ACTIVE SURVEILLANCE FOR PAPILLARY THYROID MICROCARCINOMA: NEW CHALLENGES AND OPPORTUNITIES FOR THE HEALTH CARE SYSTEM

Five-year Outcome Between Radiofrequency Ablation vs Surgery for Unilateral Multifocal Papillary Thyroid Microcarcinoma

CONTEXT

Ultrasound (US)-guided radiofrequency ablation (RFA) has been considered as an alternative to surgery or active surveillance for papillary thyroid microcarcinoma (PTMC). However, little is known about the long-term outcomes of RFA in comparison with surgery for unilateral multifocal PTMC.

OBJECTIVE

This work aims to report the comparison between RFA vs surgery for unilateral multifocal PTMC over a more than 5-year follow-up period.

METHODS

This was a retrospective study at a primary care center with a median follow-up period of 72.9 months. A total of 97 patients with unilateral multifocal PTMC were treated with RFA (RFA group, n = 44) or surgery (surgery group, n = 53). In the RFA group, patients were treated by a bipolar RFA generator and an 18-gauge bipolar RF electrode with a 0.9-cm active tip. In the surgery group, patients underwent thyroid lobectomy with prophylactic central neck dissection.

RESULTS

During the follow-up, no statistically significant differences were found in disease progression (4.5% vs 3.8%; P = ≥.999), lymph node metastasis (2.3% vs 3.8%; P = ≥.999), persistent lesion (2.3% vs 0%; P = .272), and RFS rates (97.7% vs 96.2%; P = .673) in the RFA and surgery groups. Patients undergoing RFA had a shorter hospitalization (0 vs 8.0 [3.0] d; P < .001), shorter procedure time (3.5 [2.4] vs 80.0 [35.0] min; P < .001), lower estimated blood loss (0 vs 20.0 [15.0] mL; P < .001), and lower costs ($1768.3 [0.1] vs $2084.4 [1173.8]; P = .001) than those in the surgery group. The complication rate in the surgery group was 7.5%, whereas none of the RFA-treated patients experienced any complications (P = .111).

CONCLUSION

This study revealed 6-year comparable outcomes between RFA and surgery for unilateral multifocal PTMC. RFA may be a safe and effective alternative to surgery in selected patients with unilateral multifocal PTMC.

Safety and efficacy of microwave ablation for the treatment of low-risk papillary thyroid microcarcinoma: a prospective multicenter study

OBJECTIVES

To assess the safety and efficacy of ultrasound-guided thermal ablation for low-risk papillary thyroid microcarcinoma (PTMC) via a prospective multicenter study.

METHODS

From January 2017 through June 2021, low-risk PTMC patients were screened. The management details of active surveillance (AS), surgery, and thermal ablation were discussed. Among patients who accepted thermal ablation, microwave ablation (MWA) was performed. The main outcome was disease-free survival (DFS). The secondary outcomes were tumor size and volume changes, local tumor progression (LTP), lymph node metastasis (LNM), and complication rate.

RESULTS

A total of 1278 patients were included in the study. The operation time of ablation was 30.21 ± 5.14 min with local anesthesia. The mean follow-up time was 34.57 ± 28.98 months. Six patients exhibited LTP at 36 months, of whom 5 patients underwent a second ablation, and 1 patient received surgery. The central LNM rate was 0.39% at 6 months, 0.63% at 12 months, and 0.78% at 36 months. Of the 10 patients with central LNM at 36 months, 5 patients chose ablation, 3 patients chose surgery and the other 2 patients chose AS. The overall complication rate was 1.41%, and 1.10% of patients developed hoarseness of the voice. All of the patients recovered within 6 months.

CONCLUSIONS

Thermal ablation of low-risk PTMC was observed to be safe and efficacious with few minor complications. This technique may help to bridge the gap between surgery and AS as treatment options for patients wishing to have their PTMC managed in a minimally invasive manner.

CLINICAL RELEVANCE STATEMENT

This study proved that microwave ablation is a safe and effective treatment method for papillary thyroid microcarcinoma.

KEY POINTS

Percutaneous US-guided microwave ablation of papillary thyroid microcarcinoma is a very minimally invasive treatment under local anesthesia during a short time period. The local tumor progression and complication rate of microwave ablation in the treatment of papillary thyroid microcarcinoma are very low.

Inter-observer variation in two-dimensional and three-dimensional ultrasound measurement of papillary thyroid microcarcinoma

BACKGROUNDS

The reliable ultrasound (US) measurements of papillary thyroid microcarcinoma (PTMC) are very important during active surveillance. This prospective study was design to investigate the inter-observer reliability and agreement of two- dimensional ultrasound(2DUS) and three-dimensional ultrasound(3DUS) in the measurement of maximum diameter and volume for PTMC.

METHODS

This prospective study included 51 consecutive patients with solitary PTMC confirmed by biopsy. Two independent observers performed measurements of each tumor using a standardized measurement protocol. The maximum diameter was the largest one of the three diameters measured on the largest transverse and longitudinal 2DUS images. 2DUS volume was calculated using ellipsoid formula method. The virtual organ computer aided analysis(VOCAL) was used to determine 3DUS volume. The inter-observer reliability was assessed using intraclass correlation coefficient(ICC) with 95% confidence intervals(CIs). Bland-Altman analysis was used to evaluate agreement, and expressed as a bias with 95% limits of agreement(LOA).

RESULTS

The maximum diameter was 0.78 ± 0.14 cm. Volume measured by 3DUS was significantly smaller than that by 2DUS(0.163 ± 0.074 cm3 vs. 0.175 ± 0.078 cm3, P = 0.005). The ICCs of inter-observer reliability of maximum diameter, 2DUS volume and 3DUS volume was 0.922(0.864-0.955), 0.928(0.874-0.959), and 0.974(0.955-0.985), respectively. The ICCs of 2DUS and 3DUS volume was 0.955(0.909-0.976). The inter-observer agreement of maximum diameter, 2DUS volume and 3DUS volume was 1.096(0.7322 to 1.459), 1.008(0.5802-1.435), and 1.011(0.7576-1.265), respectively. The inter-observer agreement of 2DUS and 3DUS volume was 1.096(0.7322 to 1.459).

CONCLUSION

Maximum diameter had the lowest degree of observer variation among all the measurements. Volume measured by 3DUS had lower variability and higher repeatability than that by 2DUS, which might be helpful to provide more reliable estimates of tumor size for PTMC.

Survival outcomes of low-risk papillary thyroid carcinoma at different risk levels: a corollary for active surveillance

Background

This study aims to compare the outcomes of active surveillance (AS) in low-risk papillary thyroid carcinoma (PTC) patients with different tumor sizes and lymph node metastasis status, in order to establish appropriate management strategies. By analyzing these results, this study provides valuable insights for the effective management of such patients, addressing the issues and challenges associated with AS in practical clinical practice.

Methods

The study utilized the SEER database supported by the National Cancer Institute of the United States, extracting data of PTC diagnosed between 2000 and 2015. Statistical analyses were conducted using inverse probability weighting (IPTW) and propensity score matching (PSM), including Kaplan-Meier survival curves and Cox regression models, to evaluate the impact of different tumor sizes and lymph node metastasis status on thyroid cancer-specific survival (TCSS).

Results

A total of 57,000 PTC patients were included, with most covariates having standardized mean differences below 10% after IPTW and PSM adjustments. The TCSS of PTC with a diameter smaller than 13mm is significantly better than that of tumors with a diameter larger than 13mm, regardless of the presence of lymph node metastasis. Among PTC cases with a diameter smaller than 13mm, the TCSS of patients is similar, regardless of the presence of lymph node metastasis. However, in PTC cases with a diameter larger than 13mm, the presence of lateral neck lymph node metastasis (N1b stage) significantly impacts the TCSS, although the absolute impact on TCSS rate is minimal.

Conclusion

The treatment strategy of AS is safe for patients with T1a stage papillary thyroid microcarcinoma (PTMC). However, for patients with T1b stage, if the tumor diameter exceeds 13mm or there is lymph node metastasis in the lateral neck region, the TCSS will be significantly affected. Nevertheless, the absolute impact on survival is relatively small.

Risk factors for recurrent disease in small papillary thyroid cancers - a Swedish register-based study

AIMS

To study the correlation between clinicopathological risk factors and the risk for intervention-requiring cancer recurrence in patients with small papillary thyroid cancers (sPTCs).

