Risk characteristics of papillary thyroid cancer > 1-4 cm is associated with increased tumour size

Recent guidelines recommend total thyroidectomy for papillary thyroid cancers (PTC) larger than 4 cm. For papillary macrocarcinoma with a diameter >1-4 cm, less intensive surgery can be managed, but this is still a matter for debate. The aim of our study was to assess the prevalence of risk factors such as vascular invasion, positive margin, extrathyroidal extension, aggressive histology, lymph nodes and distant metastases associated with a primary PTC tumour with a diameter >1-4 cm, and the association between tumour size and the risk of having one or more of these factors. A retrospective analysis of the medical records of 857 patients who underwent total thyroidectomy between 2000 and 2020, with a final post-operative diagnosis of a PTC >1-4 cm. Overall, less than a half (47.0%) of tumours were associated with at least one risk factor. The prevalence of analysed risk factors, except aggressive histology and a positive margin status, was significantly associated with larger tumour size (>2-4 cm). The optimal cut-off value for a cumulative risk of having one or more risk factors was estimated as 2.0 cm. Patients with a primary tumour < 2.0 cm had almost double less risk (p-value < 0.0001; OR 1.95; 95% CI 1.47-2.58) of having one or more risk factors than patients with PTC ≥ 2.0 cm. In an era of de-escalation, the cut-off value of 2 cm can be helpful in identifying patients with PTC >1-4 cm and lower risk of having aggressive disease providing less extensive treatment approach.

Association of Radioactive Iodine Administration With Outcome Among Patients With Low-Risk Differentiated Thyroid Cancer: A Real-World Data Analysis

OBJECTIVE

Despite the generally favourable long-term prognosis of low-risk differentiated thyroid cancer (DTC), questions remain about disease-free survival (DFS) after initial treatment, particularly regarding the use of radioactive iodine (RAI). Although there are RCT trial confirming that RAI ablation therapy is not superior to follow-up in terms of the 3-year DFS rate in low-risk thyroid cancer, its longer-term prognosis remains to be established. The objective of this study was to assess the impact of RAI ablation on the presence of structural persistent/recurrent disease in patients with low-risk DTC.

METHODS

We retrospectively identified 720 low-risk DTC patients who had undergone total or near-total thyroidectomy (TT) at a tertiary medical centre between January 2008 and July 2018. Propensity scores were calculated using a multivariable logistic regression model that accounted for age, sex, tumour size, neck dissection, multifocality, capsular invasion and lymph node (LN) metastasis. We compared DFS between patients who received RAI and those who did not using log-rank tests and multivariate Cox analyses. Subgroup analyses were also conducted.

RESULTS

Of the total cohort, 180 (25.0%) patients received RAI, while 540 (75.0%) did not before matching. The median follow-up duration was 59.5 months. After matching, the RAI group comprised 135 (39.8%) patients and the non-RAI group comprised 204 (60.2%) patients. In the entire cohort, the 5-year DFS rate was 97.6% for patients receiving RAI compared to 96.8% for those not receiving RAI (p = 0.704). In the matched cohort, the rates were 98.5% and 95.6%, respectively (p = 0.090). Matched multivariate Cox analysis demonstrated that RAI was neither significantly nor independently associated with DFS (hazard ratio [HR] = 0.29; 95% CI 0.06-1.37; p = 0.118). Further subgroup analyses reaffirmed that RAI ablation did not significantly reduce the risk of developing structural persistent/recurrent disease.

CONCLUSION

Administering RAI ablation following TT did not result in improved DFS for low-risk DTC patients. Our findings suggest that decisions regarding RAI should be made judiciously to avoid overtreatment in this clinical scenario.

Lobectomy sufficiency for 1-4 cm differential thyroid cancer: a large retrospective study in China

This study aimed to determine whether lobectomy is appropriate for the long-term prognosis of 1-4-cm-sized differential thyroid cancer (DTC). This retrospective study included 2,178 patients with 1-4-cm DTC treated via thyroid lobectomy (LT) or total or near-total thyroidectomy (TT) and who were followed up for at least 3 years. The primary endpoint was a structural incomplete response, which was confirmed via imaging with or without a positive histological or cytological examination. Subgroup analysis was performed according to tumor size. LT was performed in 1,535 patients (70.48%), and TT was conducted in the remaining 643 (29.55%) patients. During an average follow-up period of 48.08 months, the recurrence rate was 7.2% in the LT group and 5.3% in the TT group, which was not significantly different (p = 0.108). There were no significant differences in disease-free survival between both groups (hazard ratio, 1.394; 95% confidence interval, 0.9761-1.990; p = 0.089). In the subgroup analysis, the recurrence rates in the LT group were higher than those in the TT group for both the 2-3-cm (13.6% vs. 2.6%, p < 0.01) and 3-4-cm categories (20.6% vs. 4.8%, p < 0.01). For 1-2-cm DTC, surgeons can choose LT or TT owing to their similar recurrence rate, whereas for 2-4-cm DTC, TT is preferred.

