Active Surveillance in Adults with Low-Risk Papillary Thyroid Microcarcinomas: A Prospective Study

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.

Dynamic risk assessment in patients with differentiated thyroid cancer

The current approach for patients with differentiated thyroid carcinoma should be individualized according to the risk of recurrence, and this stratification could be used to identify the risk of persistent/recurrent disease in three scenarios: preoperatively, immediately postoperatively, and during long-term follow-up. The initial risk of recurrence will tailor the management of the patient in the preoperative and immediate postoperative settings, while the dynamic risk, which considers the responses to treatment, could guide the decision-making process for remnant ablation and long-term management.This review provides a summary of the existing information regarding the dynamic risk of recurrence and recommended management for patients with differentiated thyroid cancer. The application of this approach is essential to avoid unnecessary treatments for most patients who will have a favorable prognosis. On the other hand, it allows specific therapeutic interventions for those patients at high risk of recurrence. In the future, analysis of tumor biology and prospective studies will surely improve the accuracy of recurrence risk prediction.

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.

Conservative management of low-risk papillary thyroid carcinoma: a review of the active surveillance experience

The detection of low-risk thyroid carcinoma has increased in recent decades, although disease-specific mortality remained without changes. The high prevalence of occult carcinomas in autopsy studies, and hence the underlying indolent course of this entity, prompted the emergence of active surveillance as an alternative approach to these tumors. This strategy aims to recognize the minority group of patients who will develop clinical progression and probably benefit from deferred surgery. Experience around the world has shown that during active surveillance these tumors are mostly unchanged in size, with very-slow growth and even a decrease in diameter. Moreover, the rates of lymph node metastases were low and easily handled by rescue surgery, and distant metastases have not been reported. Given the high prevalence of small thyroid carcinomas and the excellent outcomes for observation, active surveillance provides a safe and feasible alternative in properly selected patients with low-risk thyroid cancer.

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

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

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Feasibility of a snowball sampling survey to study active surveillance for thyroid microcarcinoma treatment among endocrinologists and surgeons of Brazil

OBJECTIVES

This study aims to investigate if a sampling method using virtual networks is feasible to survey AS adoption among this "hard-to-reach" population of Brazilian doctors.

METHODS

An online piloted 11-point structured survey questionnaire (designed using Googleforms®) probed the actual treatment patterns for adult patients with PTMCs, including treatment decision-making nonoperative options, was undertaken between 10 November and 30 November 2020. Participants were reached by the mobile phone Application (APP) and a snowball sampling strategy was used to recruit a total of 4783 members (maximum number of potential reach), which is the total of doctors of the all 21 social media WhatsApp® groups.

RESULTS

From a total of 4783 members (maximum number of potential reach), there were 657 (13.7%) doctors (actual reach) who clicked the web link of the questionnaire, out of whom 512 (10.7%) fully completed the online survey. Among the survey respondents, 361 were endocrinologists (70.5%) and 151 were surgeons (29.5%). Overall, for low-risk PTMCs in an elderly patient, 118 responders (23%) recommend AS, while 390 (76%) recommend immediate surgery as the management, including lobectomy (18.5%) and Total Thyroidectomy (58.2%). The present responders tended to recommend surgery for PTMCs that were located adjacent to the dorsal surface of the thyroid, were multiple, or raised the size during the follow-up.

CONCLUSION

Using snowball sampling strategy as an innovative route to conduct surveys was feasible and applicable but the rate of response was still very low. Our data also suggests the need to investigate if AS is embraced by Brazilian doctors.

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.

Observational management of papillary microcarcinoma appearing in the remnant thyroid after hemithyroidectomy

Active surveillance for papillary thyroid microcarcinomas (PTMCs) initiated in Japan is becoming adopted worldwide as a management option. However, it remains unclear how to manage newly appearing PTMCs in the remnant thyroid after hemithyroidectomy. We investigated the outcomes of similar observational management (OM) for PTMCs appearing in the remnant thyroid after hemithyroidectomy for papillary thyroid carcinoma (PTC) and benign thyroid nodules. Eighty-three patients were newly diagnosed with PTMC in the remnant thyroid between January 1998 and March 2017. Of these, 42 patients underwent OM with >3 times ultrasound examinations. Their initial diagnoses were PTC (initially malignant group) in 37 patients and benign nodule (initially benign group) in 5 patients. We calculated the tumor volume doubling rate (TV-DR) during OM for each PTMC. The TV-DR (/year) was <-0.1, -0.1-0.1, 0.1-0.5, and >0.5 in 12, 19, 5, and 6 patients, respectively. The TV-DRs in both groups did not statistically differ, but six patients (16%) in the initially malignant group showed moderate growth (TV-DR >0.5/year). They underwent conversion surgery and none of them had further recurrence. The remaining 36 patients retained OM without disease progression. The TV-DR in the initially malignant group was not significantly associated with patients' backgrounds or their initial clinicopathological features. None of the patients in this study showed distant metastases/recurrences or died of thyroid carcinoma. Although a portion of PTMCs appearing after hemithyroidectomy for thyroid malignancy are moderately progressive, OM may be acceptable as a management option for PTMCs appearing in the remnant thyroid after hemithyroidectomy.