MATERIALS AND METHODS

Records for 397 patients with sPTC (T1 ≤ 20mm) were obtained from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery (SQRTPA) between 2010 and 2016. Follow-up time was at least 5 years. Data regarding intervention-requiring cancer recurrence were obtained from patient medical records and analysed regarding lymph node (LN) status (N0, N1a and N1b) and recurrence.

RESULTS

Age was significantly lower in the N1a and N1b groups compared to N0 (45 vs. 40.5 vs. 49 years, respectively; p = 0.002). Tumour size was smaller in the N1a group compared to N1b group (9 vs. 11.8 mm; p <0.01). The mean number of metastatic LNs at initial surgery was higher in the N1b compared to N1a group (6.6 vs. 3; p = 0.001), and in the recurrent compared to the non-recurrent group (7 versus 3.9; p <0.01). The recurrence rate was higher in the N1b group than the N1a and N0 groups (25% vs. 2.4% vs. 1.4%, respectively; p = 0.001).

CONCLUSIONS

Lymph node stage N1b at diagnosis, and having five or more metastatic nodes, are strong risk factors for cancer recurrence and decreased disease-free survival in sPTC. The management of patients with sPTC should include thorough lymph node mapping for optimal treatment and individual risk stratification.

Multi-omics profiling of papillary thyroid microcarcinoma reveals different somatic mutations and a unique transcriptomic signature

BACKGROUND

Papillary thyroid microcarcinoma (PTMC) incidence has significantly increased, and some cases still exhibit invasive traits. The entire molecular landscape of PTMC, which can offer hints for the etiology of cancer, is currently absent.

METHODS

We compared our findings with those for PTMC in the TCGA by analyzing the largest study at the current stage of whole exome sequencing and RNA-sequencing data from 64 patients with PTMC. Then, we systematically demonstrated the differences between the two PTMC subtypes based on multi-omics analyses. Additionally, we created a molecular prediction model for the PTMC subtypes and validated them among TCGA patients for individualized integrative assessment.

RESULTS

In addition to the presence of BRAF mutations and RET fusions in the TCGA cohort, we also discovered a new molecular signature named PTMC-inflammatory that implies a potential response to immune intervention, which is enriched with AFP mutations, IGH@-ext fusions, elevated immune-related genes, positive peroxidase antibody, and positive thyroglobulin antibody. Additionally, a molecular prediction model for the PTMC-inflammatory patients was created and validated among TCGA patients, while the prognosis for these patients is poor.

CONCLUSIONS

Our findings comprehensively define the clinical and molecular features of PTMC and may inspire new therapeutic hypotheses.

The value of second opinions on thyroid nodule management provided via direct-to-consumer telemedicine service

PURPOSE

Second medical opinions (SMO) can improve patient outcomes and change medical decision-making. The purpose was to determine the concordance of initial management of thyroid nodules for patients seeking SMO to established management guidelines.

MATERIALS AND METHODS

Cases of patients consulting a single provider via telemedicine for SMO on the workup and management of thyroid nodule(s) were reviewed from September 2011 to February 2022. The primary outcome was the overall rate of adherence to 2015 ATA guidelines (correct/incorrect) and complete agreement (yes/no) between SMO and initial treatment team.

RESULTS

Most sought a second opinion for treatment options. Only 14 (29.2 %) cases had followed all the guidelines correctly. Living in North America compared to Asia (10/18 vs. 4/25, p = 0.004) and consulting endocrinology (11/21 vs. 3/26, p = 0.004) was associated with correct following of all guidelines. The most common violations of the guidelines were a lack of Bethesda scoring in pathology reports (31.8 %) and inappropriate initial FNA (25.5 %). The SMO was in complete agreement with the initial treatment recommendation in 31 cases (64.6 %), in partial agreement in 12 cases (25 %), and in disagreement in 5 cases (10.4 %).

CONCLUSIONS

In our study, adherence to guidelines was low. However, the SMO agreed with the workup and management of most patients, as most of this discordance with guidelines did not affect the overall treatment. The virtual second opinion consult was valuable in addressing patient-specific concerns, explaining additional treatment options, and, in a few cases, recommending against inappropriate surgical intervention.

Comparison of ultrasound-guided radiofrequency ablation versus thyroid lobectomy for T1bN0M0 papillary thyroid carcinoma

OBJECTIVE

To investigate and compare the clinical outcomes between radiofrequency ablation (RFA) and thyroid lobectomy (TL) for T1bN0M0 papillary thyroid carcinoma (PTC).

METHODS

This retrospective study evaluated 283 patients with solitary T1bN0M0 PTC treated with RFA (RFA group, 91 patients) or TL (TL group, 192 patients) from May 2014 to November 2018. The patients were regularly followed up after treatment. Local tumor progression, lymph node metastasis (LNM), recurrent tumor, persistent tumor, recurrence-free survival (RFS), treatment variables (hospitalization, procedure time, estimated blood loss, and cost), complication, and delayed surgery were compared.

RESULTS

During the follow-up (median [interquartile ranges], 50.4 [18.0] months), no significant differences were found in the local tumor progression (4.4% vs 3.6%, p = 1.000), LNM (1.1% vs 2.1%, p = 0.917), recurrent tumor (2.2% vs 1.6%, p = 1.000), persistent tumor (1.1% vs 0%, p = 0.146), and RFS rate (95.6% vs 96.4%, p = 0.816) in the RFA and TL groups. Distant metastasis was not detected. Patients in the RFA group had a shorter hospitalization (0 vs 7.0 [3.0] days, p < 0.001), shorter procedure time (5.6 [2.9] vs 90.0 [38.5] min, p < 0.001), lower estimated blood loss (0 vs 20 [20] mL, p < 0.001), lower cost ($1972.5 [0.1] vs $2362.4 [1009.3], p < 0.001), and lower complication rate (0 vs 12/192 [6.3%], p = 0.015) than those in the TL group. No patients in the RFA group underwent delayed surgery.

CONCLUSIONS

This study revealed comparable 4-year clinical outcomes between RFA and TL for T1bN0M0 PTC in terms of local tumor progression and RFS. As a minimally invasive modality, RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation.

KEY POINTS

• No significant difference in local tumor progression and RFS was found between RFA and TL for T1bN0M0 PTC during a median follow-up period of 50.4 months. • Compared with TL, RFA led to a shorter hospitalization, lower estimated blood loss, lower cost, and lower complication rate. • RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation.

Factors That Inform Individual Decision Making Between Active Surveillance, Hemithyroidectomy and Total Thyroidectomy for Low-Risk Thyroid Cancer: A Scoping Review

Background: Due to the excellent prognosis and relatively high incidence of small low-risk thyroid cancers, more conservative management strategies such as active surveillance (AS) or hemithyroidectomy (HT) may be preferable to total thyroidectomy (TT) for patients seeking to balance long-term survival rates with the potential adverse effects of overtreatment. The aim of this review was to synthesize key factors or variables that inform patient decision making about treatment for low-risk thyroid cancer, from current primary investigations that presented participants with information facilitating this choice. Methods: Studies were identified from the Medline, Cochrane, and Embase databases up until March 2022. Study characteristics were extracted into a pre-piloted form. Factors were hypothesized to include treatment-related risks and possible outcomes and identified from a review of studies with consensus by discussion. Results: The search identified 444 unique studies: 397 were excluded on review of abstract and title with 47 studies undergoing a full text review and 6 studies identified to be eligible. Four were cross-sectional: one a prospective cohort study and one a mixed-methods study with both a prospective observational and qualitative component. The decisions addressed included: the choice between AS versus surgery (HT and/or TT) and HT versus TT and enrolled participants ranging from healthy volunteers to thyroid cancer patients. Treatment choice was the primary outcome in five studies. Across the studies, participants who were given the option of AS or surgery predominately chose the more conservative pathway, with a range of 70-84%. The major factors represented by information provision in the studies were risk of cancer recurrence or spread, need for hormone replacement therapy, and voice change. Conclusions: A framework of key factors informing patient treatment choice may be derived from current studies involving information provision for low-risk thyroid cancer management. Further research evaluating the efficacy and optimal timing for decision support interventions would help inform the design and clinical use of these tools to promote shared decision making.

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.

