Differentiated Thyroid Cancer: A Health Economic Review

Course and predictors of excellent response to therapy in patients with differentiated thyroid cancer at long-term follow-up

OBJECTIVES

To investigate the long-term outcomes of differentiated thyroid cancer (DTC) and the predictive factors for excellent and incomplete responses to therapy on long-term follow-up of patients.

METHODS

A retrospective chart review and analysis was carried out at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Demographic, histological, and therapeutic data were collected from patients older than 13 years at the time of diagnosis, with a minimum follow-up of 18 months. Outcomes were divided into excellent, indeterminate, biochemically incomplete, and structurally incomplete responses. Odds ratios (ORs) for predictors of incomplete response at the last visit were determined. We first tested associations univariately with incomplete responses, and then variables with significant associations were included in a multivariable logistic model.

RESULTS

Among 230 patients with DTC, 61.7% had excellent responses to therapy on long-term follow-up, and 24.3% had incomplete biochemical and structural responses. The median follow-up was 4.6 years. Factors significantly associated with incomplete response to therapy in the multivariate analysis (p<0.05) were age >55 years (OR=5) and lymph node (OR=3.4) and distant metastases (OR=29). Older age did not affect the outcome in low-risk patients with DTC but was significantly associated with incomplete responses in those with intermediate risk (p=0.04) and high risk (p=0.003).

CONCLUSION

We strongly advocate incorporating age into recurrence risk assessment for patients with DTC.

Accuracy and diagnostic performance of the Bethesda system for reporting thyroid cytopathology in a tertiary endocrine surgical referral center in Belgium

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology is a commonly used classification for fine needle aspiration (FNA) cytology of suspicious thyroid nodules. The risk of malignancy (ROM) for each category has recently been analyzed in three international databases. This paper compares the diagnostic performance of the Bethesda classification in a high-volume referral center in Belgium.

METHODS

All consecutive thyroid procedures were registered in a prospective database from January 2010 till August 2022. Patient and surgical characteristics, preoperative Bethesda categories, and postoperative pathology results were analyzed.

RESULTS

Out of 2219 consecutive thyroid procedures, 1226 patients underwent preoperative FNA. Papillary thyroid cancer was the most prevalent malignancy (N = 119, 70.4%), followed by follicular (N = 17, 10.1%) and medullary thyroid cancer (N = 15, 8.9%). Micropapillary thyroid cancer was incidentally found in 46 (3.8%) patients. Bethesda categories I, II, III, IV, V, and VI, respectively, represented 250 (20.4%; ROM 4.4%), 546 (44.5%; ROM 3.8%), 96 (7.8%; ROM 20.8%), 231 (18.8%; ROM 15.2%), 62 (5.1%; ROM 72.6%), and 41 (3.3%; ROM 90.2%) patients. Overall ROM was 13.8%. An negative predictive value (NPV) of 96.2% was found. Overall specificity was 64.2% with a positive predictive value (PPV) of 31.9%. Diagnostic accuracy was 67.8%. Compared to international databases (CESQIP, EUROCRINE, and UKRETS), ROM in this study appeared lower for Bethesda category IV (15.2 vs. 26.7% and p = 0.612).

CONCLUSION

Despite being validated in numerous studies, ROM based on preoperative FNA cytology classified according to the Bethesda classification may vary among surgical centers and countries as this study reveals a higher NPV and lower PPV.

The Frequency of Differentiated Thyroid Cancer Recurrence in 2302 Patients With Excellent Response to Primary Therapy

CONTEXT

Discrepant data on the recurrence rate of differentiated thyroid cancer (DTC) are reported.

OBJECTIVE

To evaluate the frequency and risk factors of true recurrence in DTC patients with excellent responses (ExR) to initial therapy.

METHODS

A retrospective analysis of the 2302 consecutive DTC patients with ExR to primary therapy, treated during 24 years at single center. The percentage of recurrence and cumulative recurrence rate (CRR) were analyzed. Risk factors for recurrence for patients with papillary thyroid cancer (PTC) were investigated and methods for establishing a diagnosis of recurrence were evaluated.