Cost-Effectiveness of the ACR TIRADS Compared to the ATA 2015 Risk Stratification Systems in the Evaluation of Incidental Thyroid Nodules

RATIONALE AND OBJECTIVES

Thyroid nodules are a common incidental imaging finding and prone to overdiagnosis. Several risk stratification systems have been developed to reduce unnecessary work-up, with two of the most utilized including the American Thyroid Association 2015 (ATA2015) and the newer American College of Radiology Thyroid Imaging, Reporting and Data System (TIRADS) guidelines. The purpose of this study is to evaluate the cost-effectiveness of the ATA2015 versus the TIRADS guidelines in the management of incidental thyroid nodules.

METHODS

A cost-utility analysis was conducted using decision tree modeling, evaluating adult patients with incidental thyroid nodules < 4 cm. Model inputs were populated using published literature, observational data, and expert opinion. Single-payer perspective, Canadian dollar currency, five-year time horizon, willingness to pay (WTP) threshold of $50,000, and discount rate of 1.5% per annum were utilized. Scenario, deterministic and probabilistic sensitivity analyses were performed. The primary outcome was the incremental cost-effectiveness ratio (ICER) expressed as incremental cost per quality-adjusted life year (QALY) gained.

RESULTS

For the base case scenario, TIRADS dominated the ATA2015 strategy by a slim margin, producing 0.005 more QALYs at $25 less cost. Results were sensitive to the malignancy rate of biopsy and the utilities of a patient with a benign nodule/subclinical malignancy or under surveillance. Probabilistic sensitivity analysis showed that TIRADS was the more cost-effective option 79.7% of the time.

CONCLUSION

The TIRADS guidelines may be the more cost-effective strategy by a small margin compared to ATA2015 in most scenarios when used to risk stratify incidental thyroid nodules.

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.

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.

Surgical management of low-risk papillary thyroid cancer in real life in Spain: a nationwide survey of endocrine neck surgeons and endocrinologists

BACKGROUND

The extent of surgery in patients with papillary thyroid cancer (PTC) is a subject of ongoing debate. We aimed to explore the attitude of Spanish specialists (endocrinologists, surgeons, and otolaryngologists) in real life on the surgical management of low-risk PTC.

METHODS

We designed an anonymous, web-based survey to inquire information regarding the preferences of interviewees for hemithyroidectomy (Hem), total thyroidectomy (TT) and prophylactic central neck dissection (pCND) in one standard patient with PTC and six clinical variants. We differentiated between small (1.1-2.5 cm) and large (2.6-4.0 cm) tumors.

RESULTS

A total of 278 valid responses were received and divided into two groups: group END (n = 135) and group SUR (n = 143, 101 general surgeons and 42 otolaryngologists). The preference for Hem was low in the standard patient and similar between both groups (40.6 vs 49.0%, NS). This preference decreased for tumors measuring 2.6-4.0 cm, multifocal, with risk location, family history of thyroid cancer, or history of irradiation, and increased in patients older than 65 years or with comorbidity. Preference for pCND ranged from 12.6-71.1% in the group END and from 22.4-65.0% in the group SUR, with few differences between the two. In multivariate analysis, being a high-volume specialist was associated with a lower preference for Hem, while having private practice was associated with a more favorable opinion of Hem.

CONCLUSION

The real clinical practice of Spanish specialists is far from what is recommended by the clinical guidelines in patients with low-risk PTC, especially among high-volume professionals.

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.

Microwave ablation vs. surgery for papillary thyroid carcinoma with minimal sonographic extrathyroid extension: a multicentre prospective study

OBJECTIVES

Minimal extrathyroid extension (mETE) was removed from the TNM staging system. This study was designed prospectively to compare the safety and efficacy of microwave ablation (MWA) versus surgery for treating T1N0M0 papillary thyroid carcinomas (PTC) with sonographically detected mETE.

METHODS

From December 2019 to April 2021, 198 patients with T1N0M0 mETE-PTCs evaluated by preoperative ultrasound from 10 hospitals were included. Ninety-two patients elected MWA, and 106 patients elected surgery for treatment. MWA was performed using extensive ablation with hydrodissection. Surgery consisted of lobectomy with ipsilateral central lymph node dissection (CLD), lobe and isthmus excision with ipsilateral CLD and total thyroidectomy with ipsilateral CLD. The rates of technical success, cost, oncologic outcomes, complications and quality of life of the two groups were assessed.

RESULTS

The follow-up times for the MWA and surgery groups were 12.7 ± 4.1 and 12.6 ± 5.0 months, respectively. The technical success rate was 100% for both groups. Oncological outcomes of the two groups were similar during the follow-up (all p > 0.05). The MWA group had a shorter operation time, less blood loss and lower costs (all p < 0.001). Three complications (3.3%) were reported in the MWA group and 4 (3.8%) in the surgery group (p = 0.846). The surgery group had higher scores for scar problems and anxiety (p < 0.001 and p = 0.003, respectively).