Active Surveillance Versus Immediate Surgery for Low-Risk Papillary Thyroid Microcarcinoma Patients in South Korea: A Cost-Minimization Analysis from the MAeSTro Study

Background: Active surveillance (AS) has been established as an alternative to immediate surgery for low-risk papillary thyroid microcarcinoma (PTMC). Nonetheless, it remains difficult to decide between AS and immediate surgery, since limited objective evidence exists regarding risks and benefits. The aim of study is to compare the cumulative costs of AS and immediate surgery. Methods: To estimate cumulative costs, a hypothetical model is simulated based on the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Micro-Carcinoma (MAeSTro) study, a multicenter prospective cohort study of AS for PTMC. Direct and indirect costs are estimated from diagnosis to the treatment decision and follow-up for 10 years and a longer period. In the case of the scenarios, AS, AS to surgery due to changing their mind, and lobectomy (analyzed regardless of levothyroxine [LT4] treatment, as well as subdivided into lobectomy/LT4[-] and lobectomy/LT4[+]) are considered. A sensitivity analysis is performed using different discount rates to address uncertainties in future time costs. To compare the cumulative costs, we referred to previous research conducted in Hong Kong, the United States, and Japan. Results: The initial cost of AS is estimated to be 5.6 times lower than that of lobectomy (regardless of LT4 use), while the 10-year cumulative costs of AS ($2545) and lobectomy regardless of LT4 ($3045) are similar under a discount rate of 3%. However, in the long-term follow-up period, immediate surgery is going to be estimated more economical than AS. The costs of the two management approaches are similar in Hong Kong, but substantially different in the United States and Japan, implying that it could be affected by each country's national health insurance coverage and the thyroid ultrasound interval during follow-up. Conclusion: Considering both direct and indirect costs, the cumulative costs of AS and immediate surgery in low-risk PTMC patients are similar during 10 years, and surgery could be more economical for patients with a life expectancy in long-term follow-up. However, careful interpretation is needed for long-term follow-up and the country's health care system and environment. Nevertheless, considering the representative protocols and objective costs in South Korea, it is expected to be a key to suggest the appropriate treatment for PTMC patients.

Effect of Hashimoto's thyroiditis on the extent of the ablation zone in early stages of ultrasound-guided radiofrequency ablation for papillary thyroid microcarcinoma: a large cohort study of 772 patients

PURPOSE

To evaluate the effect of Hashimoto's thyroiditis (HT) on the extent of ablation zone in ultrasound (US)-guided radiofrequency ablation (RFA) for early stages of papillary thyroid microcarcinoma (PTMC).

METHOD

We selected 772 patients with 797 PTMCs who underwent with RFA from August 2017 to August 2020. They were subdivided into two groups as follows: (i) 216 patients (224 PTMCs) with HT in the 'HT + PTMC' group and (ii) 556 patients (573 PTMCs) with healthy thyroid in the 'PTMC' group. We assessed the extent (maximum diameter and volume) of the ablation zone by contrast-enhanced ultrasound (CEUS) immediately, one day, and 1 week following RFA.

RESULTS

The ablation zone of the 'HT + PTMC' group was smaller than that of the 'PTMC' group at 1 week of RFA (maximum diameter: 14.6 ± 3.1 mm vs. 15.2 ± 3.2 mm and volume: 0.932 ± 0.498 mL vs. 1.028 ± 0.540 mL, respectively, p < .05). However, there were no differences before, immediately, and one day post-RFA (p > .05). Life-threatening complications did not develop in any of the patients.

CONCLUSION

RFA-treated PTMCs were smaller in size in patients with HT than in those with a healthy thyroid at 1 week of RFA. However, the exact mechanism underlying this phenomenon and its clinical significance warrant further investigation.

Comparison of clinicopathological features and prognosis of papillary thyroid carcinoma and microcarcinoma: A population-based propensity score matching analysis

BACKGROUND

Overtreatment of papillary thyroid microcarcinoma (PTMC) has become a common concern. This study aimed to compare clinicopathological features between PTMC and papillary thyroid carcinoma (PTC) and to explore whether surgery can confer significant survival benefits in all patients with PTC or PTMC.

METHODS

Data of 145,951 patients with PTC registered in Surveillance, Epidemiology, and End Results (SEER) database and 8,751 patients with PTC in our institution were retrospectively collected. Patients with tumors less than 10 mm in diameter were classified as PTMC cohort and the rest as PTC cohort. Clinicopathological features between PTMC and PTC were compared on the basis of SEER cohort and validated with institutional data. Survival analysis was conducted to explore the effect of surgery on the prognosis of patients. To minimize potential confounders and selection bias, we performed propensity score matching (PSM) analysis to match more comparable cohorts.

RESULTS

Compared with PTC, PTMC exhibited the following characteristics: more common in women and whites, older age at diagnosis, lower proportion of follicular variants, intraglandular dissemination, extraglandular and capsular invasion, higher proportion of multifocality, fewer lymph node and distant metastases, and higher cancer-specific survival (CSS) and overall survival (OS) (all p-value < 0.05). Regarding treatment, patients with PTMC received a lower proportion of radiotherapy, chemotherapy, and total thyroidectomy but a higher proportion of lobectomy and/or isthmectomy. There was no significant difference in CSS for patients with PTMC at stage T1N0M0 with or without surgery (P = 0.36).

CONCLUSION

Generally, PTMC showed higher biological indolence than PTC, which meant a higher survival rate for patients in both OS and CSS. For patients with PTMC at staged T1N0M0, active surveillance (AS) may be a potentially feasible management strategy. However, the maintenance of good medical compliance and the management of psychological burden cannot be ignored for patients included in AS.

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.

Cost-Effectiveness Analysis of Ultrasound Screening for Thyroid Cancer in Asymptomatic Adults

Objectives: This study evaluated the long-term cost-effectiveness of ultrasound screening for thyroid cancer compared with non-screening in asymptomatic adults.

Methods: Applying a Markov decision-tree model with effectiveness and cost data from literature, we compared the long-term cost-effectiveness of the two strategies: ultrasound screening and non-screening for thyroid cancer. A one-way sensitivity analysis and a probabilistic sensitivity analysis were performed to verify the stability of model results.

Results: The cumulative cost of screening for thyroid cancer was $18,819.24, with 18.74 quality-adjusted life years (QALYs), whereas the cumulative cost of non-screening was $15,864.28, with 18.71 QALYs. The incremental cost-effectiveness ratio of $106,947.50/QALY greatly exceeded the threshold of $50,000. The result of the one-way sensitivity analysis showed that the utility values of benign nodules and utility of health after thyroid cancer surgery would affect the results.

Conclusions: Ultrasound screening for thyroid cancer has no obvious advantage in terms of cost-effectiveness compared with non-screening. The optimized thyroid screening strategy for a specific population is essential.

Total thyroidectomy can be overtreatment in cN1a papillary thyroid carcinoma patients whose tumor is smaller than 1 cm

BACKGROUND

The 2015 American Thyroid Association (ATA) guidelines recommend pursuing total thyroidectomy with therapeutic central lymph-node dissection (CND) in patients with clinically apparent nodal disease (cN1a), regardless of tumor size. The aim of this study was to investigate whether total thyroidectomy is necessary for thyroid papillary microcarcinoma (PTMC) patients with preoperative unilateral cN1a.

METHODS

This study included 295 papillary thyroid microcarcinoma patients who underwent total thyroidectomy with bilateral CND from January 2012 to June 2015.

RESULTS

The median follow-up time was 42.5 months. Locoregional recurrence (LRR) was observed in only two (0.9%) patients. Among 70 cN1a patients, only 19 (27.1%) were at intermediate risk for disease recurrence and required total thyroidectomy per the ATA guidelines. Lobectomy can be considered as a treatment option for the remaining patients (72.9%).

CONCLUSIONS

Our study showed that more than two-thirds of PTMC patients with clinical nodal disease who underwent total thyroidectomy and CND were actually lobectomy candidates. Total thyroidectomy as the first surgical option for cN1a, especially in PTMC patients, should be reconsidered.

Ultrasound-guided thermal ablation for papillary thyroid microcarcinoma: a multicenter retrospective study

PURPOSE

Ultrasound-guided thermal ablation (including microwave ablation [MWA] and radiofrequency ablation [RFA]) has emerged as a remarkable technology for the treatment of benign and malignant diseases. The objective of this multicenter study was to assess the efficacy and safety of thermal ablation in a large cohort of patients with papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

Retrospective study of 725 patients who underwent MWA/RFA at 11 centers between March 2015 and March 2020. The mean age of patients was 46 ± 11 years (range, 22-81); the mean follow-up time was 21 ± 13 months (range, 6-60). Changes in size of tumor, the rates of tumor disappearance, disease progression, and complications were assessed.

