Insights into the Management of Papillary Microcarcinoma of the Thyroid

Management of low-risk papillary thyroid cancer. Minimally-invasive treatments dictate a further paradigm shift?

BACKGROUND

Current management options for PTMC include lobo-isthmectomy and active surveillance (AS). Recently, ultrasound-guided minimally invasive procedures (MITs) are offered as a nonsurgical therapy for PTMC because they do not require hospitalization and general anaesthesia, and do not result in loss of thyroid function or cosmetic damage. MITs are reported to consistently provide, mostly in large retrospective series of patients, a rapid, safe, and cost-effective way to eradicate low-risk thyroid malignancies. However, conclusive data from well-conducted prospective studies on the histologically-proven completeness of tumor ablation and the long-term clinical advantages versus AS are still lacking.

OBJECTIVES

This study aimed to evaluate the efficacy and safety of ultrasound-guided minimally invasive treatments (MITs) for PTMC in comparison to traditional surgical methods and active surveillance, and to assess their role in current clinical practice.

METHODS

A structured literature review was conducted using keywords related to PTMC, MIT, and comparative techniques. Studies were evaluated based on treatment modality, patient selection, follow-up duration, complication rates, and clinical outcomes.

RESULTS

MITs have shown promising results in the management of PTMC. These treatments offer several advantages over surgery, such as reduced use of surgical resources, lower costs, minimal work disruption, and fewer major complications. However, there are still limitations, including the need for long-term surveillance and the potential risk of incomplete tumor ablation.

CONCLUSIONS

MITs represent a promising non-surgical option for managing low-risk PTMC, especially for patients ineligible for or refusing surgery. Despite favorable outcomes, more robust prospective data are needed to confirm their long-term benefits and completeness of tumor ablation. Interdisciplinary discussions and thorough patient education on the advantages and limitations of MITs are crucial for informed decision-making.

Ultrasound Imaging in Active Surveillance of Small, Low-Risk Papillary Thyroid Cancer

The recent surge in the incidence of small papillary thyroid cancers (PTCs) has been linked to the widespread use of ultrasonography, thereby prompting concerns regarding overdiagnosis. Active surveillance (AS) has emerged as a less invasive alternative management strategy for low-risk PTCs, especially for PTCs measuring ≤1 cm in maximal diameter. Recent studies report low disease progression rates of low-risk PTCs ≤1 cm under AS. Ongoing research is currently exploring the feasibility of AS for larger PTCs (<20 mm). AS protocols include meticulous ultrasound assessment, emphasis on standardized techniques, and a multidisciplinary approach; they involve monitoring the nodules for size, growth, potential extrathyroidal extension, proximity to the trachea and recurrent laryngeal nerve, and potential cervical nodal metastases. The criteria for progression, often defined as an increase in the maximum diameter of the PTC, warrant a review of precision and ongoing examinations. Challenges exist regarding the reliability of volume measurements for defining PTC disease progression. Although ultrasonography plays a pivotal role, challenges in assessing progression and minor extrathyroidal extension underscore the importance of a multidisciplinary approach in disease management. This comprehensive overview highlights the evolving landscape of AS for PTCs, emphasizing the need for standardized protocols, meticulous assessments, and ongoing research to inform decision-making.

The clinical value of artificial intelligence in assisting junior radiologists in thyroid ultrasound: a multicenter prospective study from real clinical practice

BACKGROUND

This study is to propose a clinically applicable 2-echelon (2e) diagnostic criteria for the analysis of thyroid nodules such that low-risk nodules are screened off while only suspicious or indeterminate ones are further examined by histopathology, and to explore whether artificial intelligence (AI) can provide precise assistance for clinical decision-making in the real-world prospective scenario.

METHODS

In this prospective study, we enrolled 1036 patients with a total of 2296 thyroid nodules from three medical centers. The diagnostic performance of the AI system, radiologists with different levels of experience, and AI-assisted radiologists with different levels of experience in diagnosing thyroid nodules were evaluated against our proposed 2e diagnostic criteria, with the first being an arbitration committee consisting of 3 senior specialists and the second being cyto- or histopathology.

RESULTS

According to the 2e diagnostic criteria, 1543 nodules were classified by the arbitration committee, and the benign and malignant nature of 753 nodules was determined by pathological examinations. Taking pathological results as the evaluation standard, the sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) of the AI systems were 0.826, 0.815, 0.821, and 0.821. For those cases where diagnosis by the Arbitration Committee were taken as the evaluation standard, the sensitivity, specificity, accuracy, and AUC of the AI system were 0.946, 0.966, 0.964, and 0.956. Taking the global 2e diagnostic criteria as the gold standard, the sensitivity, specificity, accuracy, and AUC of the AI system were 0.868, 0.934, 0.917, and 0.901, respectively. Under different criteria, AI was comparable to the diagnostic performance of senior radiologists and outperformed junior radiologists (all P < 0.05). Furthermore, AI assistance significantly improved the performance of junior radiologists in the diagnosis of thyroid nodules, and their diagnostic performance was comparable to that of senior radiologists when pathological results were taken as the gold standard (all p > 0.05).

CONCLUSIONS

The proposed 2e diagnostic criteria are consistent with real-world clinical evaluations and affirm the applicability of the AI system. Under the 2e criteria, the diagnostic performance of the AI system is comparable to that of senior radiologists and significantly improves the diagnostic capabilities of junior radiologists. This has the potential to reduce unnecessary invasive diagnostic procedures in real-world clinical practice.

USP15 promotes the progression of papillary thyroid cancer by regulating HMGB1 stability through its deubiquitination

Purpose: Papillary thyroid cancer (PTC) stands as one of the most prevalent types of thyroid cancers, characterized by a propensity for in-situ recurrence and distant metastasis. The high mobility group protein (HMGB1), a conserved nuclear protein, plays a pivotal role in carcinogenesis by stimulating tumor cell growth and migration. Nevertheless, the underlying mechanism driving aberrant HMGB1 expression in PTC necessitates further elucidation. Materials and methods: Our study unraveled the impact of low and overexpression of USP15 on the proliferation, invasion, and metastasis of PTC cells. Through a comprehensive array of molecular techniques, we uncovered the intricate relationship between HMGB1 and USP15 in the progression of PTC. Results: In this study, we identified USP15, a deubiquitinase in the ubiquitin-specific proteases family, as a true deubiquitylase of HMGB1 in PTC. USP15 was shown to interact with HMGB1 in a deubiquitination activity-dependent manner, deubiquitinating and stabilizing HMGB1. USP15 depletion significantly decreased PTC cell proliferation, migration, and invasion. In addition, the effects induced by USP15 depletion could be rescued by further HMGB1 overexpression. But when HMGB1 is knocked down, even overexpression of USP15 could not promote the progression of PTC cells. Conclusion: In essence, our discoveries shed light on the previously uncharted catalytic role of USP15 as a deubiquitinating enzyme targeting HMGB1, offering a promising avenue for potential therapeutic interventions in the management of PTC.

Diagnostic performance of ACR-TIRADS combined with superb microvascular imaging for differential diagnosis of mummified thyroid nodules and papillary thyroid carcinomas

Objective

The aim was to investigate the ability of superb microvascular imaging (SMI) to improve the differential diagnosis of mummified thyroid nodules (MTNs) and papillary thyroid carcinomas (PTCs) using the 2017 American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS).

Materials and methods

We enrolled 110 cases of MTNs and 110 cases of PTCs confirmed by fine needle aspiration (FNA) or surgery. Conventional ultrasound (US) and the quantity of microvessels detected by SMI were analyzed for all nodules. Thyroid nodules were initially categorized by ACR-TIRADS based on US imaging features and then reclassified based on ACR-TIRADS combined with SMI blood-flow grade (SMI-TIRADS). We compared the diagnostic performances of ACR-TIRADS and SMI-TIRADS by receiver operating characteristic curve, sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV).

Results

US-detected margin, shape, and echogenic foci differed between MTNs and PTCs (P < 0.05). The SMI blood-flow grade was significantly greater in PTCs compared with MTNs (Χ2 = 158.78, P < 0.05). There was no significant difference in ACR-TIRADS indicators between MTNs and PTCs (Χ2 = 1.585, P = 0.453); however, reclassification by SMI-TIRADS showed significant differences between the groups (Χ2 = 129.521, P < 0.001). The area under the curve was significantly lower for ACR-TIRADS compared with SMI-TIRADS (0.517 vs 0.887, P < 0.05). SMI-TIRADS had significantly higher diagnostic value for distinguishing MTNs and PTCs than ACR-TIRADS (sensitivity: 91.82% vs 74.55%, P < 0.05; specificity: 84.55% vs 21.82%, P < 0.05; accuracy: 88.18% vs 48.18%, P < 0.05; PPV: 85.59% vs 48.81%, P < 0.05; and NPV: 91.18% vs 46.15%, P < 0.05).

Conclusion

The detection of microvascular flow and large vessels in thyroid nodules by SMI resulted in high diagnostic specificity and sensitivity. ACR-TIRADS combined with SMI could effectively distinguish between MTNs and PTCs, to avoid unnecessary FNA or surgical excision.

The relationship between ablation range and ablation energy in papillary thyroid microcarcinoma: a comparison between microwave ablation and laser ablation

OBJECTIVES

To study the relationship between the ablation range and applied energy of laser ablation (LA) and microwave ablation (MWA) in papillary thyroid microcarcinoma (PTMC).

METHODS

A total of 201 PTMC patients were treated with LA (n = 102) or MWA (n = 99) with single-applicator fixed ablation. The ablation range was determined by contrast-enhanced ultrasound. The ratios of ablation volume, longitudinal diameter, and orthogonal diameter to ablation energy (RAV/E, RAL/E, RAO/E) were analyzed and compared between MWA and LA. The effects of PTMC characteristics and Hashimoto's thyroiditis (HT) on ablation efficiency were evaluated by linear regression.

RESULTS

The RAV/E was 0.72 (0.65-0.84) mm3/J for MWA and 0.48 (0.39-0.54) mm3/J for LA. HT was significantly correlated with RAV/E of LA (coefficient =  - 0.367, p < 0.0001). RAL/E did not differ significantly between MWA and LA (MWA 0.026 mm/J, LA 0.025 mm/J; p = 0.957). However, MWA had a greater RAO/E than LA (MWA 0.014 mm/J, LA 0.012 mm/J; p < 0.0001). The plateau values of MWA and LA on the ablation orthogonal diameter were 10.7 mm and 8.69 mm, respectively.

CONCLUSIONS

MWA showed a higher RAV/E than LA. More intuitively, MWA had a better ablation performance than LA on the orthogonal axis rather than the longitudinal axis. Theoretically, MWA and LA could achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin. HT had a negative effect on LA but not on MWA.

CLINICAL RELEVANCE STATEMENT

This study establishes strong connections between ablation energy and ablation range in papillary thyroid microcarcinoma (PTMC) in vivo, possibly contributing to the supplementation of the PTMC Ablation Consensus or Guidelines and providing a scientific basis for choosing clinical ablation parameters in PTMC.