CONCLUSIONS

Microwave ablation was comparable in the short term to surgery in terms of treatment safety and efficacy in selected patients with T1N0M0 mETE-PTC detected by ultrasound.

KEY POINTS

• Microwave ablation is comparable to surgery in the safety and short-term efficacy for PTCs with sonographically detected mETE. • Thermal ablation is technically feasible for mETE-PTC treatment. • Patients with mETE-PTC have similar quality of life in the two groups, except for worse scar problems and anxiety in the surgery group.

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.

Thyroid stimulating hormone suppression and recurrence after thyroid lobectomy for papillary thyroid carcinoma

BACKGROUND

Thyroid lobectomy is recommended as the primary treatment for low-risk thyroid cancer. However, recurrence and hypothyroidism may develop after lobectomy, necessitating thyroid hormone supplementation. The 2015 American Thyroid Association (ATA) guidelines recommended post-lobectomy thyroid-stimulating hormone (TSH) suppression. This study examined the need for TSH suppression and recurrence after lobectomy for unilateral papillary thyroid carcinoma (PTC).

METHODS

This study involved 369 patients who underwent thyroid lobectomy and ipsilateral central neck dissection for PTC between 2007 and 2015. Thyroid function tests were performed before and regularly after lobectomy. Binary logistic regression analyses were used to find factors predictive of the post-lobectomy need for TSH suppression that was defined by the 2015 ATA guidelines.

RESULTS

Serum TSH concentrations gradually increased after lobectomy: proportions with TSH >2 mIU/L at post-lobectomy 1, 3-6, 12, and 24 months were found in 77.0%, 82.3%, 66.7%, and 59.9%, respectively. After lobectomy, 168 (45.5%) patients received levothyroxine (T4) supplementation. Multivariate logistic regression analyses showed that pre-TSH level >2 mIU/L was the sole independent variable predictive of the need for post-lobectomy TSH suppression (P = 0.003). During the median follow-up of 72 months, recurrence was found in 4 (1.1%) patients who never received T4 supplementation and had post-lobectomy TSH levels >2 mIU/L.

CONCLUSIONS

Our data show that thyroid lobectomy for unilateral PTC is associated with a low recurrence rate, but a significant risk of hypothyroidism. Preoperative TSH level can predict the need for post-lobectomy TSH suppression compliant with the 2015 ATA guidelines.

Benefits and harms of hemithyroidectomy, total or near-total thyroidectomy in 1-4 cm differentiated thyroid cancer

OBJECTIVE

For 1-4 cm differentiated thyroid cancer (DTC), current ATA guideline recommended hemithyroidectomy (HT) as an acceptable alternative initial procedure to total or near-total thyroidectomy (TT). The aim of this study was to evaluate benefits and harms of HT, TT in 1-4 cm DTC.

DESIGN

Retrospective cohort study.

PATIENTS

DTC patients aged 18 years or older who underwent initial thyroidectomy in a tertiary medical centre were included from January 2008 to July 2018.

MEASUREMENTS

The structural persistent/recurrent disease, reoperation rates and surgical complications were compared using Cox proportional regression and logistic regression. Propensity score matching was performed to adjust for related clinicopathological variables.

RESULTS

Among 1824 DTC patients, 795 patients sized 1-4 cm were included. A total of 286 patients underwent HT and 509 patients underwent TT. In the matched analysis, no significant difference in disease-free survival (DFS) between HT and TT was observed during the median follow-up period of 56.5 months (hazard ratio [HR] 0.86; 95% CI, 0.37-2.00; p = .733). The difference in DFS between two groups was consistent regardless of age, sex, tumour size, follow-up duration. Meanwhile, HT was associated with a decreased risk of surgical complications (odds ratio [OR] 0.47, 95% CI 0.31-0.71, p < .001), as well as lower proportion of levothyroxine replacement (p = .007). Two cases in HT group received reoperation. Further multivariate analysis showed surgical procedure was not associated with structural persistence/recurrence (HR 0.68; 95%CI, 0.29-1.58, p = .367).

CONCLUSIONS

For patients with 1-4 cm DTC without clinical evidence of lymph node metastasis or extrathyroidal extension, HT was associated with lower risk of surgical complications than TT while provided similar benefits as TT.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Less extensive surgery for low-risk papillary thyroid cancers post 2015 American Thyroid Association guidelines in an Australian tertiary centre

INTRODUCTION

The 2015 American Thyroid Association guidelines (ATA15) consider hemithyroidectomy (HT) a viable treatment option for low-risk papillary thyroid cancers (PTCs) between 1 and 4 cm. We aimed to examine the impact of ATA15 in a high-volume Australian endocrine surgery unit.