RESULTS

From 6 months post-ablation, the size of tumors was significantly reduced compared with those recorded pre-ablation (p < 0.001 for all). Five hundred and fifteen (71.0%) PTMCs had completely disappeared as assessed by ultrasound examination. Six (0.8%) patients developed disease progression post-ablation; of these, 5 (0.7%) patients developed new PTMCs, while one (0.1%) patient developed cervical lymph node metastasis. Nineteen (2.6%) patients developed complications post-ablation; of these 14 (1.9%) patients developed voice hoarseness, 4 (0.6%) developed hematoma, and one (0.1%) patient developed cough.

CONCLUSIONS

Ultrasound-guided thermal ablation represents an effective and safe treatment for patients with PTMC besides active surveillance and surgery.

Terminology Change for Small Low-Risk Papillary Thyroid Cancer As a Response to Overtreatment: Results from Three Australian Community Juries

Background: The majority of small papillary thyroid cancers (sPTCs) are treated surgically, rather than by active surveillance. Patient and clinician preference for surgery may be partially driven by the use of cancer terminology. Some experts propose that changing terminology would better communicate the indolent nature of sPTCs and improve uptake of active surveillance. Others argue that terminology that includes "cancer" correctly reflects the biological nature of these tumors. The views of informed lay publics can provide value-based perspectives on complex issues and guide policy discussions. Methods: We recruited 40 people for three community juries, held in Sydney, Wodonga, and Cairns, Australia. Participants were of diverse backgrounds and ages, recruited through random digit dialing and a topic-blinded social media strategy. Juries were informed about thyroid cancer, overdiagnosis, and overtreatment, and heard arguments for and against terminology change before deliberation. The deliberative process in Jury 1 led to a refinement of jury charge, the updated version that was then used in Juries 2 and 3. Results: Jury 1 favored no terminology change, and Juries 2 and 3 were divided on the topic. Key reasons for opposing terminology change included a strong desire to retain terminology that aligns with the pathological definition of cancer, and to avoid even a minimal risk of harm that could arise if patients became complacent in follow-up. Key reasons to support terminology change included a desire to reduce psychological distress, stigma, and discrimination associated with a cancer diagnosis, and an argument that terminology change may be a more effective trigger for health system reform compared with other options. The juries unanimously recommended community education and health system reforms to reduce harms of overtreatment, and expressed an expectation that clinicians and researchers reach agreement on clinical guidelines to promote better uptake of active surveillance. Conclusions: The conceptual tension between a pathological and an outcome-based understanding of cancer was apparent in deliberation. This highlights an ongoing challenge for those advocating changing disease terminology. Regardless of action on terminology, jurors shared a strong expectation that practical changes would be made to respond to the harms of overtreatment.

Adoption of Active Surveillance for Very Low-Risk Differentiated Thyroid Cancer in the United States: A National Survey

CONTEXT

Active surveillance (AS) of thyroid cancer with serial ultrasounds is a newer management option in the United States.

OBJECTIVE

This work aimed to understand factors associated with the adoption of AS.

METHODS

We surveyed endocrinologists and surgeons in the American Medical Association Masterfile. To estimate adoption, respondents recommended treatment for 2 hypothetical cases appropriate for AS. Established models of guideline implementation guided questionnaire development. Outcome measures included adoption of AS (nonadopters vs adopters, who respectively did not recommend or recommended AS at least once; and partial vs full adopters, who respectively recommended AS for one or both cases).

RESULTS

The 464 respondents (33.3% response) demographically represented specialties that treat thyroid cancer. Nonadopters (45.7%) were significantly (P < .001) less likely than adopters to practice in academic settings, see more than 25 thyroid cancer patients/year, be aware of AS, use applicable guidelines (P = .04), know how to determine whether a patient is appropriate for AS, have resources to perform AS, or be motivated to use AS. Nonadopters were also significantly more likely to be anxious or have reservations about AS, be concerned about poor outcomes, or believe AS places a psychological burden on patients. Among adopters, partial and full adopters were similar except partial adopters were less likely to discuss AS with patients (P = .03) and more likely to be anxious (P = .04), have reservations (P = .03), and have concerns about the psychological burden (P = .009) of AS. Few respondents (3.2%) believed patients were aware of AS.

CONCLUSION

Widespread adoption of AS will require increased patient and physician awareness, interest, and evaluation of outcomes.

Association of Hyperparathyroidism and Papillary Thyroid Cancer: A Multicenter Retrospective Study

BACKGROUND

Concomitant papillary thyroid cancer (PTC) and hyperparathyroidism (HPT) have been reported in several studies. Our study aimed to investigate the incidence of concomitant PTC in HPT patients upon preoperative diagnosis and present a clinical opinion on detecting thyroid malignancy in case of parathyroidectomy.

METHODS

Patients who underwent parathyroidectomy between January 2009 and December 2019 in two medical centers were included. Of the 279 participants 154 were diagnosed as primary hyperparathyroidism (pHPT) and 125 as secondary hyperparathyroidism (sHPT). The incidence of concomitant PTC and its clinical characteristics were compared with 98 patients who underwent thyroidectomy and were diagnosed with classical PTC during the same period.

RESULTS

Concurrent PTC was detected in 14 patients (9.1%) with pHPT and in nine patients (7.2%) with sHPT. Ten (71.4%) and seven (77.8%) PTCs were microcarcinomas in the pHPT and sHPT cases respectively. In the pHPT patients, vitamin D was lower in the pHPT+PTC group (13.0±3.7 ng/mL) than in the pHPT-only group (18.5±10.4 ng/mL; P=0.01). Vitamin D levels were also lower in the sHPT+PTC group (12.3±5.6 ng/mL) than in the sHPT-only group (18.0±10.2 ng/mL; P=0.12). In the concomitant PTC group, lymph node ratio was higher than in the classical PTC group (P=0.00).

CONCLUSION

A high prevalence of concomitant PTC was seen in patients with pHPT and sHPT. Those concomitant PTCs were mostly microcarcinomas and had more aggressive features, suggesting that efforts should be made to detect concomitant malignancies in the preoperative parathyroidectomy evaluation.

2020 Chinese guidelines for ultrasound malignancy risk stratification of thyroid nodules: the C-TIRADS

Thyroid nodules are very common all over the world, and China is no exception. Ultrasound plays an important role in determining the risk stratification of thyroid nodules, which is critical for clinical management of thyroid nodules. For the past few years, many versions of TIRADS (Thyroid Imaging Reporting and Data System) have been put forward by several institutions with the aim to identify whether nodules require fine-needle biopsy or ultrasound follow-up. However, no version of TIRADS has been widely adopted worldwide till date. In China, as many as ten versions of TIRADS have been used in different hospitals nationwide, causing a lot of confusion. With the support of the Superficial Organ and Vascular Ultrasound Group of the Society of Ultrasound in Medicine of the Chinese Medical Association, the Chinese-TIRADS that is in line with China's national conditions and medical status was established based on literature review, expert consensus, and multicenter data provided by the Chinese Artificial Intelligence Alliance for Thyroid and Breast Ultrasound.

Active surveillance of low-risk papillary thyroid microcarcinomas

In 1993, active surveillance of low-risk papillary thyroid microcarcinomas (PTMCs) started in Kuma Hospital, Kobe, Japan. It has spread globally after the publishing of American Thyroid Association (ATA) guidelines. During our hospital's active surveillance program, few patients (8.0%) showed tumor size enlargement ≥3 mm or the new appearance of node metastasis (3.8%) at 10-year follow-up. Conversion surgery was recommended for patients with disease progression. To date, no patients showed significant recurrence or metastasis or died with thyroid carcinoma when patients underwent active surveillance or after surgery due to PTMC progression. Unlike clinical papillary thyroid carcinoma (PTC), elderly patients' PTMCs were less progressive compared to those of young and middle-aged patients, indicating that elderly patients are strong candidates for the active surveillance of their PTMC. Although young patients' PTMCs are the most progressive, >50% and >75% of patients in their 20s and 30s would avoid conversion surgical treatment in their lifetime, respectively (according to estimated lifetime probability), indicating that such young patients are still candidates for active surveillance. It can thus be concluded that active surveillance is appropriate to be first management for PTMCs, based on the accumulation of favorable outcomes of PTMC patients who have undergone active surveillance, as well as the lower incidences of unfavorable events and lower medical cost than immediate surgery.