KEY POINTS

• Both microwave ablation (MWA) and laser ablation (LA) have excellent performance on the ablation longitudinal axis (easily exceeding 10 mm) for papillary thyroid microcarcinoma (PTMC). • MWA performed much better than LA on the ablation orthogonal axis. • MWA and LA are expected to achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin.

The use of thyroid isthmusectomy for management of well differentiated thyroid carcinoma - A systematic review and meta-analysis

OBJECTIVE

With the growing global incidence of thyroid carcinomas, there is an increasing need for distinct guidelines for isthmus-confined carcinomas. Here, we performed the first systematic review on the topic to date, aiming to provide understanding to isthmusectomy as surgical management for well-differentiated thyroid carcinoma of the isthmus.

METHODS

We conducted a systematic review following the PRISMA guidelines, analyzing English-language studies from the past decade that report on thyroid isthmusectomy. Exclusion criteria included isthmusectomy performed alongside full thyroidectomy or partial thyroid lobectomy, lack of data on tumor characteristics or survival outcomes, and non-English publications where a translation was unavailable. Our review identified a total of 227 patients from seven studies.

RESULTS

The average 5-year overall survival and disease-free survival rates for patients with isthmus-confined PTC who underwent isthmusectomy were 100 % and 93.1 %, respectively. Similar to that of total thyroidectomy. 3.1 % of patients required completion thyroidectomy. Furthermore, isthmusectomy resulted in fewer surgical complications than total thyroidectomy.

CONCLUSIONS

The scarcity of studies providing detailed tumor characteristics and patient outcomes limits our ability to fully evaluate the safety and efficacy of isthmusectomy for isthmus-confined PTC. Additionally, the variable sample sizes and restricted geographic distribution of the included studies calls into questions the generalizability of their findings. Despite these limitations, the data suggest that isthmusectomy may be a viable surgical option for select patients with small, isthmus-confined PTC. In the absence of a randomized controlled trial on the noninferiority of isthmusectomy, significantly more publications are needed before strong conclusions can be drawn.

Lateral lymph node metastasis in papillary thyroid microcarcinoma: a study of 5241 follow-up patients

PURPOSE

To investigate the impact of lateral lymph node metastasis in papillary thyroid microcarcinoma (PTMC).

METHODS

5241 PTMC patients with follow-up information were enrolled in the current study. These patients underwent primary surgery in our situation from January 1997 to December 2016. Additionally, a validation cohort consisting of 274 PTMC patients who underwent primary surgery between January 2020 and December 2021 was also included. Univariable and multivariate logistic analyses were conducted to identify the association between clinicopathologic features and lateral lymph node metastasis (LLNM). Kaplan-Meier survival curve analysis was used to calculate the disease-free survival (DFS) rate. The fitting curve was generated to identify the quantitative relationship between central lymph node metastases (CLNM) and LLNM.

RESULTS

Of 5241 PTMC patients, cervical lymph node metastasis was detected in 1494 (28.5%) cases, including 1364 (26.0%) with CLNM only and 130 (2.5%) with LLNM. With a median follow-up time of 60 months (interquartile range [IQR], 44-81), recurrence was detected in 114 patients (2.2%). Multivariate Cox regression analyses showed that LNM was the only independent risk factor for recurrence, with HR values of 3.03 in CLNM and 11.14 in LLNM, respectively. Tumor diameter >0.5 cm (hazard ratio [HR]:1.80), multifocality (HR:2.59), bilaterality (HR:2.13), extrathyroidal invasion (HR:2.13), and CLNM (HR:5.11) were independent risk factors for LLNM. The prevalence of LLNM escalated significantly with increasing number of lymph node involvement in CLNM when stratified by the number of metastatic lymph nodes and trend was observed similarly in the validation cohort. The fitting curve showed that the incidence of LLNM could be as high as 20.7% when the number of CLNM ≥ 5.

CONCLUSIONS

By analyzing a large database with follow-up information, our study provides evidence that LLNM is significantly correlated with tumor recurrence in patients with PTMC. Tumor size (>0.5 cm), multifocality, bilaterality, extrathyroidal extension (ETE) and CLNM are independent risk factors for LLNM.

Active surveillance for micropapillary thyroid carcinoma: a clinical review

With the rapid rise in the incidence of micropapillary carcinoma, there is increasing concern about its overdiagnosis and overtreatment. There is considerable interest in managing patients with micropapillary carcinoma with active surveillance or deferred intervention. Various institutions around the world are practicing active surveillance. The major question remains as to who the ideal candidates are and how best to monitor these patients. This clinical review will discuss the ideal, appropriate, and inappropriate patients for active surveillance. It will also discuss the follow-up strategy for these patients and some of the adverse clinical features that will be used to decide against active surveillance. There are uncertainties as to who should be offered active surveillance. Various studies have shown approximately 10% of the patients switching to surgery primarily related to fear factor rather than increase in the tumor size or lymph node metastasis. The results of immediate surgery do raise issues related to complications of thyroid surgery and quality of life. The most ideal candidate would be patients with a tumor below 1 cm, intrathyroidal. For the patient who is a minimalist, the follow up strategy includes, ultrasound every 6 months for the first 1 or 2 years, and then every year after that. If there is a substantial change in the tumor volume or nodal metastasis, surgery should be considered, which happens in less than 10 percent of patients according to many studies. Based on existing literature and clinical experience, it appears that active surveillance is an appropriate strategy for monitoring micropapillary carcinoma.

Whether Detection of Gene Mutations Could Identify Low- or High-Risk Papillary Thyroid Microcarcinoma? Data from 393 Cases Using the Next-Generation Sequencing

Objective

The objective of this study is to explore the utilization of next-generation sequencing (NGS) technology in evaluating the likelihood of identifying individuals with papillary thyroid microcarcinoma (PTMC ≤10 mm) who are at high or low risk.

Design

NGS was used to analyze 393 formalin-fixed, paraffin-embedded tissues of PTC tumors, all of which were smaller than 15 mm.

Results

The study found that bilateralism, multifocality, intrathyroidal spread, and extrathyroidal extension were present in 84 (21.4%), 153 (38.9%), 16 (4.1%), and 54 (13.7%) cases, respectively. Metastasis of cervical lymph nodes was identified in 226 (57.5%) cases and 96 (24.4%) cases with CLNM >5. Out of the total number of cases studied, 8 cases (2.3%) showed signs of tumor recurrence, all of which were localized and regional. Genetic alterations were detected in 342 cases (87.0%), with 336 cases revealing single mutations and 6 cases manifesting compound mutations. 332 cases (84.5%) had BRAFV600E mutation, 2 cases had KRASQ61K mutation, 2 cases had NRASQ61R mutation, 8 cases had RET/PTC1 rearrangement, 3 cases had RET/PTC3 rearrangement, and 1 case had TERT promoter mutation. Additionally, six individuals harbored concurrent mutations in two genes. These mutations were of various types and combinations: BRAFV600E and NRASQ61R (n = 2), BRAFV600E and RET/PTC3 (n = 2), BRAFV600E and RET/PTC1 (n = 1), and BRAFV600E and TERT promoter (n = 1). The subsequent analysis did not uncover a significant distinction in the incidence of gene mutation or fusion between the cN0 and cN1 patient cohorts. The presence of BRAFV600E mutation and CLNM incidence rates were found to be positively correlated with larger tumor size in PTMC. Our data showed that gene mutations did not appear to have much to do with high-risk papillary thyroid microcarcinoma (PTMC). However, when we looked at tumor size, we found that if the tumor was at least 5 millimeters in size, there was a higher chance of it being at high risk for PTM (P < 0.001, odds ratio (OR) = 2.55, 95% confidence interval (CI): 1.57-4.14). Identification of BRAFV600E mutation was not demonstrated to be significantly correlated with advanced clinicopathological characteristics, although it was strongly associated with a bigger tumor diameter (OR = 4.92, 95% CI: 2.40-10.07, P < 0.001).

Conclusion

In clinical practice, BRAFV600E mutation does not consistently serve as an effective biomarker to distinguish high-risk PTMC or predict tumor progression. The size of the tumor has a significant correlation with its aggressive characteristics. PTMC with a diameter of ≤5 mm should be distinguished and targeted as a unique subset for specialized treatment.

Lymph node imaging for thyroid cancer

Cervical lymph nodes (LNs) in the central (level VI) and lateral (levels II-V) compartments of the neck are the most common sites of locoregional metastases associated with thyroid cancer. Prophylactic nodal dissections are uncommon in modern thyroid surgery and are not routinely performed due to concern for increased morbidity and do not offer improved survival. Therefore, a selective approach for LN dissections is increasingly important. Preoperatively, this is most frequently assessed with cervical ultrasound (US). Contrast-enhanced computed tomography (CT) of the neck can also be used for preoperative assessment. Both US and CT imaging can be used to characterise LNs in levels II-VI and their risk of malignancy based on size, morphology, and growth. US-guided fine-needle aspiration of equivocal LN with thyroglobulin (Tg) washout can also determine if a LN harbours malignancy. For postoperative surveillance after total thyroidectomy, both US and CT continue to play an important role at 6-12 months intervals. These patients may also benefit from additional biochemical data such as Tg levels in addition to LN and thyroid bed imaging. Thyroid uptake scans may also play a role in LN surveillance postoperatively for well-differentiated thyroid carcinoma in certain clinical contexts. Less commonly, positron emitted tomography may play a role, but is typically reserved for patients with aggressive or radioactive iodine refractory disease.

Long-term efficacy of microwave ablation for multifocal papillary thyroid microcarcinoma: a 5-year follow-up study

OBJECTIVES

Microwave ablation (MWA) has achieved excellent long-term efficacy in treating unifocal papillary thyroid microcarcinoma (UPTMC). The therapeutic effect of this treatment on multifocal papillary thyroid microcarcinoma (MPTMC) is unknown. Therefore, we evaluated the long-term efficacy of MWA for low-risk MPTMC and to provide evidence-based medicine for the revision of clinical guidelines.

METHODS

This study included 66 MPTMC patients with a total of 158 lesions, all of whom received MWA. We collected and retrospectively analyzed the patients' follow-up data before MWA, at 1, 3, 6, and 12 months posttreatment and every 6 months thereafter until 5 years posttreatment. We evaluated the MWA complication rate, technical success rate (TSR), lesion volume reduction rate (VRR), and complete disappearance rate (CDR) during follow-up and in those patients with tumor progression and delayed surgery.

RESULTS

After 60 months of follow-up, all 158 lesions disappeared in 66 patients, and the volume was reduced from 43.82 mm3 to 0.00 mm3. The TSR and VRR were both 100%. The CDRs at 1 year, 2 years, and 3 years were 57.59%, 93.67%, and 100%, respectively. The complication rate was 3.03% (2/66), and the incidence of tumor progression was 3.03% (2/66), including one new intrathyroidal lesion and one cervical lymph node metastasis (LNM). These lesions were retreated with MWA, and the lesions disappeared during the follow-up period.

CONCLUSIONS

Ultrasound-guided MWA for low-risk MPTMC is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance (AS).

CLINICAL RELEVANCE STATEMENT

This study concludes that ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance.