METHODS

A retrospective study of all patients undergoing thyroidectomy from January 2010 to December 2019.

INCLUSION CRITERIA

PTC histopathology, Bethesda V-VI, size 1-4 cm, and absence of clinical evidence of lymph node or distant metastases pre-operatively. Primary outcome was rate of HT before and after ATA15.

RESULTS

Of 5408 thyroidectomy patients, 339 (6.3%) met the inclusion criteria - 186 (54.9%) pre-ATA15 (2010-2015) and 153 (45.1%) post-ATA15 (2016-2019). The patient groups were similar; there were no significant differences between groups in age, sex, tumour size, proportion with Bethesda VI cytology, compressive symptoms, or thyrotoxicosis. Post-ATA15, there was a significant increase in HT rate from 5.4% to 19.6% (P = 0.0001). However, there was no corresponding increase in completion thyroidectomy (CT) rate (50.0% versus 27.6%, P = 0.2). The proportion managed with prophylactic central neck dissection (pCND) fell from 80.5% to 10.8% (P < 0.0001). Pre-ATA15, the only factor significantly associated with HT was Bethesda V. In contrast, post-ATA15, HT was more likely in patients with younger age, smaller tumours, and Bethesda V.

CONCLUSION

After the release of 2015 ATA guidelines, we observed a significant increase in HT rate and a significant decrease in pCND rate for low-risk PTCs in our specialised thyroid cancer unit. This reflects a growing clinician uptake of a more conservative approach as recommended by ATA15.

Thyroid cancer, recent advances in diagnosis and therapy

Over the past several decades, the approach to the diagnosis and management of patients with follicular cell-derived thyroid cancer has evolved based on improved classification of patients better matching clinical outcomes, as well as advances in imaging, laboratory, molecular technologies and knowledge. While thyroid surgery, radioactive iodine therapy and TSH suppression remain the mainstays of treatment, this expansion of knowledge has enabled de-escalation of therapy for individuals diagnosed with low-risk well-differentiated thyroid cancer; better definition of treatment choices for patients with more aggressive disease; and improved ability to optimize treatments for patients with persistent and/or progressive disease. Most recently, the advancement of knowledge regarding the molecular aspects of thyroid cancer has improved thyroid cancer diagnosis and has enabled individualized therapeutic options for selected patients with the most aggressive forms of the disease. Guidelines from multiple societies across the world reflect these changes, which focus on taking a more individualized approach to clinical management. In this review, we discuss the current more personalized approach to patients with follicular cell-derived thyroid cancer and point toward areas of future research still needed in the field.

Preoperative ultrasound characteristics in determining the likelihood of cytologically confirmed (Bethesda VI), 1-4 cm papillary thyroid tumours requiring completion thyroidectomy

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most commonly diagnosed differentiated thyroid carcinoma. There is controversy about performing upfront lobectomy vs thyroidectomy for smaller well differentiated thyroid carcinoma.

METHODS

A retrospective study from 2015 to 2020 was conducted consisting of consecutive patients with a preoperative malignant (Bethesda VI) cytology on fine needle aspirate (FNA) consistent with PTC. Specific ultrasonographic features such as taller than wide, hypoechogenicity, irregular margins, internal vascularity and microcalcifications were recorded. Criteria for exclusion was the presence of positive lymph nodes, extrathyroidal extension, familial thyroid carcinoma and bilateral disease detected preoperatively. Outcome was defined as a lobectomy being adequate treatment or a completion thyroidectomy recommended based on current 2015 ATA guidelines.

RESULTS

Preoperative malignant cytological nodules (Bethesda VI) with irregular margins on sonography were significantly (p = 0.025) at increased risk (OR = 2.48) of requiring a completion thyroidectomy. There was also no statistically significant difference between groups when stratified by size with 50% of tumours between 1 and 2 cm requiring a completion thyroidectomy.

CONCLUSIONS

The presence of irregular margins on ultrasound predicts an increased risk of requiring a completion thyroidectomy. Specific consideration of this sonographic finding should be made when counselling patients who have cytologically confirmed papillary thyroid carcinoma regarding the best choice of thyroid operation.

Controversy: For or against thyroid lobectomy in>1cm differentiated thyroid cancer?