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.

Papillary Thyroid Microcarcinoma: Active Surveillance Against Surgery. Considerations of an Italian Working Group From a Systematic Review

Introduction

Active surveillance is considered a viable option for papillary thyroid microcarcinoma. Since the last decade of the 20th century, this method has spread from Japan to other countries, but has not yet been fully accepted and validated by the major Western Scientific Societies. In 2016, a systematic review on the results of active surveillance was published, based on two articles that showed encouraging results. Other reviews published subsequently, were mainly based on articles from the Far East. The aim of this review is to assess the most recent results published from 2017 to 2020 on this subject.

Materials and Methods

A systematic literature search was performed on MEDLINE via PUBMED, Web of Science, and Scopus according to PRISMA criteria. The MESH terms “papillary thyroid microcarcinoma” and “active surveillance” were adopted. Tumor progression, secondary localizations, and quality of life were the main benchmarks.

Results

Nine studies met the inclusion criteria. The increase in volume ranged from 2.7% and 23.2%; the occurrence of lymph node metastases from 1.3% to 29%; QoL was improved in both articles that addressed this topic. The level of evidence is considered low due to the retrospective and uncontrolled nature of most of the studies included in the review.

Conclusion

The evidence from the literature currently available on AS falls into two strands: a robust data set from the Japanese experience, and an initial experience from Western countries, whose data are still limited but which show a lack of substantial alerts against this practice. Further data is useful to validate the spread of Active Surveillance.

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.

Management of Low-Risk Thyroid Cancers: Is Active Surveillance a Valid Option? A Systematic Review of the Literature

Thyroid cancer is the most common endocrine malignancy, representing 2.9% of all new cancers in the United States. It has an excellent prognosis, with a five-year relative survival rate of 98.3%.Differentiated Thyroid Carcinomas (DTCs) are the most diagnosed thyroid tumors and are characterized by a slow growth rate and indolent course. For years, the only approach to treatment was thyroidectomy. Active surveillance (AS) has recently emerged as an alternative approach; it involves regular observation aimed at recognizing the minority of patients who will clinically progress and would likely benefit from rescue surgery. To better clarify the indications for active surveillance for low-risk thyroid cancers, we reviewed the current management of low-risk DTCs with a systematic search performed according to a PRISMA flowchart in electronic databases (PubMed, Web of Science, Scopus, and EMBASE) for studies published before May 2021. Fourteen publications were included for final analysis, with a total number of 4830 patients under AS. A total of 451/4830 (9.4%) patients experienced an increase in maximum diameter by >3 mm; 609/4830 (12.6%) patients underwent delayed surgery after AS; metastatic spread to cervical lymph nodes was present in 88/4213 (2.1%) patients; 4/3589 (0.1%) patients had metastatic disease outside of cervical lymph nodes. Finally, no subject had a documented mortality due to thyroid cancer during AS. Currently, the American Thyroid Association guidelines do not support AS as the first-line treatment in patients with PMC; however, they consider AS to be an effective alternative, particularly in patients with high surgical risk or poor life expectancy due to comorbid conditions. Thus, AS could be an alternative to immediate surgery for patients with very-low-risk tumors showing no cytologic evidence of aggressive disease, for high-risk surgical candidates, for those with concurrent comorbidities requiring urgent intervention, and for patients with a relatively short life expectancy.

Active surveillance for thyroid Cancer: a qualitative study of barriers and facilitators to implementation

BACKGROUND

The 2015 American Thyroid Association guidelines supported active surveillance (AS) as a strategy for managing select low-risk thyroid cancers. Data examining physicians' attitudes about the acceptability of this option are limited. This study aimed to characterize the barriers and facilitators to implementing AS as perceived by practicing endocrinologists and surgeons in the United States.

