Long-term surveillance of papillary thyroid cancer patients who do not undergo postoperative radioiodine remnant ablation: is there a role for serum thyroglobulin measurement?

Differentiated Thyroid Cancer after Thyroidectomy

The widespread use of neck US and other imaging modalities has contributed to a phenomenon of increased detection of differentiated thyroid cancer (DTC). Most of these cancers remain indolent, without requiring surgical intervention. Nonetheless, a subset of patients who require surgical treatment experience subsequent disease recurrence. This most commonly occurs in the cervical lymph nodes and thyroid bed, followed by distant metastasis to the lungs and bones. Because imaging is an integral part of postoperative surveillance, radiologists play a central role in the detection of recurrent tumors and in guiding treatment in these patients. US is the primary imaging modality used for postoperative evaluation. Other modalities such as CT, MRI, radioactive iodine imaging, and PET/CT aid in the accurate diagnosis and characterization of recurrent disease. Therefore, radiologists must have a thorough understanding of the utility of these imaging techniques and the imaging characteristics of recurrent DTC when interpreting these multimodality studies. The interpretation of imaging findings should also be correlated with the clinical status of patients and their biochemical markers to minimize interpretative errors. The authors present a broad overview of the postoperative evaluation of DTC, including its initial primary management, staging, and prognostication; clinical risk stratification for recurrent disease; postoperative surveillance with imaging and evaluation of biochemical markers; and management of recurrent DTC. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Lobectomy in patients with differentiated thyroid cancer: experience of a Chilean tertiary center

PURPOSE

Thyroid lobectomy (TL) is an appropriate treatment for up to 4 cm intrathyroidal differentiated thyroid cancer (DTC). There is scarce data regarding TL outside first-world centers. Our aim is to report a cohort of patients with DTC treated with TL in Chile.

METHODS

We included DTC patients treated with TL, followed for at least 6 months, characterized their clinicopathological features and classified their risk of recurrence and response to treatment.

RESULTS

Eighty-two patients followed for a median of 2.3 years (0.5-7.0). Seventy-three (89%) patients had papillary, 8 (9.8%) follicular and 1 (1.2%) high-grade DTC. The risk of recurrence was low in 56 (68.3%) and intermediate in 26 (31.7%). Eight (9.8%) patients required early completion thyroidectomy and radioiodine. At last follow-up, 52 (70.3%) had excellent, 19 (25.7%) had indeterminate, and 1 (1.4%) had structural incomplete response.

CONCLUSION

In a developing country, TL is an adequate option for appropriately selected DTC patients.

Lymph node ratio independently associated with postoperative thyroglobulin levels in papillary thyroid cancer

OBJECTIVES

To investigate the impact of the lymph node ratio (LNR) on postoperative thyroglobulin (Tg) levels in patients with papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

This was a retrospective, cohort study. The association between clinicopathological variables and postoperative unstimulated Tg (uTg) levels, preablative-stimulated Tg (sTg) levels, and postablative unstimulated Tg levels was analysed.

RESULTS

A total of 300 patients with PTC were identified. Multivariate logistic analysis showed that M classification (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.62-3.34), and postoperative thyroid-stimulating hormone levels (OR, 1.01; 95% CI, 1.01-1.02) were independently associated with postoperative uTg levels. One hundred and sixteen patients underwent radioactive iodine (RAI) therapy. Multivariate analysis showed that LNR in the central neck (OR, 1.24; 95% CI, 1.02-1.51), LNR in the lateral neck (OR, 1.73; 95% CI, 1.09-2.77), RAI dose (OR, 1.43; 95% CI, 1.21-1.69), and M classification (OR, 1.79; 95% CI, 1.22-2.61) were independently associated with preablative sTg levels. Tumour size (OR, 1.01; 95% CI, 1.00-1.01), LNR in the central neck (OR, 1.28; 95% CI, 1.08-1.51), LNR in the lateral neck (OR, 1.66; 95% CI, 1.10-2.49), RAI dose (OR, 1.54; 95% CI, 1.34-1.79), and M classification (OR, 1.56; 95% CI, 1.12-2.19) were also independently associated with postablative uTg levels.