RESULTS

Of DTC patients, 32 (1.4%) experienced recurrence. PTC patients with recurrence were more likely to have younger age (P = .0182), larger tumor size (P = .0013), lymph node metastases (P = .0013), incomplete resection (P = .0446), higher ATA risk (P = .0002), and had more frequently been treated with 131I (P = .0203). CRRs at 5, 10, 15, 20, and 24 years after surgery were 1.2%, 1.9%, 2.5%, 2.9%, and 2.9%, respectively. The CRRs according to histological type were highest for poorly differentiated thyroid cancer (PDTC), lower for oncocytic (OTC) and follicular thyroid cancer (FTC), and lowest for PTC. Most recurrences occurred within the first 5 years of observation. The most effective method for detecting local recurrence was ultrasonography with fine needle aspiration cytology, and for distant metastases, 18F-FDG PET.

CONCLUSION

True recurrence is rare in DTC patients. PTC patients with ExR to primary therapy and N0/Nx can be dismissed from oncological follow-up. Despite ExR to primary therapy, DTC patients with N1, and PDTC, OTC, FTC should remain under oncological follow-up.

Hearing the Voices of Australian Thyroid Cancer Survivors: Qualitative Thematic Analysis of Semistructured Interviews Identifies Unmet Support Needs

Background: Most thyroid cancer survivors regain their physical health-related quality of life, but psychological and social deficits persist. The nature of these detriments remains poorly understood and they are insufficiently captured by survey data alone. To address this, qualitative data exploring the breadth and depth of thyroid cancer survivors' experiences and priorities for supportive care are required. Methods: Twenty semistructured interviews were undertaken with a purposive, maximum variation sample of thyroid cancer survivors. Interviews were transcribed verbatim and coded independently by two researchers. A hybrid model of inductive and realistic codebook analysis was undertaken with themes developed. Results: Patient experiences centered around three themes: (1) impact of diagnosis and treatment, (2) thyroid cancer does not happen in isolation, and (3) role of clinicians and formalized support structures. The word "cancer" had negative connotations, but for many, the reality of their experience was more positive. Despite feeling "lucky" at the relative low-risk nature of thyroid cancer, many patients reported fatigue, weight gain, and difficulty returning to usual activities; concerns that were largely dismissed or minimized by clinicians. Few were offered any support beyond their treating doctors; where patients attempted to access formalized supportive care, little was available or appropriate. Life stage and concurrent family and social stressors greatly impacted patients' ability to cope with diagnosis and treatment. Addressing thyroid cancer in isolation felt inappropriate without appreciating the broader context of their lives. Interactions with clinicians were largely positive, particularly where information was communicated as a means of empowering patients to participate in shared decision-making and where clinicians "checked in" emotionally with patients. Information about initial treatments was largely adequate but information on longer term effects and follow-up was lacking. Many patients felt that clinicians focused on physical well-being and scan results, missing opportunities to provide psychological support. Conclusions: Thyroid cancer survivors can struggle to navigate their cancer journey, particularly with regard to psychological and social functioning. There is a need to acknowledge these impacts at the time of clinical encounters, as well as develop information resources and support structures that can be individualized to optimize holistic well-being for those in need.

Applications of machine and deep learning to thyroid cytology and histopathology: a review

This review synthesises past research into how machine and deep learning can improve the cyto- and histopathology processing pipelines for thyroid cancer diagnosis. The current gold-standard preoperative technique of fine-needle aspiration cytology has high interobserver variability, often returns indeterminate samples and cannot reliably identify some pathologies; histopathology analysis addresses these issues to an extent, but it requires surgical resection of the suspicious lesions so cannot influence preoperative decisions. Motivated by these issues, as well as by the chronic shortage of trained pathologists, much research has been conducted into how artificial intelligence could improve current pipelines and reduce the pressure on clinicians. Many past studies have indicated the significant potential of automated image analysis in classifying thyroid lesions, particularly for those of papillary thyroid carcinoma, but these have generally been retrospective, so questions remain about both the practical efficacy of these automated tools and the realities of integrating them into clinical workflows. Furthermore, the nature of thyroid lesion classification is significantly more nuanced in practice than many current studies have addressed, and this, along with the heterogeneous nature of processing pipelines in different laboratories, means that no solution has proven itself robust enough for clinical adoption. There are, therefore, multiple avenues for future research: examine the practical implementation of these algorithms as pathologist decision-support systems; improve interpretability, which is necessary for developing trust with clinicians and regulators; and investigate multiclassification on diverse multicentre datasets, aiming for methods that demonstrate high performance in a process- and equipment-agnostic manner.