METHODS

We conducted 24 semi-structured interviews probing physicians' attitudes toward AS for patients with small, low-risk thyroid cancer. We used deductive content analysis guided by a well-known model of guideline implementation. Analysis characterized concepts and themes related to AS implementation as physician, guideline, or external factors. We performed member checking to validate results.

RESULTS

The most prominent barriers to AS were related to physician factors, although guideline-specific and external barriers were also observed. Physician attitudes towards AS comprised the majority of physician-related barriers, while lack of knowledge about the guideline was also discussed. Participants' concerns about the potential negative outcomes resulting from observing a cancer were notable as were the lack of confidence in performing and offering surveillance. Beliefs about patient expectations and lack of knowledge about the guideline were also identified as barriers to offering surveillance. Guideline-specific and external barriers included the vagueness of surveillance protocols, lack of data supporting active surveillance, and societal beliefs about cancer. Facilitators of active surveillance included patients' desire to avoid surgery and shared decision-making.

CONCLUSIONS

Barriers and facilitators of active surveillance for low-risk thyroid cancers exist at multiple levels. Strategies to increase adoption of active surveillance should focus on physicians' attitudes, patient expectations, data supporting surveillance outcomes, and promoting societal-level acceptance of surveillance.

Choosing Optimal Microcarcinoma Patients for Active Surveillance Study (Compass): Effectiveness Evaluation of a Preoperative Clinical Framework

OBJECTIVE

Active surveillance (AS) is a management alternative for patients with low-risk papillary thyroid microcarcinoma (PTMC). To decide the best candidates for AS, clinicians can use a framework to classify PTMC patients as ideal, appropriate, or inappropriate. This study aimed to explore the correlation between the framework categories and surgical pathology.

METHODS

This multicenter retrospective study was conducted between 2014 and 2016. We included 1997 patients who underwent thyroid surgery for the first time due to suspected PTMC and were confirmed as PTMC by postoperative pathology. The consistency of modified preoperative risk stratification and the pathologic condition were evaluated using a consistency ratio and the Kappa coefficient. Stratified analysis was also performed to test consistency in different age groups.

RESULTS

Based on the decision-making framework, 558 (27.9%) patients could receive AS while 810 (40.6%) patients did not require immediate surgery according to the actual postoperative pathology. The sensitivity, false-positive rate, specificity, false-negative rate, and consistency rate were 82.39%, 56.91%, 43.09%, 17.61%, and 66.45%, respectively. The Kappa value was 0.268. Stratified analysis showed that the sensitivity was 87.7% among patients aged 18 to 59 years. In the group aged ≥60 years, the specificity was up to 87.5%, but the sensitivity was low.

CONCLUSION

The results of the modified risk-stratified clinical decision-making framework did not have a high consistency with the postoperative results. However, the framework showed a good effect in selecting patients for immediate surgery in the younger group and patients for AS in the older group.

[Current treatment strategies for papillary thyroid microcarcinoma]

Surgical treatment of papillary thyroid microcarcinoma (PTMC) is evolving more and more into a controversial issue. As in Japan more than 50% of PTMCs are only observed, an increasing number of physicians in the western world are calling for active surveillance instead of lobectomy or total thyroidectomy. Unifocal carcinomas of older patients without extrathyroidal growth or lymph node involvement seem to be candidates for active surveillance. First estimations for a lifelong observation show that patients <30 years old will have a probability of tumor progression of more than 60%. A decision for surgery versus active surveillance has to weigh up all the arguments for and against, which have to be discussed and planned in detail together with the patient.

Active Surveillance of Thyroid Microcarcinoma-Can This Approach Be Safely Implemented Worldwide?

The incidence of thyroid cancer has been increasing exponentially worldwide, mainly due to increased detection of small papillary thyroid microcarcinomas (PTMCs). Given the indolent nature of the disease, active surveillance (AS) has been suggested as an alternative approach to immediate surgery in the management of low-risk PTMCs. The decision to proceed with AS must take into account patient characteristics, tumor characteristics, and medical team characteristics. In this review, we discuss the rationale and evidence to support AS, as well as important considerations and limitations to implementing this approach for PTMC worldwide.

