Experience with Active Surveillance of Thyroid Low-Risk Carcinoma in a Developing Country

Long-term comparison of image-guided thermal ablation vs. lobectomy for solitary papillary thyroid microcarcinoma: a multi-center retrospective cohort study

BACKGROUND

Image-guided thermal ablation has been applied in patients with papillary thyroid microcarcinoma (PTMC) who refuse surgery or active surveillance. However, evidence to support ablation is limited by single-center designs and a lack of long-term data. The purpose of this study was to compare long-term outcomes between ablation and lobectomy for patients with solitary PTMC.

MATERIALS AND METHODS

This multi-center retrospective study included 1021 consecutive patients with solitary PTMC who underwent ablation ( n =444) or lobectomy ( n =577) at the four university-affiliated hospitals. The primary outcomes were disease progression [lymph node metastasis (LNM), recurrent tumors, persistent tumors and distant metastasis] and disease-free survival (DFS). Secondary outcomes were complications, hospitalization, procedure time, estimated blood loss and cost. The two groups were compared using propensity score matching.

RESULTS

After matching, no significant differences were observed in disease progression (4.7% vs. 3.4%, P =0.307), LNM (1.6% vs. 1.6%, P =1.000), recurrent tumors (2.9% vs. 1.8%, P =0.269), persistent tumors(0.2% vs. 0%, P =0.317) and DFS (95.5% vs. 97.1%, P =0.246) between the ablation and lobectomy groups during the median follow-up of 96.5 months. The ablation group had significantly lower complication rates (0.7% vs. 5.2%, P <0.001), shorter post-treatment hospitalization {median [interquartile range (IQR)], 0 vs. 4.0 [3.0] days, P <0.001}, shorter procedure time [8.5 (2.8) vs. 90.0 (43.8) min, P <0.001], reduced estimated blood loss [0 vs. 20.0 (10.0) ml, P <0.001], and lower cost [$1873.2 (254.0) vs. $2292.9 (797.8), P <0.001] than the lobectomy group.

CONCLUSIONS

This study revealed comparable disease progression and survival outcomes between ablation and lobectomy for solitary PTMC. Imaged-guided thermal ablation could be effective and safe alternatives to lobectomy for properly selected patients with PTMC.

Implementing active surveillance for low-risk thyroid carcinoma into clinical practice: collaborative recommendations for Latin America

The incidence of thyroid cancer is increasing globally, but mortality rates have remained steady. Many patients with thyroid cancer have low-risk, nonmetastatic intrathyroidal tumors smaller than 2 cm. Active surveillance has shown benefits in these patients, but the adoption of this approach remains below standard in Latin America. The purpose of this article is to identify ways to improve the incorporation of active surveillance into clinical practice for patients with low-risk thyroid carcinoma in Latin America, taking into consideration cultural and geographic factors. Current recommendations include three steps involving patient participation. The first step, which consists of the initial clinical examination, has eight factors requiring special attention. Anxiety must be managed while considering individual, disease-related, cognitive, and environmental aspects. Terms like "overdiagnosis", "incidentaloma," and "overtreatment" must be explained to the patient. Implementing precise terminology contributes to adequate disease perception, substantially reducing stress and anxiety. Clarifying the nonprogressive nature of thyroid cancer helps dispel myths surrounding the disease. The second step includes advice about procedures and guidelines for patients who choose active surveillance. Flexible monitoring techniques should be implemented, with regular check-ins scheduled based on patient needs. Reasons for adjusting treatment must be clearly communicated to the patient, and changes in preference regarding active surveillance should be considered in advance. The third step includes assistance during follow-up. Patients must be educated about ultrasound results and receive surgical indications from specialized physicians. The effectiveness of active surveillance can be reinforced by explaining to the patients the dynamics of changes in nodule size using clear and concise visual aids.

Diagnostic Accuracy of Preoperative Radiologic Findings in Papillary Thyroid Microcarcinoma: Discrepancies with the Postoperative Pathologic Diagnosis and Implications for Clinical Outcomes

BACKGRUOUND

The diagnostic accuracy of preoperative radiologic findings in predicting the tumor characteristics and clinical outcomes of papillary thyroid microcarcinoma (PTMC) was evaluated across all risk groups.

METHODS

In total, 939 PTMC patients, comprising both low-risk and non-low-risk groups, who underwent surgery were enrolled. The preoperative tumor size and lymph node metastasis (LNM) were evaluated by ultrasonography within 6 months before surgery and compared with the postoperative pathologic findings. Discrepancies between the preoperative and postoperative tumor sizes were analyzed, and clinical outcomes were assessed.

RESULTS

The agreement rate between radiological and pathological tumor size was approximately 60%. Significant discrepancies were noted, including an increase in tumor size in 24.3% of cases. Notably, in 10.8% of patients, the postoperative tumor size exceeded 1 cm, despite being initially classified as 0.5 to 1.0 cm based on preoperative imaging. A postoperative tumor size >1 cm was associated with aggressive pathologic factors such as multiplicity, microscopic extrathyroidal extension, and LNM, as well as a higher risk of distant metastasis. In 30.1% of patients, LNM was diagnosed after surgery despite not being suspected before the procedure. This group was characterized by smaller metastatic foci and lower risks of distant metastasis or recurrence than patients with LNM detected both before and after surgery.

CONCLUSION

Among all risk groups of PTMCs, a subset showed an increase in tumor size, reaching 1 cm after surgery. These cases require special consideration due to their association with adverse clinical outcomes, including an elevated risk of distant metastasis.

A Preliminary Study on the Microwave Ablation of Multifocal Papillary Thyroid Microcarcinoma

RATIONALE AND OBJECTIVES

To evaluate the feasibility, efficiency, and safety of microwave ablation (MWA) for multifocal papillary thyroid microcarcinoma (PTMC).