Contemporary Thyroid Nodule Evaluation and Management

CONTEXT

Approximately 60% of adults harbor 1 or more thyroid nodules. The possibility of cancer is the overriding concern, but only about 5% prove to be malignant. The widespread use of diagnostic imaging and improved access to health care favor the discovery of small, subclinical nodules and small papillary cancers. Overdiagnosis and overtreatment is associated with potentially excessive costs and nonnegligible morbidity for patients.

EVIDENCE ACQUISITION

We conducted a PubMed search for the recent English-language articles dealing with thyroid nodule management.

EVIDENCE SYNTHESIS

The initial assessment includes an evaluation of clinical risk factors and sonographic examination of the neck. Sonographic risk-stratification systems (e.g., Thyroid Imaging Reporting and Data Systems) can be used to estimate the risk of malignancy and the need for biopsy based on nodule features and size. When cytology findings are indeterminate, molecular analysis of the aspirate may obviate the need for diagnostic surgery. Many nodules will not require biopsy. These nodules and those that are cytologically benign can be managed with long-term follow-up alone. If malignancy is suspected, options include surgery (increasingly less extensive), active surveillance or, in selected cases, minimally invasive techniques.

CONCLUSION

Thyroid nodule evaluation is no longer a 1-size-fits-all proposition. For most nodules, the likelihood of malignancy can be confidently estimated without resorting to cytology or molecular testing, and low-frequency surveillance is sufficient for most patients. When there are multiple options for diagnosis and/or treatment, they should be discussed with patients as frankly as possible to identify an approach that best meets their needs.

The Clinical Application of Core-Needle Biopsy after Radiofrequency Ablation for Low-risk Papillary Thyroid Microcarcinoma: A Large Cohort of 202 Patients Study

Purpose: To evaluate the clinical application of core-needle biopsy (CNB) for low-risk papillary thyroid microcarcinoma (PTMC) after radiofrequency ablation (RFA) Methods: A total of 202 patients with 211 low-risk PTMCs were included in this study. RFA procedure was used the hydrodissection technique and moving-shot technique. Patients were followed at 1, 3, 6, 12 months and every 6 months thereafter. The volume of ablation area and the volume reduction ratio (VRR) were calculated. At 3 or 6 months after RFA, CNB was performed to the central zone, the peripheral zone and surrounding thyroid parenchyma for post-ablation evaluation. Results: The mean volume of tumors was 102.34±93.84 mm³ (range 4.19-424.10 mm³), which decreased significantly to 1.37±7.74 mm³ (range 0-73.30 mm³) at a mean follow-up time of 24.42±9.15 months (range 3-42 months) with a mean VRR of 99.14±4.18% (range 71.88-100%). A total of 3 ablation areas had positive CNB in the peripheral zone and underwent additional RFA. No recurrent or suspicious metastatic lymph nodes were detected Conclusion: CNB is a feasible and effective evaluation for low-risk PTMC after RFA, which can detect residual cancer cells early.

Laser and radiofrequency ablations for benign and malignant thyroid tumors

A growing body of evidence is being published regarding the safety and efficacy of minimally invasive image-guided ablation techniques. While clinical applications of these techniques are increasing, international societies have started to publish treatment guidelines and to make efforts to standardize both terminology and reporting criteria for image-guided thyroid ablations. Laser ablation and radiofrequency ablation (RFA) are among the most common ablation techniques either for benign and malignant thyroid nodules. Unlike laser ablation and RFA in the treatment of benign thyroid nodules, where safety and efficacy have been widely demonstrated, evidence regarding local tumor control of thyroid malignancies is still limited. However, preliminary results are encouraging and image-guided thermal ablation techniques can be considered a valid alternative to surgery for the treatment of benign thyroid nodules and recurrent thyroid cancers. This review evaluates the basic concept of RFA and laser ablations, their techniques, clinical outcomes, and complications based on the suggestions of several society guidelines. Multidisciplinary collaboration remains critical to identify patients which may benefit from minimally invasive image-guided thermal ablations, especially if surgery or radioiodine therapy are not feasible options.

[Anxiety and depression in patients treated for differentiated thyroid microcarcinoma]

Introduction

Le microcarcinome de la thyroïde est un cancer de bon pronostic mais qui peut avoir un retentissement sur la qualité de vie des patients. L'objectif de l'étude est d'évaluer la dépression et l'anxiété chez les patients suivis pour microcarcinome différencié de la thyroïde et de les comparer aux autres stades du cancer.

Méthodes

Étude transversale observationnelle menée entre octobre 2013 et février 2015. L'étude a inclus les patients adultes suivis pour carcinome différencié de la thyroïde. La dépression et l'anxiété ont été évaluées en utilisant deux échelles de qualité de vie, dont la traduction a été validée en arabe: le Hamilton anxiété et Hamilton dépression. Les patients ont été répartis en deux groupes, un groupe microcarcinome de la thyroïde et un groupe non microcarcinome. L'analyse des données faite par le logiciel SPSS. 16.

Résultats

L'étude a concerné 37 patients suivis pour un microcarcinome différencié de la thyroïde, et un groupe de comparaison de 87 patients suivis pour autres stades de cancer différencié de la thyroïde. La qualité de vie des patients dans le groupe avec microcarcinome de la thyroïde était meilleure par rapport aux autres stades de carcinome différencié de la thyroïde. La présence de microcarcinome de la thyroïde était associée significativement à une absence d'anxiété (p = 0,042), une tendance positive a été notée sur le Hamilton dépression (mais p non significatif).

Conclusion

La qualité de vie des patients dans le groupe avec microcarcinome de la thyroïde était meilleure par rapport aux autres stades de carcinome différencié de la thyroïde. Ceci pouvant être expliqué par la non agressivité du traitement (absence de traitement par l'iode, et objectif de TSH plus souple).

Trends in nonoperative management of papillary thyroid microcarcinoma

BACKGROUND

In 2010, a Japanese trial of nonoperative management for papillary thyroid microcarcinomas (PTmC) was published. This study determines if the prevalence of nonoperative management in the United States has changed and if there are predictors of this approach.

METHODS

Patients treated for PTmC between 2004 and 2015 in the National Cancer Data Base were identified. Inclusion criteria were: classic or follicular variant papillary cancer histology, tumor size 1 to 10 mm, cN0 disease and no extrathyroidal extension or metastatic disease. Nonoperative management was assessed over time and compared between 2004-2010 and 2010-2015. Logistic regression identified factors associated with nonoperative management.

RESULTS

Of 65 381 PTmC patients, 344 (0.5%) were treated nonoperatively. The annual rate of nonoperative management was similar at 0.6% in 2004 to 0.4% in 2010 (P = .755) but increased to 0.9% in 2015 (P < .001). There was no difference in patient age, race, comorbidities, or reason for nonoperative management between the two periods. Academic centers managed more patients nonoperatively. Multivariable logistic regression suggests older age, facility type, location, Hispanic, Asian, and Native American ethnicity were associated with nonoperative management.

CONCLUSION

The vast majority of PTmC in the United States is treated with an operation. A small but significant increase in nonoperative management occurred between 2004-2010 and 2010-2015.

Low-risk papillary thyroid microcarcinoma: Optimal management toward a more conservative approach

The incidence of papillary thyroid microcarcinoma (microPTC) has dramatically increased in the last decades. Most of these tumors remain small and clinically "silent", only small number progress. Although thyroid surgery used to be the only therapeutic approach, recent guidelines now consider active surveillance for low-risk microPTC. For this reason, more accurate risk stratification of microPTC is needed. The optimal management of low-risk microPTC through accurate risk stratification represents a major clinical issue.

Fine-Needle Aspiration of Subcentimeter Thyroid Nodules in the Real-World Management

BACKGROUND

The Korea Thyroid Association published the revised guidelines for thyroid nodules in 2016. However, whether fine-needle aspiration is accurately performed based on indications and whether the results of this procedure are appropriately addressed according to clinical guidelines, particularly in subcentimeter nodules, are unclear.

METHODS

We retrospectively analyzed the fine-needle aspiration data of 331 thyroid nodules of patients who were referred to a tertiary hospital clinic for fine-needle aspiration. Each nodule was categorized according to ultrasonography findings based on the recommendations of the Korea Thyroid Association for fine-needle aspiration. Only nodules with a final pathological diagnosis of benign or malignant made using the Bethesda system were included.