CONCLUSION

LNR was independently associated with postoperative Tg levels in patients with PTC. Patients with high LNR were more likely to have incomplete biochemical responses after surgery.

Radioiodine versus no radioiodine outcomes in low-risk differentiated thyroid cancers: A propensity-score matched analysis

OBJECTIVE

The 2015 American Thyroid Association guidelines recommend against radioiodine (RAI) ablation for patients with low-risk papillary microcarcinoma. However, its role in other low-risk differentiated thyroid cancer (DTC) patients remains controversial. Here, we compare long-term outcomes with RAI versus no-RAI in a large cohort comprising all low-risk DTCs.

METHODS

Patients with low-risk, histologically-proven DTC post-thyroidectomy, treated with RAI or kept on follow-up without RAI, between 1990 and 2019 were included. The main outcomes included recurrence rate and recurrence-free survival (RFS), and were validated by propensity-score matching analysis.

RESULTS

Of the 2074 low-risk DTC patients (median age: 35 years), 1686 patients underwent RAI-ablation (RAI group), while 388 patients underwent no-RAI follow-up (NOI group). Over a median follow-up of 8 years (range: 3-29), the recurrence rates were similar between the RAI and NOI groups (2.0% vs. 3.3%, p = .161). The 5- and 10-year RFS probabilities were 99.2% and 97.4%, respectively in RAI group versus 98.4% and 96.2%, respectively, in NOI group (p = .055). Subgroup regression analyses showed that patients with age <55 years (p = .044), male sex (p = .015), papillary histology (p = .043), pT3a tumours (p = .049) and postoperative thyroglobulin ≥5 ng/mL (p = .002) had significantly better RFS with RAI compared to NOI follow-up. Propensity-score matching generated 776 matched pairs with no significantly different outcomes between the two groups.

CONCLUSIONS

In low-risk DTC patients post-thyroidectomy, RAI ablation does not confer significant survival advantage over no-RAI follow-up. Further studies are required to demonstrate any long-term benefit with RAI, specifically in patients with tumour size >4 cm and elevated postoperative thyroglobulin.

Thyroglobulin and thyroglobulin antibody: an updated clinical and laboratory expert consensus

OBJECTIVE

Thyroglobulin measurement is the cornerstone of modern management of differentiated thyroid cancer, with clinical decisions on treatment and follow-up based on the results of such measurements. However, numerous factors need to be considered regarding measurement with and interpretation of thyroglobulin assay results.

DESIGN

The present document provides an integrated update to the 2013 and 2014 separate clinical position papers of our group on these issues.

METHODS

Issues concerning analytical and clinical aspects of highly-sensitive thyroglobulin measurement will be reviewed and discussed based on an extensive analysis of the available literature.

RESULTS

Thyroglobulin measurement remains a highly complex process with many pitfalls and major sources of interference, especially anti-thyroglobulin antibodies, need to be assessed, considered and, when necessary, dealt with appropriately.

CONCLUSIONS

Our expert consensus group formulated 53 practical, graded recommendations for guidance on highly-sensitive thyroglobulin and TgAb in laboratory and clinical practice, especially valuable where current guidelines do not offer sufficient guidance.

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.

Active surveillance in differentiated thyroid cancer: a strategy applicable to all treatment categories response

Currently, the differentiated thyroid cancer (DTC) management is shifted toward a tailored approach based on the estimated risks of recurrence and disease-specific mortality. While the current recommendations on the management of metastatic and progressive DTC are clear and unambiguous, the management of slowly progressive or indeterminate disease varies according to different centers and different physicians. In this context, active surveillance (AS) becomes the main tool for clinicians, allowing them to plan a personalized therapeutic strategy, based on the risk of an unfavorable prognosis, and to avoid unnecessary treatment. This review analyzes the main possible scenarios in treated DTC patients who could take advantage of AS.

