Surgery for papillary thyroid carcinoma: is lobectomy enough?

Papillary thyroid carcinoma: A bibliometric analysis of the top 100 cited articles

Objectives

To describe the current trends and key themes that are shaping the literature surrounding papillary thyroid carcinoma.

Methods

The Thomson Reuters Web of Science citation database was used to identify manuscripts relevant to papillary thyroid carcinoma. These were then subdivided into title, author, journal, publication date, theme, and manuscript types. Themes were then identified.

Results

A total of 1506 manuscripts were returned. The mean citation number was 163 (range 885-74), with the highest citation rate of 73.5. The highest impact factor was JAMA (impact factor of 56.27). 85% were original research, 10% review articles, and 5% were guidelines. The highest number of manuscripts were published in South Korea (21%).

Conclusions

This bibliometric analysis describes the most influential papers published in the topic of papillary thyroid carcinoma. Historic key themes have been endocrinology and metabolism, followed by surgical management and oncology (subdivided into surgery, pathology, radiology and public health/epidemiology). South Korea leads the world with the largest number of publications in this field; with an incidence rate of papillary thyroid carcinoma that is significantly higher than most parts of the world. Despite concerns with overdiagnosis, a collaborative radiological team skilled in ultrasonography of the neck appears to be of great value to the workup of thyroid cancers.

Management of Small Papillary Thyroid Cancers

Thyroid cancer is the most common endocrine malignancy. With increasing imaging utilization, there has been an increase in the recognition of small, indolent cancers that would otherwise go undiagnosed. Historically, the surgical recommendation for all patients with thyroid cancer was a total thyroidectomy. However, over the last 20 years, there have been numerous studies evaluating the de-escalation of interventions for low-risk thyroid cancers, transitioning from total thyroidectomy to thyroid lobectomy or active surveillance when indicated. Here, we review the current literature and recommendations with each of these treatment options.

Theranostics of Thyroid Cancer

Molecular imaging is pivotal in evaluating and managing patients with different thyroid cancer histotypes. The existing, pathology-based, risk stratification systems can be usefully refined, by incorporating tumor-specific molecular and molecular imaging biomarkers with theranostic value, allowing patient-specific treatment decisions. Molecular imaging with different radioactive iodine isotopes (ie, I131, I123, I124) is a central component of differentiated carcinoma (DTC)'s risk stratification while [18F]F-fluorodeoxyglucose ([18F]FDG) PET/CT is interrogated about disease aggressiveness and presence of distant metastases. Moreover, it is particularly useful to assess and risk-stratify patients with radioiodine-refractory DTC, poorly differentiated, and anaplastic thyroid cancers. [18F]F-dihydroxyphenylalanine (6-[18F]FDOPA) PET/CT is the most specific and accurate molecular imaging procedure for patients with medullary thyroid cancer (MTC), a neuroendocrine tumor derived from thyroid C-cells. In addition, [18F]FDG PET/CT can be used in patients with more aggressive clinical or biochemical (ie, serum markers levels and kinetics) MTC phenotypes. In addition to conventional radioiodine therapy for DTC, new redifferentiation strategies are now available to restore uptake in radioiodine-refractory DTC. Moreover, peptide receptor theranostics showed promising results in patients with advanced and metastatic radioiodine-refractory DTC and MTC, respectively. The current appropriate role and future perspectives of molecular imaging and theranostics in thyroid cancer are discussed in our present review.

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.

Outcomes of Patients with an Intermediate-Risk Group According to the Japanese Risk Classification of Papillary Thyroid Carcinoma

BACKGROUND

The management of intermediate-risk group of papillary thyroid cancer (PTC) is still vague, particularly regarding whether or not total thyroidectomy, postoperative radioactive iodine ablation (RAI-a), and postoperative TSH suppression are mandatory.

METHODS

This retrospective study evaluated 680 PTC patients from 2010 to 2017, who were classified into the three risk groups as low, intermediate, and high-risk groups according to the criteria of the Japanese Association of Endocrine Surgeons (JAES) 2010 and underwent surgery according to the JAES guidelines. We retrospectively collected patient data for analyses of disease-free survivals in the intermediate-risk group patients.

RESULTS

We performed surgery on 680 PTC patients from 2010 to 2017. Of them, 297 were classified as the intermediate-risk group. DFS was not statistically significantly different in patients with/without total thyroidectomy and postoperative TSH suppression therapy. For RAI-a, DFS (95% confidence interval) at 3, 5, and 8 years were 93.2% (84.6 ~ 97.2), 81.6% (68,3 ~ 90.2), and 70.7% (51.4 ~ 84.6) in patients with postoperative RAI-a and 100%, 100%, and 100% in patients without postoperative RAI-a after total thyroidectomy, respectively. DFS of patients without RAI-a was superior to those with RAI-a (P < 0.0004). Multivariable analysis by stepwise selection method revealed that postoperative RAI-a was a risk factor with a hazard ratio of 5.69. (95% CI 1.998-16.21) (P = 0.001131).

CONCLUSIONS

Our study did not show the efficacy of RAI-a in patients with intermediate-risk PTC. This study implies that judging the efficacy of adjuvant therapy such as RAI or TSh suppression in intermediate-risk patients is difficult.

Impact of thyroid hormone replacement on the risk of second cancer after thyroidectomy: a Korean National Cohort Study

We aimed to investigate the effect of thyroid hormone administration on the risk of second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer. Data were extracted from the medical billing data of the Health Insurance Review and Assessment Service in South Korea. Patients between 19 and 80 years old who underwent thyroid surgery at least once between January 2009 and June 2020 were included. Data of patients with second primary cancer and control patients with matched age, sex, operation date, and follow-up duration were extracted at a ratio of 1:4. A nested case-control analysis was performed to exclude length bias to confirm the correlation between the duration of thyroid hormone administration, dose, and incidence of second primary cancer. Of the 261,598 patients who underwent surgery for thyroid cancer included in the study, 11,790 with second primary cancer and 47,160 without second primary cancer were matched. The average dose of thyroid hormone increased the adjusted odds ratio (OR) for both low (≤ 50 μg, OR 1.29, confidence interval (CI) 1.12-1.48) and high (< 100 μg, OR 1.24, CI 1.12-1.37) doses. Analyzing over time, the adjusted OR of second primary cancer increased, especially in short (≤ 1 year) (OR 1.19; CI 1.06-1.34) and long (> 5 years) duration (OR 1.25; CI 1.10-1.41). In conclusion, insufficient and excessive thyroid hormone replacement might be linked to increased second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer.

Reassessing surgical guidelines for papillary thyroid cancer impact on survival: Expanding indications for lobectomy

BACKGROUND

Comparisons of lobectomy versus total thyroidectomy for papillary thyroid cancer have not addressed significant threats to valid inference from observational data. The purpose of this study was to compare survival after lobectomy versus total thyroidectomy for papillary thyroid cancer while addressing bias from unmeasured confounding.

METHODS

This retrospective cohort study included 84,300 patients treated with lobectomy or total thyroidectomy for papillary thyroid cancer in the National Cancer Database from 2004 to 2017. The primary outcome was overall survival evaluated by flexible parametric survival models and inverse probability weighting on the propensity score. Bias from unobserved confounding was assessed using two-way deterministic sensitivity analysis and 2-stage least squares regression.

RESULTS

The median age of treated patients was 48 years (interquartile range, 37-59), 78% were women, and 76% were white. We found no statistically significant differences in overall survival or 5- and 10-year survival between patients treated with lobectomy or total thyroidectomy. Additionally, we found no statistically significant difference in survival by subgroups, including tumor size (<4 cm or ≥4 cm), age (<65 or ≥65), or estimated risk of mortality. Sensitivity analyses suggested that an unmeasured confounder would need to have an extremely large effect to change the primary finding.

CONCLUSION

This is the first study to compare lobectomy and total thyroidectomy outcomes while adjusting for and quantifying the potential effects of unmeasured confounding variables on observational data. The findings suggest that total thyroidectomy is unlikely to offer a survival advantage over lobectomy regardless of tumor size, patient age, or overall risk of death.

Is lobectomy sufficient for multifocal papillary thyroid microcarcinoma?

IMPORTANCE

Multifocal papillary thyroid microcarcinoma (PTMC) has been associated with a higher incidence of lymph node involvement, bilateral involvement, and extrathyroidal extension compared to unifocal papillary thyroid cancer (PTC).

OBJECTIVE

To describe the incidence and determinants of survival for patients with multifocal PTMC using the Surveillance, Epidemiology, and End Result (SEER) database.

DESIGN, SETTING, PARTICIPANTS

The SEER registry was utilized to calculate survival trends for patients with PTMC between 2010 and 2015. Patient data was then analyzed with respect to age, sex, race, multifocality, and types of surgery rendered.