KEY POINTS

• Ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective. • During 5 years of follow-up, multifocal papillary thyroid microcarcinoma patients treated with microwave ablation had a favorable prognosis. • To provide evidence-based medicine for the revision of clinical guidelines.

Subcentimetric Papillary Thyroid Carcinoma: Does the Diagnosis Kind Impact Prognosis?

INTRODUCTION

Subcentimetric papillary thyroid carcinoma (SPTC) (papillary thyroid carcinoma with less than 10 mm in size) usually presents an excellent prognosis, with few aggressive reported cases. Given the globally increased incidence of SPTC, physicians are struggling with the need to identify prognostic factors to stratify SPTC. The aim was to compare clinicopathological variables and prognosis between clinically and incidentally diagnosed SPTC. Materials and methodsː This is a retrospective observational study on patients with SPTC who underwent thyroidectomy between 2002 and 2015. Two groups were considered: G1 (n=60 (61.9%)), clinical diagnosis (Bethesda III-VI cytology in the thyroid tumor/in cervical lymphadenopathies) and G2 (n=37 (38.1%)), incidental diagnosis (thyroidectomy for benign thyroid pathology). The histological material was reviewed, and molecular analysis of the BRAF, RAS, and TERT promoter (TERTp) genes was performed. Resultsː Ninety-seven individuals were included, 60 (61.9%) of which were from G1, with a predominance of female sex (n=83 (85.6%)). Individuals of G1 were younger (53.0±14.2 versus 59.3±13.9 years; p=0.035), were more frequently treated with 131-iodine (39.2% versus 13.4%; p=0.007), had the largest diameter (8 (p25-p75: 7-9) versus 5 (p25-p75: 4-6.5) mm; p<0.001), and higher frequency of minimal extracapsular invasion (45% versus 24.3%; p=0.041). Increased tumor size was the only independent predictor of a clinical diagnosis (p<0.001). Conclusionsː Clinically and incidentally diagnosed SPTC showed excellent medium- to long-term prognosis. A larger SPTC was more likely a driver of clinical detection than a marker of tumor aggressiveness, but caution should be taken as contradictory data persists.

Subcentimetric papillary thyroid carcinoma with extensive lymph node and brain metastasis: case report and review of literature

Summary

We report a 61-year-old male patient without personal history of thyroid carcinoma or radiation exposure. In 2011, he presented with a cervical mass whose biopsy diagnosed a papillary thyroid carcinoma (PTC) in a lymph node metastasis (LNM). Total thyroidectomy with lymphadenectomy of central and ipsilateral compartment was performed. Histopathology identified a 2 mm follicular variant of PTC and LNM in 25/25 lymph nodes. The patient was treated with 150 mCi of radioactive iodine (RAI), followed by levothyroxine suppressive therapy. In 2016, a retrotracheal mass was diagnosed, suggesting local recurrence; patient was submitted to surgical excision and RAI therapy (120 mCi). Due to seizures, in 2019, a brain CT was performed that diagnosed brain metastases. The patient underwent debulking of the main lesion. Histopathology analysis confirmed a metastatic lesion with variated morphology: classical PTC and follicular pattern and hobnail and tall cell features. Molecular analysis revealed BRAFV600E in LNM at presentation and BRAFV600E and TERT promoter (TERTp) mutations in the recurrent LNM and brain metastasis. Based upon this experience we review the reported cases of subcentimetric PTC with brain metastases and discuss the molecular progression of the present case.

Learning points

Papillary microcarcinoma (PMCs) usually have very good prognosis with low impact on patient survival. PMCs presenting in elderly patients with LNM at diagnosis may carry a guarded outcome. Brain metastasis although rare indicate aggressive phenotypic features. Patient risk stratification of PMCs based on histopathological analysis and genetic testing may have a significant impact on prognosis providing therapeutic markers, that may predict disease progression and overall outcome.

Active Surveillance Outcomes of Patients with Low-Risk Papillary Thyroid Microcarcinoma According to Levothyroxine Treatment Status

Background: During active surveillance (AS), serum thyrotropin (TSH) levels may affect papillary thyroid microcarcinoma (PTMC) progression. We investigated AS outcomes according to whether levothyroxine (LT4) treatment was administered. Patients and Methods: From 2005 to 2019, 2896 patients with low-risk PTMC underwent AS. Of these, 2509 patients were included: 2187 patients did not receive LT4 at diagnosis (group I), 1935 patients did not receive LT4 during AS (group IA), and 252 patients started LT4 during AS (group IB). The remaining 322 patients were administered LT4 before or at diagnosis (group II). The tumor volume doubling rate (TVDR) and tumor size based on ultrasound examination results and time-weighted detailed TSH scores were calculated. Disease progression was defined as tumor enlargement ≥3 mm and/or the appearance of novel lymph node metastasis. Results: At diagnosis, group II had more high-risk features, such as younger age and larger tumors, than group I. However, group II had a lower disease progression rate (2.9% at 10 years) than group I (6.1%) (p = 0.091). The disease progression rate of group IB (13.8% at 10 years) was significantly higher than that of groups IA (5.0%) and II (2.9%) (p < 0.01). The TVDR of group IB before LT4 administration was significantly higher than that of groups IA and II (0.095 per year, -0.0085 per year, and -0.057 per year, respectively; p < 0.01), suggesting that patients with progression signs during AS were selectively prescribed LT4. The time-weighted detailed TSH score of group IB significantly decreased after LT4 administration compared with those before administration (3.35 and 3.05, respectively; p < 0.01). The TVDR also decreased from 0.13 per year to 0.036 per year (p = 0.08). The proportions of patients with rapid or moderate growth decreased significantly after LT4 (from 26.8% to 12.5%, p < 0.01). A multivariable analysis revealed group IB status was independently associated with disease progression (odds ratio [OR] = 3.42 [CI 2.15-5.44], p < 0.01), whereas age ≥40 years and <60 years and age ≥60 years were independently negatively associated with this outcome (OR = 0.23 [CI 0.14-0.38, p < 0.01 and OR = 0.16 [CI 0.10-0.27], p < 0.01). Conclusion: LT4 treatment may be associated with decreased tumor growth during AS of PTMC, but further confirmatory research is needed.

A novel nomogram for identifying high-risk patients among active surveillance candidates with papillary thyroid microcarcinoma

Objective

Active surveillance (AS) has been recommended as the first-line treatment strategy for low-risk (LR) papillary thyroid microcarcinoma (PTMC) according to the guidelines. However, preoperative imaging and fine-needle aspiration could not rule out a small group of patients with aggressive PTMC with large-volume lymph node micro-metastasis, extrathryoidal invasion to surrounding soft tissue, or high-grade malignancy from the AS candidates.

Methods

Among 2,809 PTMC patients, 2,473 patients were enrolled in this study according to the inclusion criteria. Backward stepwise multivariate logistic regression analysis was used to filter clinical characteristics and ultrasound features to identify independent predictors of high-risk (HR) patients. A nomogram was developed and validated according to selected risk factors for the identification of an HR subgroup among "LR" PTMC patients before operation.

Results

For identifying independent risk factors, multivariable logistic regression analysis was performed using the backward stepwise method and revealed that male sex [3.91 (2.58-5.92)], older age [0.94 (0.92-0.96)], largest tumor diameter [26.7 (10.57-69.22)], bilaterality [1.44 (1.01-2.3)], and multifocality [1.14 (1.01-2.26)] were independent predictors of the HR group. Based on these independent risk factors, a nomogram model was developed for predicting the probability of HR. The C index was 0.806 (95% CI, 0.765-0.847), which indicated satisfactory accuracy of the nomogram in predicting the probability of HR.

Conclusion

Taken together, we developed and validated a nomogram model to predict HR of PTMC, which could be useful for patient counseling and facilitating treatment-related decision-making.

Concordance of the ACR TI-RADS Classification With Bethesda Scoring and Histopathology Risk Stratification of Thyroid Nodules

Importance

Although most thyroid nodules are benign, 10% to 15% of them harbor cancer. Thyroid ultrasonography is useful for risk stratification of nodules, and American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) classification provides recommendations for fine-needle aspiration cytology (FNAC) based on objective ultrasonographic features of these nodules.

Objective

To validate the concordance of ACR TI-RADS classification with Bethesda classification and histopathology.

Design, Setting, and Participants

This retrospective cohort study was performed to evaluate the concordance of ACR TI-RADS classification with Bethesda classification and histopathology and was conducted in Singapore General Hospital Outpatient Otolaryngology clinic in March 2021 to May 2021. Data analysis was performed in May 2021.

Main Outcomes and Measures

Results were deemed concordant when ACR TI-RADS recommendations aligned with Bethesda scores. Conversely, results were classified as nonconcordant with Bethesda scores and/or histopathology results when nodules that were recommended for FNAC yielded benign results or nodules that were not recommended for FNAC yielded malignant results.

Results

A total of 446 patients (370 women [83%]; mean [range] age, 60 [24-89] years) who underwent ultrasonography of the thyroid and ultrasonography-guided thyroid FNACs were identified. A total of 492 of 630 nodules (78.1%) were benign on FNAC (Bethesda II). Score 3 ACR TI-RADS nodules yielded the highest negative predictive values: 94.6% (95% CI, 92.9%-95.9%; P < .001) compared with Bethesda scoring and 100.0% (95% CI, 15.8%-100.0%; P = .003) compared with histopathology. Score 4 or 5 ACR TI-RADS nodules yielded positive predictive values of 2.8% and 16.2%, respectively, compared with Bethesda scoring and 6.1% and 66.7%, respectively, compared with histopathology. Small (<1.5 cm) ACR TI-RADS nodules of scores of 4 and 5 that were not recommended for FNAC yielded a malignant risk of 5.7% and 25.0% on Bethesda 5 and 6, respectively. On surgical excision, 5 of 46 (10.9%) ACR TI-RADS 4 nodules and 15 of 21 (71.4%) of ACR TI-RADS 5 nodules were confirmed to be malignant. Among nodules initially not recommended for FNAC, histopathology-proven cancer was found in 4 of 13 (30.7%) and 3 of 6 (50.0%) of nodules, respectively.

Conclusions and Relevance

These findings suggest that ACR TI-RADS score 3 nodules have a low risk of cancer and should be considered for FNAC only if nodules are 2.5 cm or larger. Patients with small (<1.5 cm) ACR TI-RADS 4 and 5 nodules should be appropriately counseled for FNAC to exclude cancer.

The impact of lymph node ratio on disease recurrence in papillary thyroid microcarcinoma

INTRODUCTION

Lymph node (LN) metastases in papillary thyroid microcarcinomas (microPTCs) are common. The lymph node ratio (LNR) has been proposed as a risk factor for recurrence in papillary thyroid cancer. However, its relevance in microPTC is undetermined.

METHODS

Patients who underwent resection of their microPTC with concomitant LN clearance between 2005 and 2018 were identified. The LNR was calculated as the ratio of positive LNs to the total number of LNs.