Cell-Free DNA Analysis within the Challenges of Thyroid Cancer Management

Simple Summary

Liquid biopsy is a minimally invasive method that emerged as a new promising tool for improving diagnosis, risk stratification, follow-up, and treatment of cancer patients. To date, the majority of the research in the area of liquid biopsy has focused on plasma-based cell-free DNA as a potential surrogate for tumor DNA obtained from a tissue biopsy. In the last decades, breakthrough advancements have been performed in the knowledge of thyroid cancer genetics, and the role of molecular characterization in clinical decision-making is continuously rising, from diagnosis completion to the personalization of treatment approach. Hence, it is expectable for cell-free DNA to be applicable in thyroid cancer management. This review aims to investigate the cell-free DNA utility for thyroid cancer patients’ care.

Abstract

Thyroid cancer is the most frequent endocrine malignancy with an increasing incidence trend during the past forty years and a concomitant rise in cancer-related mortality. The circulating cell-free DNA (cfDNA) analysis is a patient’s friendly and repeatable procedure allowing to obtain surrogate information about the genetics and epigenetics of the tumor. The aim of the present review was to address the suitability of cfDNA testing in different forms of thyroid cancer, and the potential clinical applications, as referred to the clinical weaknesses. Despite being limited by the absence of standardization and by reproducibility and validity issues, cfDNA assessment has great potential for the improvement of thyroid cancer management. cfDNA may support the pre-surgical definition of thyroid nodules by complementing invasive thyroid fine needle aspiration cytology. In addition, it may empower risk stratification and could be used as a biomarker for monitoring the post-surgical disease status, both during active surveillance and in the case of anti-tumor treatment.

Applicability of Dynamic Risk Stratification for Differentiated Thyroid Cancer (DTC) in a Resource Limited Setting

Dynamic risk stratification (DRS) in DTC has been considered necessary to deliver correct follow-up (FU) treatment, avoiding overtreatment of low risk/intermediate risk patients as well as inadequate treatment of high risk patients. However, it's clinical applicability has been questioned in comparison with more conventional FU protocols. We aimed to know the predictive reliability of DRS in monitoring FU of DTC in a resource-constrained setting across various risk groups, especially when compared with clinical examination alone.

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

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

Serum Thyroglobulin Measurement Following Surgery Without Radioactive Iodine for Differentiated Thyroid Cancer: A Systematic Review

Background: The utility of serum thyroglobulin (Tg) measurement following partial thyroidectomy or total/near-total thyroidectomy without radioactive iodine (RAI) for differentiated thyroid cancer is unclear. This systematic review examines the diagnostic accuracy of serum Tg measurement for persistent, recurrent, and/or metastatic cancer in these situations. Methods: Ovid MEDLINE, Embase, and Cochrane Central were searched in October 2021 for studies on Tg measurement following partial thyroidectomy or total/near-total thyroidectomy without or before RAI. Quality assessment was performed, and evidence was synthesized qualitatively. Results: Thirty-seven studies met inclusion criteria. Four studies (N = 561) evaluated serum Tg measurement following partial thyroidectomy, five studies (N = 751) evaluated Tg measurement following total/near-total thyroidectomy without RAI, and 28 studies (N = 7618) evaluated Tg measurement following total or near-total thyroidectomy before RAI administration. Following partial thyroidectomy, Tg measurement was not accurate for diagnosing recurrence or metastasis, or estimates were imprecise. Following total/near-total thyroidectomy without RAI, evidence was limited due to few studies with very low rates of recurrence or metastasis, but indicated that Tg levels were usually stable and low. For Tg measurements before RAI administration, diagnostic accuracy for metastatic disease or persistence varied, although sensitivity appeared high (but specificity low) at a cutoff of >1 to 2.5 ng/mL. However, applicability to patients who do not undergo RAI is uncertain because patients selected for RAI are likely to represent a higher risk group. The evidence was very low quality for all scenarios. All studies had methodological limitations, and there was variability in the Tg thresholds evaluated, patient populations, outcomes assessed, and other factors. Conclusions: Very limited evidence suggests low utility of Tg measurement for identifying recurrent or metastatic disease following partial thyroidectomy. Following total/near-total thyroidectomy, Tg levels using a cutoff of 1-2.5 ng/mL might identify patients at low risk for persistent or metastatic disease. Additional research is needed to clarify the role of Tg measurement in these settings, determine optimal Tg thresholds, and determine appropriate measurement intervals.