In this controversy article, the respective advantages of lobectomy vs. total thyroidectomy in differentiated thyroid cancers are argued. The authors conclude that lobectomy has the same oncological prognosis as thyroidectomy in terms of specific survival or recurrence, in case of low risk of recurrence (T1-2N0). However, as a precaution, and taking into account current data, thyroidectomy is recommended in N0 thyroid papillary cancers with aggressive subtype, with even minimal infiltration of perithyroid tissue and/or vascular invasion, and in N1 cancers with more than 5 lymphadenopathies or lymphadenopathies with a major axis greater than or equal to 0.2cm. Other forms of papillary cancer should be treated with lobectomy, as risk of morbidity is low and hospital stay is short. Lobectomy allows reliable monitoring, especially by ultrasound. On the other hand, total thyroidectomy, despite a higher rate of surgical complications due to the risk of recurrent paralysis and permanent hypoparathyroidism, is nevertheless preferable to lobectomy. Indeed lobectomy is not always avoiding hormone replacement therapy, for more precise monitoring by thyroglobulin assay, which is an uninterpretable tool after lobectomy but allows early diagnosis of local or metastatic recurrence with reducing mortality. Thus, in situations where the diagnostic criteria for high-risk cancer are not rigorously determined or taken into account, thyroidectomy is recommended. In addition, it will remain preferable as long as the recommendations for administration of radioactive iodine do not change in favor of use reserved for high-risk cancers as in US guidelines.

Current surgical treatment of intermediate risk differentiated thyroid cancer: a systematic review

Introduction: Surgical treatment of thyroid cancer has become less aggressive but for many patients, the threshold for performing total thyroidectomy (TT), as opposed to thyroid lobectomy (TL), has remained unclear. Current American Thyroid Association (ATA) guidelines encourage more individualization of treatment options, which necessitates explicit review of the pros and cons of the different options with patients.Areas covered: This review focuses on the extent of surgery for treatment of intermediate-risk differentiated thyroid cancer, restricted to relevant literature available after publication of the 2015 ATA guidelines.Expert opinion: Dynamic risk-stratification facilitates a tailored approach when deciding on the extent of surgery for thyroid cancer. Treatment with TT allows for a lower recurrence risk, a simpler follow-up regimen, and treatment with adjuvant post-operative radioactive iodine. Treatment with TL has a lower associated risk of complications and avoidance of lifelong thyroid hormone replacement but has a significant risk of requiring a completion thyroid lobectomy (CT). Overall, treatment with TL and TT have comparable survival outcomes, but TL is the more cost-effective option. Larger cancer size is correlated with worse clinical outcomes, and numerous subgroup analyses have shown poorer outcomes for cancers with a diameter that is 2-4 cm compared to 1-2 cm.

Additional Surgery for Occult Risk Factors After Lobectomy in Solitary Thyroid Nodules is Predicted by Cytopathology Classification and Tumor Size

OBJECTIVE

Clinical practice for differentiated thyroid cancer is moving towards lobectomy rather than total thyroidectomy in patients at low risk of recurrence. However, recurrence risk assessment depends on post-operative findings, while the surgical decision is based on preoperative factors. We determined the preoperative predictors of occult higher-risk pathology and rates of completion thyroidectomy among surgical candidates with nonbenign thyroid nodules 10 to 40 mm and no evidence of extrathyroidal extension or metastasis on preoperative evaluation.

METHODS

Thyroid surgery cases at a single institution from 2005-2015 were reviewed to identify those meeting American Thyroid Association (ATA) criteria for lobectomy. ATA-based risk stratification from postoperative surgical pathology was compared to preoperative cytopathology, ultrasound, and clinical findings.

RESULTS

Of 1,995 thyroid surgeries performed for nonbenign thyroid nodules 10 to 40 mm, 349 met ATA criteria for lobectomy. Occult high-risk features such as tall cell variant, gross extrathyroidal invasion, or vascular invasion were found in 36 cases (10.7%), while intraoperative lymphadenopathy led to surgical upstaging in 13 (3.7%). Intermediate risk features such as moderate lymphadenopathy or minimal extrathyroidal extension were present in an additional 44 cases. Occult risk features were present twice as often in Bethesda class 6 cases (35%) as in lower categories (12 to 17%). In multivariable analysis, Bethesda class and nodule size, but not age, race, sex, or ultrasound features, were significant predictors of occult higher-risk pathology.

CONCLUSION

Most solitary thyroid nodules less than 4 cm and with cytology findings including atypia of undetermined significance through suspicious for papillary thyroid cancer would be sufficiently treated by lobectomy.

ABBREVIATIONS

ATA = American Thyroid Association; CND = central neck dissection; DTC = differentiated thyroid cancer; ETE = extrathyroidal extension; FNA = fine needle aspiration; FTC/HCC = follicular thyroid carcinoma/Hurthle cell carcinoma; NIFTP = noninvasive follicular thyroid neoplasm with papillary-like nuclear features; OR = odds ratio; PTC = papillary thyroid cancer; US = ultrasound.

Thyroid Lobectomy for Low to Intermediate Risk Differentiated Thyroid Cancer

Simple Summary

Total thyroidectomy used to be recommended for all thyroid cancers. We now know that some thyroid cancers have a relatively low risk of recurrence. Today, for some of these cancers, depending on the type of tumor, its’ size and other tumor characteristics, a thyroid lobectomy (or hemithyroidectomy) can be performed without increasing the patient’s risk of cancer recurrence. Thyroid lobectomy has the advantages of having less risk of surgical complications and a less frequent need for thyroid hormone replacement therapy. This approach is not optimal for all thyroid cancers, however, and careful tumor and patient selection are necessary. This review explains the rationale and criteria for patient selection for thyroid lobectomy for selected thyroid cancers.