Development of a novel clinical support tool for active surveillance of low risk papillary thyroid cancer

Background

Active surveillance (AS) is an alternative to surgery in select patients with very low risk papillary thyroid cancer (PTC). Many clinicians feel ill-equipped in selecting appropriate patients. We aimed to 1) Develop an evidence-based web delivered decision support tool to assist clinicians in identifying patients appropriate for AS; and 2) Evaluate the prevalence of patients suitable for AS in a tertiary high volume thyroid cancer centre.

Method

A REDCap web based clinical support tool was developed utilising evidence-based characteristics for AS suitability available to clinicals during initial assessment. A retrospective database was interrogated for patients who underwent hemithyroidectomy between 2012 - 2021 with final histopathology demonstrating PTC. Patients with PTCs>2cm, missing data, benign disease on surgical histopathology or incidental PTC were excluded.

Results

Between 2012 - 2021, 763 patients underwent hemithyroidectomy with final histopathology confirming PTC. Of these, 316 patients were excluded (missing data, incidental PTC, concomitant hyperparathyroidism were most common reasons for exclusion) and 114/447 remaining patients had a pre-operative fine needle aspirate (FNA) of Bethesda V or VI (high likelihood of malignancy). Using the tool, 59/114 (52%) met criteria for AS. The majority of patients were female (85% vs 15% male); median age 36 years (range 19 - 78). Following initial surgery, 10/59 patients had a completion thyroidectomy, with 4/10 demonstrating malignancy in contralateral lobe and eight of those patients undergoing I131 ablation. During a median follow up of over 3 years, 49/59 (83%) did not require further surgery or intervention with no patients developing recurrence. A subgroup analysis with second radiology assessment excluded 4/59 patients as meeting criteria for AS based on presence of ETE on preoperative ultrasound. None of these 4 patients had completion thyroidectomy.

Conclusion

Our clinical support tool identifies patients with PTC potentially suitable for AS which could be utilised during initial patient assessment. In a retrospective cohort of patients who had hemithyroidectomy for PTC with a pre-operative FNA diagnosis of Bethesda V or VI, 55/114 (48%) patients may have been suitable for AS. Prospective validation studies are required for implementation of the tool in clinical practice.

Thyroid surgery in the elderly: a surgical cohort

PURPOSE

The need for thyroid surgery in the elderly is rising due to an ageing population, the liberal use of imaging studies, and the increasing prevalence of thyroid nodules and cancer with age. Data on surgical outcomes in this population are scarce and conflicting, but essential to assess safety of short-stay surgery. This study aims to compare surgical outcomes by age.

METHODS

All consecutive patients undergoing thyroid surgery from January 2010 to July 2021 in a large tertiary referral centre for endocrine surgery were included in this surgical cohort. The indication for surgery, surgical morbidity (hypocalcaemia, bleeding, recurrent laryngeal nerve (RLN) palsy), and length of hospital stay were assessed in three age groups (young: 18-64y, older: 65-74y, and the elderly: 75 years and older).

RESULTS

A total of 2,030 patients (1,499 young, 370 older, and 161 elderly) were included. The indication for surgery was significantly different, with the main indications in the elderly being multinodular goitre (70.2% vs. 47.7% in young patients) and thyroid cancer (9.9% vs. 7.0%). Reintervention for bleeding was more often required in the older (4.6%) and the elderly (2.5%) patients (vs. 1.4%). There was no difference in the proportion of hypocalcaemia or RLN palsy. The length of hospital stay was significantly longer in the elderly (length of stay longer than one day 43.5% vs. 9.8%).

CONCLUSION

Thyroid surgery in patients aged 75 years and older is a safe procedure with morbidity comparable to younger patients. However, the risk of reintervention for bleeding is higher, rendering ambulatory surgery not advisable.