Thyroidectomy without Radioiodine in Patients with Low-Risk Thyroid Cancer

BACKGROUND

In patients with low-risk differentiated thyroid cancer undergoing thyroidectomy, the postoperative administration of radioiodine (iodine-131) is controversial in the absence of demonstrated benefits.

METHODS

In this prospective, randomized, phase 3 trial, we assigned patients with low-risk differentiated thyroid cancer who were undergoing thyroidectomy to receive ablation with postoperative administration of radioiodine (1.1 GBq) after injections of recombinant human thyrotropin (radioiodine group) or to receive no postoperative radioiodine (no-radioiodine group). The primary objective was to assess whether no radioiodine therapy was noninferior to radioiodine therapy with respect to the absence of a composite end point that included functional, structural, and biologic abnormalities at 3 years. Noninferiority was defined as a between-group difference of less than 5 percentage points in the percentage of patients who did not have events that included the presence of abnormal foci of radioiodine uptake on whole-body scanning that required subsequent treatment (in the radioiodine group only), abnormal findings on neck ultrasonography, or elevated levels of thyroglobulin or thyroglobulin antibodies. Secondary end points included prognostic factors for events and molecular characterization.

RESULTS

Among 730 patients who could be evaluated 3 years after randomization, the percentage of patients without an event was 95.6% (95% confidence interval [CI], 93.0 to 97.5) in the no-radioiodine group and 95.9% (95% CI, 93.3 to 97.7) in the radioiodine group, a difference of -0.3 percentage points (two-sided 90% CI, -2.7 to 2.2), a result that met the noninferiority criteria. Events consisted of structural or functional abnormalities in 8 patients and biologic abnormalities in 23 patients with 25 events. Events were more frequent in patients with a postoperative serum thyroglobulin level of more than 1 ng per milliliter during thyroid hormone treatment. Molecular alterations were similar in patients with or without an event. No treatment-related adverse events were reported.

CONCLUSIONS

In patients with low-risk thyroid cancer undergoing thyroidectomy, a follow-up strategy that did not involve the use of radioiodine was noninferior to an ablation strategy with radioiodine regarding the occurrence of functional, structural, and biologic events at 3 years. (Funded by the French National Cancer Institute; ESTIMABL2 ClinicalTrials.gov number, NCT01837745.).

Outcomes of nonsuspicious contralateral nodules with active surveillance after lobectomy in patients with papillary thyroid carcinoma

OBJECTIVE

To observe the outcomes of nonsuspicious contralateral nodules with active surveillance in patients with papillary thyroid carcinoma (PTC).

METHODS

4pt?>Consecutive patients who underwent lobectomy for PTC were retrospectively reviewed. Patients with one or more nodules with nonsuspicious ultrasonography (US) features in the contralateral lobe were included.

RESULTS

Two hundred and eighty-three patients were included. All patients underwent thyroid lobectomy with ipsilateral prophylactic central neck dissection. A total of 123 patients (43.5%) were classified as ATA low-risk, and 160 patients (56.5%) were classified as intermediate-risk. The median size of the contralateral nodules was 3 mm (range, 2 to 16 mm). After a period of follow-up, the median size change of contralateral nodules was 0 mm (range, -7 to 8 mm). Eight patients (2.8%) had nodule growth >3 mm, 223 patients (78.8%) had stable or decreased nodules, and 52 patients (18.4%) had no detectable nodules. Nodules in 24 patients had suspicious US features, 16 of which were diagnosed with PTMC by either cytology after FNA (in 7 patients) or histopathology after completion thyroidectomy (in 9 patients). Another four patients received completion thyroidectomy for ipsilateral cervical lymph node metastasis. The 5-year residual lobe recurrence (RLR) rate and recurrence-free survival (RFS) rate were 7.4% and 89.8%, respectively. Multivariate analysis showed that multifocality and ATA intermediate-risk were independent predictors for RLR (HR4.083, 95%CI 1.480-11.261, P = 0.007; HR 6.045, 95%CI 1.370-26.662, P = 0.017, respectively) and RFS (HR 5.240, 95%CI 2.114-12.991, P < 0.001; HR 5.223, 95%CI 1.353-17.765, P = 0.008, respectively).