METHODS

This was a retrospective study, and the data of patients who underwent MWA for multifocal PTMC from October 2016 to December 2021 were reviewed. After ablation, the changes in tumor size and volume, as well as the rates of technical success, tumor disappearance, disease progression, and complications, were assessed. According to the tumor location, the cases were further divided into a unilateral multifocal disease (UMD) subgroup and a bilateral multifocal disease (BMD) subgroup. Further analyses were carried out.

RESULTS

There was a total of 94 cases enrolled in the present study, which included 24 males and 70 females. The median age was 40 years (22-66 years); the median follow-up time was 14 months (6-48 months). Complete ablation was achieved in all enrolled cases. Therefore, the technical success rate was 100%. Due to expanding ablation, the MD and volume of the ablation zone increased at the 1st and 3rd months after ablation and decreased from the 12th month after ablation (p < 0.05 for all). The total complete tumor disappearance rates were 45/94 (47.87%) overall, 40.625% (13/32) in the UMD subgroup and 51.61% (32/62) in the BMD subgroup (p = 0.312). The total disease progression rates were 4.26% (4/94) overall, 6.25% (2/32) in the UMD subgroup and 3.23% (2/62) in the BMD subgroup (p = 0.881). The overall complication rate was 4.26% (4/94).

CONCLUSION

This preliminary study indicates that MWA is a safe and effective treatment for multifocal PTMC.

Decision Regret Following the Choice of Surgery or Active Surveillance for Small, Low-Risk Papillary Thyroid Cancer: A Prospective Cohort Study

Background: It is important to understand cancer survivors' perceptions about their treatment decisions and quality of life. Methods: We performed a prospective observational cohort study of Canadian patients with small (<2 cm) low-risk papillary thyroid cancer (PTC) who were offered the choice of active surveillance (AS) or surgery (Clinicaltrials.gov NCT03271892). Participants completed a questionnaire one year after their treatment decision. The primary intention-to-treat analysis compared the mean decision regret scale total score between patients who chose AS or surgery. A secondary analysis examined one-year decision regret score according to treatment status. Secondary outcomes included quality of life, mood, fear of disease progression, and body image perception. We adjusted for age, sex, and follow-up duration in linear regression analyses. Results: The overall questionnaire response rate was 95.5% (191/200). The initial treatment choices of respondents were AS 79.1% (151/191) and surgery 20.9% (40/191). The mean age was 53 years (standard deviation [SD] 15 years) and 77% (147/191) were females. In the AS group, 7.3% (11/151) of patients crossed over to definitive treatment (two for disease progression) before the time of questionnaire completion. The mean level of decision regret did not differ significantly between patients who chose AS (mean 22.4, SD 13.9) or surgery (mean 20.9, SD 12.2) in crude (p = 0.730) or adjusted (p = 0.29) analyses. However, the adjusted level of decision regret was significantly higher in patients who initially chose AS and crossed over to surgery (beta coefficient 10.1 [confidence interval; CI 1.3-18.9], p = 0.02), compared with those remaining under AS. In secondary adjusted analyses, respondents who chose surgery reported that symptoms related to their cancer or its treatment interfered with life to a greater extent than those who chose AS (p = 0.02), but there were no significant group differences in the levels of depression, anxiety, fear of disease progression, or overall body image perception. Conclusions: In this study of patients with small, low-risk PTC, the mean level of decision regret pertaining to the initial disease management choice was relatively low after one year and it did not differ significantly for respondents who chose AS or surgery.

Clinical and molecular features of progressive papillary thyroid microcarcinoma

In recent decades, the prevalence of thyroid cancer has risen substantially, with papillary thyroid microcarcinoma (PTMC) constituting over 50% of cases. Although most PTMCs exhibit indolent growth and a favorable prognosis, some present an increased risk of recurrence and an unfavorable prognosis due to high-risk characteristics such as lymph node metastasis, extrathyroidal extension, and distant metastasis. The early identification of clinically progressing PTMC remains elusive. In this review, the authors summarize findings from PTMC progression-related literature, highlighting that factors such as larger tumor size, cervical lymph node metastasis, extrathyroidal extension, younger age, higher preoperative serum thyroid-stimulating hormone levels, family history, and obesity positively correlate with PTMC progression. The role of multifocality in promoting PTMC progression; however, remains contentious. Furthermore, recent studies have shed light on the impact of mutations, such as BRAF and TERT mutations, on PTMC progression. Researchers have identified several mRNAs, noncoding RNAs, and proteins associated with various features of PTMC progression. Some studies propose that peripheral and tumor tissue-infiltrating immune cells could serve as biomarkers for the clinical progression of PTMC. Collectively, these clinical and molecular features offer a rationale for the early detection and the development of precision theranostic strategies of clinically progressive PTMC.

Tumor volume-doubling rate is negatively associated with patient age in papillary thyroid microcarcinomas under active surveillance

BACKGROUND

Active surveillance of low-risk papillary thyroid microcarcinomas has gained popularity worldwide as a management strategy. We previously reported that young age was associated with tumor enlargement by ≥3 mm. Here, we used the tumor volume-doubling rate to study the age-related tumor volume dynamics of papillary thyroid microcarcinomas under active surveillance.

METHODS

Between 2005 and 2019, 2,896 patients diagnosed with low-risk papillary thyroid microcarcinomas underwent active surveillance. We excluded patients who underwent ultrasound examination fewer than 4 times, had coexisting Graves' disease, or were treated with levothyroxine at the time of diagnosis, and we enrolled 2,129 patients for this study. We divided them into 3 subsets based on the age at diagnosis: young (<40 years), middle-aged (40-59 years), and elderly (≥60 years). The tumor volume-doubling rate was calculated based on ultrasound-derived tumor sizes and the respective examination date for each patient.