MAIN OUTCOMES AND MEASURES

Overall Survival (OS) and Disease Specific Survival (DSS).

RESULTS

22,283 cases of papillary thyroid microcarcinoma (T1a N0 M0) were identified. The cohort was composed of 82.6 % females, and about 82 % of patients were of white race. The mean age at diagnosis was 51.9 years. Multifocal PTMC was present in 32.2 % of the tumors (n = 7186). 73.9 % of patients underwent total thyroidectomy and 23.0 % received lobectomy. OS at 2 and 5 years was 98 % and 95 %, respectively. Multivariate analysis revealed that age, sex, and multifocality were determinants of OS. Only age was a determinant of DSS. Kaplan-Meier survival analysis revealed that multifocal PTMC had similar mean OS between lobectomy and total thyroidectomy patients (69.59 months versus 69.82 months).

CONCLUSIONS AND RELEVANCE

PTMC has a good prognosis. Our analysis revealed that age was a determinant of OS and DSS; sex and multifocality were also prognosticators for OS. The type of surgery, whether lobectomy or total thyroidectomy, was not a determinant of survival in multifocal PTMC.

Urban and Rural Surgical Practice Patterns for Papillary Thyroid Carcinoma

Background: The 2015 American Thyroid Association (ATA) guidelines shifted recommendations toward less aggressive management of papillary thyroid cancer (PTC). Subsequently, several studies demonstrated a trend in performing thyroid lobectomy (TL) over total thyroidectomy (TT). However, regional variation has persisted without a clear indication of what factors may be influencing practice variation. We aimed to evaluate the surgical management of PTC in patients in rural and urban settings to assess trends of TL compared with TT following the implementation of the 2015 ATA guidelines. Methods: A retrospective cohort analysis was performed using the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2019 of patients with localized PTC <4 cm who underwent TT or TL. Patients were classified as living in urban or rural counties based on the 2013 Rural-Urban Continuum Codes. Procedures performed from 2004 to 2015 were categorized as preguidelines, while those performed from 2016 to 2019 were categorized as postguidelines. Chi-square, Student's t-test, logistic regression, and Cochran-Mantel-Haenszel test were used. Results: A total of 89,294 cases were included in the study. Eighty thousand one hundred and fifty (89.8%) were from urban settings and 9144 (9.2%) were from rural settings. Patients from rural settings were older (52 vs. 50 years, p < 0.001) and had smaller nodules (p < 0.001). On adjusted analysis, patients in rural areas were less likely to undergo TT (adjusted odds ratio 0.81, confidence interval [CI] 0.76-0.87). Before the 2015 guidelines, patients in urban settings had a 24% higher odds of undergoing TT compared with those in rural settings (odds ratio 1.24, CI 1.16-1.32, p < 0.001). There was no difference in the proportions of TT and TL based on setting following guideline implementation (p = 0.185). Conclusions: The 2015 ATA guidelines led to a change in overall practice in surgical management of PTC toward increasing TL. While urban and rural practice variation existed before 2015, both settings had an increase in TL following the guideline change, emphasizing the importance of clinical practice guidelines to ensure best practice in both rural and urban settings.

Advances in Molecular Profiling and Their Potential Influence on the Extent of Surgery in Well-Differentiated Thyroid Carcinoma (WDTC)

Thyroid cancer surgery has evolved dramatically with advances in our understanding of the biological behaviour of WDTC. Molecular profiling is shedding light on the subset that may behave aggressively. In an era when thyroid cancer management is becoming increasingly conservative, decision making regarding the extent of surgery must be objectively guided by molecular markers. The aim of the present article is to summarise the current published literature and provide possible practice recommendations. An online search for relevant published articles was performed using several databases. Title, abstract, and full-text screening, along with data extraction, was performed by two independent reviewers after the inclusion and exclusion criteria were defined. A total of 1241 articles were identified, and 82 relevant articles were extracted and scrutinised. BRAF V600E and TERT promoter mutations were found to be associated with an increased risk of disease recurrence and distant metastases. Several other mutations have been identified that enhance disease aggressiveness (such as RET/PTC, PTEN, and TP53). One of the most important determinants of the outcome in WDTC is the extent of surgical resection. The evolution of molecular testing has reached a stage of personalised incorporation into surgical practice. Guidelines for molecular testing and surgery in WDTC will need to be clearly defined, arguably representing the next chapter in the management of the disease.

Hemithyroidectomy in Papillary Thyroid Cancers: A Prospective, Single Institutional Surgical Audit and Contemplating on the Clinical Implications of 2015 American Thyroid Association Guidelines

Papillary thyroid carcinoma (PTC) contributes to 88% of thyroid malignancies and its extent of surgical management has been a topic of debate in the past 2 decades. American thyroid association (ATA) recommendations have been periodically updated for its robust and evidence-based management. We present our experience in implementing 2015 ATA guidelines, assessment of surgical outcomes of hemithyroidectomy in PTC ≤ 4 cm and contemplating on the potential clinical implications of 2015 ATA guidelines. A prospective study in a cohort of Bethesda class V and VI PTC with nodule ≤ 4 cm who underwent Hemithyroidectomy between 2012 and 2020. Data on thyroid nodule evaluation, management, histopathology and follow up were used for risk stratification. Of 37 patients, 27 (72.9%) were low risk and 10 (37%) were intermediate risk ATA group. 4 (40%) intermediate risk patients had structural incomplete response and underwent completion thyroidectomy. 1 (2.7%) out of 4 completion surgery patients required adjuvant radio-ablation iodine (RAI) and 3 patients were under surveillance. Overall, 2 (5.4%) of 37 patients, 1 each from low and intermediate groups were given remnant RAI in view of aggressive histology, old age and unwillingness for a completion surgery. During follow up of 4.94 ± 2.4 years, 35 (94.5%) showed excellent response and 2 (5.4%) showed biochemical incomplete response. The difference in RFS between two groups was statistically significant with p < 0.001. Thyroid preserving surgery combined with real time risk stratification seems appropriate for low and intermediate risk PTC ≤ 4 cm.

Thyroid Lobectomy for Low-Risk 1-4 CM Papillary Thyroid Cancer is not Associated with Increased Recurrence Rates in the Dutch Population with a Restricted Diagnostic Work-Up

INTRODUCTION

The 2015 American Thyroid Association guidelines recommend to de-escalate treatment such as Thyroid lobectomy instead of total thyroidectomy for 1-4 cm papillary thyroid cancer (PTC). Dutch guidelines endorse restricted work-up for thyroid incidentalomas recommending only fine needle aspiration in case of a 'palpable thyroid nodule'. This diagnostic work-up algorithm may result in the identification of less indolent PTCs and may lead to a patient population with relatively more aggressive PTCs. This study aims to retrospectively analyze recurrence rates of low-risk 1-4 cm PTC in the Netherlands.

METHODS

From the national cancer registry, patients with low-risk 1-4 cm PTC between 2005 and 2015 were included for analysis. Disease free survival (DFS) and overall survival were compared between patients who underwent TT ± RAI and TL without RAI. Post-hoc propensity score analysis was performed correcting for age, sex, T-stage, and N-stage.

RESULTS

In total 901 patients were included, of which 711 (78.9%) were females, with a median follow-up of 7.7 years. TT was performed in 893 (94.8%) patients. Recurrence occurred in 23 (2.6%) patients. Multivariable analysis showed no significant correlation between extent of surgery and DFS (p = 0.978), or overall survival (p = 0.590). After propensity score matching, multivariable analysis showed no significant difference on extent of surgery and recurrence.

CONCLUSION

Low-risk PTC patients with 1-4 cm tumor who underwent TL showed similar recurrence rates as those who underwent TT ± adjuvant RAI, which suggests that TL can be sufficient in treating low-risk 1-4 cm PTC, possibly reducing morbidity of these patients in the Netherlands.

Lobectomy or Total Thyroidectomy-Where Is the Pendulum now for Differentiated Thyroid Cancer?

Thyroid surgery remains an essential treatment of thyroid cancer. The historical one-size-fits-all approach to differentiated (papillary and follicular) thyroid carcinoma of total thyroidectomy with central lymph node dissection has been shown to be overtreatment with associated risk of perioperative complications including nerve palsy and hypoparathyroidism. Furthermore, thyroid lobectomy may obviate life-long thyroid hormone replacement. Low-risk thyroid cancers have a low risk of recurrence and those that do recur can be salvaged with reoperation without compromising prognosis. Perioperative risk stratification for recurrence and death greatly influence the need for total thyroidectomy.