Abstract

Many recent publications and guidelines have promoted a “more is less” approach in terms of treatment for low to intermediate risk differentiated thyroid cancer (DTC), which comprise the vast majority of thyroid cancers: less extensive surgery, less radioactive iodine, less or no thyroid hormone suppression, and less frequent or stringent follow-up. Following this approach, thyroid lobectomy has been proposed as a means of decreasing short- and long-term postoperative morbidity while maintaining an excellent prognosis for tumors meeting specific macroscopic and microscopic criteria. This article will examine the pros and cons of thyroid lobectomy for low to intermediate risk cancers and discuss, in detail, criteria for patient selection and oncological outcomes.

Case for staged thyroidectomy

Recent modifications in the management of well-differentiated thyroid cancer have resulted in significant alterations in clinical approach. Utilizing a series of preoperative and postoperative risk factors involving both the patient and the disease pathology, we offer the term "staged thyroidectomy" to help organize these risk factors for patients and the endocrine team to optimize management. This approach is intended to incorporate our latest nuanced understanding of certain endocrine pathology and may serve to optimize patient outcomes.

Ultrasound-Guided Radiofrequency Ablation Versus Surgery for Low-Risk Papillary Thyroid Microcarcinoma: Results of Over 5 Years' Follow-Up

Background: Papillary thyroid microcarcinoma (PTMC) typically carries an excellent prognosis regardless of the treatment option pursued. Radiofrequency ablation (RFA) for thyroid disease has been utilized for benign lesions and in patients who are poor surgical candidates for thyroid cancers with compression symptoms, but the efficacy and limitations of RFA as first-line therapy for PTMC has not been described in adequate detail. The purpose of our study was to investigate RFA versus thyroidectomy in terms of efficacy, oncologic outcomes, quality of life, complications, and costs over a 5-year period of follow-up. Methods: From January 2013 to November 2013, 174 consecutive patients with an isolated, solitary intrathyroidal PTMC were identified in a Chinese teaching hospital. Those with more aggressive or advanced PTMCs were not included. Ninety-four patients elected RFA and 80 patients elected surgery for treatment of these PTMC. Nodules were confirmed to be PTMC without an aggressive histological type by core needle biopsy in the RFA group and by final surgical pathology in the surgery group. The extent of surgery was decided based on patient preferences in consultation with the surgeons. Of all the patients, 58 (72.5%) underwent lobectomy, 22 (27.5%) underwent total thyroidectomy, and 53 (66.3%) underwent lymph node dissection. Pre- and post-treatment variables were compared between the two groups, including demographics, tumor characteristics, treatment, local tumor progression, lymph node metastasis, distant metastasis, local recurrence, complications, and quality-of-life findings. Results: Patient-specific variables were similar between groups, as were oncologic outcomes after 5 years of follow-up. When compared with RFA, surgery took longer, had a longer hospitalization time, and was costlier (all p < 0.001). The surgery group had three complications, with 2 (2.5%) permanent recurrent laryngeal nerve injuries and 1 (1.3%) case of permanent hypoparathyroidism, while none was reported in the RFA group (p = 0.095). The surgery group had a lower post-treatment thyroid-related quality of life. Conclusions: For carefully selected low-risk intrathyroidal PTMC, RFA was not oncologically inferior to open surgery, and it was associated with a higher quality of life and lower overall costs.

Health Utility Book (HUB)-Cancer: Protocol for a Systematic Literature Review of Health State Utility Values in Cancer

Background. Treatment options in oncology are rapidly advancing, and public payer systems are increasingly under pressure to adopt new but expensive cancer treatments. Cost-utility analyses (CUAs) are used to estimate the relative costs and effects of competing interventions, where health outcomes are measured using quality-adjusted life years (QALYs). Health state utility values (HSUVs) are used to reflect health-related quality of life or health status in the calculation of QALYs. To support reimbursement agencies in the appraisal of oncology drug submissions, which typically include a CUA component, we have proposed a systematic literature review of published HSUV estimates in the field of oncology. Methods. The following databases will be searched: MEDLINE, EMBASE, EconLit, and CINAHL. A team of reviewers, working independently and in duplicate, will evaluate abstracts and full-text publications for eligibility against broad inclusion criteria. Studies using a direct, indirect, or combination approach to eliciting preferences related to cancer or cancer treatments are eligible. Data extraction will capture details of study methodology, participants, health states, and corresponding HSUVs. We will summarize our findings with descriptive analyses at this stage. A pilot review in thyroid cancer is presented to illustrate the proposed methods. Discussion. This systematic review will generate a comprehensive summary of the oncology HSUV literature. As a component of the Health Utility Book (HUB) project, we anticipate that this work will assist both health economic modelers as well as critical reviewers in the development and appraisal of CUAs in oncology.