RESULTS

Overall, 140 patients (6.6%) had moderate or rapid growth (tumor volume-doubling rate ≥0.3/year), and the incidence significantly decreased with advanced age (P < .01): 11.3%, 7.1%, and 5.0% in the young, middle-aged, and elderly groups, respectively. Tumor regression (tumor volume-doubling rate <0/year) was detected in 1,200 patients (56.4%), and the incidence significantly increased with age (P < .01): 44.6%, 55.3%, and 60.0% in the young, middle-aged, and elderly groups, respectively. On multivariate analysis, both the ≥60 years and 40 to 59 years age groups were independent negative predictors of papillary thyroid microcarcinoma enlargement and positive predictors of tumor regression.

CONCLUSION

Tumor volume-doubling rate analysis demonstrated that the incidence of tumor enlargement decreased and that of tumor regression increased with advancing age in patients with papillary thyroid microcarcinomas.

Active Surveillance for Low-Risk Papillary Thyroid Carcinoma as an Acceptable Management Option with Additional Benefits: A Comprehensive Systematic Review

BACKGRUOUND

Active surveillance (AS) has been introduced as a management strategy for low-risk papillary thyroid carcinoma (PTC) due to its typically indolent nature. Despite this, the widespread adoption of AS has encountered several challenges. The aim of this systematic review was to evaluate the safety of AS related to disease progression and its benefits compared with immediate surgery (IS).

METHODS

Studies related to AS in patients with low-risk PTC were searched through the Ovid MEDLINE, Embase, Cochrane Library, and KoreaMed databases. Studies on disease progression, surgical complication, quality of life (QoL), and cost-effectiveness were separately analyzed and narratively synthesized.

RESULTS

In the evaluation of disease progression, the proportions of cases with tumor growth ≥3 mm and a volume increase >50% were 2.2%-10.8% and 16.0%-25.5%, respectively. Newly detected lymph node metastasis was identified in 0.0%-1.4% of patients. No significant difference was found between IS and delayed surgery in surgical complications, including vocal cord paralysis and postoperative hypoparathyroidism. AS was associated with better QoL than IS. Studies on the cost-effectiveness of AS reported inconsistent data, but AS was more cost-effective when quality-adjusted life years were considered.

CONCLUSION

AS is an acceptable management option for patients with low-risk PTC based on the low rate of disease progression and the absence of an increased mortality risk. AS has additional benefits, including improved QoL and greater QoL-based cost-effectiveness.

Active Surveillance for Low-Risk Thyroid Cancers: A Review of Current Practice Guidelines

The indolent nature and favorable outcomes associated with papillary thyroid microcarcinoma have prompted numerous prospective studies on active surveillance (AS) and its adoption as an alternative to immediate surgery in managing low-risk thyroid cancer. This article reviews the current status of AS, as outlined in various international practice guidelines. AS is typically recommended for tumors that measure 1 cm or less in diameter and do not exhibit aggressive subtypes on cytology, extrathyroidal extension, lymph node metastasis, or distant metastasis. To determine the most appropriate candidates for AS, factors such as tumor size, location, multiplicity, and ultrasound findings are considered, along with patient characteristics like medical condition, age, and family history. Moreover, shared decision-making, which includes patient-reported outcomes such as quality of life and cost-effectiveness, is essential. During AS, patients undergo regular ultrasound examinations to monitor for signs of disease progression, including tumor growth, extrathyroidal extension, or lymph node metastasis. In conclusion, while AS is a feasible and reliable approach for managing lowrisk thyroid cancer, it requires careful patient selection, effective communication for shared decision-making, standardized follow-up protocols, and a clear definition of disease progression.

Recommend with caution: A meta-analysis investigating papillary thyroid carcinoma tumor progression under active surveillance

BACKGROUND

Papillary thyroid carcinoma (PTC) is an indolent disease with favorable outcomes. The non-surgical treatment approach known as active surveillance (AS) has been introduced as an alternative treatment instead of the traditional thyroidectomy. However, 10-15 % of PTC tend to progress. We sought to determine factors predicting the progression of PTC under AS.

METHODS

A systematic search was performed in January 2022 using PubMed, Embase, Google Scholar, Web of Science, and ScienceDirect. PRISMA guidelines were used by multiple reviewers to extract study characteristics (author name, publication date, journal name, country, institution, and study design), as well as main outcomes and measures. A combination of utilization of thyroid replacement therapy, baseline tumor size and volume, follow-up tumor size and volume, and the presence of lymph node metastasis and its distribution, as well as surveillance duration, were the main measures of this study.

RESULTS

Nine studies with 4166 patients were included, of which 354 showed tumor progression during AS (15 %; 95%CI = 7 % - 23 %). The average follow-up period was 41.58 months. The mean tumor maximum diameter was 8.54 mm (95%CI = 7.04-10.03). Tumor progression was most commonly secondary to an increase in volume by ≥50 % (75 %; 95%CI = 68 % - 80 %), then increase in diameter by ≥3 mm (41 %; 95%CI = 13 % - 76 %), and finally the development of lymph node metastasis (13 %; 95%CI = 9 % - 19 %). Approximately only 2 % of all patients thus developed new lymph node metastasis. Patient age, sex, and tumor size were not associated with higher risks of tumor progression. 12 % of AS patients eventually underwent surgery, though only 40 % (95%CI = 27 % - 53 %) of these patients displayed tumor progression.

CONCLUSIONS

Our meta-analysis determined a tumor progression rate of 15 % in patients who underwent AS management, 13 % of which (2 % of all patients) developed lymph node metastasis. We found no protective or risk factors for tumor progression, and that almost half of all patients who underwent delayed surgery did so for reasons other than tumor progression. While not biopsying small (<1 cm) or very low suspicious nodules is already recommended, AS may be an appropriate treatment option in patients appropriately counseled, considering the low risk of advanced tumor progression but also the considerable patient population who fail to adhere to treatment. Alternatively, in aim of preventing overtreatment in patients who would rather take proactive measures against their low-risk carcinoma, minimally-invasive ablation techniques may be an attractive option.