Serum thyroglobulin testing after thyroid lobectomy in patients with 1-4 cm papillary thyroid carcinoma

BACKGROUND

The role of measuring serum thyroglobulin (Tg) levels in patients who have undergone lobectomy has not been proven. The goal of this research is to see if serum Tg levels can predict the recurrence of papillary thyroid carcinoma (PTC) after lobectomy.

METHODS

The 463 patients with 1-4 cm PTC who underwent lobectomy between January 2005 and December 2012, were included in this retrospective cohort study. Postoperative serum Tg levels and neck ultrasound were evaluated every 6-12 months after lobectomy during a median 7.8-year follow-up period. The receiver operating characteristic (ROC) curve and its area under the ROC curve (AUC) was used to assess the diagnostic performance of serum Tg levels.

RESULTS

During the follow-up, the structural recurrent disease was confirmed in 30 patients (6.5%). The serum Tg levels measured by initial Tg, maximal Tg, and last Tg did not differ statistically between the recurrence and non-recurrence groups. According to our findings, serial patterns of serum maximal Tg variations in 30 patients with recurrence showed no obvious trend and no rising trend toward recurrence before detecting recurrence. The AUC was 54.5% (IQR 43.1%-65.9%) in the ROC curve analysis, indicating that it was not significantly different from the random classifier.

CONCLUSION

Serum Tg levels did not differ significantly between the recurrence and non-recurrence groups, and there was no tendency for the recurrence group to increase Tg levels. In patients with PTC who underwent lobectomy, monitoring Tg levels regularly provides little benefit in predicting recurrence.

Examining National Guideline Changes Association With Hemithyroidectomy Rates by Surgeon Volume

INTRODUCTION

The 2015 American Thyroid Association (ATA) guidelines established that hemithyroidectomy (HT) is an appropriate treatment for patients with low-risk thyroid cancer. HT rates increased since the ATA guidelines were released; however, the relationship between surgeon volume and the initial extent of surgery has not been established.

METHODS

A statewide database was used to identify patients with thyroid cancer who underwent initial thyroidectomy from 2013 to 2020. High-volume thyroid surgeons were defined as those who performed >25 thyroid procedures per year. A mixed-effect logistic model was used to compare low- and high-volume surgeons' initial extent of surgery pre-2015 and post-2015 ATA guidelines. Descriptive statistics were used to describe other surgical outcomes.

RESULTS

The analysis included 3199 patients with thyroid cancer who underwent initial thyroidectomy. Twenty-four surgeons (6%) were considered high-volume; they performed 48% (n = 1349) of the operations. After the 2015 ATA guidelines were released, the rate of HT increased significantly for low- (23% to 28%, P = 0.042) but not high-volume (19% to 23%, P = 0.149) surgeons. Low-volume surgeons had significantly higher rates of readmission (P = 0.008), re-operation (P = 0.030), complications (P < 0.001), and emergency room visits (P = 0.002) throughout the entire study period.

CONCLUSIONS

The publication of the 2015 ATA guidelines was associated with a significant increase in HT rates, primarily in low-volume thyroid surgeons. While low-volume surgeons began performing more HTs, they continued to have higher rates of readmission, reoperations, complications, and emergency room visits than high-volume surgeons.

Lobo-isthmectomy in the management of differentiated thyroid cancer

We have recently witnessed a rapid increase in the incidence of differentiated thyroid carcinoma (DTC), particularly low and very low-risk papillary thyroid carcinoma. Simultaneously, the number of cancer-related deaths has remained stable for more than 30 years. Such an indolent nature and long-term survival prompted researchers and experts to an ongoing discussion on the adequacy of DTC management to avoid, on the one hand, the overtreatment of low-risk cases and, on the other hand, the undertreatment of highly aggressive ones.The most recent guidelines of the American Thyroid Association (ATA GL) moved primary thyroid surgery in DTC towards a less aggressive approach by making lobectomy an option for patients with intrathyroidal low-risk DTC tumors up to 4 cm in diameter without evidence of extrathyroidal extension or lymph node metastases. It was one of the key changes in DTC management proposed by the ATA in 2015.Following the introduction of the 2015 ATA GL, the role of thyroid lobectomy in DTC management has slowly become increasingly important. The data coming from analyses of the large databases and retrospective studies prove that a less extensive surgical approach, even if in some reports it was related to a slight increase of the risk of recurrence, did not show a negative impact on disease-specific and overall survival in T1T2N0M0 low-risk DTC. There is no doubt that making thyroid lobectomy an option for low-risk papillary and follicular carcinomas was an essential step toward the de-escalation of treatment in thyroid carcinoma.This review summarizes the current recommendations and evidence-based data supporting the necessity of de-escalation of primary thyroid surgery in low-risk DTC. It also discusses the controversies raised by introducing new ATA guidelines and tries to resolve some open questions.

Establishment and validation of a nomogram to predict structural incomplete response in papillary thyroid carcinoma patients: a retrospective study

OBJECTIVE

To identify risk factors related to structural incomplete response (SIR) in papillary thyroid carcinoma (PTC) and develop a nomogram for PTC patients.

METHODS

In this respective study, clinical, ultrasonic, and pathological data of PTC patients treated at our institute between 2016 and 2020 were analyzed. Patients were randomly split into training and validation sets at a ratio of 7:3. Multivariate Cox regression analysis was conducted to determine independent prognostic factors. On the basis of these factors, a nomogram was built to predict SIR. P value, concordance index, calibration plots and decision curve analysis were used to evaluate the model.

RESULTS

Multivariate Cox regression analysis showed that BRAF V600E status, lymph node metastasis, sex, tumor size, margin, and surgical procedure were independent prognostic factors. In the validation set, the concordance index of the nomogram was 0.774 (95% confidence interval: 0.703-0.845). Calibration plots at 3 and 5 years showed no apparent difference between predicted SIR probability and the actual SIR proportion. Additionally, the nomogram had good net clinical benefit according to the decision curve analysis compared with cases that were treat-all or treat-none.

CONCLUSION

We build a nomogram to predict individualized outcomes and help postoperative surveillance in PTC patients.

Current Controversies in Low-Risk Differentiated Thyroid Cancer: Reducing Overtreatment in an Era of Overdiagnosis

CONTEXT

Low-risk differentiated thyroid cancer (DTC) is overdiagnosed, but true incidence has increased as well. Owing to its excellent prognosis with low morbidity and mortality, balancing treatment risks with risks of disease progression can be challenging, leading to several areas of controversy.

EVIDENCE ACQUISITION

This mini-review is an overview of controversies and difficult decisions around the management of all stages of low-risk DTC, from diagnosis through treatment and follow-up. In particular, overdiagnosis, active surveillance vs surgery, extent of surgery, radioactive iodine (RAI) treatment, thyrotropin suppression, and postoperative surveillance are discussed.

EVIDENCE SYNTHESIS

Recommendations regarding the diagnosis of DTC, the extent of treatment for low-risk DTC patients, and the intensity of posttreatment follow-up have all changed substantially in the past decade. While overdiagnosis remains a problem, there has been a true increase in incidence as well. Treatment options range from active surveillance of small tumors to total thyroidectomy followed by RAI in select cases. Recommendations for long-term surveillance frequency and duration are similarly broad.

CONCLUSION

Clinicians and patients must approach each case in a personalized and nuanced fashion to select the appropriate extent of treatment on an individual basis. In areas of evidential equipoise, data regarding patient-centered outcomes may help guide decision-making.

[Hemithyroidectomy or total thyroidectomy for low-risk papillary thyroid cancer? : Surgical criteria for primary and secondary choice of treatment in an interdisciplinary treatment concept]

The increase in small intrathyroid papillary thyroid cancer (PTC) observed worldwide over the past two decades, with no increase in cancer-specific mortality, has challenged the previous concept of total thyroidectomy as a one-size-fits-all panacea. After exclusion of papillary microcarcinomas, a systematic review of 20 clinical studies published since 2002, which compared hemithyroidectomy (HT) to total thyroidectomy (TT), found comparable long-term oncological outcomes for low-risk papillary thyroid cancer (LRPTC) 1-4 cm in diameter, whereas postoperative complication rates were markedly lower for HT. To refine individual treatment plans, HT should be combined with ipsilateral central lymph node dissection and intraoperative frozen section analysis for staging. Based on recent evidence from studies and in consideration of individual risk factors, patients with LRPTC can be offered the concept of HT as an alternative to the standard TT. A prerequisite for the treatment selection and decision is a comprehensive patient clarification of the possible advantages and disadvantages of both approaches.