RESULTS

Data on 50 patients (36 female [72%]; median age 47 years [range: 19-84]) who underwent LN clearance (28 central [56%] vs 22 central + lateral [44%]) were analysed. Positive LNs were found in over two-thirds of the patients (n = 34; 68%). After a median follow-up of 61 months, 14 patients (28%) had developed recurrence. Positive LNs were not found to impact recurrence-free survival; extranodal extension and an LNR ≥ 0.26 were found to significantly increase the risk of recurrence on unadjusted analyses (p < 0.05).

CONCLUSIONS

LN metastases are frequent among patients with microPTC. A higher LNR seems to be associated with recurrence. Additional studies are needed to further clarify these findings and to assess the possible role of LNR in treatment and surveillance.

Long-term Outcomes of Ultrasound-guided Thermal Ablation for the Treatment of Solitary Low-risk Papillary Thyroid Microcarcinoma: A Multicenter Retrospective Study

OBJECTIVE

To report more than 5-year outcomes of ultrasound-guided thermal ablation (TA) for patients with solitary low-risk papillary thyroid microcarcinoma (PTMC) in a large multicenter cohort.

BACKGROUND

TA, including radiofrequency ablation (RFA) and microwave ablation (MWA) have been used in patients with low-risk PTMC who refuse surgery or active surveillance. However, its clinical value remains controversial.

MATERIALS AND METHODS

This retrospective multicenter study included 474 patients with solitary low-risk PTMC treated with TA (357 for RFA; 117 for MWA) from 4 centers and followed up for at least 5 years. Disease progression including lymph node metastasis and recurrent tumors, volume reduction rate (VRR), tumor disappearance rate, complications, and delayed surgery were assessed. RFA and MWA outcomes were compared using propensity score matching.

RESULTS

During the median follow-up period of 77.2 months, disease progression incidence, lymph node metastasis, and recurrent tumors rates were 3.6%, 1.1%, and 2.5%, respectively. Age below 40 years old, male sex, Hashimoto thyroiditis, and tumor size were not independent factors associated with disease progression by Cox analysis. The median VRR was 100% and 471 tumors disappeared radiographically. Eight patients experienced transient voice change (1.7%) which recovered within 3 months. None of the patients underwent delayed surgery because of anxiety. After 1:1 matching, no significant differences were found in the disease progression, VRR, tumor disappearance rate, or complications between RFA and MWA subgroups.

CONCLUSION

This multicenter study revealed that TA was an effective and safe treatment for patients with solitary low-risk PTMC, which could be offered as a treatment option for the management for low-risk PTMC.

The Significance of Unsampled Microscopic Thyroid Carcinomas in Multinodular Goiter

Thorough gross examination and appropriate sampling of the thyroidectomy specimens are fundamental to the diagnosis and clinical risk management of patients. This study aims to investigate the frequency and clinical significance of initially unsampled microscopic thyroid carcinomas in total thyroidectomy specimens with presumed benign multinodular thyroid disease. Seventy-two total thyroidectomy specimens belonging to multinodular goiter patients were randomly selected and included in this prospectively designed study. Inclusion criteria were set as no suspicion of malignancy before surgery as well as lack of intra-parenchymal primary thyroid carcinoma after histopathological evaluation of slides generated from initial sampling. Subsequently, the remaining thyroidectomy specimens were submitted for microscopic examination and sign-outs were finalized following the microscopic examination of the entire thyroid tissue. Microcarcinomas, with a maximum diameter of 3.5 mm, were detected in 29 cases (40.2%) after the whole gland sampling. Although most of these tumors were low-risk papillary microcarcinomas confined to the thyroid, one specimen also showed a medullary microcarcinoma measuring 1.5 mm. Three had micrometastatic nodal disease. There was no local recurrence or distant metastatic disease during the follow-up (mean 51.4 months). This study further supports microscopic carcinomas, including papillary microcarcinoma, and medullary microcarcinoma might stay hidden in thyroidectomy specimens. Increased glandular weight, male gender, and advanced age were significant risk factors in the detection of microcarcinomas in this series. While each multinodular thyroidectomy specimen is unique, we recommend dynamic extensive sampling (rather than bare-minimum approach) strategy based on careful gross and initial histologic examination findings as well as by taking into consideration risk factors.

Comparison of Postoperative Unfavorable Events in Patients with Low-Risk Papillary Thyroid Carcinoma: Immediate Surgery Versus Conversion Surgery Following Active Surveillance

Background: Active surveillance (AS) for low-risk papillary thyroid microcarcinoma (PTMC) was initiated at Kuma Hospital in 1993 and has gradually spread worldwide. We previously demonstrated that AS is associated with a much lower incidence of unfavorable events than immediate surgery (IS). However, conversion surgery (CS) raises concerns about increased surgical complications due to advanced disease. In this study, we conducted a comparative analysis of unfavorable events after IS and CS. Methods: Between 2005 and 2019, 4635 patients clinically diagnosed with low-risk PTMC at Kuma Hospital were enrolled. Of these, 2896 underwent AS (AS group), and the remaining 1739 underwent IS (IS group). To date, 242 patients (0.8%) in the AS group have undergone CS for various reasons (CS group). Results: The incidence of unfavorable events, such as levothyroxine administration after surgery, postoperative hematoma, transient/persistent hypoparathyroidism, and transient/persistent vocal cord paralysis, did not differ between the CS and IS groups. None of the patients in the CS group had permanent vocal cord paralysis; however, this occurred in 15 patients (0.9%) in the IS group and was caused by accidental injury in 4 patients and carcinoma invasion in 11 patients. The incidence of surgery, levothyroxine administration, postoperative hematoma, transient/permanent hypoparathyroidism, and vocal cord paralysis was significantly higher (p < 0.001) in the IS group than in the AS group. There were no differences in the incidence of lymph node recurrence and overall mortality between the AS and IS groups. None of the patients in the AS and IS groups showed distant metastasis or died from thyroid carcinoma. Conclusions: There were no differences in the incidence of unfavorable events between the CS group and the IS group. Although none of the CS and AS groups had permanent vocal cord paralysis, accidental injury of the recurrent laryngeal nerve occurred in four patients (0.2%) in the IS group. The IS group had a significantly higher incidence of unfavorable events than the AS group. The prognoses of patients in both the AS and IS groups were excellent. Therefore, we recommend AS as the first-line management for low-risk PTMC.

Clinical value of artificial intelligence in thyroid ultrasound: a prospective study from the real world

OBJECTIVE

To evaluate the diagnostic performance of a commercial artificial intelligence (AI)-assisted ultrasonography (US) for thyroid nodules and to validate its value in real-world medical practice.

MATERIALS AND METHODS

From March 2021 to July 2021, 236 consecutive patients with 312 suspicious thyroid nodules were prospectively enrolled in this study. One experienced radiologist performed US examinations with a real-time AI system (S-Detect). US images and AI reports of the nodules were recorded. Nine residents and three senior radiologists were invited to make a "benign" or "malignant" diagnosis based on recorded US images without knowing the AI reports. After referring to AI reports, the diagnosis was made again. The diagnostic performance of AI, residents, and senior radiologists with and without AI reports were analyzed.

RESULTS

The sensitivity, accuracy, and AUC of the AI system were 0.95, 0.84, and 0.753, respectively, and were not statistically different from those of the experienced radiologists, but were superior to those of the residents (all p < 0.01). The AI-assisted resident strategy significantly improved the accuracy and sensitivity for nodules ≤ 1.5 cm (all p < 0.01), while reducing the unnecessary biopsy rate by up to 27.7% for nodules > 1.5 cm (p = 0.034).

CONCLUSIONS

The AI system achieved performance, for cancer diagnosis, comparable to that of an average senior thyroid radiologist. The AI-assisted strategy can significantly improve the overall diagnostic performance for less-experienced radiologists, while increasing the discovery of thyroid cancer ≤ 1.5 cm and reducing unnecessary biopsies for nodules > 1.5 cm in real-world medical practice.

KEY POINTS

• The AI system reached a senior radiologist-like level in the evaluation of thyroid cancer and could significantly improve the overall diagnostic performance of residents. • The AI-assisted strategy significantly improved ≤ 1.5 cm thyroid cancer screening AUC, accuracy, and sensitivity of the residents, leading to an increased detection of thyroid cancer while maintaining a comparable specificity to that of radiologists alone. • The AI-assisted strategy significantly reduced the unnecessary biopsy rate for thyroid nodules > 1.5 cm by the residents, while maintaining a comparable sensitivity to that of radiologists alone.

Thyroid-Stimulating Hormone, Age, and Tumor Size are Risk Factors for Progression During Active Surveillance of Low-Risk Papillary Thyroid Microcarcinoma in Adults

BACKGROUND

Active surveillance (AS) of low-risk papillary thyroid microcarcinoma (PTMC) was initiated at Kuma Hospital in 1993 and is gradually spreading worldwide. We assessed the effect of thyroid-stimulating hormone (TSH) levels on PTMC enlargement in patients on AS.

METHODS

We enrolled 2705 patients with cytologically diagnosed PTMC who had undergone AS between January 2005 and July 2019. Patients with Graves disease were excluded. The median AS period was 5.5 years (range 1.0-15.7 years). Tumor enlargement was defined as a size increase ≥3 mm. Chi-square test, Kaplan-Meier method, log-rank test, Cox proportional hazard, and logistic regression were used to compare variables.

RESULTS

Ninety-two patients (3.4%) experienced tumor enlargement; the 5-, 10-, and 15-year enlargement rates were 3.0%, 5.5%, and 6.2%, respectively. Young age (<40 years, p < 0.001), large tumor size (≥9 mm, p = 0.017), and high detailed TSH score (≥3, higher than the lower normal limit, p = 0.011) were significant factors relating to tumor enlargement in the multivariate analysis. In a subset of patients aged <40 years, a low detailed TSH score (<3) was an independent factor against tumor enlargement (p = 0.039). Only 22 patients (0.8%) experienced novel lymph node metastasis; the 5-, 10-, and 15-year node metastasis rates were very low, at 0.9%, 1.1%, and 1.1%, respectively.

CONCLUSIONS

Young patients with PTMC are more likely to experience tumor growth. Mild TSH suppression to achieve a low normal range may prevent carcinoma enlargement; however, prospective studies are needed to draw more reliable conclusions.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules : Follow-up: How and how long?

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians, surgeons, and other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the follow-up of thyroid nodules, low-grade tumors and microcarcinomas.

A systematic review and meta-analysis comparing tumor progression and complications between radiofrequency ablation and thyroidectomy for papillary thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid cancers worldwide. The efficacy and acceptability of radiofrequency ablation (RFA) in the treatment of PTC have been intensively studied. The aim of this study is to focus on extra detailed that may influent for PTC or papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

We identified a total of 1,987 records of a primary literature searched in PubMed, Embase, Cochrane Library, and Google Scholar by key words, from 2000 to 2022. The outcome of studies included complication, costs, and local tumor progression. After scrutiny screening and full-text assessment, six studies were included in the systematic review. Heterogeneity was estimated using I2, and the quality of evidence was assessed for each outcome using the GRADE guidelines.