Active surveillance of low-risk papillary thyroid microcarcinoma

Recently, the incidence of thyroid carcinoma has been increasing rapidly worldwide. This is interpreted as an increase in the incidental detection of small papillary thyroid carcinomas by the widespread use of high-resolution imaging techniques such as ultrasonography. However, the mortality rates of thyroid carcinoma have not changed, suggesting that small papillary thyroid carcinomas may be overdiagnosed and overtreated. Active surveillance management has been introduced from Japan since the 1990s, as one of the measures to prevent overtreatment of low-risk papillary thyroid microcarcinoma. Based on the favorable outcomes, active surveillance has been gradually adopted worldwide as an alternative to immediate surgery. The management should be carried out with strict eligibility criteria and close monitoring for cancer progression, under a multidisciplinary team. In addition, an adequate shared decision-making is mandatory for individual patients. Papillary thyroid microcarcinomas with clinically apparent lymph node metastasis, distant metastasis, or invasion to adjacent organs should have surgery.

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.

Clair J, Chen MM, Vasquez M, Fan X, van Deen WK, Haile RW, Daskivich TJ, Zumsteg ZS, Braunstein GD, Sacks WL. Expanded Parameters in Active Surveillance for Low-risk Papillary Thyroid Carcinoma: A Nonrandomized Controlled Trial

Importance

Unlike for prostate cancer, active surveillance for thyroid cancer has not achieved wide adoption. The parameters by which this approach is feasible are also not well defined, nor is the effect of patient anxiety.

Objective

To determine if expanded size/growth parameters for patients with low-risk thyroid cancer are viable, as well as to assess for cohort differences in anxiety.

Design, Setting, and Participants

This prospective nonrandomized controlled trial was conducted at a US academic medical center from 2014 to 2021, with mean [SD] 37.1 [23.3]-month follow-up. Of 257 patients with 20-mm or smaller Bethesda 5 to 6 thyroid nodules, 222 (86.3%) enrolled and selected treatment with either active surveillance or immediate surgery. Delayed surgery was recommended for size growth larger than 5 mm or more than 100% volume growth. Patients completed the 18-item Thyroid Cancer Modified Anxiety Scale over time.

Interventions

Active surveillance.

Main Outcomes and Measures

Cumulative incidence and rate of size/volume growth.

Results

Of the 222 patients enrolled, the median (IQR) age for the study population was 46.8 (36.6-58) years, and 76.1% were female. Overall, 112 patients (50.5%) underwent treatment with active surveillance. Median tumor size was 11.0 mm (IQR, 9-15), and larger tumors (10.1-20.0 mm) comprised 67 cases (59.8%). One hundred one (90.1%) continued to receive treatment with active surveillance, 46 (41.0%) had their tumors shrink, and 0 developed regional/distant metastases. Size growth of more than 5 mm was observed in 3.6% of cases, with cumulative incidence of 1.2% at 2 years and 10.8% at 5 years. Volumetric growth of more than 100% was observed in 7.1% of cases, with cumulative incidence of 2.2% at 2 years and 13.7% at 5 years. Of 110 patients who elected to undergo immediate surgery, 21 (19.1%) had equivocal-risk features discovered on final pathology. Disease severity for all such patients remained classified as stage I. Disease-specific and overall survival rates in both cohorts were 100%. On multivariable analysis, immediate surgery patients exhibited significantly higher baseline anxiety levels compared with active surveillance patients (estimated difference in anxiety scores between groups at baseline, 0.39; 95% CI, 0.22-0.55; P < .001). This difference endured over time, even after intervention (estimated difference at 4-year follow-up, 0.50; 95% CI, 0.21-0.79; P = .001).

Conclusions and Relevance

The results of this nonrandomized controlled trial suggest that a more permissive active surveillance strategy encompassing most diagnosed thyroid cancers appears viable. Equivocal-risk pathologic features exist in a subset of cases that can be safely treated, but suggest the need for more granular risk stratification. Surgery and surveillance cohorts possess oppositional levels of worry, elevating the importance of shared decision-making when patients face treatment equivalence.

Trial Registration

ClinicalTrials.gov Identifier: NCT02609685.

Treatment strategies for low-risk papillary thyroid carcinoma: a position statement from the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism (SBEM)

Increasingly sensitive diagnostic methods, better understanding of molecular pathophysiology, and well-conducted prospective studies have changed the current approach to patients with thyroid cancer, requiring the implementation of individualized management. Most patients with papillary thyroid carcinoma (PTC) are currently considered to have a low risk of mortality and disease persistence/recurrence. Consequently, current treatment recommendations for these patients include less invasive or intensive therapies. We used the most recent evidence to prepare a position statement providing guidance for decisions regarding the management of patients with low-risk PTC (LRPTC). This document summarizes the criteria defining LRPTC (including considerations regarding changes in the TNM staging system), indications and contraindications for active surveillance, and recommendations for follow-up and surgery. Active surveillance may be an appropriate initial choice in selected patients, and the criteria to recommend this approach are detailed. A section is dedicated to the current evidence regarding lobectomy versus total thyroidectomy and the potential pitfalls of each approach, considering the challenges during long-term follow-up. Indications for radioiodine (RAI) therapy are also addressed, along with the benefits and risks associated with this treatment, patient preparation, and dosage. Finally, this statement presents the best follow-up strategies for LRPTC after lobectomy and total thyroidectomy with or without RAI.