Differentiated thyroid carcinoma: An update

Differentiated thyroid carcinoma (DTC) is the most common endocrine cancer. Particularly the incidence of small clinically indolent tumors has been increasing significantly during the last decades because of increased diagnostic scrutiny, while the DTC-related mortality remained unchanged. In light of the increased awareness of the significant risk of detecting clinically indolent tumors and the potential harm and burden associated with overly diagnosis and the treatment, the approach towards management of DTC recently underwent a critical appraisal. The focus lays on reducing the unnecessary burden for patients with very low risk DTC and the correct identification of those who require treatment that is more intensive and/or follow-up. Management of DTC includes a range of different modalities, making multidisciplinary collaboration expedient. In this review, we elaborate on the recent developments in diagnosis, staging and management of DTC with specific focus on the more individualized risk assessment-based approach.

Advances in Endocrine Surgery

Recent changes in the landscape of endocrine surgery include a shift from total thyroidectomy for almost all patients with papillary thyroid cancer to the incorporation of thyroid lobectomy for well-selected patients with low-risk disease; minimally invasive parathyroidectomy with, and potentially without, intraoperative parathyroid hormone monitoring for patients with well-localized primary hyperparathyroidism; improvement in the management of parathyroid cancer with the incorporation of immune checkpoint blockade and/or targeted therapies; and the incorporation of minimally invasive techniques in the management of patients with benign tumors and selected secondary malignancies of the adrenal gland.

Surgical management of T1/T2 node-negative papillary thyroid cancer with tall cell histology: Is lobectomy enough?

BACKGROUND

The tall cell variant of papillary thyroid carcinoma has traditionally been treated more aggressively than classic papillary thyroid carcinoma. However, this may not be justified in patients with T1/T2 tall cell variant node-negative tumors.

METHODS

We evaluated well-differentiated thyroid cancers treated surgically between 1985 and 2015 at our institution. We compared patients undergoing lobectomy for node-negative T1/T2 tall cell variant tumors with the same cohort with classic papillary thyroid carcinoma. Patients who underwent early planned completion thyroidectomy were excluded. Tall cell variant tumors were defined as those with ≥30% tall cells. Survival and recurrence outcomes were determined by the Kaplan-Meier method and groups compared using the log-rank test.

RESULTS

Thyroid lobectomy was performed for T1/T2 N0X disease in 70 (15%) tall cell cases and 429 (23%) classic papillary thyroid carcinoma cases. There was no significant difference in 10-year overall survival (P = .56) or locoregional recurrence-free probability (P = .52). Disease-specific survival and local or central nodal recurrence-free probability were 100% in both groups. In 9 papillary thyroid carcinoma cases, subsequent contralateral lobe tumors developed, and in 5, lateral neck metastases developed. No recurrences were seen in the tall cell group.

CONCLUSION

T1 node-negative tumors with tall cell histology can be satisfactorily managed with thyroid lobectomy, with equivalent oncological outcomes to classic papillary thyroid carcinoma.

Pathological multifocality is not a prognosis factor of papillary thyroid carcinoma: a single-center, retrospective study

INTRODUCTION

Non-total thyroidectomy (non-TTx) is a widely accepted operative procedure for low-risk papillary thyroid carcinoma (PTC). PTC patients preoperatively diagnosed with unifocal disease are often revealed as having multifocal foci by microscopy. The present study determined whether or not patients with clinically unifocal, but pathologically multifocal non-high-risk PTC treated with non-TTx have an increased risk of a poor prognosis compared to those with pathologically unifocal PTC.

MATERIALS AND METHODS

PTC patients diagnosed as unifocal preoperatively who underwent non-TTx were multifocal in 61 and unifocal in 266 patients microscopically. Oncologic event rates were compared between pathologically multifocal and unifocal PTC patients.

RESULTS

Pathological multifocality was associated with positive clinical lymph node metastasis (cN1) (odds ratio [OR] 4.01, 95% confidence interval [CI]: 1.91-8.04) and positive pathological lymph node metastasis (pN1) in > 5 nodes (OR 3.68, 95% CI: 1.60-8.49). No patients died from PTC. There was no significant difference in the disease-free survival rate, remnant thyroid disease-free survival rate, lymph node disease-free survival rate, or distant disease-free survival rate between the two groups. Recurrence in pathologically multifocal PTC patients was locoregional in all cases and able to be salvaged by reoperation. Cox proportional hazard model analyses showed no significant difference in recurrence rates with regard to pathological multifocality and cN or number of pNs.

CONCLUSION

The prognosis of PTC with pathological multifocality treated by non-TTx was not inferior to that of unifocal PTC. Immediate completion thyroidectomy is not necessary when microscopic foci are proven.

Prevalence of Postoperatively Detected High-risk Features in 2- to 4-cm Papillary Thyroid Cancers

CONTEXT

The 2015 American Thyroid Association guidelines proposed thyroid lobectomy as an acceptable option for 1- to 4-cm papillary thyroid cancers (PTC) without extrathyroidal extension (ETE) or lymph node (LN) metastasis. However, high-risk features are often detected postoperatively, even in tumors that are considered low risk on preoperative workup. A continued evaluation is necessary to determine the optimal treatment strategies.

OBJECTIVE

We examined the frequency of preoperatively and postoperatively detected high-risk features in 2- to 4-cm PTCs to assess the appropriate surgical extent.

METHODS

All patients who underwent a thyroid surgery between 2015 and 2020 with a final diagnosis of 2- to 4-cm PTC were selected. Demographics, preoperative findings, perioperative course, and surgical pathology were retrospectively analyzed.

RESULTS

Of the entire study cohort (N = 424), 244 (57.5%) patients had at least 1 of the following high-risk features: gross ETE (18.6%), distant metastasis (1.2%), >3 LN involvement with extranodal extension (24.8%), any LN > 3 cm (0.5%), positive margin (13.2%), TERT mutation (2.6%), vascular invasion (10.8%), cN1 disease (28.5%), and > 5 LN involvement (30.4%). Two hundred patients had neither ETE nor LN metastasis on preoperative imaging, but 62/200 (31.0%) were found to have at least 1 of the aforementioned high-risk features on final pathology. Preoperative imaging had sensitivities of 75.9% and 44.4% for detecting gross ETE and LN metastasis, respectively.

CONCLUSION

A significant portion of patients with 2- to 4-cm PTCs, including those who preoperatively met the criteria for lobectomy, were found to have high-risk features on final pathology. Careful patient selection and appropriate counseling are necessary when considering lobectomy for tumors greater than 2 cm.

Endocrine surgeons are performing more thyroid lobectomies for low-risk differentiated thyroid cancer since the 2015 ATA guidelines

BACKGROUND

The 2015 American Thyroid Association guidelines recommended either total thyroidectomy or lobectomy for surgical treatment of low-risk differentiated thyroid cancer and de-escalated recommendations for central neck dissections. The study aim was to investigate how practice patterns among endocrine surgeons have changed over time.

METHODS

All adult patients with low-risk differentiated thyroid cancers (T1-T2, N0/Nx, M0/Mx) in the Collaborative Endocrine Surgery Quality Improvement Program (2014-2021) were identified. The outcomes between patients undergoing lobectomy versus total thyroidectomy were compared using multivariable logistic regression. The annual percent change in the proportion of lobectomies and central neck dissections performed was estimated using joinpoint regression.

RESULTS

In total, 5,567 patients with low-risk differentiated thyroid cancers were identified. Of these, 2,261 (40.6%) were very low-risk tumors ≤1 cm, and 2,983 (53.6%) were low-risk tumors >1 and <4 cm. Most patients (67.9%) underwent total thyroidectomy. Compared to total thyroidectomy, lobectomy was associated with outpatient surgery (adjusted odds ratio 5.19, P < .001), a decreased risk of postoperative emergency department visits (adjusted odds ratio 0.63, P = .03), and decreased risk of hypoparathyroidism events (adjusted odds ratio 0.03, P < .001). Compared to before (2014-2015), patients undergoing surgery after publication of the revised guidelines (2016-2021) had higher odds of lobectomy and lower odds of central neck dissection for tumors ≤1 cm (lobectomy adjusted odds ratio 2.70, P < .001; central neck dissections adjusted odds ratio 0.64, P = .03) and tumors between 1 and 4 cm (lobectomy adjusted odds ratio 2.27, P < .001; central neck dissection adjusted odds ratio 0.62, P < .001).

CONCLUSION

After publication of the 2015 American Thyroid Association guidelines, there has been an increase in thyroid lobectomies as a proportion of all thyroid operations performed by endocrine surgeons for low-risk differentiated thyroid cancer. This has implications for reduced health care use and costs, with potential population-level benefits.