RESULTS

Our review enrolled 1,708 patients reported in six articles in the final analysis. There were 397 men and 1,311 women in the analysis. Two of these studies involved PTC and four focused on PTMC. There were 859 patients in the RFA group and 849 patients in the thyroidectomy group. By contrast, the tumor progression of RFA group was as same as that surgical groups [odds ratio, 1.31; 95% CI, 0.52-3.29; heterogeneity (I2 statistic), 0%, p = 0.85]. The risk of complication rates was significantly lower in the RFA group than that in the surgical group [odds ratio, 0.18; 95% CI, 0.09-0.35; heterogeneity (I2 statistic), 40%, p = 0.14].

CONCLUSIONS

RFA is a safe procedure with a certain outcome for PTC. RFA can achieve a good efficacy and has a lower risk of major complications.

Nomograms for the prediction of lateral lymph node metastasis in papillary thyroid carcinoma: Stratification by size

Background

Lateral lymph node metastasis (LLNM) is a risk factor of poor prognosis in papillary thyroid cancer (PTC). We aimed to determine predictive factors and develop the nomograms for LLNM in patients with papillary thyroid microcarcinoma (PTMC) and macro-PTC.

Methods

We reviewed the medical records of 1,106 patients who underwent surgery between January 2019 and January 2022. Patients were divided into a PTMC and a macro-PTC group. We developed preoperative and postoperative nomograms for predicting LLNM based on results of multivariate analysis. Internal calibration was performed for these models.

Results

The number of metastatic lymph nodes in lateral compartment was higher in macro-PTC patients. LLNM was independently associated with gender, the number of foci, location, shape, and central lymph node metastasis (CLNM) in PTMC patients. For macro-PTC patients, chronic lymphocytic thyroiditis, the number of foci, location, margin, CLNM, and central lymph node ratio were all independent predictors for LLNM. All the above factors were incorporated into nomograms, which showed the perfect discriminative ability.

Conclusion

The diameter of the tumor has an impact on the rate of LLNM. Separate predictive systems should be used for PTMC and macro-PTC patients for more accurate clinical assessment of lateral lymph node status. Through these nomograms, we can not only detect high-risk patients with occult LLNM preoperatively, but also form appropriate treatment protocols for postoperative management of PTC patients with different risks.

Incidentally discovered papillary thyroid microcarcinoma in patients undergoing thyroid surgery for benign disease

INTRODUCTION

The incidence of thyroid carcinoma has grown significantly over the last few decades. A possible explanation is the increased diagnosis of small thyroid microcarcinoma (TMc). TMc reach a maximum diameter of ≤1 cm, identified during histopathology examination following a thyroidectomy performed for reasons not pertaining to malignancy. This study aims to investigate the prevalence of papillary thyroid microcarcinoma (PTMc) according to the benign pathology that refers patients to surgery and its trend evolution.

METHODS

Retrospective cohort analysis of 1815 patients who underwent total thyroidectomy for non-malignant diseases in the 2005-2020 period.

RESULTS

The mean age of the subjects was 53.5 years, with a higher proportion of women (1481, 82.1%). A total of 167 PTMc (9.3%) were incidentally discovered. A multivariate logistic regression analysis was performed, showing no differences in prevalence according to sex or age in patients with PTMc compared to final benign histology. Multinodular goiter increases the risk of PTMc with an odds ratio of 2.2 (p = 0.001) compared to Hashimoto's thyroiditis and Graves' disease (GD). There is a statistically significant increase in the incidence of PTMc in the group operated in the 2017-2020 vs. 2005-2008 period (p = 0.005).

CONCLUSION

The overall prevalence of PTMc in patients who underwent thyroid surgery for the benign disease was 9.3%. Thyroid nodular hyperplasia was the most frequent benign pathology associated with PTMc compared to Hashimoto's or GD. Gender and age were not correlated with the prevalence of TMc. Over the years, surgical findings of PTMc have grown, particularly in the 2017-2020 period.

A Cross-Sectional Survey of Patient Treatment Choice in a Multicenter Prospective Cohort Study on Active Surveillance of Papillary Thyroid Microcarcinoma (MAeSTro)

Background: Active surveillance (AS) is offered as a choice to patients with low-risk papillary thyroid microcarcinoma (PTMC). This study aimed to identify patient and physician factors associated with the choice of AS. Methods: We conducted a cross-sectional survey of patients with low-risk PTMC who were enrolled in a prospective study comparing outcomes following AS and surgery. Patients completed a questionnaire to assess their prior knowledge of the disease, considerations in the decision-making process, and reasons for choosing the treatment. We also surveyed 19 physician investigators about their disease management preferences. Variables affecting the patients' choice of AS, including patients' characteristics and their decision-making process, were analyzed in a multivariable analysis. Results: The response rate of the patient survey was 72.8% (857/1177). Among the patients who responded to the survey, 554 patients (128 male; mean age 49.4 ± 11.6 years; response rate 73.4%) with low-risk PTMC chose AS (AS group), whereas 303 patients (55 male; 46.6 ± 10.7 years; 71.8%) chose immediate surgery (iOP group). In the AS group, 424 patients (76.5%) used a decision aid, and 144 (47.5%) used it in the iOP group. The choice of AS was associated with the following variables: patient age >50 years (odds ratio 1.713 [confidence interval, CI 1.090-2.690], p = 0.020), primary tumor size ≤5 mm (odds ratio 1.960 [CI 1.137-3.379], p = 0.015), and consulting an endocrinologist (odds ratio 114.960 [CI 48.756-271.057], p < 0.001), and use of a decision aid (odds ratio 2.469 [CI 1.320-4.616], p = 0.005). The proportion of patients who were aware of AS before their initial consultation for treatment decision was higher in the AS group than in the iOP group (64.6% vs. 56.8%). Family members were reported to have influenced the treatment decisions more in the iOP group (p = 0.025), whereas the AS group was more influenced by information from the media (p = 0.017). Physicians' attitudes regarding AS of low-risk PTMC tended to be more favorable among endocrinologists than surgeons and all became more favorable as the study progressed. Conclusions: Emerging evidence suggests that physicians' attitudes and communication tools influence the treatment decision of low-risk PTMC patients. Support is needed for patient-centered decision making. (Clinical trial No: NCT02938702).

Barriers to the Use of Active Surveillance for Thyroid Cancer Results of a Physician Survey

OBJECTIVE

The aim of this study was to determine physician-reported use of and barriers to active surveillance for thyroid cancer.

SUMMARY BACKGROUND DATA

It is not clear whether active surveillance for thyroid cancer is widely used.

METHODS

Surgeons and endocrinologists identified by thyroid cancer patients from the Surveillance, Epidemiology, and End Results (SEER) registries of Georgia and Los Angeles County were surveyed between 2018 and 2019. Multivariable weighted logistic regression analyses were conducted to determine physician acceptance and use of active surveillance. Results: Of the 654 eligible physicians identified, 448 responded to the survey (69% response rate). The majority (76%) believed that active surveillance was an appropriate management option, but only 44% used it in their practice. Characteristics of physicians who stated that active surveillance was appropriate management, but did not report using it included more years in practice (reference group <10 years in practice): 10 to 19 years [odds ratio, OR 0.50 [95% confidence interval, CI 0.28-0.92]; 20 to 29 years [OR 0.31 (95% CI 0.15-0.62)]; >30 years [OR 0.30 (95% CI 0.15-0.61)] and higher patient volume 11 to 30 patients per year [OR 0.39 (95% CI 0.21 -0.70)] and >50 patients per year [OR 0.33 (95% CI 0.16-0.71)] compared to < 10, with no significant difference in those seeing 31 to 50 patients. Physicians reported multiple barriers to implementing active surveillance including patient does not want (80.3%), loss to follow-up concern (78.4%), more patient worry (57.6%), and malpractice lawsuit concern (50.9%).

CONCLUSION AND RELEVANCE

Despite most physicians considering active surveillance to be appropriate management, more than half are not using it. Addressing existing barriers is key to improving uptake.

Less-Intensive Management Options for Low-Risk Thyroid Cancer

The incidence of thyroid cancer is increasing, whereas mortality remains relatively stable. An increasing body of research supports the use of less-intensive treatment for low-risk thyroid cancer, as the overall prognosis is excellent. Although total thyroidectomy was the gold standard for many years, the options of lobectomy alone, active surveillance, and other ablative modalities are increasingly being used. The clinicohistologic features of any thyroid cancer are important to help determine the optimal management for a given tumor. However, the patient's own desires and goals in their cancer treatment must be evaluated.

Risk-stratified papillary thyroid microcarcinoma: post-operative management and treatment outcome in a single center

PURPOSE

This article aims to review and assess the post-operative management and treatment outcomes of papillary thyroid microcarcinoma (PTMC) in risk-stratified patients.

METHODS

We retrospectively analyzed the data of PTMC patients who underwent thyroid surgery with or without radioactive iodine treatment (RAI) in a single center between January 2011 and December 2017. Demographic and clinicopathologic data were collected. Risk stratification according to the 2015 American Thyroid Association guideline was applied.

RESULTS

Three hundred forty PTMC patients were included. Post-operative RAI was performed in 216/340 (63.53%) patients. In the non-RAI scenario, there were 122 low-risk and two intermediate-risk patients. In total, 261 (76.77%), 57 (16.76%), and 22 (6.47%) patients were classified as low, intermediate, and high risk, respectively. With a median follow-up time of 36 months (interquartile range: 23, 52), we found unfavorable outcomes (evidenced by imaging or out-of-range serum tumor marker levels: high thyroglobulin [Tg] or rising Tg antibody [TgAb] levels) in 8/340 (2.35%) patients, all of which received RAI. PTMC patients with unfavorable outcomes were stratified as low risk (4/261 [1.53%]), intermediate risk (1/57 [1.75%]), or high risk (3/22 [13.64%]). One death occurred in a patient with initial distant metastasis in the high-risk group. Initial high-risk stratification and initial stimulated Tg (of at least 10 ng/mL) were demonstrated as independent predictors for PTMC unfavorable outcomes (persistent or recurrent disease). Five patients with unfavorable outcomes (four with persistent disease and one with recurrent disease) had abnormal Tg or TgAb values despite unremarkable imaging findings. Moreover, 79/124 (63.71%) patients in the non-RAI scenario were only followed up with neck ultrasound.

CONCLUSIONS

In general, at least 98% of low-risk and intermediate-risk PTMC patients showed favorable outcomes without persistent or recurrent disease, defined by either imaging or serum tumor markers. Nevertheless, aggressive disease could occur in few PTMC patients. Decisions on post-operative management and follow-up may be guided by initial high-risk stratification and initial stimulated Tg levels (≥10 ng/mL) as independent predictors for PTMC unfavorable outcomes. Monitoring using both imaging and serum tumor markers is crucial and should be implemented for patients with PTMC.

The Prognosis of Skip Metastasis in Papillary Thyroid Microcarcinoma Is Better Than That of Continuous Metastasis

CONTEXT

A few papillary thyroid microcarcinomas (PTMCs) may have skip metastasis (SLNM), but the risk factors remain controversial and the prognosis is unclear.

OBJECTIVES

To investigate the incidence, lymph node metastasis (LNM) patterns, risk factors, and prognosis of SLNM in PTMCs.