Microwave Ablation versus Surgical Resection for Solitary T1N0M0 Papillary Thyroid Carcinoma

Background Microwave ablation (MWA) has attracted interest as a minimally invasive treatment for papillary thyroid carcinoma (PTC). However, comparisons between MWA and surgical resection (SR) in the management of T1N0M0 PTC are rare. Purpose To compare the technical effectiveness, disease progression, and complications of MWA and SR for solitary T1N0M0 PTC. Materials and Methods This retrospective study was conducted in a single center. A total of 1029 patients with T1N0M0 PTC treated with either MWA or SR from January 2015 to May 2021 were studied and divided into two groups according to treatment modality. Propensity score matching and inverse probability of treatment weighting were used to control for confounding factors. Disease progression was analyzed in T1N0M0 PTCs as well as T1a and T1b subgroups by using Kaplan-Meier curves and Cox proportional hazards regression models. Results A total of 404 patients (mean age, 43 years ± 12 [SD]; 289 women; 337 with T1a PTC) underwent MWA, and 625 (mean age, 46 years ± 12; 495 women; 521 with T1a PTC) underwent SR. During the follow-up (median, 25 months; IQR, 7-61 months), there was no evidence of differences regarding disease progression in T1N0M0 (4.0% vs 4.0%; P = .97), T1a (3.4% vs 3.8%; P = .89), or T1b PTCs (6.8% vs 5.0%; P = .72). Compared with SR, MWA resulted in less blood loss (2 mL vs 10 mL) and a shorter procedure time (23 minutes vs 72 minutes) (both P < .001). The rate of major complications was 5.4% (19 of 350 patients) in the MWA group and 6.3% (22 of 350 patients) in the SR group (P = .75). Permanent hoarseness only occurred in the SR group (1.7%; P = .03). Conclusion For T1a and T1b solitary T1N0M0 papillary thyroid carcinomas, there was no evidence of differences regarding disease progression and major complications between microwave ablation and surgical resection. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by vanSonnenberg and Simeone in this issue.

Carcinoma de tiroides: Descripción de 634 pacientes atendidos en el Hospital Universitario San Ignacio, Bogotá, D.C., Colombia

Introducción. La incidencia del carcinoma de tiroides ha aumentado a nivel mundial, probablemente relacionado con el sobre diagnóstico de nódulos tiroideos asintomáticos. La alta sobrevida del carcinoma diferenciado de tiroides ha permitido posibilidades de manejo quirúrgico menos radicales, o inclusive, la vigilancia activa de tumores seleccionados. Existen reportes de características clínico-patológicas del carcinoma de tiroides de nuestro país distintas a las reportadas en la literatura internacional. Métodos. Estudio observacional descriptivo de una cohorte retrospectiva de pacientes con carcinoma de tiroides atendidos en un hospital universitario entre 2015 y 2020. Resultados. Se identificaron 634 pacientes, el 83,4 % de sexo femenino. La tiroidectomía total con vaciamiento central fue el procedimiento más realizado (86,7 %). De 613 carcinomas diferenciados de tiroides, el 94,2 % corresponden al tipo papilar, seguido por el carcinoma de células de Hürtle (1,6 %); el 26,2 % presentaron subtipos histológicos agresivos y el 28,4 % compromiso tumoral bilateral. En los vaciamientos centrales se encontró 58,7 % de enfermedad metastásica; que fue de 49 % en los pacientes con microcarcinomas papilares (19 %). De las 68 lesiones del nervio laríngeo recurrente, 47 % fueron por secciones oncológicas. Discusión. En nuestra serie, la proporción de pacientes con carcinoma papilar de tiroides y de sus variantes histológicas agresivas, así como el compromiso tumoral bilateral es mayor a lo reportado en la literatura científica. Conclusión. El comportamiento biológico del carcinoma de tiroides es variable y puede tener características diferentes entre regiones; el manejo en nuestro medio debería considerar las características propias de nuestra población.

Active Surveillance Versus Thyroid Surgery for Differentiated Thyroid Cancer: A Systematic Review

Background: Active surveillance has been proposed as an appropriate management strategy for low-risk differentiated thyroid cancer (DTC), due to the typically favorable prognosis of this condition. This systematic review examines the benefits and harms of active surveillance vs. immediate surgery for DTC, to inform the updated American Thyroid Association guidelines. Methods: A search on Ovid MEDLINE, Embase, and Cochrane Central was conducted in July 2021 for studies on active surveillance vs. immediate surgery. Studies of surgery vs. no surgery for DTC were assessed separately to evaluate relevance to active surveillance. Quality assessment was performed, and evidence was synthesized narratively. Results: Seven studies (five cohort studies [N = 5432] and two cross-sectional studies [N = 538]) of active surveillance vs. immediate surgery, and seven uncontrolled treatment series of active surveillance (N = 1219) were included. One cross-sectional study was rated fair quality, and the remainder were rated poor quality. In patients with low risk (primarily papillary), small (primarily ≤1 cm) DTC, active surveillance, and immediate surgery were associated with similar, low risk of all-cause or cancer-specific mortality, distant metastasis, and recurrence after surgery. Uncontrolled treatment series reported no cases of mortality in low-risk DTC managed with active surveillance. Among patients managed with active surveillance, rates of tumor growth were low; rates of subsequent surgery varied and primarily occurred due to patient preference rather than tumor progression. Four cohort studies (N = 88,654) found that surgery associated with improved all-cause or thyroid cancer mortality compared with nonsurgical management, but findings were potentially influenced by patient age and tumor risk category and highly susceptible to confounding by indication; eligibility for, and receipt of, active surveillance; and timing of surgery was unclear. Conclusions: In patients with small low-risk (primarily papillary) DTC, active surveillance and immediate surgery may be associated with similar mortality, risk of recurrence, and other outcomes, but methodological limitations preclude strong conclusions. Studies of no surgery vs. surgery are difficult to interpret due to clinical heterogeneity and potential confounding factors and are unsuitable for assessing the utility of active surveillance. Research is needed to clarify the benefits and harms of active surveillance and determine outcomes in nonpapillary DTC, larger (>1 cm) cancers, and older patients.