Clinical assessment of T2 papillary thyroid carcinoma: a retrospective study conducted at a single tertiary institution

The extent of surgery among patients with T2 papillary thyroid carcinoma (PTC) remains controversial. Thus, we herein aimed to evaluate the risk factors for recurrence, particularly based on the extent of surgery, among patients with T2 PTC at a single tertiary institution. We assessed 251 patients who underwent thyroid surgery for T2 PTC from January 2009 to December 2014 at Seoul St. Mary's Hospital (Seoul, Korea). The mean follow-up duration was 100.7 months. Eleven (4.4%) patients had recurrence. The recurrence rates did not significantly differ in terms of the extent of surgery (p = 0.868). Patients with a high lymph node ratio (LNR) had a significantly higher recurrence rate than those with a low LNR (p < 0.001). According to a recurrence pattern analysis, five of six patients in the lobectomy group had recurrence in the ipsilateral lateral compartment. A multivariate analysis revealed that a high LNR was a significant risk factor for recurrence (hazard ratio: 11.025, p = 0.002). Our results suggest that patients without clinical evidence of any lymph node metastases and those with limited lesions in the thyroid gland can undergo lobectomy and LNR can serve as an independent risk factor for predicting recurrence in T2 PTC.

Central Lymph Node Ratio Predicts Recurrence in Patients with N1b Papillary Thyroid Carcinoma

Simple Summary

The lymph node ratio (LNR) is an emerging predictive marker for recurrence in papillary thyroid carcinoma (PTC). The purpose of this study was to investigate the association between LNR and disease-free survival (DFS) in patients with N1b PTC. Unlike that in the lateral or whole neck, LNR in the central compartment (CLNR) was found to have prognostic significance. The high-CLNR group (CLNR ≥ 0.7) had worse DFS and was 4.5 times more likely to experience recurrence in patients with N1b PTC.

Abstract

The lymph node ratio (LNR) indicates the number of metastatic lymph nodes (LNs) to the total number of LNs. The prognostic value of LNR in papillary thyroid carcinoma (PTC) and other solid tumors is known. This study aimed to investigate the relationship between LNR and disease-free survival (DFS) in patients with PTC with lateral LN metastases (N1b PTC). A total of 307 patients with N1b PTC who underwent total thyroidectomy and therapeutic central and lateral LN dissection were retrospectively analyzed. The DFS and recurrence risk in the patients with LNR, central-compartment LNR (CLNR), and lateral-compartment LNR (LLNR) were compared. The mean follow-up duration was 93.6 ± 19.9 months. Eleven (3.6%) patients experienced recurrence. Neither LNR nor LLNR affected the recurrence rate in our analysis (p = 0.058, p = 0.106, respectively). However, there was a significant difference in the recurrence rates between the patients with low and high CLNR (2.1% vs. 8.8%, p = 0.017). In the multivariate analysis, CLNR ≥ 0.7 and perineural invasion were independent predictors of tumor recurrence. High CLNR was associated with an increased risk of recurrence, and was shown to be a significant predictor of prognosis in patients with N1b PTC.

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.

Health-Related Quality of Life following Total Thyroidectomy and Lobectomy for Differentiated Thyroid Carcinoma: A Systematic Review

Health-related quality of life (HrQoL) is a major concern for patients with differentiated thyroid carcinoma (DTC). We aimed to systematically review the literature comparing HrQol following total thyroidectomy (TT) and hemithyroidectomy (HT) in DTC patients. A systematic review of publications indexed in Medline, Embase, and EBM reviews—Cochrane Central Register of Controlled Trials, which evaluated HrQoL following thyroid surgery for DTC, was conducted. Of 2507 identified records, 25 fulfilled the inclusion criteria. Our results suggest that patients undergoing TT may suffer more impairment in physical and social HrQoL than patients undergoing HT. Psychological-related HrQoL and long-term global HrQoL are, however, equivalent in both groups, which highlights the multidimensional nature of HrQoL and the importance of a multitude of factors aside from treatment modalities and related morbidities, such as the experience of receiving a cancer diagnosis, the fear of cancer recurrence, and other psychosocial factors. Addressing postoperative HrQoL when discussing therapeutic options with patients is an integral part of patient-centered care and informed shared decision-making, and should be approached in a holistic manner, accounting for its physical, psychological, and social aspects. This review supplies evidence regarding HrQoL following thyroid surgery, which can be employed in such decisions.

Complication Rates of Total Thyroidectomy vs Hemithyroidectomy for Treatment of Papillary Thyroid Microcarcinoma: A Systematic Review and Meta-analysis

Importance

Papillary thyroid microcarcinomas (PTMCs) have been associated with increased thyroid cancer incidence in recent decades. Total thyroidectomy (TT) has historically been the primary treatment, but current guidelines recommend hemithyroidectomy (HT) for select low-risk cancers; however, the risk-benefit ratio of the 2 operations is incompletely characterized.

Objective

To compare surgical complication rates between TT and HT for PTMC treatment.

Data Sources

SCOPUS, Medline via the PubMed interface, and the Cochrane Central Register of Controlled Trials (CENTRAL); through January 1, 2021, with no starting date restriction. Terms related to papillary thyroid carcinoma and its treatment were used for article retrieval. This meta-analysis used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline and was written according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) proposal.

Study Selection

Original investigations of adults reporting primary surgical treatment outcomes in PTMC and at least 1 complication of interest were included. Articles evaluating only secondary operations or non-open surgical approaches were excluded. Study selection, data extraction, and risk of bias assessment were performed by 2 independent reviewers and conflicts resolved by a senior reviewer.

Data Extraction and Synthesis

Pooled effect estimates were calculated using a random-effects inverse-variance weighting model.

Main Outcomes and Measures

Cancer recurrence and site, mortality (all-cause and disease-specific), vocal fold paralysis, hypoparathyroidism, and hemorrhage/hematoma. Risk of bias was assessed using the McMaster Quality Assessment Scale of Harms scale.

Results

In this systematic review and meta-analysis, 17 studies were analyzed and included 1416 patients undergoing HT and 2411 patients undergoing TT (HT: pooled mean [SD] age, 47.0 [10.0] years; 1139 [84.6%] were female; and TT: pooled mean [SD] age, 48.8 [10.0] years; 1671 [77.4%] were female). Patients undergoing HT had significantly lower risk of temporary vocal fold paralysis compared with patients undergoing TT (3.3% vs 4.5%) (weighted risk ratio [RR], 0.4; 95% CI, 0.2-0.7), temporary hypoparathyroidism (2.2% vs 21.3%) (weighted RR, 0.1; 95% CI, 0.0-0.4), and permanent hypoparathyroidism (0% vs 1.8%) (weighted RR, 0.2; 95% CI, 0.0-0.8). Contralateral lobe malignant neoplasm recurrence was 2.3% in the HT group, while no such events occurred in the TT group. Hemithyroidectomy was associated with a higher overall recurrence rate (3.8% vs 1.0%) (weighted RR, 2.6; 95% CI, 1.3-5.4), but there was no difference in recurrence in the thyroid bed or neck.

Conclusions and Relevance

The results of this systematic review and meta-analysis help characterize current knowledge of the risk-benefit ratio of HT vs TT for treatment of PTMC and provide data that may have utility for patient counseling surrounding treatment decisions.

The 2015 American Thyroid Association guidelines and trends in hemithyroidectomy utilization for pediatric thyroid cancer

BACKGROUND

In 2015, the American Thyroid Association (ATA) released its inaugural recommendations for the management of thyroid cancer in children. We aim to evaluate whether there has been a change in hemithyroidectomy utilization for pediatric differentiated thyroid cancer, and the association between those changes and the release of the ATA guidelines.

METHODS

The National Cancer Database was queried and identified 4776 patients ≤18 years old with differentiated thyroid cancer. Causal impact time-series analysis and logistic analysis were utilized to assess factors associated with use of hemithyroidectomy.

RESULTS

Post-2015 hemithyroidectomy rate was greater than predicted based on preguideline trends (predicted: 8.4%, actual: 12.6%, p = 0.001). In logistic analysis of factors associated with hemithyroidectomy use, we find that Papillary histology, tumor size >1 cm, nodal examination, and positive nodes were associated with lower rate of hemithyroidectomy (OR: 0.23, 0.51, 0.62, and 0.18, respectively).

CONCLUSION

There has been a significant increase in hemithyroidectomy utilization for pediatric differentiated thyroid cancer.

Impact of Endocrinologist and Surgeon Density on Well-Differentiated Thyroid Cancer Survival

BACKGROUND

The influence of provider density and access on well-differentiated thyroid cancer (DTC) survival is uncertain.

METHODS

We used the SEER18 database to study DTC patients undergoing surgery from 2000-2012. County-level endocrinologist and surgeon density were calculated. We evaluated the relationship between provider density and cause-specific survival controlling for demographic, socioeconomic, and treatment characteristics.

RESULTS

Median endocrinologist density was 1.4/100 000 residents, with 15.5% of patients living in a county with no endocrinologist. Survival increased by 11% for each endocrinologist/100,000 people (P = .007). Median surgeon density was 14.8/100 000 residents, with only 1.7% of patients living in a county with no general surgeon or otolaryngologist. No significant association between surgeon density and survival was identified (P = .06). Rural residence was independently associated with lower survival (P = .009).