METHODS

We reviewed the medical records of PTMC patients who underwent thyroid surgery in our institution. Analyses of risk factors were performed for SLNM. Recurrence-free survival (RFS) of SLNM, central lymph node metastasis (CLNM), and continuous metastasis (CLNM and lateral lymph node metastasis [CLNM + LLNM]) were compared after propensity score matching (PSM).

RESULTS

SLNM was detected in 1.7% (50/3923) and frequently involved level III (66.7%). Compared with CLNM + LLNM, SLNM had more LNM at a single level (P < 0.01) and less LNM at 2 levels (P < 0.05). A tumor size of 0.5 to 1 cm (odds ratio [OR], 2.26; 95% CI, 1.27-4.00) and location in the upper pole (OR, 3.30; 95% CI, 2.02-5.40) were independent risk factors for SLNM. A total of 910 (23.2%) PTMCs with LNM were included in the prognostic analysis. At a median follow-up of 60 months, the RFS of SLNM did not differ from that of CLNM (P = 0.10) but was significantly higher than that of CLNM + LLNM (P < 0.01) after using PSM.

CONCLUSIONS

When the tumor size is 0.5 to 1 cm or its location is in the upper pole, we must remain vigilant to SLNM in PTMC. Because its prognosis is comparable to that of only CLNM and better than that of CLNM + LLNM, less intensive treatment should be considered.

Non-Marked Hypoechogenic Nodules: Multicenter Study on the Thyroid Malignancy Risk Stratification and Accuracy Based on TIRADS Systems Comparison

Background and Objectives: The aim of the study was to evaluate the predictive value of the ultrasound criterion “non-marked hypoechogenicity” for malignancy and to determine whether classification of these nodules as TIRADS 3 could improve the overall accuracy of consequently adjusted M-TIRADS score. Materials and Methods: A total of 767 patients with 795 thyroid nodules were subject to ultrasonography examination and ultrasound-guided fine needle aspiration biopsy. Nodules were classified by Kwak TIRADS and modified (M-TIRADS) categories 4A, 4B, and 5 according to number of suspicious US features (marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, taller-than-wide shape, metastatic lymph nodes). Non-marked hypoechoic nodules were classified as TIRADS 3. Results: Thyroid nodules were classified as TIRADS 2, 3, 4A, 4B, and 5 in 14.5, 57.5, 14.2, 8.1, and 5.7%, respectively. Only histopathologic results (125 nodules underwent surgery) and highly specific cytology results (Bethesda II, VI) were accepted as a standard of reference, forming a sub-cohort of 562/795 nodules (70.7%). Malignancy was found in 7.7%. Overall, M-TIRADS showed sensitivity/specificity of 93.02/81.31%, and for PPV/NPV, these were 29.2/99.29%, respectively (OR—18.62). Irregular margins showed the highest sensitivity and specificity (75.68/93.74%, respectively). In TIRADS 3 category, 37.2% nodules were isoechoic, 6.6% hyperechoic, and 52.2% hypoechoic (there was no difference of malignancy risk in hypoechoic nodules between M-TIRADS and Kwak systems—0.9 vs. 0.8, respectively). Accuracy of M-TIRADS classification in this cohort was 78.26% vs. 48.11% for Kwak. Conclusions: The non-marked hypoechoic nodule pattern correlated with low risk of malignancy; classification of these nodules as TIRADS 3 significantly improved the predictive value and overall accuracy of the proposed M-TIRADS scoring with malignancy risk increase in TIRADS 4 categories by 20%; and no significant alteration of malignancy risk in TIRADS 3 could contribute to reducing overdiagnosis, obviating the need for FNA.

Risk factors and diagnostic prediction models for papillary thyroid carcinoma

Thyroid nodules (TNs) represent a common scenario. More accurate pre-operative diagnosis of malignancy has become an overriding concern. This study incorporated demographic, serological, ultrasound, and biopsy data and aimed to compare a new diagnostic prediction model based on Back Propagation Neural Network (BPNN) with multivariate logistic regression model, to guide the decision of surgery. Records of 2,090 patients with TNs who underwent thyroid surgery were retrospectively reviewed. Multivariate logistic regression analysis indicated that Bethesda category (OR=1.90, P<0.001), TIRADS (OR=2.55, P<0.001), age (OR=0.97, P=0.002), nodule size (OR=0.53, P<0.001), and serum levels of Tg (OR=0.994, P=0.004) and HDL-C (OR=0.23, P=0.001) were statistically significant independent differentiators for patients with PTC and benign nodules. Both BPNN and regression models showed good accuracy in differentiating PTC from benign nodules (area under the curve [AUC], 0.948 and 0.924, respectively). Notably, the BPNN model showed a higher specificity (88.3% vs. 73.9%) and negative predictive value (83.7% vs. 45.8%) than the regression model, while the sensitivity (93.1% vs. 93.9%) was similar between two models. Stratified analysis based on Bethesda indeterminate cytology categories showed similar findings. Therefore, BPNN and regression models based on a combination of demographic, serological, ultrasound, and biopsy data, all of which were readily available in routine clinical practice, might help guide the decision of surgery for TNs.

Cytomorphological study of thyroid carcinoma

The most common neoplasm of the endocrine system is found in the thyroid gland with a significant increase in recent decades largely due to modern diagnostic methods. Thyroid tumors generally have a favorable evolution, but there are also aggressive variants with a poor prognosis. In these aggressive tumors, the most reliable method of detecting and making a differential diagnosis is represented by ultrasound-guided fine-needle cytopuncture, confirmed by histopathological examination. Although fine-needle aspiration puncture and cytological examination are considered to have a high sensitivity and specificity, diagnostic certainty is established later only by histopathological examination. Fine-needle aspiration cytopuncture of the thyroid gland correlated with histopathological examination has played a crucial role in recognizing and identifying variants of papillary carcinoma known to have aggressive biological behavior, especially in cases of poorly differentiated carcinoma. Recognition of aggressive variants of papillary carcinoma is of major importance in the prognosis and clinical management of patients. The aim of this study was to present the correlations found in a series of thyroid tumors from patients treated in surgery and oncology departments, as well as tumors accidentally detected during autopsies in the department of forensics. All the cases selected in the study benefited from a complex histopathological diagnosis adapted to each case in order to ensure maximum efficiency.

A 5-year follow-up study on the efficacy and safety of ultrasound-guided laser ablation in elderly patients with papillary thyroid microcarcinoma: A retrospective, single-center study from China

OBJECTIVE

The aim of this study is to evaluate the long-term efficacy and safety of ultrasound-guided percutaneous laser ablation (PLA) for the treatment of elderly patients with papillary thyroid microcarcinoma (PTMC).

METHODS

From September 2015 to April 2017, 38 elderly patients with PTMC confirmed through fine-needle aspiration biopsy (FNAB) were treated with PLA. Before the treatment, the location and volume of the nodule together with the patients' symptoms were evaluated. Twenty-four hours after the treatment, contrast-enhanced ultrasound (CEUS) was performed to evaluate the completeness of the ablation. To evaluate the volume of the ablation area and recurrence or metastasis, ultrasound examination was performed at 1, 3, 6, and 12 months after the treatment and every 6 months thereafter. FNAB was performed for any suspicious recurrence or metastasis lesions.

RESULT

The ablation of all the 38 patients was all achieved completely as confirmed by CEUS. No obvious complications were found. The success rate of single ablation was 100%. The average follow-up time was 64.58 ± 5.29 months (60-78 months). By the time of the last follow-up, 31 (81.58%) ablation lesions disappeared completely and seven (18.42%) ablation lesions showed scar-like changes. The volume of nodules was 40.69 ± 16.45 mm³ before operation, which decreased to 0.22 ± 0.76 mm³ by the end of 42 months, and all nodules disappeared 4 years after ablation (P < 0.01). At 6, 12, 18, 24, 30, 36, and 42 months after ablation, the average volume reduction rates (VRRs) were 12.09%, 31.21%, 50.9%, 72.06%, 84.79%, 95.65%, and 100%, respectively. Of all the patients enrolled, one patient (2.6%) had local recurrence and was treated with PLA again. No regrowth of treated nodule or lymph node metastasis and distant metastases was detected.

CONCLUSION

Ultrasound-guided PLA is effective and safe for the treatment of elderly patients with PTMC who are ineligible for surgery.

The Risk Stratification of Papillary Thyroid Cancer With Bethesda Category III (Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance) by Thyroid Fine-Needle Aspiration Could Be Assisted by Tumor Size for Precision Treatment

PURPOSE

To investigate the clinical characteristics of papillary thyroid cancer (PTC) classified as Bethesda category III [atypia of undetermined significance (AUS)/follicular lesion of undetermined significance (FLUS)] by fine-needle aspiration (FNA) for precision treatment.

METHODS

A total of 1,739 patients diagnosed with Bethesda category III (AUS/FLUS) by FNA were investigated, and 290 patients diagnosed with PTC were analyzed.

RESULTS

The rate of papillary thyroid microcarcinoma (PTMC) was 82.1% (238/290). The rates of lymph node metastases were 44.9% (22/49) and 25.2% (56/222) for PTC and PTMC, respectively (p = 0.006). The rates of extra-thyroid extension were 46.2% (24/52) and 19.8% (47/237) (p < 0.001). Compared with PTMC, PTC had significantly higher odds ratios (ORs) of 3.41 (1.81-6.44, p < 0.001), 2.19 (1.16-4.13, p = 0.016), and 2.51 (1.29-4.88, p = 0.007) for extra-thyroid extension, multifocality, and lymph node metastases, respectively, after adjustment for age and gender. The larger size and BRAF V600E mutation had a robust synergistic effect for invasive features. The rates of lymph node metastases, multifocality, and extra-thyroid extension were significantly increased with larger sizes harboring BRAF V600E mutation. Compared with PTMC harboring wild type (WT)-BRAF, PTC harboring BRAF V600E mutation had adjusted higher ORs of 3.01 (1.26-8.68, p = 0.015), 3.20 (1.22-8.42, p = 0.018), and 5.62 (2.25-14.01, p < 0.001) for lymph node metastases, multifocality, and extra-thyroid extension, respectively.

CONCLUSIONS

In this study, risk stratification was recommended for patients with Bethesda category III (AUS/FLUS) nodules with a size under 1 cm harboring WT-BRAF being regarded as low risk and should be recommended for active surveillance. Nodules with a size over 1 cm harboring WT-BRAF or those under 1 cm harboring BRAF V600E mutation could be regarded as moderate risk, and molecular testing should be recommended. However, those with a size over 1 cm harboring BRAF V600E mutation should be regarded as high risk, and a diagnostic surgery should be recommended.

TERT Promoter Mutations Are an Independent Predictor of Distant Metastasis in Middle Eastern Papillary Thyroid Microcarcinoma

BACKGROUND

Papillary thyroid microcarcinomas (PTMCs) have been attributed to the recent increased incidence of thyroid cancer. Although indolent, a subset of PTMC could potentially develop distant metastasis (DM). This study aimed to evaluate the clinico-pathological features and molecular characteristics of PTMC and identify the risk factors for DM in PTMC patients from Middle Eastern ethnicity.