CONCLUSIONS

Active surveillance for nonsuspicious contralateral nodules in patients with low-risk and selected intermediate-risk PTC is safe. Multifocality and ATA intermediate-risk are predicters for recurrence. Early detection and salvage surgery are effective.

The Role of Thyroglobulin in Preoperative and Postoperative Evaluation of Patients With Differentiated Thyroid Cancer

Thyroglobulin (Tg) is secreted by thyroid follicular cells and stored in the thyroid follicular lumen as a component of thyroid hormone. It is known that both benign and well-differentiated malignant thyroid tissue can secrete Tg. In recent years, growing lines of evidence have shown that Tg plays an important role in the diagnosis and metastasis of preoperative differentiated thyroid carcinoma (DTC). The levels of Tg, whether in the serum or in a fine-needle aspiration washout fluid, are usually viewed as an excellent indicator in the monitoring of postoperative DTC, including the guidance and evaluation of radioactive iodine ablation. Nevertheless, some factors limit the application of Tg, such as the method used to measure Tg and the presence of Tg antibodies. This review aimed to summarize the role of Tg in the preoperative and postoperative evaluation of patients with DTC, and the factors influencing Tg. This review could provide a reference for a more accurate application of Tg in patients with DTC.

A New Dynamic Response to Therapy Assessment in Postoperative Patients With Low-Risk Differentiated Thyroid Cancer Treated Without Radioactive Iodine

Background

Total thyroidectomy (TT) or lobectomy without radioactive iodine (RAI) is becoming a common management for patients with low-risk differentiated thyroid cancer (DTC). However, the assessment of response to therapy for these patients remains controversial. The aim of this study was to propose and validate a new dynamic evaluation strategy to assess the response to therapy in patients with low-risk DTC treated with TT or lobectomy but without RAI.

Methods

We performed a retrospective analysis of 543 adult patients with low-risk DTC who underwent TT or lobectomy without RAI therapy. Follow-up consisted of trends of serum thyroglobulin (Tg), anti-thyroglobulin antibody (TgAb) levels and neck ultrasonography (US) were conducted every 6-24 months. Response to therapy assessments were defined as excellent response, biochemical incomplete response, structural incomplete response, and indeterminate response according to the follow-up findings.

Results

At a median follow-up of 51 months (range 33-66 months), 517 (95%) had excellent response, while the other 26 had either biochemical incomplete response (an increasing trend of suppressed serum Tg levels, n=9; an increasing trend of TgAb levels, n=3) or indeterminate response (a stable or decreasing trend of suppressed serum Tg levels, but a stable positive trend of TgAb levels, n=14). No patients had structural incomplete response or no deaths related to thyroid cancer. The risk of incomplete response was significantly higher in lobectomy than in TT (p<0.001).

Conclusion

Our study proposed and validated a new dynamic response to therapy assessment depending on trends of suppressed serum Tg, TgAb levels, and neck US findings which could be an appropriate tool for postoperative follow-up in low-risk DTC patients without RAI therapy. Our findings provided further evidence to support no routine recommendation of RAI after surgery in low-risk DTC.

Outcomes after radioiodine ablation in patients with thyroid cancer: Long-term follow-up of a Chinese randomized clinicaltrial

OBJECTIVE

Two large randomized trials of patients with differentiated thyroid cancer (DTC) reported recently (HiLo and ESTIMABL1) found that the recurrence rate among patients who underwent 1.1 GBq radioactive iodine (RAI) ablation was not higher than that of patients who underwent 3.7 GBq radioactive iodine (RAI) ablation. However, no similar studies have been conducted in China. We aimed to report clinical outcomes in Chinese patients with low/intermediate risk of recurrence DTC after long-term follow-up, and evaluate the risk factors that influence the presence or absence of incomplete response at the final follow-up.

DESIGN

A long-term follow-up of a Chinese randomized clinical trial (October 2014 and February 2021) was conducted.