Risk-oriented concept of treatment for intrathyroid papillary thyroid cancer

Adapting treatment and follow-up according to the risk of recurrence and/or death from thyroid cancer is a relatively recent concept of "personnalized" medicine, developed particularly to avoid overtreatment of low-risk thyroid cancer which represents the majority of thyroid cancers diagnosed in the world today. For low-risk thyroid cancer, this decrease in extent of treatment involves the extent of surgery-total thyroidectomy, lobectomy or no surgery with active surveillance-but also the indications, doses and methods of stimulation when or if administering radioactive iodine (RAI), the indication for suppressive thyroxin therapy and the extent and modalities for follow-up that should be adapted to the risk of recurrence. The aim is to optimize medical resources and quality of life, particularly for low-risk patients whose life expectancy is that of the general population.

Lobectomy Compared to Total Thyroidectomy for Low-Risk Papillary Thyroid Cancer: A Systematic Review

BACKGROUND

The 2015 American Thyroid Association (ATA) guidelines called for consideration of thyroid lobectomy (TL) as an acceptable surgical treatment for small and less aggressive papillary thyroid cancers (PTC) with no clinical evidence of metastasis or extrathyroidal extension. Optimal extent of surgery, however, remains controversial.

METHODS

A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. PUBMED, EMBASE, Scopus, and Cochrane Library databases were searched to identify studies comparing TL to total thyroidectomy (TT) for low-risk PTC. Studies were grouped according to the major outcomes in the literature: survival and the need for completion thyroidectomy (CT).

RESULTS

Overall survival for low-risk PTC patients who underwent TL was comparable to TT. Locoregional recurrence (LRR) rate following TL was less than 6% and salvaged with CT. The proportion of patients meeting the 2015 ATA guidelines selection criteria for TL who subsequently would need CT varied by study but averaged 34%. After excluding microscopic extrathyroidal extension and positive resection margin as indications for CT to facilitate radioactive iodine ablation, the estimated rate across the included studies was 11%.

CONCLUSIONS

We performed a systematic review of outcomes following TL or CT for low-risk PTC according to 2015 ATA guidelines. Initial operative approach did not have a negative impact on overall survival. There is a paucity of high-quality data on this topic across the literature. Long-term follow-up studies on oncologic and patient-centered outcomes are essential.

Extent of Surgery for Low-Risk Differentiated Thyroid Cancer

Although the incidence of thyroid cancer is increasing, survival remains unchanged. Due to concern for overtreatment, surgical management of thyroid cancer has evolved. Papillary thyroid microcarcinoma measuring 1 cm or smaller are considered very low risk and can be managed with either thyroid lobectomy or active surveillance. Total thyroidectomy is no longer recommended for these cancers unless there is evidence of metastasis, local invasion, or aggressive disease. Recommendations for low-risk differentiated thyroid cancer measuring 1 cm to 4 cm remain controversial. This article explores the controversies over the extent of surgery for patients with very low-risk and low-risk differentiated thyroid cancer.

The 2015 American Thyroid Association guidelines are associated with an increasing rate of hemithyroidectomy for thyroid cancer

BACKGROUND

In an attempt to prevent overly aggressive treatment of low-risk thyroid cancers, the American Thyroid Association changed guideline recommendations in late 2015 to state that either hemithyroidectomy or total thyroidectomy are acceptable operations for these patients. We hypothesized that surgeons would increasingly perform hemithyroidectomy after the release of these guidelines.

METHODS

The database of the National Surgery Quality Improvement Program was queried to identify all patients with thyroid cancer who were undergoing thyroidectomy between 2009 and 2017. Patients treated before the release of the 2015 American Thyroid Association guidelines were compared with those treated afterward. Temporal trends in operative rates were assessed quarterly using interrupted time series analyses.

RESULTS

A total of 35,291 patients were included in the study. Of those, 26,882 (76.2%) were female and 25,193 (71.3%) were white. After the release of the American Thyroid Association guidelines, there was an increase in hemithyroidectomy rate for patients with cancer from 17.3% to 22.0% (P < .001). Interrupted time series analysis controlling for patient factors demonstrated that quarterly growth in the hemithyroidectomy rate accelerated almost 10-fold (P < .001) after publication of the revised guidelines. Of note, there was no corresponding increase in the completion thyroidectomy rate (8.3% versus 7.9%, respectively, P = .213). Patients treated with hemithyroidectomy were more likely to be managed as outpatients (70.8% versus 57.1%, P < .001), had fewer surgical site infections (0.3% versus 0.5%, P = .050), and had fewer unplanned reintubations (0.2% versus 0.4%, P = .005).