METHODS

We retrospectively analyzed 210 patients with histologically confirmed PTMC. Clinico-pathological associations for DM, BRAF mutation and TERT mutation were analyzed successfully in 184 patients. Multivariate analysis was performed using Cox proportional hazards model and logistic regression analysis.

RESULTS

Among the PTMC patients included in this cohort, DM was noted in 6.0% (11/184), whereas tumor relapse occurred in 29/184 (15.8%). Of the 11 cases with DM, lung metastasis occurred in 8 cases, bone metastasis in 2 cases and brain metastasis in 1 case. Presence of extrathyroidal extension and male sex were significantly associated with DM. Molecular analysis showed BRAF V600E mutations to be the most frequent, being detected in 45.7% (84/184). TERT promoter mutations were detected in 16 (8.7%) cases and were significantly associated with DM and shorter metastasis-free survival in multivariate analysis.

CONCLUSIONS

Our study indicates a surprisingly high frequency of TERT promoter mutation in Saudi patients with PTMC. Identifying TERT promoter mutations as an independent predictor of DM in patients with microcarcinoma could explain the inherent aggressive nature of PTMC from Middle Eastern ethnicity and magnify its role in patient risk stratification, which might help in improving therapeutic strategy for these patients.

Trends in Diagnosis of Noninvasive Follicular Thyroid Neoplasm With Papillarylike Nuclear Features and Total Thyroidectomies for Patients With Papillary Thyroid Neoplasms

Importance

Increasing detection of early-stage papillary thyroid neoplasms without improvements in mortality has prompted development of strategies to prevent or mitigate overtreatment.

Objective

To determine adoption rates of 2 recent strategies developed to limit overtreatment of low-risk thyroid cancers: (1) a new classification, noninvasive follicular thyroid neoplasm with papillarylike nuclear features (NIFTP), and (2) hemithyroidectomy for selected papillary thyroid carcinomas (PTCs) up to 4 cm in size.

Design, Setting, and Participants

This is a cross-sectional analysis of 3368 pathology records of 2 cohorts of patients from 18 hospitals in 6 countries during 2 time periods (2015 and 2019). Participating hospitals were included from the US (n = 12), Canada (n = 2), Denmark (n = 1), South Korea (n = 1), South Africa (n = 1), and India (n = 1). The records of the first 100 patients per institution for each year who underwent thyroid-directed surgery (hemithyroidectomy, total thyroidectomy, or completion thyroidectomy) were reviewed.

Main Outcomes and Measures

Frequency of diagnosis of NIFTP, PTCs, and thyroidectomies during the study period.

Results

Of the 790 papillary thyroid neoplasms captured in the 2019 cohort, 38 (4.8%) were diagnosed as NIFTP. Diagnosis of NIFTP was observed in the US, South Africa, and India. There was minimal difference in the total proportion of PTCs in the 2015 cohort compared with the 2019 cohort (778 [47.1%] vs 752 [44.5%]; difference, 2.6% [95% CI, -16.9% to 22.1%]). The proportion of PTCs eligible for hemithyroidectomy but treated with total thyroidectomy in the 2 cohorts demonstrated a decreasing trend from 2015 to 2019 (341 of 453 [75.3%] vs 253 of 434 [58.3%]; difference, 17.0% [95% CI, -1.2% to 35.2%]).

Conclusions and Relevance

Results of this cohort study showed that the 2 mitigation strategies for preventing overtreatment of early-stage thyroid cancer have had mixed success. The diagnosis of NIFTP has only been applied to a small proportion of thyroid neoplasms compared with expected rates. However, more patients eligible for hemithyroidectomy received it in 2019 compared with 2015, showing some success with this deescalation strategy.

Predictive Factors of Recurrence of Papillary Thyroid Microcarcinomas: Analysis of 2,538 Patients

Introduction  The incidence of papillary thyroid microcarcinoma (PTMC) has increased, and its treatment remains controversial.

Objective  To identify the clinical and pathological factors predictive of tumor recurrence.

Methods  We retrospectively analyzed 2,538 consecutive patients treated for PTMC, most submitted to total thyroidectomy (98%) followed by radioactive iodine (RAI) ablation (51.7%) at a cancer center from 1996 to 2015. The patients were stratified according to the American Thyroid Association (ATA) risk categories (low, intermediate, or high), and the clinicopathological features were evaluated by multivariate Cox regression analysis to identify independent prognostic factors for recurrence.

Results  After a mean follow-up of 58 months (range: 3 to 236.5 months), tumor recurrence was diagnosed in 63 (2.5%) patients, mostly in the lymph nodes. Distant metastasis occurred in 2 (0.1%) patients. There were no cancer-related deaths. The multivariate analysis showed that age < 55 years ( p  = 0.049; hazard ratio [HR]: 2.54; 95% confidence interval [95%CI]: 0.95 to 0.99), multifocality ( p  = 0.032; HR: 1.76; 95%CI: 1.05 to 2.96), and the presence of lymph-node metastasis ( p  < 0.001; HR: 3.69; 95%CI: 2.07–6.57) were independent risk factors for recurrence. Recurrence was observed in 29 (1.5%) out of 1,940 low-risk patients, 32 (5.4%) out of 590 intermediate-risk patients, and in 2 (25%) out of 8 high-risk patients.

Conclusions  The prognosis of PTMC is excellent, favoring a conservative treatment for most patients. Age < 55 years, multifocality, and node metastasis at diagnosis, as well the ATA staging system effectively predict the risk of recurrence. The presence of these risk factors can help identify patients who should be considered for more aggressive management and more frequent follow-up.

Evaluation of thyroid nodules in the Brazilian Public Health Care System, Supplementary Health System, and Private Health System in the northeastern region of the State of São Paulo

OBJECTIVE

To obtain data about the evaluation of thyroid nodules (TNs) in the northeastern of the State of São Paulo, compared by health care type, and measure the performance of cytology as a screening test for thyroid cancer (TC).

METHODS

We collected data of 597 patients treated in the Brazilian public health care system (SUS), supplementary health (SH) and in private health system (PHS) in 2014. A total of 803 TNs were aspirated, and 125 patients underwent surgery.

RESULTS

The distribution of all cytologic results according to the Bethesda system was: I, 135 (16.8%); II, 475 (59.2%); III, 107 (13.3%); IV, 32 (4.0%); V, 20 (2.5%); VI, 34 (4.2%). The time between cytologic analysis and surgery was longer in the SUS than in the SH for TNs in general (p < 0.001) and for TNs with Bethesda V and VI cytology (p = 0.01). The sizes of the TNs and resected malignant TNs was larger in the SUS than in the SH (p = 0.001 and p = 0.02, respectively). The number of PHS surgeries was too small and was not compared. The prevalence of TC was 9.2% and 23.6% of them were treated in the SUS. Cytology showed a 93.6% sensitivity, 95.8% specificity, and 94.7% accuracy when Bethesda III and IV were excluded.

CONCLUSION

Cytology was a good screening test for TC categories Bethesda II, V, and VI. The differences between the SUS and SH indicate a need for improved access to consultations and specialized tests in the SUS.

Long-Term Outcome of Lobectomy for Thyroid Cancer

INTRODUCTION

Recent guidelines of the American Thyroid Association (ATA) suggest that a lobectomy may be sufficient to treat low- to intermediate-risk patients with thyroid tumors ≤40 mm, without extrathyroidal extension or lymph node metastases. The present study aimed to evaluate long-term recurrence after lobectomy for differentiated thyroid cancer and to analyze factors associated with recurrence.

METHODS

In this retrospective cohort study, patients who underwent a lobectomy for thyroid cancer in a tertiary center between 1970 and 2010 were included. The outcome was the proportion of pathology-confirmed thyroid cancer recurrence, assessed in the whole cohort or in subgroups according to tumor size (≤ or >40 mm).

RESULTS

A total of 295 patients were included, and these were followed-up for a mean (standard deviation, SD) 19.1 (7.8) years (5,649 patient-years); 61 (20.7%) were male and the mean (SD) age at diagnosis was 39.7 (12) years. Histological subtype was papillary in 263 (89.2%) patients and mean cancer size was 22.9 (16.9) mm. According to the 2015 ATA guidelines, 271 (91.9%) cancers had a low risk of recurrence and 24 (8.1%) an intermediate risk. A reoperation was performed in 54 patients (18.3%) and recurrence was confirmed in 40 (13.6%), diagnosed for 55% of cases more than 10 years after their initial surgery. Among recurrent patients, 14 (4.8% of the cohort) were operated for a contralateral papillary thyroid microcarcinoma and 26 (8.8% of the cohort) for a locoregional or metastatic recurrence. Non-suspicious nodular recurrences were monitored without reoperation in 53 (18.0%) patients. At the end of follow-up, 282 (95.6%) patients were in remission. Tumors with locoregional or metastatic recurrence were more frequent among tumors with aggressive histology (19.2 vs. 4.1%, p = 0.015) and of intermediate risk category (28.6 vs. 7.1%, p = 0.018). Tumors >40 mm, which would have been treated by thyroidectomy according to the 2015 ATA guidelines criteria, were found in 34 (11.5%) patients and were associated with a higher frequency of recurrence (20.6 vs. 7.3%, p = 0.024) and less remission (85.3 vs. 96.9%, p = 0.001).

CONCLUSION

The outcome of thyroid cancer treated by lobectomy is very good, particularly for cancer ≤40 mm. A prolonged follow-up is required due to the risk of late recurrence.

Ultrasound-Guided Radiofrequency Ablation Versus Thyroid Lobectomy for Low-Risk Papillary Thyroid Microcarcinoma: A Propensity-Matched Cohort Study of 884 Patients

Background: Thermal ablation (TA) has been applied in patients with low-risk papillary thyroid microcarcinoma (PTMC) who refuse surgery or active surveillance (AS). Recently, TA has been proposed as a potential therapeutic option for patients who are suitable for surgery or AS. However, the clinical outcomes of TA versus surgery remains controversial because of a lack of sufficient data. This study aimed to compare the clinical outcomes between radiofrequency ablation (RFA) versus thyroid lobectomy (TL) for low-risk PTMC in a large cohort. Methods: This retrospective study evaluated 884 patients with unifocal low-risk PTMC treated with TL or RFA from June 2014 to March 2018. Among them, 460 patients underwent TL (TL group) and 424 patients, who refused surgery or AS, underwent RFA (RFA group). Patients were regularly followed up after treatment. Local tumor progression, recurrence-free survival (RFS), complications, and treatment variables, including procedure time, estimated blood loss, hospitalization, and cost, were compared after propensity score matching (PSM). Results: After PSM, a total of 332 patients underwent TL (mean ages 43.8 ± 9.5 years) and 332 underwent RFA (mean ages 44.1 ± 9.5 years). During the follow-up (median [interquartile ranges], 48.3 [23.2] months), no significant differences were observed in local tumor progression (1.8% vs. 3.3%, p = 0.209), lymph node metastasis (0.6% vs. 0.6%, p = 1.000), recurrent PTMC (1.2% vs. 2.4%, p = 0.244), persistent lesion (0% vs. 0.3%, p = 0.317), and 4-year RFS rates (98.2% vs. 97.0%, p = 0.223) between the TL and RFA groups. Distant metastasis was not detected. None of the patients who were treated by RFA underwent delayed surgery. Patients undergoing RFA had shorter procedure time (3.4 [2.5] vs. 86.0 [37.0] minutes, p < 0.001), lower estimated blood loss (0 vs. 20 [10.0] mL, p < 0.001), shorter hospitalization (0 vs. 7.0 [3.0] days, p < 0.001), lower cost ($2035.7 [254.0] vs. $2269.1 [943.4], p < 0.001) and lower complication rate (0% vs. 4.5%, p < 0.001) than those treated by TL. The association between treatment modality and recurrence remained nonsignificant after Cox analysis (p = 0.247). Conclusions: This large matched study revealed comparable four-year clinical outcomes between RFA and TL for low-risk PTMC. As a minimally invasive modality, RFA may be a promising alternative to the existing treatment options for low-risk PTMC.