A Quantitative Analysis Examining Patients' Choice of Active Surveillance or Surgery for Managing Low-Risk Papillary Thyroid Cancer

Background: It is important to understand patient preferences on managing low-risk papillary thyroid cancer (PTC). Methods: We prospectively followed patients with low-risk PTC <2 cm in maximal diameter, who were offered the choice of thyroidectomy or active surveillance (AS) at the University Health Network (UHN), in Toronto, Canada. The primary outcome was the frequency of AS choice (percentage with confidence interval [CI]). Univariate and multivariable analyses were performed to identify predictors of the choice of AS. Results: We enrolled 200 patients of median age 51 years (interquartile range 42-62). The primary tumor measured >1 cm in 55.5% (111/200) of participants. The AS was chosen by 77.5% [71.2-82.7%, 155/200] of participants. In a backwards conditional regression model, the clinical and demographic factors independently associated with choosing AS included: older age (compared with referent group <40 years)-age 40-64 years-odds ratio (OR) 2.78 [CI, 1.23-6.30, p = 0.014], age ≥65 years-OR 8.43 [2.13-33.37, p = 0.002], and education level of high school or lower-OR 4.41 [1.25-15.53, p = 0.021]; AS was inversely associated with the patient's surgeon of record being affiliated with the study hospital-OR 0.29 [0.11-0.76, p = 0.012]. In a separate backwards conditional logistic regression model examining associations with psychological characteristics, AS choice was independently associated with a fear of needing to take thyroid hormones after thyroidectomy-OR 1.24 [1.11-1.39, p < 0.001], but inversely associated with fear of PTC progression-OR 0.94 [0.90-0.98, p = 0.006] and an active coping mechanism ("doing something")-OR 0.43 [0.28-0.66, p < 0.001]. Conclusions: Approximately three-quarters of our participants chose AS over surgery. The factors associated with choosing AS included older age, lower education level, and having a surgeon outside the study institution. Patients' fears about either their PTC progressing or taking thyroid hormone replacement as well as the level of active coping style were associated with the decision. Our results inform the understanding of patients' decisions on managing low-risk PTC. Registration: Clinicaltrials.gov NCT03271892.

Rethinking Low-Risk Papillary Thyroid Cancers < 1cm (Papillary Microcarcinomas): An Evidence Review for Recalibrating Diagnostic Thresholds and/or Alternative Labels

Background: Recalibrating diagnostic thresholds or using alternative labels may mitigate overdiagnosis and overtreatment of papillary microcarcinoma (mPTC). We aimed at identifying and collating relevant epidemiological evidence on mPTC, to assess the case for recalibration and/or new labels. Methods: We searched EMBASE and PubMed databases from inception to December 2020 for natural history, autopsy, diagnostic drift, and diagnostic reproducibility studies. Where a relevant systematic review was pre-identified, only new articles were additionally included. Non-English articles were excluded. One author screened titles and abstracts. Two authors screened full text articles, performed quality assessments, and extracted data. We undertook narrative synthesis of included evidence (pooled estimates from systematic reviews and single estimates from primary studies). Results: One systematic review of patients undergoing active surveillance found that after 5 years of follow-up, 5.3% (95% confidence interval [CI 4.4-6.4%]) of the mPTC lesions had increased in size by ≥3 mm, and 1.6% [CI 1.1-2.4%] of patients had lymph node metastases. Among 7 new primary studies (including 3 updates on 2 studies included in the systematic review), 1-5% of patients undergoing active surveillance had lymph node metastases after a median follow-up of 1-10 years. One systematic review found that subclinical thyroid cancer incidentally discovered at autopsy is relatively common, with a pooled prevalence of 11.2% [CI 6.7-16.1%] among studies that examined the whole thyroid. Four diagnostic drift studies evaluated the new classification of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Three studies of cases previously diagnosed as papillary thyroid cancer found 1.3-2.3% were reclassified as NIFTP (reclassifications were from follicular variation of papillary thyroid cancer [FVPTC]). One study of 48 cases previously diagnosed as mPTC found that 23.5% were reclassified as NIFTP. Thirteen reproducibility studies of papillary thyroid lesions found substantial variation in the histopathological diagnosis of thyroid lesions, including FVPTC and NIFTP classifications (no study evaluated mPTC). Conclusions: This review supports consideration of recalibrating diagnostic thresholds and/or alternative labels for low-risk mPTC.

Current therapeutic options for low-risk papillary thyroid carcinoma: A scoping evidence review

Most cases of thyroid carcinoma are classified as low risk. These lesions have been treated with open surgery, remote access thyroidectomy, active surveillance, and percutaneous ablation. However, there is lack of consensus and clear indications for a specific treatment selection. The objective of this study is to review the literature regarding the indications for management selection for low-risk carcinomas. Systematic review exploring inclusion and exclusion criteria used to select patients with low-risk carcinomas for treatment approaches. The search found 69 studies. The inclusion criteria most reported were nodule diameter and histopathological confirmation of the tumor type. The most common exclusions were lymph node metastasis and extra-thyroidal extension. There was significant heterogeneity among inclusion and exclusion criteria according to the analyzed therapeutic approach. Alternative therapeutic approaches in low-risk carcinomas can be cautiously considered. Open thyroidectomy remains the standard treatment against which all other approaches must be compared.

Nomogram prediction for the involution of the ablation zone after radiofrequency ablation treatment in patients with low-risk papillary thyroid carcinoma

OBJECTIVES

To construct a prognostic nomogram to predict the involution of the ablation zone for patients with low-risk papillary thyroid carcinoma (PTC) who underwent radiofrequency ablation (RFA) treatment.

METHODS

Data from 204 patients with low-risk PTC without extrathyroidal extension or cervical lymph node or distant metastasis who underwent RFA treatment were collected from January 2018 to January 2019. Clinicopathological and imaging characteristics were analyzed. The prognostic factors associated with the involution of the ablation zone within 12 months after RFA were identified by logistic analysis, and the nomogram was established. Calibration curve and decision curve analysis were used to evaluate the nomogram performance.