Active surveillance for low-risk small papillary thyroid cancer in North American countries: past, present and future (bridging the gap between North American and Asian practices)

Papillary thyroid cancer (PTC) is increasingly being diagnosed worldwide; yet the mortality remains very low, suggesting widespread overdiagnosis. While traditional management of PTC includes thyroid surgery, sometimes followed by radioactive iodine treatment, there is a global trend towards more conservative approaches for patients who are considered as the lowest risk of recurrence or death from their disease. Active surveillance (AS), once called watchful waiting, involves close follow-up, with the intention to intervene if the cancer progresses, or on patient request. The Kuma Hospital in Japan was the first to introduce AS as an alternative to immediate thyroid surgery for low-risk papillary thyroid microcarcinomas (PTMC, <1 cm) in 1993. Accumulated evidence over the years has shown that AS is a safe and effective approach in select patients, with a low rate of cancer progression during AS. Consequently, the Japanese Clinical Guidelines for treatment of thyroid tumor approved AS as a first-line management for patients with asymptomatic PTMC in 2010. Subsequently, the latest 2015 American Thyroid Association guidelines endorsed AS as an alternative approach to immediate surgery for cytologically confirmed very low-risk PTC. However, the acceptance, feasibility and results of AS in patients with low-risk PTC outside of Japan are still largely unknown. Most guidelines recommend that thyroid nodules <1 cm should not be aspirated but instead monitored regardless of the ultrasonographic characteristics. In essence, these patients are also being subjected to AS. Specific recommendations and the role of molecular testing for the optimal selection of PTMC patients for an AS management approach are not well established. Furthermore, research is needed to assess the long-term clinical and psychosocial outcomes in patients with larger tumor sizes (>1 cm) who undergo screening and diagnosis according to the North American guidelines and practices. The first Canadian prospective observational study launched in 2016 is intended to complement the existing data for AS of small low-risk PTC (≤2 cm) and may provide insight into the different approaches in North American and Asian practices. This review intends to summarize the development and the rationale of AS for PTMC and highlights significant differences between North American and Japanese practices.

Lymphovascular invasion of papillary thyroid carcinoma revisited in the era of active surveillance

INTRODUCTION

Lymphovascular invasion (LVI) is associated with disease recurrence and compromised survival in patients with thyroid cancer. Nonetheless, LVI is not identifiable on preoperative ultrasound or cytologic assessment. We aimed to explore the clinicopathological features associated with LVI.

PATIENTS AND METHODS

We conducted a retrospective review of our prospectively maintained database from 2009 to 2018. Multivariate analyses were performed to determine the associations between clinicopathological parameters and LVI. Generalized additive models were used to examine the nonlinear relationship between continuous variables and LVI.

RESULTS

A total of 795 patients were included in the analysis, and 174 (22%) had LVI. Patients' age (odds ratio [OR] = 0.982), tumor size (OR = 1.466), clinical lymphadenopathy (OR = 6.975), and advanced extrathyroidal extension (OR = 2.938) were independently associated with LVI. In the subset analysis of 198 patients with available genetic information, tumor size (OR = 1.599), clinical lymph node metastasis (OR = 3.657), and TERT promoter mutation (OR = 4.726) were predictive of LVI. Among 573 patients who had no clinical lymphadenopathy or advanced extrathyroidal extension, tumor size was the only predictor of LVI. Tumor size >1.5 cm had an increased risk of LVI based on the generalized additive model plot and receiver operating characteristic curve analysis.

CONCLUSION

Tumor size is positively associated with the risk of LVI in papillary thyroid cancer. To avoid delayed treatment in patients with LVI, a tumor size of 1.5 cm may be considered as the safe upper limit for active surveillance.

Active surveillance in low risk papillary thyroid carcinoma

In recent decades, while the incidence of thyroid cancer has increased exponentially around the world, mortality has remained stable. The vast majority of this increase is attributable to the identification of intrathyroidal papillary microcarcinomas, which exhibit slow growth rates with indolent courses. A diagnosis of thyroid cancer based upon the presence of these small tumors could be considered as an overdiagnosis, as the majority of these tumors would not likely result in death if left untreated. Although surgical resection was the classical standard therapy for papillary microcarcinomas, active surveillance (AS) has emerged over the last three decades as an alternative approach that is aimed to recognize a minority group of patients who will clinically progress and would likely benefit from rescue surgery. Despite the encouraging results of AS, its implementation in clinical practice is strongly influenced by psychosocial factors. The aim of this review is to describe the epidemiology, clinical evolution, prognostic factors, and mortality of papillary thyroid microcarcinomas. We also summarize the AS strategy according to published evidence, characterize the criteria for selecting patients for AS according to risk factors and environmental characteristics, as well as analyze the current limitations for AS implementation.