RESULTS

Up to 32% of thyroid nodules that were not indicated for fine-needle aspiration were aspirated. Regarding subcentimeter nodules, only 28 of 123 (22.8%) aspirated nodules were indicated for fine-needle aspiration. Of the 49 malignant subcentimeter nodules, 33 (67.3%) underwent immediate surgery. Meanwhile, 14 (28.6%) nodules were lost to follow-up, and two (4.1%) were under active surveillance. Eighteen (36.7%) malignant subcentimeter nodules were not indicated for fine-needle aspiration but underwent surgical resection instead of active surveillance.

CONCLUSION

Despite the recommendations in the revised guidelines, several thyroid nodules that do not meet the indications for FNA are aspirated in real-world practice. To reduce overtreatment, a widespread knowledge of the correct indications for fine-needle aspiration is important in clinical practice, particularly for subcentimeter nodules.

Performance of a Multigene Genomic Classifier in Thyroid Nodules With Indeterminate Cytology: A Prospective Blinded Multicenter Study

Question

Can the diagnosis of benign disease or cancer in thyroid nodules with indeterminate cytology be established by molecular testing instead of diagnostic surgery?

Findings

This prospective, blinded, multicenter cohort study of a multigene genomic classifier (ThyroSeq v3) test included 257 indeterminate cytology thyroid nodules with informative test results. It demonstrated a high sensitivity (94%) and reasonably high specificity (82%), with 61% of the nodules yielding a negative test result and only 3% residual cancer risk in these nodules.

Meanings

Up to 61% of patients with indeterminate cytology thyroid nodules may avoid diagnostic surgery by undergoing multigene genomic classifier testing.

Importance

Approximately 20% of fine-needle aspirations (FNA) of thyroid nodules have indeterminate cytology, most frequently Bethesda category III or IV. Diagnostic surgeries can be avoided for these patients if the nodules are reliably diagnosed as benign without surgery.

Objective

To determine the diagnostic accuracy of a multigene classifier (GC) test (ThyroSeq v3) for cytologically indeterminate thyroid nodules.

Design, Setting, and Participants

Prospective, blinded cohort study conducted at 10 medical centers, with 782 patients with 1013 nodules enrolled. Eligibility criteria were met in 256 patients with 286 nodules; central pathology review was performed on 274 nodules.

Interventions

A total of 286 FNA samples from thyroid nodules underwent molecular analysis using the multigene GC (ThyroSeq v3).

Main Outcomes and Measures

The primary outcome was diagnostic accuracy of the test for thyroid nodules with Bethesda III and IV cytology. The secondary outcome was prediction of cancer by specific genetic alterations in Bethesda III to V nodules.

Results

Of the 286 cytologically indeterminate nodules, 206 (72%) were benign, 69 (24%) malignant, and 11 (4%) noninvasive follicular thyroid neoplasms with papillary-like nuclei (NIFTP). A total of 257 (90%) nodules (154 Bethesda III, 93 Bethesda IV, and 10 Bethesda V) had informative GC analysis, with 61% classified as negative and 39% as positive. In Bethesda III and IV nodules combined, the test demonstrated a 94% (95% CI, 86%-98%) sensitivity and 82% (95% CI, 75%-87%) specificity. With a cancer/NIFTP prevalence of 28%, the negative predictive value (NPV) was 97% (95% CI, 93%-99%) and the positive predictive value (PPV) was 66% (95% CI, 56%-75%). The observed 3% false-negative rate was similar to that of benign cytology, and the missed cancers were all low-risk tumors. Among nodules testing positive, specific groups of genetic alterations had cancer probabilities varying from 59% to 100%.

Conclusions and Relevance

In this prospective, blinded, multicenter study, the multigene GC test demonstrated a high sensitivity/NPV and reasonably high specificity/PPV, which may obviate diagnostic surgery in up to 61% of patients with Bethesda III to IV indeterminate nodules, and up to 82% of all benign nodules with indeterminate cytology. Information on specific genetic alterations obtained from FNA may help inform individualized treatment of patients with a positive test result.

Surgical approach to the substernal goiter

Surgery for substernal goiters can be technically demanding. Extensive mediastinal extension brings the thyroid gland into close quarters with vital intrathoracic structures. Proper preoperative planning is required to determine the potential need for an extracervical approach. Assessing the risk of requiring an extracervical approach is typically based on findings from cross-sectional imaging of the neck and chest. This article addresses the important anatomical considerations when resecting a large substernal goiter and also reviews various extracervical approaches.

Preliminary report of microwave ablation for the primary papillary thyroid microcarcinoma: a large-cohort of 185 patients feasibility study

PURPOSE

To assess the safety and efficacy of microwave ablation (MWA) for primary papillary thyroid microcarcinoma (PTMC) with a large sample of 185 patients.

METHODS

A total of 185 patients underwent MWA for 206 primary PTMC nodules. They received ultrasound follow-up at 1, 3, 6, and 12 months after MWA and every 6 months thereafter. Nodule volumes were calculated at each follow-up and compared with those before MWA. Additionally, the volume reduction rate (VRR) of the nodules was calculated. Patients' thyroid functions were tested before and 1 month after MWA.

RESULTS

The mean follow-up time of the 185 patients was 20.7 ± 8.8 months (range 12-36 months). During the follow-up period, the mean volume of the 206 nodules was 100.1 ± 92.9 mm³ (range 3.6-423.9) before MWA, which decreased to 2.2 ± 5.6 mm³ (range 0-20.3 mm³) after MWA (P = 0.000). The mean VRR of the nodules was 98.65 ± 3.60% after MWA (range 83.85-100%). One hundred and seventy four of 206 nodules (84.5%) were fully absorbed. Compared with the preoperative results, no significant variation in thyroid function was observed 1 month after MWA. Thirty-eight patients (20.5%) had different types of complications, ranging from minor to major. Five patients (2.7%) had hoarseness, 11 patients (5.9%) had bleeding, 21 patients (11.4%) had earache or toothache, and one patient had another lesion 1 month after MWA.

CONCLUSIONS

This preliminary study suggests that MWA is safe and effective in the treatment of primary PTMC and offers a new alternative for clinical treatment.

Can Active Surveillance be an Alternative to Surgery in Papillary Thyroid Microcarcinoma?: The Current Situation Worldwide

Papillary thyroid carcinoma is the most common endocrine malignancy. Papillary thyroid microcarcinomas (PTMCs) are tumors with a size of ≤1 cm. The biological behavior of these tumors differs due to the presence of their aggressive features. The prognosis of PTMCs with high-risk features, such as clinical node metastasis, distant metastasis, and significant extrathyroidal extension to the tracheal or recurrent laryngeal nerve invasion, is poor, even if a sufficient immediate surgery is performed at diagnosis. However, PTMCs without these aggressive features are low-risk tumors because of their indolent and slow growth behaviors. The increase in thyroid cancer incidence is mostly a result of overdiagnosis of small low-risk PTMCs with indolent clinical course. Despite the sudden increase in thyroid cancer incidence worldwide, cancer mortality did not increase. Although the traditional treatment strategy for PTMC is immediate surgery at diagnosis, because of the rather low disease-specific mortality rate, low recurrence rate, and potential risk for postoperative complications, active surveillance has been proposed recently as an alternative option for PTMCs without invasion, metastasis, or cytological or molecular characteristics. The recent data support that active surveillance of low-risk PTMC should be the initial treatment modality, because only a small percentage of low-risk PTMCs show signs of progression, and delayed surgery has not caused significant recurrence. However, recent management guidelines are shifting toward more conservative treatments, such as active surveillance. Although there is an increase in the number of studies related to active surveillance, prospective studies have been mostly from academic referral centers in Japan. The world still needs class 1 evidence extended prospective studies originating from different geographic regions. Active surveillance may be a good alternative to immediate surgery for appropriately selected patients with PTMC.

Implementing Key Changes in the American Thyroid Association 2015 Thyroid Nodules/Differentiated Thyroid Cancer Guidelines Across Practice Types

OBJECTIVE

This article provides suggestions to help clinicians implement important changes in the 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma ("ATA 2015") across diverse settings.

METHODS

Key ATA 2015 changes are summarized regarding: ( 1) thyroid nodule management; ( 2) lobectomy versus thyroidectomy for differentiated thyroid carcinoma (DTC); and ( 3) surveillance following primary treatment of DTC. Advice to facilitate implementation is based on clinical experience and selected literature.

