes, and tracheal infiltration (Fig. 1) then underwent a bronchoscopy showing involvement of the second, third, and fourth tracheal ring. Bilateral neck dissection with sleeve resection of trachea with overlying residual tumor was done and was sent for frozen which revealed positive margins and re-excision of margins was done, which lead to large defect (Fig. 2) which could not be closed primarily with a Montgomery T Tube. A de-epithelized pectoralis major myocutaneous flap used to close the tracheal defect followed by placing the Montgomery T Tube (Fig. 3).Post-operative period was uneventful. The final histopathology report showed R0 resection of tumor. T tube was removed after 4 weeks.

Multi-Omics and Management of Follicular Carcinoma of the Thyroid

Follicular thyroid carcinoma (FTC) is the second most common cancer of the thyroid gland, accounting for up to 20% of all primary malignant tumors in iodine-replete areas. The diagnostic work-up, staging, risk stratification, management, and follow-up strategies in patients who have FTC are modeled after those of papillary thyroid carcinoma (PTC), even though FTC is more aggressive. FTC has a greater propensity for haematogenous metastasis than PTC. Furthermore, FTC is a phenotypically and genotypically heterogeneous disease. The diagnosis and identification of markers of an aggressive FTC depend on the expertise and thoroughness of pathologists during histopathological analysis. An untreated or metastatic FTC is likely to de-differentiate and become poorly differentiated or undifferentiated and resistant to standard treatment. While thyroid lobectomy is adequate for the treatment of selected patients who have low-risk FTC, it is not advisable for patients whose tumor is larger than 4 cm in diameter or has extensive extra-thyroidal extension. Lobectomy is also not adequate for tumors that have aggressive mutations. Although the prognosis for over 80% of PTC and FTC is good, nearly 20% of the tumors behave aggressively. The introduction of radiomics, pathomics, genomics, transcriptomics, metabolomics, and liquid biopsy have led to improvements in the understanding of tumorigenesis, progression, treatment response, and prognostication of thyroid cancer. The article reviews the challenges that are encountered during the diagnostic work-up, staging, risk stratification, management, and follow-up of patients who have FTC. How the application of multi-omics can strengthen decision-making during the management of follicular carcinoma is also discussed.

Surgical strategy of locally advanced differentiated thyroid cancer

Approximately 20% of patients with differentiated thyroid cancer (DTC) have direct tumor extension with invasion of the surrounding tissues such as the larynx, trachea, esophagus, or recurrent laryngeal nerve. Recent progress of molecular-targeted therapy, such as the use of tyrosine kinase inhibitors, improves survival outcome in patients with advanced DTC. However, induction of tyrosine kinase inhibitors for locally-advanced DTC has presented novel fatal adverse events including fistula in patients with infiltration toward to the trachea, pharynx and esophagus, and fatal bleeding in patients with great vessel invasion. Surgery therefore still has an important role in DTC management, particularly in local control. The surgical strategy for laryngeal/tracheal invasion, which commonly occurs by DTC, is decided according to the extension (depths and area) of the tumor. The "shave procedure" is performed when the tumor has superficially invaded the larynx/trachea. However, intra-luminal extension requires resection and reconstruction of the larynx/trachea wall. Large veins, such as the internal jugular vein and the subclavian vein, are also frequently directly invaded by DTC. Three types of jugular vein reconstruction have been advocated to avoid fatal complications according to bilateral jugular vein ligation. The majority of carotid artery invasion by DTC can be managed with tumor resection of the sub-adventitial layer without reconstruction surgery using an artificial vessel. In this review article, we examine surgery for advanced DTC, showing the surgical strategy toward DTC that has invaded the laryngotracheal, recurrent laryngeal nerve, esophagus/hypopharynx, or great vessels.

Targeting ACE2 as a potential prophylactic strategy against COVID-19-induced exacerbation of chronic kidney disease

Patients with chronic kidney disease (CKD) are at higher risk for severe coronavirus disease 2019 (COVID-19). Such patients are more likely to develop “COVID-19-induced acute kidney injury (AKI)”, which exacerbates the pre-existing CKD and increases the mortality rate of the patients. COVID-19-induced AKI is pathologically characterized by acute tubular necrosis and the interstitial infiltration of proinflammatory leukocytes. In our rat model with advanced CKD, immunohistochemistry for angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) demonstrated their strong expression in the cytoplasm of damaged proximal tubular cells and the infiltrating leukocytes within the cortical interstitium, which overlapped with the lesions of COVID-19-induced AKI. Since ACE2 and TMPRSS2 are enzymes that facilitate the viral entry into the cells and trigger the onset of cytokine storm, the renal distribution of these proteins in advanced CKD was thought to be responsible for the development of COVID-19-induced AKI. Concerning such mechanisms, the pharmacological blockade of ACE2 or the use of soluble forms of the ACE2 protein may halt the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into host cells. This would protect against the COVID-19-induced exacerbation of pre-existing CKD by preventing the development of AKI.