CONCLUSIONS

County-level endocrinologist density is associated with improved DTC survival. Results may reflect endocrinologist expertise, earlier diagnosis, or represent surrogacy for higher county-level access to specialized care.

PRDX4 Potentially Predicts the Postoperative Outcome in Advanced Papillary Thyroid Carcinoma

Background: Peroxiredoxin 4 (PRDX4), a secreted antioxidant enzyme, can protect against hepatocellular carcinoma and lung adenocarcinoma, but its role in papillary thyroid carcinoma (PTC) is still unclear. In this study, we investigated the association of the PRDX4 expression with the prognosis of patients with advanced PTC. Methods: We conducted a retrospective case-control study at Kanazawa Medical University Hospital. We selected PTC patients over 55 years of age who received surgery from 2006 to 2014. The PRDX4 expression was immunohistochemically analyzed in paraffin-embedded tumor specimens of 70 patients with stages Ⅱ–Ⅳ advanced PTC. We also investigated the key roles of PRDX4 in a human PTC cell line (K-1) in vitro. Result: The weak expression of PRDX4 was found to be significantly associated with recurrence. In a multivariate analysis, the weak expression of PRDX4—rather than other pathological features of high invasiveness—predicted a poor prognosis. In vitro, the viability of human PTC cells was significantly suppressed after PRXD4 plasmid transfection. Conclusion: The weak expression of PRDX4 can predict recurrence with a potential poor prognosis in advanced PTC.

Restratification of Patients with Intermediate-Risk Papillary Thyroid Carcinoma

BACKGROUND

Long-term management and follow-up strategies in patients with intermediate-risk papillary thyroid carcinoma (PTC) according to the American Thyroid Association (ATA) are still controversial due to the paucity of data on unique risk factors or a risk stratification system predictive of long-term outcomes.

PATIENTS AND METHODS

This study included 649 patients with PTC who underwent an initial surgical treatment. Retrospectively enrolled patients were categorized according to the ATA risk stratification system. Intermediate-risk patients were further categorized into subgroups by the number of ATA intermediate risk factors. The recurrence-free survival (RFS) rates of these subgroups were compared with those of low- and high-risk patient groups. Additionally, the patients were classified according to their response to the initial therapy using the dynamic risk stratification (DRS) system, and the percentages of patients in each category were compared among the subgroups.

RESULTS

The median follow-up period was 102 months. Structural recurrence occurred in 9.2% of all enrolled patients (60/649) and in 13.0% of intermediate-risk patients (40/308). Patients with two or more current intermediate risk factors had a poorer RFS than patients with only one risk factor (p < 0.001) and showed a comparable RFS to high-risk patients (p > 0.050). The percentages of patients with an excellent response category for DRS significantly decreased with an increase in the number of intermediate risk factors.

CONCLUSION

Subclassification according to the number of intermediate risk factors may be useful to better predict the RFS and the response to initial therapy in patients with intermediate-risk PTC.

Comparison between 2015 ATA guidelines and Italian Consensus for DTC management. A commented report

The 2015 ATA guidelines and 2018 Italian Consensus have produced a series of generally concordant recommendations on clinical and therapeutic management of thyroid nodules and thyroid carcinoma. Currently, the goals of treatment are to achieve the highest disease-free survival rates through the best ratio between minimum invasiveness and cost/impact on quality of life. By analysis and comparison of the ATA Guidelines and Italian Consensus, we highlighted and commented upon the key points of differentiated thyroid cancer management. Furthermore, the aim of this work is to identify and promote uniform clinical approaches among all specialists who treat differentiated thyroid cancer and represent a starting point for a consensus drafted by the Italian Society of Otolaryngology - Head and Neck Surgery.

Surgical Management of Low-/Intermediate-Risk Node Negative Thyroid Cancer: A Single-Institution Study Using Propensity Matching Analysis to Compare Thyroid Lobectomy and Total Thyroidectomy

Background: The approach for surgical treatment of patients with low-/intermediate-risk T1T2N0/Nx well-differentiated thyroid cancer (WDTC)-total thyroidectomy (TT) versus thyroid lobectomy (TL)-remains a controversial topic. Conducting a randomized controlled trial (RCT) would be the gold standard to address this issue. However, this is challenging due to excellent survival outcomes, and therefore, high number of patients and long-term follow-up would be required. As an alternative to RCT, we have used propensity score (PS) matching to determine if T1T2N0/Nx patients selected to have TL had equivalent outcomes to a similar group treated with TT. Methods: After institutional review board approval, a database of 6259 patients with WDTC treated with primary surgery at our institution between 1985 and 2016 was analyzed to identify patients with T1T2N0/Nx cancers. Of 3756 patients identified, 943 were managed by TL and 2813 by TT. To control for possible confounders and reduce potential bias, we selected age, sex, histology, ¹³¹I therapy, American Thyroid Association risk, and American Joint Committee Cancer stage as our PS matching criteria. Subsequently, 918 TL patients were successfully matched with 918 TT patients. The Pearson χ² test or Fisher's exact test was used to compare categorical covariates, and Student's t-test was used for comparison of continuous variables between the two groups. Disease-specific survival (DSS), overall survival (OS), and recurrence-free survival (RFS) were calculated using the Kaplan-Meier method and compared using the log-rank test. Results: After PS matching, there were no significant differences between TL and TT patients for OS (10-year OS: 92.2% vs. 91.3%, p = 0.9668), DSS (10-year DSS: 100% vs. 99.1%, p = 0.1967), or RFS (10-year RFS: 99.5% vs. 98.3%, p = 0.079). Conclusions: For low-/intermediate-risk patients with intrathyroidal thyroid cancer <4 cm, patients selected for TL have similar survival outcomes to a comparable group treated by TT.

Adverse Histological Features of Differentiated Thyroid Cancer Are Commonly Found in Autopsy Studies: Implications for Treatment Guidelines

Background: While the popularity of lobectomy for differentiated thyroid cancer (DTC) has increased since the 2015 ATA (American Thyroid Association) guidelines, recent studies reported that adverse histological features (minimal extrathyroidal extension [mETE], multifocality, vascular invasion, and lymph node [LN] metastases) may be found in 30-60% of lobectomy specimens, questioning the validity of this approach. Aim: To assess the prevalence adverse histological features in occult DTC detected in autopsy studies. Methods: Meta-analysis of autopsy studies of the thyroid in subjects without known history of thyroid cancer. Results: Twenty-nine studies including 8750 subjects fulfilled the inclusion criteria, with incidentally discovered DTC in 740 autopsies (8.5%). Age was reported in 17 studies, with a median age of 61 years (range 41-68 years). Multifocality was reported in 27 studies with a calculated event rate of 28.2% ([CI 23.1-33.8], I² = 46.3%), with bilateral involvement in 18% [CI 12.6-25.1]. mETE was reported in 5 studies, with an event rate of 24.5% ([CI 9.3-50.7], I² = 88.5%), and the presence of LN metastases were reported in 13 studies with an event rate of 11% ([CI 6.1-19.1], I² = 69.5%). Vascular invasion was reported in seven studies with an event rate of 16% ([CI 4-47], I² = 86.8%). Of 25 studies with whole body autopsies (722 subjects), 3 cases of distant metastases were reported, of which 2 had fatal metastatic disease (where thyroid origin was not diagnosed before death), and 1 had occult disease. Conclusions: Adverse histological features including mETE, LN metastases, multifocality, and vascular invasion are common in occult DTC. When minimal in size, these adverse histological features do not seem to be markers of aggressive disease and may not be an indication for completion thyroidectomy or radioiodine therapy.

Incidence and predictive factors of postoperative hypocalcaemia according to type of thyroid surgery in older adults

PURPOSE

Transient hypocalcaemia after thyroid surgery and its possible predictors have not been extensively described in the elderly. This study aimed to establish the frequency of postsurgical transient hypocalcaemia according to the extent of thyroid surgery in older adults and to assess mineral metabolism biochemical parameters as its predictors.

METHODS

All patients ≥60 years undergoing thyroid surgery were prospectively included. Type of surgery (hemithyroidectomy(HT) or total thyroidectomy(TT)); and preoperative 25OH Vitamin D (25OHD) and pre and 6 (only TT), 24 h and 6 months postsurgical serum levels of calcium, magnesium, phosphate and parathormone (PTH) were considered. Postsurgical hypoparathyroidism (hPTpost) was defined at PTH levels ≤11 pg/mL.