RESULTS

Strategies are described to enhance acquisition of high-quality information that helps identify patients who may possibly avoid fine-needle aspiration (FNA) of thyroid nodules or total thyroidectomy for DTC, or undergo less intense postoperative surveillance. Sonographic imaging of nodules may improve if sonograms are obtained by clinicians ordering or performing FNA or trusted high-volume sonographers. Cytopathologic assessment and reporting can be improved by working with regional or national experts. Pre-operative evaluation by endocrinologists is important so that patients are referred to experienced, proficient surgeons and assisted with well-informed decision-making regarding surgical radicality. Endocrinologists and surgeons should ensure performance of pre-operative neck ultrasonography, voice/laryngeal evaluation, and contrast-enhanced cross-sectional imaging when appropriate. Findings should be disseminated to all healthcare team members, ideally through a comprehensive medical record accessible to the entire team.

CONCLUSION

Optimization of the sequence of specialist visits and assembly of interactive multidisciplinary teams coupled with intensified interdisciplinary and patient communication may enable clinicians to more effectively implement ATA 2015, which calls for more individualized, and often, less "invasive" management of thyroid nodules and DTC.

ABBREVIATIONS

ATA 2009 = 2009 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma; ATA 2015 = 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma; DTC = differentiated thyroid carcinoma; FNA = fine-needle aspiration; PET/CT = positron emission tomography/computed tomography.

Percutaneous laser ablation for benign and malignant thyroid diseases

Minimally invasive image-guided thermal ablation is becoming increasingly common as an alternative to surgery for the treatment of benign thyroid nodules. Among the various techniques for thermal ablation, laser ablation (LA) is the least invasive, using the smallest applicators available on the market and enabling extremely precise energy deposition. However, in some cases, multiple laser fibers must be used simultaneously for the treatment of large nodules. In this review, the LA technique is described, and its main clinical applications and results are discussed and illustrated.

Predictive factors of lateral lymph node metastasis in solitary papillary thyroid microcarcinoma without gross extrathyroidal extension

BACKGROUND

Solitary papillary thyroid microcarcinoma (PTMC) without gross extrathyroidal extension (ETE) were the main candidates for active surveillance (AS). Predictive factors of lateral lymph node metastasis (LLNM) in solitary PTMC without gross ETE were essential but still unknown.

METHODS

Altogether, 171 patients of solitary PTMC without gross ETE were enrolled in our study and divided into two groups. Group A: 123 patients without lateral lymph node dissection (LLND) were considered to be LLNM negative because there was no lateral recurrence by at least 8-year follow up for all patients. Group B: 48 patients with LLND were considered to be LLNM positive which confirmed by postoperative pathology.

RESULTS

Multivariate logistic regression showed male gender, upper location of tumor and diameter of tumor ≥7 mm to be predictive factors (odds ratio = 4.237 [confidence interval (CI) 1.365-13.149, p = 0.012; odds ratio = 2.933 [CI 1.117-7.700, p = 0.029; odds ratio = 4.557 [CI 1383-15.016, p = 0.013) for LLNM in solitary PTMC patients without gross ETE. Multiple level metastasis happened in 29 (60.42%) cases while single level metastasis in 19 (39.58%). Within the lateral cervical lymph node chain, level Ⅲ nodes were consistently the most frequently involved (38/48, 79%), following by level Ⅳ (27/48, 56%), level Ⅱ (25/48, 52%) and level V (5/48, 10%). Most interesting, there are 12 (12/48, 25%) skip metastatic (positive in lateral neck and negative in central neck) patients among LLNM positive group.

CONCLUSIONS

Male gender, upper location of tumor and diameter of tumor ≥0.7 cm to be predictive factors of LLNM in solitary PTMC without gross ETE.

How to handle borderline/precursor thyroid tumors in management of patients with thyroid nodules

Thyroid carcinomas originating from follicular cells have the prognosis of heterogeneous diseases, but pathologists classify them all as malignant disease. Epidemiologists have issued a stern warning regarding over-diagnosis and overtreatment of patients with indolent thyroid tumors that cause no harm to the patients. Review of the literature revealed that there were several proposals of borderline/precursor tumors to some indolent thyroid carcinomas. Thyroid tumor of uncertain malignant potential (UMP) was first proposed by Williams for encapsulated follicular pattern thyroid tumors to solve problems due to observer variation. Rosai et al. proposed to rename papillary microcarcinoma (PMC) to papillary micro-tumor as the overwhelming majority of them are of no clinical significance. Liu et al. proposed well-differentiated tumor with uncertain behavior (WDT-UB) which covered WDT of UMP (WDT-UMP) and non-invasive encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC). The EFVPTC without invasion was renamed as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) by an international panel of pathologists. A new prognostic classification of thyroid tumors was proposed by Kakudo et al., in which extremely low risk tumors were grouped in a borderline tumors category. The borderline/precursor thyroid tumors included encapsulated tumors [capsular invasion only follicular carcinoma, encapsulated papillary carcinoma without invasion, WDT-UMP and follicular tumor of UMP (FT-UMP)] and non-encapsulated tumors (PMC). The UMP and NIFTP were incorporated in the 4th edition WHO classification of thyroid tumors as a new tumor entity in chapter 2-2A: other encapsulated follicular patterned thyroid tumors. Their behavior codes were decided to be 1 (borderline or uncertain behavior), and not 0 (benign), 2 (in situ carcinoma) or 3 (malignant). These borderline/precursor thyroid tumors are indolent tumors biologically and should be treated more conservatively than as previously recommended for thyroid follicular cell carcinomas [total thyroidectomy (TTX) followed by radio-active iodine (RAI) treatment] by western clinical guidelines.

Circulating BRAFV600E Levels Correlate with Treatment in Patients with Thyroid Carcinoma

BACKGROUND

BRAF^V600E is the most common mutation in papillary thyroid carcinoma (PTC) and can be associated with aggressive disease. Previously, a highly sensitive blood RNA-based BRAF^V600E assay was reported. The objective of this study was to assess the correlation of BRAF^V600E circulating tumor RNA levels with surgical and medical treatment.

METHODS

Circulating BRAF^V600E levels were assessed in (i) a murine model of undifferentiated (anaplastic) thyroid carcinoma with known BRAF^V600E mutation undergoing BRAF^V600E-inhibitor (BRAFi) treatment, and (ii) in 111 patients enrolled prior to thyroidectomy (n = 86) or treatment of advanced recurrent or metastatic PTC (n = 25). Blood samples were drawn for BRAF^V600E analysis before and after treatment. Testing characteristics were assessed and positivity criteria optimized. Changes in blood BRAF^V600E values were assessed and compared to clinical characteristics and response to therapy.

RESULTS

In a murine model of anaplastic thyroid carcinoma with BRAF^V600E mutation, blood BRAF^V600E RNA correlated with tumor volume in animals treated with BRAFi. In tissue BRAF^V600E-positive (n = 36) patients undergoing initial surgery for PTC, blood BRAF^V600E levels declined postoperatively (median 370.0-178.5 fg/ng; p = 0.002). In four patients with metastatic or poorly differentiated thyroid carcinoma receiving targeted therapies, blood BRAF^V600E declined following therapy and corresponded with radiographic evidence of partial response or stable disease.

CONCLUSIONS

This study shows the correlation of blood BRAF^V600E levels in response to treatment in both an established animal model of thyroid cancer and in patients with BRAF^V600E-positive tumors with all stages of disease. This assay represents an alternative biomarker in patients with positive thyroglobulin antibodies, and tumors, which do not express thyroglobulin.

Long-term efficacy of ultrasound-guided low power microwave ablation for the treatment of primary papillary thyroid microcarcinoma: a 3-year follow-up study

PURPOSE

To evaluate the safety and efficacy of ultrasound-guided low-power microwave ablation (MWA) for the treatment of papillary thyroid microcarcinoma (PTMC) with a 3-year follow-up.

METHODS

A total of 21 nodules diagnosed as PTMC from the 15 patients were performed with MWA at a power of 20 W. The images of the nodules were recorded by ultrasound before MWA and 1, 3, 6, 12 months after MWA, and every 6 months thereafter, respectively. The volumes of the nodules were compared before MWA and at each follow-up point after MWA. The volume reduction rate (VRR) of nodules was also calculated.