CONCLUSION

In hospitals participating in the National Surgery Quality Improvement Program, the hemithyroidectomy rate increased significantly after the release of the 2015 American Thyroid Association guidelines. Surgeons at hospitals that participate in the National Surgery Quality Improvement Program may be changing practice patterns in response to these guidelines.

Changes in total thyroidectomy versus thyroid lobectomy for papillary thyroid cancer during the past 15 years

BACKGROUND

The incidence of papillary thyroid cancer has increased substantially during the past 15 years, which is likely related to an increased detection of small, nonlethal cancers. Studies have shown that patients may have a similar prognosis when undergoing less aggressive surgical intervention, such as thyroid lobectomy. The objective of this study is to determine whether surgical treatment patterns for papillary thyroid cancer have changed during the past 15 years.

METHODS

We performed a retrospective cohort study evaluating changes in the incidence and proportion of total thyroidectomy versus thyroid lobectomy for histologically confirmed papillary thyroid cancers, using the National Cancer Institute Surveillance, Epidemiology, and End Results cancer registries between 2000 and 2014.

RESULTS

During the study period, 44,537 patients underwent surgical treatment for papillary thyroid cancer, of which 77% were female and 81.3% were white. The incidence of papillary thyroid cancer more than doubled: from 6.2 (5.9-6.5) to 13.0 (12.5-13.4) per 100,000. The proportion of total thyroidectomy among all papillary cases increased from 78.16% in 2000 to 85.67% in 2014, and the proportion of thyroid lobectomy dropped from 16.62% to 11.41%. When stratified by tumor size, we observed a sustained and increasing gap in the proportions of total thyroidectomy and thyroid lobectomy.

CONCLUSION

The incidence of total thyroidectomy has not decreased despite recommendations encouraging consideration of lobectomy for patients with small papillary thyroid cancers. Although these findings could be attributed to the lag between scientific evidence and clinical practice, further work is warranted to explore any additional patient and provider factors that may explain this lack of change.

Paradoxes in thyroid carcinoma treatment: analysis of the SEER database 2010-2013

Thyroid cancer is a common malignant disease with high survival rate (98.1%, 2006-2012, Surveillance Epidemiology and End Results (SEER) program). In this study, we investigated the treatment paradoxes in thyroid T0 and micro-carcinoma patients. 48,234 thyroid carcinoma patients were identified from 2010 to 2013 in SEER*Stat database (version 8.2.1) released in 2016. Survival analysis showed a significantly lower thyroid carcinoma-specific survival in T0 patients compared with T1-T3 patients. In propensity score analysis, T0 patients had a similar survival curve with T1-T3 patients when lymph node and distant metastasis stages were matched. When all variables, including radiation and surgery treatment, were matched, T0 patients had significantly higher survival compared to T3 patients. These findings suggested that more metastasis and less treatment led to poorer prognosis in T0 patients. Another paradox is about thyroid micro-carcinoma. The survival rate of micro-carcinoma patients was high (4 years survival rate was 99.92%), and more than 99% micro-carcinoma patients received surgery. Interestingly, all the patients who died because of thyroid carcinoma received surgery. Survival analysis showed no difference in survival when patients stratified by surgery or radiation. In conclusion, we suggested paradoxes in thyroid carcinoma treatment: over-treated in micro-carcinoma patients and less-treated in T0 patients.

Correct extent of thyroidectomy is poorly predicted preoperatively by the guidelines of the American Thyroid Association for low and intermediate risk thyroid cancers

BACKGROUND

Recent guidelines from the American Thyroid Association recommend thyroid lobectomy for intrathyroidal differentiated thyroid cancers <4 cm. Our aim was to examine histology from patients with cytologic results that were positive or suspicious for malignancy to assess the extent of initial thyroidectomy based on criteria from the 2015 American Thyroid Association guidelines.

METHODS

We studied consecutive patients who had either a positive or suspicious for malignancy cytologic diagnosis and under prior American Thyroid Association guidelines underwent initial total thyroidectomy ± lymphadenectomy.

RESULTS

Among 447 patients, high-risk features necessitating total thyroidectomy were present in 19% (72/380) of positive and 15% (10/67) of suspicious for malignancy patients (P = .5). Intermediate-risk features on histology were identified postoperatively in 46% (175/380) with positive and 15% (18/67) with suspicious for malignancy fine-needle aspiration results. In multivariable analysis, preoperative factors associated with intermediate-risk disease included age ≥45 years, women, larger tumor size, positive fine-needle aspiration cytology, and BRAF V600E or RET/PTC positivity.

CONCLUSION

When patients are considered for lobectomy under the 2015 American Thyroid Association guidelines, ~ 60% with positive and 30% with suspicious for malignancy cytology would need completion thyroidectomy based on intermediate-risk disease. The cost and risk implications of the new American Thyroid Association strategy were substantial and better tools are needed to improve preoperative risk stratification.

Controversies in the Management of Low-Risk Differentiated Thyroid Cancer

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