RESULTS

Of the 204 patients included in this study, the ablation zone in 78 (38%) patients did not completely disappear in the 12 months after RFA. Four variables, including sex (odds ratio [OR], 3.303; 95% confidence interval [CI], 1.418-8.418; p = 0.008), age (OR, 1.045; 95% CI, 1.012-1.081; p = 0.009), calcification size (OR, 1.666; 95% CI, 1.041-2.701; p = 0.035), and RFA energy (OR, 2.902; 95% CI, 1.333-6.683; p = 0.009), were found to be closely associated with ablation zone non-disappearance at 12 months after RFA by multivariate analysis. A nomogram model was constructed, and its accuracy was well validated (C-index = 0.787).

CONCLUSIONS

This study constructed and validated a risk model that could accurately predict the involution of the ablation zone after RFA for patients with PTC. This could provide clinicians with useful resource to guide patient counseling regarding tumor prognosis after RFA.

Position paper from the Japan Thyroid Association task force on the management of low-risk papillary thyroid microcarcinoma (T1aN0M0) in adults

The incidence of thyroid carcinoma has been increasing worldwide. This is interpreted as an increase in the incidental detection of papillary thyroid microcarcinomas (PTMCs). However, mortality has not changed, suggesting overdiagnosis and overtreatment. Prospective clinical trials of active surveillance for low-risk PTMC (T1aN0M0) have been conducted in two Japanese institutions since the 1990s. Based on the favorable outcomes of these trials, active surveillance has been gradually adopted worldwide. A task force on the management of PTMC in adults organized by the Japan Thyroid Association therefore conducted a systematic review and has produced the present position paper based on the scientific evidence concerning active surveillance. This paper indicates evidence for the increased incidence of PTMC, favorable surgical outcomes for low-risk PTMC, recommended criteria for diagnosis using fine needle aspiration cytology, and evaluation of lymph node metastasis (LNM), extrathyroidal extension (ETE) and distant metastasis. Active surveillance has also been reported with a low incidence of disease progression and no subsequent recurrence or adverse events on survival if conversion surgery was performed at a slightly advanced stage. Active surveillance is a safe and valid strategy for PTMC, because it might preserve physical quality of life and reduce 10-year medical costs. However, some points should be noted when performing active surveillance. Immediate surgery is needed for PTMC showing high-risk features, such as clinical LNM, ETE or distant metastasis. Active surveillance should be performed under an appropriate medical team and should be continued for life.

Efficacy and safety of ultrasound-guided radiofrequency ablation for low-risk papillary thyroid microcarcinoma in patients aged 55 years or older: a retrospective study

PURPOSE

To evaluate the efficacy and safety of radiofrequency ablation for low-risk papillary thyroid microcarcinoma (PTMC) in patients aged 55 years or older.

METHODS

This retrospective study included 95 patients aged 55 years or older who underwent radiofrequency ablation (RFA) for PTMCs between June 2014 and January 2019. Incidence and duration of postoperative complications were recorded and evaluated. Tumor volume and volume reduction rate (VRR) changes were calculated. Patients were also closely monitored for tumor recurrence, regrowth, and lymph node metastasis.

RESULTS

All nodules were completely ablated. The mean initial volume of the ablated thyroid nodules was 107.27 ± 99.10 mm³, and the volume decreased significantly during the follow-up time. The VRR in 1st, 3rd, 6th, 12th, 18th, 24th and 36th month were -591.64 ± 623.65%, -170.89 ± 319.51%, 9.74 ± 128.43%, 77.99 ± 45.26%, 99.35 ± 3.61%, 99.45 ± 3.05% and 99.78 ± 1.54%, respectively. No patient had any life-threatening complications. One patient had lymph node metastasis and one had a recurrence; both underwent a second radiofrequency ablation treatment and achieved satisfactory treatment results.

CONCLUSIONS

Our study suggests that radiofrequency ablation is a safe and effective option for low-risk PTMC in patients aged 55 years or older who are at a high risk of general anesthesia and postoperative complications or those who refuse surgery.

Thyroid Cancer Active Surveillance Program Retention and Adherence in Japan

Importance

Small papillary thyroid cancers are the most common type of thyroid cancer, with the incidence increasing across the world. Active surveillance of appropriate cancers has the potential to reduce harm from overtreatment but is a significant de-escalation from prior practice. Mechanisms that inform the rates of retention and adherence have not been described and need to be understood if broader uptake is to be considered.

Objective

To evaluate patient retention, adherence, and experience in the largest and most long-standing thyroid cancer active surveillance program, to our knowledge.

Design, Setting, and Participants

A cohort study using convergent design mixed-methods analysis of attendance data, semistructured interviews, and field observation was conducted at Kuma Hospital, Kobe, Japan. Participants included 1179 patients who were enrolled in surveillance between February 1, 2005, and August 31, 2013, and followed up through December 31, 2017. Data analysis was performed from January 25, 2018, through September 30, 2020.

Main Outcomes and Measures

Patients were considered adherent if they underwent ultrasonography within at least 13 months of the previous ultrasonographic examination. Patients were considered retained if they continued surveillance with an ultrasonographic examination at least every 2 years, without having had surgery for patient preference or clinical reasons.