RESULTS

Out of 46 patients (87% female), age (mean ± SD) 70.1 ± 6.2 years, 24 h postsurgical hypocalcaemia was found in ten patients (22%). In 25 (54%) TT patients, 36% and 16% had postsurgical hypocalcaemia at 6 and 24 h respectively; 28% hPTpost but no definitive hPT was recorded and 44% had 25OHD deficiency. Lower 24 h magnesium levels were found in those TT patients with 24 h hypocalcaemia (1.6 ± 0.1 vs 1.9 ± 0.1 mg/dL (p = 0.005)). Among 21 (46%) HT patients, 28.6% had 24 h postsurgical hypocalcaemia; 9.5% had hPTpost. A positive correlation was observed between preoperative 25OHD and 24 h calcaemia (r:0.51,p = 0.02). 43% of the patients were 25OHD deficient, in whom 55% had 24 h hypocalcaemia vs only 9% in the 25OHD sufficient group (p = 0.049).

CONCLUSION

Postsurgical hypocalcaemia was common in elderly thyroidectomized patients. After TT, lower magnesium levels were found in those patients with 24 h hypocalcaemia. In the HT group, preoperative 25OHD deficiency predicted lower postsurgical calcium levels.

Long-Term Outcome of Lobectomy for Thyroid Cancer

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Overall survival is improved with total thyroidectomy and radiation for male patients and patients older than 55 with T2N0M0 Stage 1 classic papillary thyroid cancer

BACKGROUND

We examine whether surgery extent and radiation administration affect overall survival for cT2N0M0 classic papillary thyroid cancer according to age and sex.

METHODS

Patients with cT2N0M0 classic papillary thyroid cancer tumors in the National Cancer Data Base (2004-2016) were selected. Multivariable Cox regression analysis compared patients (combined male + female cohorts) having lobectomy to those having total thyroidectomy with or without radiation (primarily radioactive iodine) for ages: 18 to 45, 46 to 55, and >55 years. In addition, 1:1 propensity score matching and Kaplan-Meier curves with 10-year overall survival estimates, and log-rank test were stratified by age and sex.

RESULTS

Lobectomy had equivalent overall survival to total thyroidectomy without and with radiation for patients (combined male + female cohorts) aged 18 to 45 and 46 to 55 years on multivariable analysis. On propensity score matching there was overall survival advantage for total thyroidectomy with radiation over both lobectomy and total thyroidectomy for men (ages 18-90+ combined) and overall survival advantage in patients (combined male + female cohort) aged >55 years having total thyroidectomy with radiation versus lobectomy. On propensity score matching there were no overall survival differences in women (ages 18-90+ combined) or patients (combined male + female cohort) aged 18 to 45 and 46 to 55 years having either lobectomy, total thyroidectomy, or total thyroidectomy with radiation.

CONCLUSION

For cT2N0M0 classic papillary thyroid cancer, total thyroidectomy with radiation improves 10-year overall survival for patients (combined male + female cohort) aged >55 years and men (ages 18-90+ combined).

Impact of Extent of Surgery on Long-Term Prognosis of Follicular Thyroid Carcinoma Without Extrathyroidal Extension and Distant Metastasis

AIM

To analyze the effect of total thyroidectomy (TT) and thyroid lobectomy (LT) on the long-term prognosis of follicular thyroid carcinoma (FTC) without extrathyroidal extension and distant metastasis and to clarify whether the tumor size (≤ 40 mm vs. > 40 mm) has an important impact on the extent of surgery.

METHODS

Data on FTC patients without extrathyroidal extension and distant metastasis treated with either TT or LT between 1998 and 2016 were extracted from the Surveillance, Epidemiology, and End Results Database. Propensity score matching was performed to minimize impact of selection bias and potential confounding. Kaplan-Meier curves and Cox regression analysis were conducted to assess the impact of the extent of surgery on disease-specific survival (DSS).

RESULTS

A total of 8435 patients were identified. The DSS after LT were 100%, 98.3%, and 97.6% at 5, 10, and 15 years, respectively, compared with those seen after TT of 99.3%, 97.9%, and 96.6%. The difference between the two groups is not statistically significant (p = 0.083). Similar results were observed in cohorts after adjusting for baseline covariates. There was also similar prognosis between LT and TT in patients with tumors size ≤ 40 mm or > 40 mm.

CONCLUSIONS

For patients with FTC of any size without extrathyroidal extension and distant metastases at diagnosis, TT and LT confer equivalent DSS. Completion thyroidectomy after LT may be not necessary unless patients relapse; however, recurrence rates and development of metastases are not evaluated in this study.

Total thyroidectomy is superior for initial treatment of thyroid cancer

PURPOSE

The incidence of thyroid cancer has increased annually, and has a heavy psychological and economic burden on the society and individuals. Based on thyroid cancer data from patients treated in Liaocheng People's Hospital in 2017, with Chinese national and regional characteristics, in this study we addressed the controversy of which initial thyroid surgical mode, lobectomy, or total thyroidectomy is the most effective.

PATIENTS AND METHODS

Clinical and pathological data from 552 patients with thyroid cancer, who were initially diagnosed and treated surgically, were collected from the Department of Thyroid Surgery. Among them, 40 patients underwent endoscopic surgery, with resection, including lobectomy + central lymph node dissection of the affected lobe, while 512 cases underwent total thyroidectomy + central lymph node dissection.

RESULTS

The metastasis rate for all patients was 59.42%, with lymph node metastasis of papillary thyroid microcarcinoma of 46.92%; however, for patients with tumors >2 cm, the proportion developing metastasis was increased to 77.53%.

CONCLUSION

In thyroid cancer, rates of neck lymph node metastasis are high, particularly among patients with risk factors for poor prognosis. Our data suggest that initial treatment should comprise at least total thyroidectomy + central lymph node dissection in China, at least in tumors larger than 1 cm, to avoid the risks associated with secondary surgery and effects on patient quality of life.

The incidence of postoperative re-stratification for recurrence in well-differentiated thyroid cancer-a retrospective cohort study

Background

After diagnosing well-differentiated thyroid cancer (WDTC), assessment of the risk for disease-specific recurrence is essential for deciding between hemi-thyroidectomy (HT) and total thyroidectomy (TT). The American Thyroid Association (ATA) 2015 guidelines suggest that patients with 1-4 cm WDTC without suspicious features may be suitable for HT. Patients' preoperatively determined risk levels are re-stratified according to surgical and final histopathological findings. The incidence and clinical implications of high-risk features discovered postoperatively in patients with preoperatively determined low-risk WDTC are yet to be better defined.

Methods

Thyroidectomies performed in the Tel-Aviv Sourasky Medical Center (TASMC) [2006-2018] were included. Patients with 1-4 cm WDTC without evidence of positive cervical lymph nodes, invasion to adjacent structures, or high-risk cytology were considered at low risk for disease-specific recurrence-suitable for lobectomy. Patients were stratified according to their risk for disease-specific recurrence, pre- and postoperatively, and the rate of completion thyroidectomy was determined.

Results

In total, 301 (21%) patients were preoperatively stratified as low risk. Forty-six of them (15%) were re-stratified postoperatively as intermediate-to-high-risk. There were no significant differences in the characteristics of the patients who maintained their original stratification to patients who were upscaled to a higher risk level postoperatively.

Conclusions

We report a 15% rate of postoperative risk escalation of patients who required completion thyroidectomy according to current ATA guidelines. In our opinion, this rate of postoperative WDTC upscaling of risk requiring more radical surgery than originally planned, is acceptable. Meticulous preoperative personalized evaluation by an experienced multidisciplinary dedicated team is essential.

Total thyroidectomy vs. lobectomy in differentiated thyroid cancer: is there a reasonable size cut-off for decision? A narrative review

Objective

To analyze all the most recent guidelines/consensus as well as papers regarding the relationship between size of tumor, type of surgery, and prognosis, and to try to produce a critical synthesis for real practice.

Background

Differentiated thyroid cancer (DTC) is characterized by a wide range of biological behavior. The type of intervention can range from lobectomy (LT) to total thyroidectomy (TT), with tumor size being a point of discussion in choosing the treatment.

Methods

We carried out a search on PubMed, EMBASE, and Cochrane Library, looking at all the guidelines and consensus regarding DTC, as well as examining original articles, inserting as our research keys "total thyroidectomy vs. lobectomy in differentiated thyroid cancer" and "hemithyroidectomy in thyroid cancer". The guidelines and consensus published over the last 5 years were 6 in total: ATA Guidelines, Italian Consensus of Six Italian Societies, United Kingdom National Multidisciplinary Guidelines, ESMO Clinical Practice Guidelines, a Practical Guidance of a Multidisciplinary Panel of Experts, and The Revised Clinical Practise Guidelines on the Management of Thyroid Tumours by the Japanese Association of Endocrine Surgeons. There were 13 papers cited in the guidelines, and we found another 5 original articles, all of which were retrospective studies.