A 6 transcription factors-associated nomogram predicts the recurrence-free survival of thyroid papillary carcinoma

Various researches demonstrated that transcription factors (TFs) played a crucial role in the progression and prognosis of cancer. However, few studies indicated that TFs were independent biomarkers for the prognosis of thyroid papillary carcinoma (TPC). Our aim was to establish and validate a novel TF signature for the prediction of TPC patients' recurrence-free survival (RFS) from The Cancer Genome Atlas (TCGA) database to improve the prediction of survival in TPC patients.The genes expression data and corresponding clinical information for TPC were obtained from TCGA database. In total, 722 TFs and 545 TPC patients with eligible clinical information were determined to build a novel TF signature. All TFs were included in a univariate Cox regression model. Then, the least absolute shrinkage and selection operator Cox regression model was employed to identify candidate TFs relevant to TPC patients' RFS. Finally, multivariate Cox regression was conducted via the candidate TFs for the selection of the TF signatures in the RFS assessment of TPC patients.We identified 6 TFs that were related to TPC patients' RFS. Receiver operating characteristic analysis was performed in training, validation, and whole datasets, we verified the high capacity of the 6-TF panel for predicting TPC patients' RFS (AUC at 1, 3, and 5 years were 0.880, 0.934, and 0.868, respectively, in training dataset; 0.760, 0.737, and 0.726, respectively, in validation dataset; and 0.777, 0.776, and 0.761, respectively, in entire dataset). The result of Kaplan-Meier analysis suggested that the TPC patients with low scores had longer RFS than the TPC patients with high score (P = .003). A similar outcome was displayed in the validation dataset (P = .001) and the entire dataset (P = 2e-05). In addition, a nomogram was conducted through risk score, cancer status, C-index, receiver operating characteristic, and the calibration plots analysis implied good value and clinical utility of the nomogram.We constructed and validated a novel 6-TF signature-based nomogram for predicting the RFS of TPC patients.

Ultrasound in active surveillance for low-risk papillary thyroid cancer: imaging considerations in case selection and disease surveillance

Active surveillance (AS) of small, low-risk papillary thyroid cancers (PTCs) is increasingly studied in prospective observational studies. Ultrasound is the primary imaging modality for case selection. While researchers have put forward selection criteria for PTCs based on size, absence of suspicious lymph nodes and tumor location, there are limited reported data highlighting inherent ultrasound limitations and guidelines for case selection and follow-up. We report our experience including imaging limitations encountered in the ongoing AS prospective observational study for PTCs measuring < 2 cm at our institute. We define disease progression as an increase in size of > 3 mm in the largest dimension of nodule or evidence of metastatic disease or extrathyroidal extension. Accurate, consistent and reproducible measurements of PTCs are essential in risk stratifying patients for the option of AS or disease progression. Interobserver discrepancy, shadowing from coarse calcification and background parenchyma heterogeneity or thyroiditis can limit accurate PTC size assessment and therefore hinder patient eligibility evaluation or AS follow-up. Following the ACR Thyroid Imaging, Reporting and Data System (TI-RADS) protocol of three-axes technique to measure a thyroid nodule enables reproducibility of measurements. In patients with multi-nodular goiter, accurate identification and labeling of the PTC is important to avoid mistaking with adjacent benign nodules at follow-up. Ultrasound assessment for extrathyroid extension of PTC, and relationship of PTC to trachea and the anatomic course of the recurrent laryngeal nerve are important considerations in evaluation for AS eligibility.

Long-term follow-up results of PTMC treated by ultrasound-guided radiofrequency ablation: a retrospective study

OBJECTIVES

To confirm the long-term efficacy and safety of radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC).

METHODS

We retrospectively reviewed data of 102 primary papillary thyroid carcinoma patients (82 women, 20 men; mean age: 43 [19] years) treated with radiofrequency ablation and thyroid-stimulating hormone (TSH) suppression therapy before December 2018. All patients were at high surgical risk or refused surgery. They were followed up at 1, 3, 6, 9, and 12 months and every 6-12 months thereafter using ultrasound and contrast-enhanced ultrasound. The volume and volume reduction ratio was calculated. Recurrence and lymph node or distant metastasis were evaluated.

RESULTS

The mean initial tumor diameter was 0.50 (0.29) cm; the mean initial volume was 0.06 (0.09) mL. At 1, 3, 6, 9, 12, 24, 36, 48, and 60 months after RFA, complete resorption rates were 0, 0, 9.8 (10/102), 33.3 (34/102), 91.2 (93/102), 96.1 (98/102), 99 (101/102), 100, and 100%, respectively. Two patients had developed ipsilateral neck lymph node metastasis in regions IV and VI at 30- and 18-month follow-ups, respectively. After RFA, 3/102 patients (2.9%) developed hoarseness-the main side effect. No life-threatening or delayed complications occurred. The TSH value in the initial period was 0.06 (0.02) µIU/mL; the rate of reaching the TSH target was 85.7%. The TSH value at follow-up was 1.47 (0.91) µIU/mL; the compliance rate was 99.3%.

CONCLUSIONS

Ultrasound-guided RFA for PTMC is highly effective and safe. RFA can serve as a minimally invasive treatment for PTMC patients who refuse surgery or active surveillance.

Clinical outcomes of radiofrequency ablation for multifocal papillary thyroid microcarcinoma versus unifocal papillary thyroid microcarcinoma: a propensity-matched cohort study

OBJECTIVE

To investigate and compare the clinical outcomes of radiofrequency ablation (RFA) for multifocal papillary thyroid microcarcinoma (PTMC) versus unifocal PTMC in a large cohort.

METHODS

Patients with low-risk PTMC (n = 487) who underwent RFA were included in this retrospective study and divided into the unifocal group (U group) (n = 432) and the multifocal group (M group) (n = 55) according to the number of lesions. After 1:1 propensity score matching (PSM), volume, volume reduction ratio (VRR), the development of local tumor progression including lymph node metastasis (LNM), recurrent PTMC and persistent lesions, and recurrence-free survival (RFS) rate were evaluated and compared between the two groups. The different impacts of multifocality on recurrence after RFA for PTMC were investigated by Cox analysis.

RESULTS

During a mean follow-up time of 49.25 ± 12.98 months, the overall VRR was 99.40 ± 4.43% and the overall incidence of local tumor progression was 3.70% (18/487). No complications occurred after RFA. After PSM, no significant differences were found in volume (0.11 ± 0.69 mm³ vs 0 mm³, p = 0.441), VRR (99.87 ± 0.78% vs 100%, p = 0.441), complete disappearance rate (95.61% vs 89.09%, p = 0.201), incidence of local tumor progression (5.45% vs 5.45%, p = 1.000), LNM (1.82% vs 0%, p = 0.317), recurrent PTMC (1.82% vs 5.45%, p = 0.611), persistent lesions (1.82% vs 0%, p = 0.317), and RFS rate (96.36% vs 94.55%, p = 0.632) between the M group and U group. The association between multifocality and local tumor recurrence also remained nonsignificant (p = 0.619). No distant metastasis or delayed surgery occurred.

CONCLUSIONS

The impact of multifocality on the prognosis after RFA for low-risk PTMC was little. RFA might be a promising treatment for both unifocal and multifocal PTMC in properly selected patients after sufficient preoperative evaluation.

KEY POINTS

• No significant differences are found in the local tumor progression between the unifocal PTMC and multifocal PTMC. • Multifocality is not associated with higher recurrence after RFA for low-risk PTMC. • RFA is a promising alternative for both unifocal and multifocal PTMC.

Surgical Considerations in Thyroid Cancer: What the Radiologist Needs to Know

Management of thyroid cancer requires a multidisciplinary approach including head and neck/endocrine surgeons, endocrinologists, oncologists, and radiologists. The radiographic evaluation of thyroid cancer is critical for complete and precise staging and affects the surgical approach to address these cancers. The purpose of this article is to briefly review the common thyroid cancer pathologies and surgical considerations in thyroid cancer, focusing on the extent of surgery and the influence of preoperative imaging on surgical decision-making. This article assumes that a diagnosis of thyroid cancer has been made and does not discuss the workup or surveillance of thyroid nodules.

Long-Term Efficacy of Ultrasound-Guided Percutaneous Laser Ablation for Low-Risk Papillary Thyroid Microcarcinoma: A 5-Year Follow-Up Study

Objective

To evaluate the long-term efficacy and safety of ultrasound-guided percutaneous laser ablation (PLA) for the treatment of low-risk papillary thyroid microcarcinoma (PTMC).

Methods

From June 2012 to May 2015, 105 patients with solitary, pathologically confirmed PTMC lesions were treated with ultrasound-guided PLA. Nodule location, nodule volume, thyroid function, and clinical symptoms were evaluated before ablation. Contrast-enhanced ultrasound (CEUS) was performed 1 h after treatment to evaluate whether the ablation was complete. Ultrasound examination was performed at 1, 3, 6, and 12 months after ablation and every 6 months thereafter to determine the size of the ablation area and search for recurrence in the thyroid parenchyma and lymph node metastasis. Thyroid function was examined before and 1 month after ablation. Fine needle aspiration biopsy was performed for any suspicious metastatic lymph nodes and recurrent lesions in the thyroid.

Results

All 105 lesions were completely inactivated after one ablation, making the success rate for single ablation 100%. The average ablation time was 2.78 ± 1.05 min, and the average ablation energy was 505 ± 185 J. All patients could tolerate and complete the ablation. No serious complications occurred during the treatment; only minor side effects such as pain and local discomfort were reported. The volume reduction rates were −781.14 ± 653.29% at 1 h posttreatment and −268.65 ± 179.57%, −98.39 ± 76.58%, 36.78 ± 30.32%, 75.55 ± 21.81%, 96.79 ± 10.57%, and 100% at 1, 3, 6, 12, 18, and 24 months after ablation, respectively. This rate remained 100% at the later follow-up times. Overall, 28 (26.67%), 74 (70.48%), 96 (91.43%), and 103 (100%) were completely absorbed by 6, 12, 18, and 24 months after PLA. One patient developed another lesion 12 months after ablation, and two patients had central cervical lymph node metastasis 24 months after ablation.

Conclusion

PLA is a safe and effective alternative clinical treatment for low-risk PTMC.