Multiple Types of Taste Disorders among Patients with COVID-19

Objective Based on the increasing incidence of smell and taste dysfunction among coronavirus disease 2019 (COVID-19) patients, such issues have been considered an early symptom of infection. However, few studies have investigated the type of taste components that are most frequently affected in COVID-19 patients. This study investigated the difference in frequencies of the types of taste component disorders among hospitalized COVID-19 patients. Methods In this retrospective, single-center, observational study, patients' background characteristics, clinical course, laboratory and radiological findings, and details on taste and/or smell disorders were collected and analyzed from medical records. Patients A total of 227 COVID-19 patients were enrolled, among whom 92 (40.5%) complained of taste disorders. Results Multiple types of taste disorders (hypogeusia/ageusia and hypersensitivity, or hypersensitivity and changing tastes) were reported in 10 patients. In particular, 23 patients reported hypersensitivity to at least 1 type of taste, and 2 patients complained of a bitter taste on consuming sweet foods. Impairment of all taste components was found in 48 patients (52.2%). The most frequent taste disorder was salty taste disorder (81 patients, 89.0%). Hypersensitivity to salty taste was most frequently observed (19 patients, 20.9%). Conclusion Patients with COVID-19 develop multiple types of taste disorders, among which salty taste disorder was the most frequent, with many patients developing hypersensitivity to salty taste. As smell and taste are subjective senses, further studies with the combined use of objective examinations will be required to confirm the findings.

Surgery for Thyroid Cancer Invading the Trachea

Thyroid cancer invading the trachea can be asymptomatic, but when tumour invasion reaches the mucosal surface, it causes bloody sputum and dyspnoea. The treatment plan for thyroid cancer is determined based on the site, depth, and extent of the invasion. Different from tumours arising from the tracheal mucosa, in thyroid cancer, invasion begins outside the airway and progresses toward the lumen, making it difficult to accurately diagnose the extent of the invasion even with bronchoscopy. Therefore, surgeons must determine the range of resection during surgery. Invasion reaching the tracheal mucosa requires full-thickness resection and is performed using tracheal window resection combined with tracheocutaneous fistula or tracheal sleeve resection followed by end-to-end anastomosis. The airway is safely secured with window resection, but closing the tracheal stoma often requires multi-stage reconstruction. Sleeve resection is an oncologically appropriate surgical method that can be completed in one stage, although there is a risk of serious complications associated with anastomotic dehiscence. Since well-differentiated thyroid cancer progresses slowly, some degree of survival can be expected even with incomplete resection. However, when shaving is performed for tumours with deep invasion that reaches the tracheal mucosa, the residual tumour tissue continues to grow steadily and eventually leads to airway stenosis. Since reoperation for tracheal resection is difficult, radical full-thickness resection should be performed in the initial surgery. Although this surgical intervention is far more demanding for both patients and surgeons than shaving, the procedure eventually improves patient's prognosis and quality of life.

Self-reported symptom study of COVID-19 chemosensory dysfunction in Malaysia

Alterations in the three chemosensory modalities-smell, taste, and chemesthesis-have been implicated in Coronavirus Disease 2019 (COVID-19), yet emerging data suggest a wide geographic and ethnic variation in the prevalence of these symptoms. Studies on chemosensory disorders in COVID-19 have predominantly focused on Caucasian populations whereas Asians remain understudied. We conducted a nationwide, multicentre cross-sectional study using an online questionnaire on a cohort of RT-PCR-confirmed adult COVID-19 patients in Malaysia between 6 June and 30 November 2020. The aim of our study was to investigate their presenting symptoms and assess their chemosensory function using self-ratings of perceived smell, taste, chemesthesis, and nasal blockage. In this cohort of 498 patients, 41.4% reported smell and/or taste loss when diagnosed with COVID-19, which was the commonest symptom. Blocked nose, loss of appetite, and gastrointestinal disturbances were independent predictors of smell and/or taste loss on multivariate analysis. Self-ratings of chemosensory function revealed a reduction in smell, taste, and chemesthesis across the entire cohort of patients that was more profound among those reporting smell and/or taste loss as their presenting symptom. Perceived nasal obstruction accounted for only a small proportion of changes in smell and taste, but not for chemesthesis, supporting viral disruption of sensorineural mechanisms as the dominant aetiology of chemosensory dysfunction. Our study suggests that chemosensory dysfunction in COVID-19 is more widespread than previously reported among Asians and may be related to the infectivity of viral strains.Study Registration: NMRR-20-934-54803 and NCT04390165.