TRIAL REGISTRATION

Researchregistry6182 on October 29^th 2020, retrospectively registered.

The 15-year national trends of endocrine cancers incidence among Iranian men and women; 2005-2020

Cancer is one of the important health problems in Iran, which is considered as the third cause of death. Endocrine cancers are rare but mostly curable. Thyroid cancer, the most common endocrine tumors, includes about one percent of malignant cancer. In this study, we examined the 15-year national trend of endocrine cancer incidence in Iranian men and women. The data in each province were evaluated based on age, gender, and cancer type according to International Classification of Disease Codes version 10 (ICD-10) from 2005 to 2020 in Iran. All data were obtained from the reports of the Statistics Center of Iran (SCI), 6 phases of the step-by-step approach to monitoring the risk factors of chronic diseases over 18 years old (STEPs), and 3 periods of the CASPIAN study (survey of non-communicable diseases in childhood and adolescence). Statistical analyzes and graph generation were done using R statistical software. Poisson regression with mixed effects was used for data modeling and incidence rate estimation. The incidence of thyroid gland malignancy is higher in women than in men. On the other hand, the incidence of adrenal gland cancer is slightly higher in men than in women. The same pattern is observed for other endocrine neoplasms and related structures. The incidence rate of these types of cancers has generally increased from 2005 to 2020 in Iran. This increase is more in women than in men. In addition, in the middle of the country, there is a strong region in terms of the occurrence of these types of cancers. The incidence rate in these provinces is relatively higher for both sexes and all studied periods. We conducted a study to observe the changing trends for various types of endocrine cancers over 15 years in men and women. Considering the increasing trend of thyroid cancers in Iran, therefore, creating essential policies for the management of these types of cancers for prevention, rapid diagnosis, and, timely treatment is particularly important.

Pyramidal lobe-dominant papillary thyroid carcinoma-A rare entity with important clinical implications

Papillary thyroid carcinoma (PTC) primarily located in the pyramidal lobe of the thyroid gland is extremely rare, therefore the clinical and pathological features are not well understood. The authors describe a case of PTC of the pyramidal lobe, in a 77-year-old woman who underwent en bloc total thyroidectomy with pyramidal lobe, hyoid bone and cervical lymph node excision. In line with the present case, current literature reports a greater presence of worse prognostic factors, namely extrathyroidal extension, advanced T stage or presence of cervical lymph node metastasis. Recently, a new classification has been suggested-Upper Neck Papillary Thyroid Cancer (UPTC)-which encompasses these carcinomas, Delphi ganglion metastases and thyroglossal duct cyst carcinomas, with potential clinical and therapeutic implications, particularly the need for orthotopic thyroidectomy. Also, the complete excision of the pyramidal lobe during thyroidectomy may influence the success of radioactive iodine therapy and the patient's follow-up surveillance.

Molecular testing in fine-needle aspiration of thyroid nodules

BACKGROUND

Thyroid nodules are commonly faced by clinicians as palpable nodules or incidentally identified on imaging. Nodules that are found to be suspicious by imaging can be biopsied by fine needle aspiration, which can yield material for molecular testing to refine the diagnosis.

METHODS

The current literature concerning molecular testing in thyroid nodules including available commercial assays was reviewed and summarized.

RESULTS/CONCLUSIONS

Commonly encountered alterations include mutations in RAS, BRAF, TERT promoter, PTEN, and DICER1 as well as fusions of RET, ALK, PAX8-PPARγ, and NTRK. This article provides a summary of these molecular alterations, commercially available molecular assays, and general considerations for thyroid epithelial malignancies and benign thyroid nodules.