Conclusions

The type of initial surgical intervention must of course consider tumor size, but must also take into account all the risk factors, which is paramount in deciding the type of treatment. LT can have some advantages, and can represent an option that can be offered to patients. However, even in the absence of any special risk factors, a review of the literature suggests to us that patients should be informed that LT for tumors of a size between 2 and 4 cm can be associated with an increased risk of LR as well as with a possible reduced OS.

A feasibility study of microwave ablation for papillary thyroid cancer close to the thyroid capsule

BACKGROUND

To evaluate the feasibility, efficiency, and safety of microwave ablation (MWA) for papillary thyroid carcinoma (PTC) close to the thyroid capsule.

METHODS

The data of 106 cases who underwent thermal ablation from June 2014 to September 2020 were retrospectively analyzed. The mean follow-up time was 25 ± 11 months (range, 9-48 months). The strategy of fluid isolation was successfully applied in all cases, and all PTC nodules underwent extended ablation. The technical feasibility, technical success rate, and safety were analyzed. Changes in tumor size at different time points after MWA were evaluated.

RESULTS

According to the contrast-enhanced ultrasound results after ablation, MWA has been successfully applied in all enrolled cases. The capsular ablation has also been achieved for all cases. Nodules in 71 cases (70.0%) completely disappeared in the follow-up period. No local recurrence was detected. The incidence of lymph node metastasis and new tumors was 1.9% (2/106) respectively. Light voice changes were the only complication, with a rate of 5.7% (6/106), which were relieved within 6 months after MWA. The size of the ablation zone increased firstly in 6 months after MWA compared with the pretreatment tumor size (p < 0.05). At 12, 18, 24, 30, 36 and 42 months after MWA, the ablation zone shrank and the sizes were smaller than the tumor size before MWA (p < 0.05 for all).

CONCLUSIONS

MWA is an effective, safe, and feasible method in treating PTC close to the thyroid capsule.

Long-term outcomes of lobectomy for papillary thyroid carcinoma with high-risk features

BACKGROUND

Lobectomy is not advocated for papillary thyroid carcinoma (PTC) with high-risk features, although there is no high-level evidence showing that this is an inferior strategy. This study aimed to examine the association between the extent of surgery and survival of patients with PTC and high-risk features.

METHODS

Consecutive patients with PTC and at least one high-risk feature treated in 2000-2012 were included in the study. High-risk features were defined as: primary tumour larger than 4 cm, gross extrathyroidal extension, macroscopic multifocality, and confirmed nodal metastasis including pathological lateral neck metastasis (pN1b) or more than five central lymph node metastases. Cox proportional hazards models were employed to measure the association between the extent of surgery and disease-specific survival (DSS) in the whole cohort and in a matched-pair analysis.

RESULTS

Among a total of 2059 patients with high-risk features, 1224 underwent lobectomy and 835 had total thyroidectomy. Patients who underwent total thyroidectomy had significantly higher rates of bilateral cancer than those who had a lobectomy (79.4 versus 2.7 per cent respectively), macroscopic multifocality (80.8 versus 32.8 per cent) and bilateral neck metastasis (30.9 versus 3.3 per cent) (all P < 0.001). With a median follow-up of 93 months, multivariable analysis showed that the extent of surgery was not associated with DSS in the whole cohort (hazard ratio 1.36, 95 per cent c.i. 0.75 to 2.48; P = 0.310). After 1 : 1 case-control matching of 528 patients, no significant difference between lobectomy and total thyroidectomy groups was observed with respect to the 10-year DSS rate (94.3 versus 95.2 per cent respectively; P = 0.323) or 10-year recurrence-free survival rate (75.8 versus 79.2 per cent; P = 0.784).

CONCLUSION

Lobectomy was not associated with significantly worse outcomes for patients with PTC and high-risk features.

Polymorphisms at the IL17A and IL17RA genes are associated with prognosis of papillary thyroid carcinoma

BACKGROUND

Interleukin (IL)-17A has a dual role in tumor immunity, promotes anti-tumor responses and facilitates angiogenesis by interacting with IL-17 receptor A (IL-17RA). Although IL-17A has been associated with the pathogenesis of papillary thyroid carcinoma (PTC), the nucleotide variability at the IL17A and IL17RA genes is still poorly characterized.

AIM

To assess the contribution of the IL17A (-197 G >A, rs2275913) and IL17RA (-947 A >G, rs4819554) single nucleotide polymorphisms (SNP) on the development and progression of PTC and on IL-17 plasma levels.

METHODS

We studied 188 PTC patients and 170 healthy controls. SNPs were identified using PCR-amplified DNA and restriction fragment length polymorphism (RFLP) techniques. Plasma levels of IL-17A was evaluated in 83 PTC patients using ELISA. Statistical analyses were performed to evaluate the associations between SNPs and clinicohistopathological features of PTC and IL-17A levels.

RESULTS

No significant difference was observed regarding the allele and genotype distributions of both SNPs between PTC patients and controls. The IL17A GA was associated with poor biochemical and structural incomplete response to therapy, whereas no influence over the IL-17A expression was observed. The IL17RA AG was significantly associated with small-sized tumors, initial tumor stage at diagnosis and better response to therapy.

CONCLUSIONS

The IL17A SNP may predict an aggressive manifestation of PTC, whereas the IL17RA SNP was associated with a more favorable clinical outcome.

Patient-reported outcomes following total thyroidectomy and lobectomy in thyroid cancer survivors: an analysis of the PROFILES Registry data

PURPOSE

Patient-reported outcomes are important in the surgical decision-making process for low-risk, differentiated thyroid cancer. Current study aimed to assess patient-reported outcomes in thyroid cancer survivors comparing total thyroidectomy (TT) and lobectomy (LT) using the Patient Reported Outcomes Following Initial treatment and Long term Evaluation of Survivorship (PROFILES) registry.

METHODS

European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) scales, illness perception questions, Beliefs about Medicines Questionnaire (BMQ) scales and questions about thyroid surgery-related medication use were compared between thyroid cancer patients who underwent TT versus LT using descriptive analyses.

RESULTS

In total, 58 thyroid cancer patients who underwent TT or LT were included in this study. None of the EORTC QLQ-C30 scales or questions regarding illness perception were significantly different between the surgical groups. Patients in the TT group had significantly higher belief in the necessity of their medication (21.0 vs 15.4; p = 0.003) and greater concerns about taking their medicines (14.7 vs 11.1; p = 0.008) versus patients in the LT group.

CONCLUSION

Concerns about post-surgical medication use specifically in the TT group may indicate that clinicians should consider LT in patients with low-risk, differentiated thyroid cancer when LT and TT are viable surgical options. Clinicians should be aware of the impact of post-surgical medication use in particular following TT and use this knowledge to align goals of treatment with the extent of surgery, allowing for a better-informed decision-making process.

Thyroid Lobectomy for Low-Risk Papillary Thyroid Cancer: A National Survey of Low- and High-Volume Surgeons

BACKGROUND

The 2015 American Thyroid Association guidelines endorsed lobectomy for patients with low-risk papillary thyroid cancer (PTC) measuring 1-4 cm. Attitudes about the use of lobectomy for these patients are lacking, particularly from low-volume surgeons who perform the majority of thyroidectomies in the US.

METHODS

A survey was mailed to 1000 surgeons stratified by specialty (500 general surgeons and 500 otolaryngologists) registered with the American Medical Association, to evaluate beliefs and practices about the extent of surgery for low-risk PTC. Comparisons examined differences by surgeon volume.

RESULTS

Of 320 respondents who have performed thyroidectomy since 2015 (150 general surgeons, 170 otolaryngologists), 206 (64.4%) were low volume (< 26 thyroidectomies/year). The proportion of surgeons recommending lobectomy for low-risk PTC measuring 1.1 to < 4 cm ranged from 43.1 to 2.6%. High-volume surgeons recommended lobectomy more frequently for PTC measuring 1.1-3 cm, although this was not statistically significant. Thirty-three percent of respondents believed lobectomy is underused for low-risk PTC, while 10.0% believed it is overused. Additionally, 19.6% of respondents believed recurrence is more likely after lobectomy than total thyroidectomy, and 3.3% believed mortality is higher. Few believed quality of life is better after lobectomy (12.3%). Low-volume surgeons were less likely to be aware guidelines support lobectomy for low-risk PTC 1-4 cm (p < 0.001) and less likely to use clinical practice guidelines (p = 0.004).

CONCLUSIONS

Most surgeons do not support lobectomy for patients with low-risk PTC > 1 cm. Awareness of guidelines and concerns about increased risk of recurrence after lobectomy may drive surgeons' preference for total thyroidectomy.