Results

Of the 1179 patients included in the study, 1037 (88%) were women. The mean (SD) age was 56 (13.5) years (median, 57 years). Patients were followed up for up to 12.76 years (median, 5.97 years) and underwent a median of 9 ultrasonographic examinations (range, 2-50); 76 patients (6.4%) had surgery for clinical reasons. In analysis of retention, 53 of 1179 patients (4.5%) changed to surgery after a mean (SD) of 2.14 (1.53) years (median, 1.47; range, 0.14-7.17 years); at the study end point, 101 of 1179 patients (8.6%) had not been seen at Kuma Hospital in at least the past 2 years. Kaplan-Meier analysis to 10 years of follow-up time without structural progression estimated that 21.5% (95% CI, 17.0%-28.2%) of patients would not have had an ultrasonographic examination within at least the past 2 years. Mean adherence over a surveillance period of 10 follow-up ultrasonographic examinations (8878 person-examinations) was 91% (range, 85%-95%). Receipt of detailed test results, education regarding active surveillance, and supportive/collaborative style interactions with their physician were identified by patients as key factors for continuing surveillance.

Conclusions and Relevance

For patients with low-risk papillary thyroid cancer participating in active surveillance, retention in the program and adherence to follow-up ultrasonographic examination do not appear to be barriers to broader implementation of surveillance. The program's success may benefit from an approach analogous to traveler (patient) and their guide (clinician): the clinician advising on options, advocating for the optimal path over time, and supportively reaffirming the care plan or recommending alternatives as conditions change.

Microcarcinoma papilar de tiroides: ¿es adecuada la selección para protocolo de vigilancia activa?

Introducción. Los microcarcinomas papilares de tiroides son tumores de hasta 10 mm en su diámetro mayor. Su tratamiento es sujeto de debate y se propone, desde seguimiento clínico, hasta intervención quirúrgica temprana. Este estudio buscó identificar factores de riesgo relacionados con compromiso ganglionar, que permitan una mejor selección de los pacientes en nuestro medio, en quienes se propone manejo quirúrgico inmediato o vigilancia activa, en consonancia con la clasificación del riesgo de progresión. Métodos. Estudio de cohorte analítica ambispectiva que incluyó pacientes con microcarcinoma papilar de tiroides llevados a tiroidectomía más vaciamiento central. Se caracterizó la población y se realizó un análisis de regresión logística multivariado para definir factores preoperatorios asociados al compromiso ganglionar. Adicionalmente, se evaluó de manera retrospectiva la eventual asignación a grupos de riesgo de progresión, según los criterios de Miyauchi, y su comportamiento respecto al estado nodal. Resultados. Se incluyeron 286 pacientes. El 48,9 % presentó compromiso ganglionar, y de estos, el 33,5 % presentó compromiso ganglionar significativo, que modificó su clasificación de riesgo de recaída. De estos últimos, el 59,5 % hubiesen sido manejados con vigilancia activa, según los criterios propuestos por Miyauchi. Se identificó que la edad menor de 55 años, los ganglios sospechosos en la ecografía y los nódulos mayores de 5 mm, se relacionan con compromiso ganglionar significativo. Discusión. El manejo quirúrgico inmediato parece ser una opción adecuada para pacientes con sospecha de compromiso ganglionar en ecografía preoperatoria, pacientes menores de 55 años y nódulos mayores de 5 mm. Es posible que los actuales criterios para definir vigilancia activa no seleccionen adecuadamente a los pacientes en nuestro medio.

Clinical management of low-risk papillary thyroid microcarcinoma

Papillary thyroid microcarcinoma (PTMC) is well known to have an indolent nature with an excellent prognosis. Surgery has been the standard treatment during the past several decades, with metastasis or recurrence being exceedingly rare. Active surveillance (AS) is a new risk-adapted approach alternative to surgery that involves just watching, but not giving any treatment unless needed, not addressing the tumor itself. The patients for whom AS is adopted spend their time "with tumors." In follow-up, it is possible that alarming factors such as tumor progression appear, causing anxiety about progression. Furthermore, endless follow-up is needed. However, considering the indolent nature and unfavorable events such as surgical complications caused by surgery, AS is a good management plan for selected PTMC patients. Decision making balancing between the prognosis and unfavorable events is needed for the treatment plan. Consideration of the factors and timing of surgical conversion is also needed. In this review article, how AS should be adopted as a new management option that is an alternative to surgery, which has been the absolute choice of treatment up to recently, is discussed. Concurrently, the characteristics of the two treatment strategies are reviewed, while introducing the background that explains how AS came to attention.

Ultrasound-Guided Radiofrequency Ablation Versus Surgical Resection for the Treatment of T1bN0M0 Papillary Thyroid Carcinoma in Different Age Groups

PURPOSE

We aimed to compare the efficacy and safety of radiofrequency ablation (RFA) to that of surgical resection (SR) in patients with T1bN0M0 papillary thyroid carcinoma (PTC) in different age groups.

METHODS

Totally, 204 patients with an isolated, solitary, intrathyroidal T1bN0M0 PTC, who underwent either RFA (n=94) or SR (n=110) between April 2014 and December 2019, were retrospectively enrolled and were divided into two subgroups according to age (<45 years, ≧45 years). Patients with pathologically aggressive or advanced lesions were excluded from the study. Tumor progression and procedural complications were the primary and secondary endpoints, respectively. Tumor recurrence in situ, newly discovered tumors, lymph node involvement, or distant metastases indicated tumor progression. Complications included pain, fever, voice change, choking, numbness in the limbs, and cardiac events. Incidence rates of all endpoint events were compared between different age subgroups.

RESULTS

There were no significant differences in age, sex, and tumor size between the treatment groups. While the RFA group incurred less cost and experienced significantly shorter operative duration than the SR group, no significant differences were observed in incidences of both tumor progression and complications. Further, subgroup analysis of patients <45 years versus those ≧45 years showed no significant differences in the incidence of tumor progression and complications within or between different treatment groups. Older patients in the SR group incurred higher hospital costs than younger counterparts, but this difference was not observed in the RFA group.

CONCLUSIONS

Our results indicated that RFA had a similar prognosis as that of SR but was associated with lower overall cost in both young (<45 years) and middle-aged patients (≧45 years) with T1bN0M0 PTC. Therefore, RFA may be an effective and safe alternative to surgery for the treatment of patients with T1bN0M0 PTC.