RESULTS

The mean volume of the nodules was 134.3 ± 129.8 mm³ initially (the range was 7.4-423.8 mm³), which decreased significantly to 2.3 ± 10.5 mm³ (the range was 0-48.1 mm³) of the ablation area (P = 0.000) at the follow-up point of 36 months with a mean VRR as 98.78 ± 5.61% (the range was 74.28-100%). During the follow-up period (the range was 36-48 months), 20 of the 21 nodules were completely absorbed and no recurrent nodule was found.

CONCLUSIONS

After a long-term follow-up of 3 years, the low power MWA showed a good safety and efficacy for the treatment of PTMC. In addition to surgery and active surveillance, MWA might be another alternative for patients with PTMC.

Preoperative information for thyroid surgery

The preoperative information necessary to communicate to the patient to obtain informed consent in thyroid surgery is not detailed in length in the current medical literature. Advances in technology and the advent of remote access approaches in thyroid surgery have increased the need for a detailed communication of risks, benefits and alternatives to achieve an informed consent. In this review article, we outline the indications for thyroid surgery, risks of thyroid surgery, different approaches to thyroidectomy, and possible consequences of using advanced technology using intraoperative nerve monitoring (IONM) as an example. A truly detailed informed consent in the modern age of thyroid surgery is crucial. This article not only details the risks, benefits and alternatives of thyroid surgery, but also incorporates new practices, guidelines and technologies to allow patients to achieve a comprehensive preoperative understanding of treatment recommendations.

Problematic clinical trials in thyroid cancer: the issue of papillary carcinoma and observational approaches

We describe the clinical ethics problem of American thyroid cancer patients being offered ‘observation’ instead of the USA standard of care with questionable informed consent. This problem arose because some American practitioners misinterpreted 1990s Japanese studies. American proponents of these studies failed to recognize major differences in ethical oversight between Japanese and US clinical research, misrepresenting these studies as justifying clinical practices for higher risk patients that were not supported by data. The current professional environment in American thyroid cancer management is sufficiently problematic that consideration should be made, for patients who have inadvertently consented to nonevidence-based treatments, to be recontacted and provided an opportunity to revisit their care plans or seek second opinions regarding an observational approach.

Controversies in the Management of Low-Risk Differentiated Thyroid Cancer

Controversy exists over optimal management of low-risk differentiated thyroid cancer. This controversy occurs in all aspects of management, including surgery, use of radioactive iodine for remnant ablation, thyroid hormone supplementation, and long-term surveillance. Limited and conflicting data, treatment paradigm shifts, and differences in physician perceptions contribute to the controversy. This lack of physician consensus results in wide variation in patient care, with some patients at risk for over- or undertreatment. To reduce patient harm and unnecessary worry, there is a need to design and implement studies to address current knowledge gaps.

Clinical outcomes after delayed thyroid surgery in patients with papillary thyroid microcarcinoma

OBJECTIVE

Active surveillance is an option for patients with papillary thyroid microcarcinoma (PTMC). However, the long-term clinical outcomes after delayed surgery remain unclear. We compared the long-term clinical outcomes of PTMC patients according to the time interval between initial diagnosis and surgery.

DESIGN AND METHODS

In this individual risk factor-matched cohort study, PTMC patients were classified into three groups according to the delay period: ≤6 months, 6-12 months and >12 months. Patients were matched by age, sex, extent of surgery, initial tumor size as measured by ultrasonography (US), and by the presence of extrathyroidal extension, multifocal tumors and central cervical lymph node metastasis. We compared the dynamic risk stratification (DRS) and the development of structural persistent/recurrent disease of patients.

RESULTS

A total of 2863 patients were assigned to three groups. Their mean age was 50 years, 81% were female and 66% underwent lobectomy. The mean tumor size at the initial US was 0.63 cm. There were no significant differences in clinicopathological characteristics between groups after individual risk factor matching. Comparison of the DRS revealed no significant difference according to the delay period (P = 0.07). During the median 4.8 years of follow-up, there were no significant differences in the development of structural recurrent/persistent disease (P = 0.34) and disease-free survival (P = 0.25) between groups.

CONCLUSIONS

In PTMC patients, delayed surgery was not associated with higher risk of structural recurrent/persistent disease compared to immediate surgery. These findings support the notion that surgical treatment can be safely delayed in patients with PTMC under close monitoring.

Evaluation of ultrasound reporting for thyroid cancer diagnosis and surveillance

BACKGROUND

Despite the importance of ultrasound imaging in thyroid disease care, ultrasound reports vary greatly in the features described. It is essential that ultrasound reports contain and present all components necessary for a clinical decision in a reader-friendly format.

METHODS

One hundred ninety thyroid and neck ultrasound reports were scored using the universal ultrasound report template developed by Su et al, along with the American Thyroid Association (ATA) and the American Association of Clinical Endocrinologists/Associazione Medici Endocrinologi/European Thyroid Association (AACE/AME/ETA) guidelines. All ultrasounds were performed on patients seen between August and November 2015 by a single surgeon (M.L.U), and originated from a variety of physicians and institutions.

RESULTS

An average of 30.9% of Su et al's criteria was satisfactorily included in the reports. Similar results were reached when the ATA and the AACE/AME/ETA guidelines were applied as scoring templates.

CONCLUSION

Our results reveal the wide variation in ultrasound reporting. The standardization of ultrasound reporting would help to improve physicians' ability to properly diagnose and manage patients with thyroid disease.

Clinicians' Views on Management and Terminology for Papillary Thyroid Microcarcinoma: A Qualitative Study

BACKGROUND

There is growing acceptance that the increase in thyroid cancer incidence is in part a result of overdiagnosis of small low-risk papillary microcarcinomas (PMCs) with indolent clinical course. Although surgery is the cornerstone treatment for patients with PMCs, recent management guidelines are shifting toward inclusion of more conservative treatments such as active surveillance. There is little evidence on clinicians' experience in managing PMC patients and their attitudes toward treatment options, including their willingness to accept a nonsurgical option. The aim of this study was to understand how clinicians perceive a diagnosis of PMC, potential changes to terminology, and the treatment options available to patients.

METHODS

This was a qualitative study using semi-structured interviews conducted between November 2015 and May 2016 with 22 clinicians (seven endocrinologists and 15 thyroid surgeons). Transcribed audio-recordings were thematically coded, and a framework method was used to analyze the data.

RESULTS

Across a sample of clinicians who manage thyroid cancer patients, awareness of overdiagnosis and overtreatment of PMC was common. However, there was little acceptance of active surveillance to manage these patients. Clinicians did not feel comfortable recommending this management approach, as they were worried about the risk of metastases, did not feel that evidence to support this approach was strong enough, and also believed that patients currently have a high preference for surgery. The majority of clinicians did not believe that changing the terminology of this diagnosis was a viable strategy to reduce patients' anxiety and their perceived preference for more aggressive treatments. However, most clinicians felt that thyroid nodules <1 cm should not be biopsied, which could help minimize the risk of overdiagnosis of PMC.

CONCLUSIONS

This study, based on a non-representative sample of 22 clinicians, which remains an important limitation, provides revealing insight into clinicians' management preferences and decision making for small low-risk thyroid cancers at a time when management guidelines and practices are evolving. It suggests that clinicians may not be ready to accept nonsurgical options, or changes in terminology, until evidence to support these options and changes is stronger.

Oncogenic BRAF disrupts thyroid morphogenesis and function via twist expression

Thyroid cancer is common, yet the sequence of alterations that promote tumor formation are incompletely understood. Here, we describe a novel model of thyroid carcinoma in zebrafish that reveals temporal changes due to BRAF^V600E. Through the use of real-time in vivo imaging, we observe disruption in thyroid follicle structure that occurs early in thyroid development. Combinatorial treatment using BRAF and MEK inhibitors reversed the developmental effects induced by BRAF^V600E. Adult zebrafish expressing BRAF^V600E in thyrocytes developed invasive carcinoma. We identified a gene expression signature from zebrafish thyroid cancer that is predictive of disease-free survival in patients with papillary thyroid cancer. Gene expression studies nominated TWIST2 as a key effector downstream of BRAF. Using CRISPR/Cas9 to genetically inactivate a TWIST2 orthologue, we suppressed the effects of BRAF^V600E and restored thyroid morphology and hormone synthesis. These data suggest that expression of TWIST2 plays a role in an early step of BRAF^V600E-mediated transformation.

DOI:http://dx.doi.org/10.7554/eLife.20728.001