The Initial ATA Risk Classification, but Not the AJCC/TNM Stage, Predicts the Persistence or Relapse of Differentiated Thyroid Cancer in Long-Term Surveillance

Background: The American Joint Commission on Cancer on Tumor Node Metastasis (AJCC/TNM) staging system provides adequate information on the risk of differentiated thyroid cancer (DTC)-specific mortality in totally thyroidectomized patients, but its role in predicting persistence and relapse of disease is uncertain. The relatively new 2015 American Thyroid Association (ATA) guidelines recommend stratifying patients at the time of DTC diagnosis with its own risk classification system, in order to identify those at high risk of residual or recurrent morbidity who may benefit from post-operative radioiodine (RAI) administration and/or need additional work-up. Methods: To verify the prevalence proportion of persistence or relapse of disease, a consecutive cohort of 152 patients with a diagnosis of DTC, subjected to total thyroidectomy (+/− post-operative RAI administration as per guidelines indication) and to neck ultrasonography (US), as well as biochemical surveillance for a minimum of 2 years at the Endocrinology Unit of Mater-Domini Hospital (Catanzaro, Italy), was enrolled. The prognostic role of the AJCC/TNM stage and ATA risk classification system was analyzed by logistic regression. Results: At a mean of 9 years after surgical treatment, DTC was found to persist or relapse in 19 (12.5%) participants. The initial risk for these outcomes, based on the ATA classification, was mostly low (53.9%) or intermediate (39.5%). AJCC/TNM stages were predominantly stage I or stage II. Despite a small representation in this cohort, high-risk patients according to the ATA classification had 8-fold higher odds of persistence or relapse of disease than those of low-risk participants, while controlling for potential risk modifiers, including age at DTC diagnosis, male gender, and post-operative RAI administration (p = 0.008). In contrast, the AJCC/TNM stage was not associated with the disease status at the last follow-up visit (p = 0.068 for the 7th Edition; p = 0.165 for the 8th Edition). Furthermore, low-risk participants subjected to post-operative RAI administration had the same probability of persistence or relapse of DTC when compared to those who had undergone total thyroidectomy only. Conclusions: There is a need for the endocrine community to revise the current work-up of DTC. The initial ATA risk classification is a reliable tool for predicting the persistence or relapse of disease in long-term surveillance.

Feasibility and Safety of Ambulatory Transoral Endoscopic Thyroidectomy via Vestibular Approach (TOETVA)

Background

In search of an ideal cosmesis, transoral endoscopic thyroidectomy via vestibular approach (TOETVA) has recently been introduced to avoid a visible scar. Although ambulatory thyroid surgery is considered safe in carefully selected patients, this remains unclear for TOETVA.

Methods

All consecutive adult patients who underwent ambulatory TOETVA or open thyroid surgery at a French university hospital were prospectively enrolled from 12/2020 until 11/2021. The primary outcome was postoperative morbidity (recurrent laryngeal nerve (RLN) palsy, re-intervention for bleeding, wound morbidity, or hospital readmission). The secondary outcome was quality of life (QoL), measured by a survey including a validated questionnaire (SF-12) and a modified thyroid surgery questionnaire six weeks after surgery.

Results

Throughout the study period, 374 patients underwent a unilateral lobectomy or isthmectomy in ambulatory setting, of which 34 (9%) as TOETVA (including 21 (62%) for a possible malignancy). In the TOETVA group, younger age (median 40 (IQR 35–50) vs. 51 (40–60) years, P < 0.001) and lower BMI (median 23.1 (20.9–25.4) vs. 24.9 (22.1–28.9) kg/m², P = 0.001) were noted. No cases were converted to open cervicotomy. TOETVA was at least as good as open cervicotomy with nil versus four (1%) re-interventions for bleeding, one temporary (5%) versus 13 (4%) (temporary) RLN palsies, and one (<1%) wound infection (open cervicotomy group). No hospital readmissions occurred in all ambulatory surgery patients. No differences were found in physical (P = 0.280) and mental (P = 0.569) QoL between TOETVA and open surgery.

Conclusions

In carefully selected patients, the feasibility and safety of ambulatory TOETVA are comparable to open surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00268-022-06666-y.

Advanced Differentiated Thyroid Cancer: A Complex Condition Needing a Tailored Approach

Differentiated thyroid cancers (DTCs) are slow-growing malignant tumours, including papillary and follicular carcinomas. Overall, prognosis is good, although it tends to worsen when local invasion occurs with bulky cervical nodes, or in the case of distant metastases. Surgery represents the main treatment for DTCs. However, radical excision is challenging and significant morbidity and functional loss can follow the treatment of the more advanced forms. Literature on advanced thyroid tumours, both differentiated and undifferentiated, does not provide clear and specific guidelines. This emerges the need for a tailored and multidisciplinary approach. In the present study, we report our single-centre experience of 111 advanced (local, regional, and distant) DTCs, investigating the rate of radical excision, peri-procedural and post-procedural complications, quality of life, persistence, recurrence rates, and survival rates. Results are critically appraised and compared to the existing published evidence review.

Thyroid Cancer Screening Using Tumor-Associated DN T Cells as Immunogenomic Markers

Background

Thyroid nodules are an extremely common entity, and surgery is considered the ultimate diagnostic strategy in those with unclear malignant potential. Unfortunately, strategies aiming to predict the risk of malignancy have inadequate specificity. Our group recently found that the microenvironment of thyroid cancer is characterized by an enhanced immune invasion and activated immune response mediated by double-negative T lymphocytes (DN T) (CD3+CD4-CD8-), which are believed to enable or promote tumorigenesis. In the present work, we try to use the DN T cells’ proportion in thyroid fine-needle aspiration (FNA) material as a predictor of the risk of malignancy.

Methods

We recruited 127 patients and obtained ultrasound-guided FNA samples from subjects with cytology-positive or suspicious for malignancy and from those with benign nodular goiter associated with compressive symptoms (such as dysphagia, shortness of breath, or hoarseness), Hashimoto thyroiditis, and Graves’ disease. Out of 127, we investigated 46 FNA samples of patients who underwent total thyroidectomy and for which postoperative histological diagnosis by the academic pathologists was available. We specifically measured the number of cells expressing CD3+CD4-CD8- (DN T) as a function of total CD3+ cells in FNA samples using flow cytometry. We correlated their FNA DN T-cell proportions with the pathological findings.

Results

The DN T cells were significantly more abundant in lymphocytic infiltrates of thyroid cancer cases compared to benign nodule controls (p &lt; 0.0001). When the DN T-cell population exceeded a threshold of 9.14%, of total CD3+ cells, the negative likelihood ratio of being cancer-free was 0.034 (96.6% sensitivity, 95% CI, 0.915–1.000, p &lt; 0.0001). DN T cells at &lt;9.14% were not found in any subject with benign disease (specificity 100%). The high specificity of the test is promising, since it abolishes a false-positive diagnosis and in turn unnecessary surgical procedures.

Conclusion

The present study proposes DN T cells’ proportion as a preoperative diagnostic signature for thyroid cancer that with integration of RNA transcriptomics can provide a simplified technology based on the PCR assay for the ease of operation.

Endoscopic Lateral Neck Dissection: A New Frontier in Endoscopic Thyroid Surgery

Background

Endoscopic thyroidectomy and robotic thyroidectomy are effective and safe surgical options for thyroid surgery, with excellent cosmetic outcomes. However, in regard to lateral neck dissection (LND), much effort is required to alleviate cervical disfigurement derived from a long incision. Technologic innovations have allowed for endoscopic LND, without the need for extended cervical incisions and providing access to remote sites, including axillary, chest-breast, face-lift, transoral, and hybrid approaches.

Methods

A comprehensive review of published literature was performed using the search terms "lateral neck dissection", "thyroid", and "endoscopy OR endoscopic OR endoscope OR robotic" in PubMed.

Results

This review provides an overview of the current knowledge regarding endoscopic LND, and it specifically addresses the following points: 1) the surgical procedure, 2) the indications and contraindications, 3) the complications and surgical outcomes, and 4) the technical advantages and limitations. Robotic LND, totally endoscopic LND, and endoscope-assisted LND are separately discussed.

Conclusions

Endoscopic LND is a feasible and safe technique in terms of complete resection of the selected neck levels, complications, and cosmetic outcomes. However, it is recommended to strictly select criteria when expanding the population of eligible patients. A formal indication for endoscopic LND has not yet been established. Thus, a well-designed, multicenter study with a large cohort is necessary to confirm the feasibility, long-term outcomes, oncological safety, and influence of endoscopic LND on patient quality of life (QoL).