PATIENTS

A total of 506 DTC patients at low/intermediate risk of recurrence who were randomized into two groups to receive 1.1 (n = 251) or 3.7 GBq (n = 255) RAI ablation following thyroid hormone withdrawal were followed on levothyroxine treatment for a median of 4.5 years (range: 1.6-6.3).

MEASUREMENTS

Suppressed serum thyroglobulin (Tg) and anti-thyroglobulin antibody (TgAb) levels were determined, and neck ultrasonography was performed.

RESULTS

At the final follow-up, 499 (98.6%) patients showed an excellent response. The other seven patients (two patients underwent 1.1 GBq and five patients underwent 3.7 GBq RAI ablation, respectively) showed either structural incomplete response (lymph node metastasis, n = 1), biochemical incomplete response (increased serum Tg ≥ 1 ng/ml, or increased positive TgAb levels, n = 5), or indeterminate response (stable positive TgAb levels, n = 1). The risk of incomplete response at the final follow-up was significantly increased in patients with stimulated serum Tg ≥ 10 ng/ml at ablation (p = .003) and in patients with unsuccessful ablation (p = .008).

CONCLUSION

Our findings indicated that there was no difference in the long-term outcomes with RAI ablation using either 1.1 or 3.7 GBq in patients with low/intermediate risk of recurrence DTC, and 1.1 GBq RAI might be suitable for patients who are recommended for ablation.

Undetectable thyroglobulin makes 123I whole-body scan and stimulated thyroglobulin obsolete in follow-up care of differentiated thyroid cancer: a retrospective study

Background

Differentiated thyroid cancer (DTC) is a common malignancy with increasing incidence. Follow-up care for DTC includes thyroglobulin (Tg) measurement and ultrasound (US) of the neck, combined with ¹³¹I remnant ablation when indicated. Diagnostic precision has evolved with the introduction of the new high-sensitive Tg-assays (sensitivity ≤0.1 ng/mL). The aim of the study was to determine the prognostic utility of high-sensitive Tg and the need for other diagnostic tests in DTC.

Methods

This was a retrospective, observational study. Patients with pathologically confirmed DTC, treated with total thyroidectomy and ¹³¹I remnant ablation, who had their complete follow-up care in our institution were selected (October 2013–December 2018). Subjects with possible thyroglobulin autoantibody interference were excluded. Statistical analysis was performed using the IBM SPSS® Statistics 24 software package.

Results

Forty patients were eligible for analysis. A total of 24 out of the 40 patients (60%) had an undetectable high-sensitive Tg 6 months after total thyroidectomy. None of these patients had a stimulated Tg above 1 ng/mL, or remnant on the ¹²³I Whole-Body Scan (WBS) after 1 year of follow-up. Ultrasound of the neck, performed between 6 and 12 months postoperative, was negative in 21 out of the 24 patients.

Conclusions

This study shows that an undetectable high-sensitive Tg can change the management of patients with DTC and decrease the use and need of stimulated Tg and ¹²³I WBS.

Clinical significance of neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, platelet-to-lymphocyte ratio and prognostic nutritional index in low-risk differentiated thyroid carcinoma

Objective

Inflammation and nutritional status play an important role in the prognosis of cancer. Lymphocyte-to monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and prognostic nutritional index (PNI) are independent prognostic scores in numerous cancers. However, any study showed their prognostic role in low-risk differentiated thyroid carcinoma (DTC). We aimed to clarify and identify the prognostic value of inflammation indices in low-risk DTC patients.

Methods

We analysed data from 116 patients, dividing the population into two groups, according to AJCC staging system (8^th edition). The LMR, NLR, PLR and PNI cut-off value were determined using receiver operating characteristic (ROC) curve. Disease-free survival (DFS) was calculated with Kaplan-Meyer and Log-Rank tests and the risk of recurrence was calculated with univariate and multivariate Cox regression. Statistical significance was p < 0.05.

Results

We found a baseline NLR value ≥ 1.750 (75% sensitivity, 40.2% specificity) and a baseline LMR value of 3.83 (66.7% sensitivity, 48.9% specificity). Overall DFS was 74.995 ± 3.236 with a p value of 0.678. NLR showed a hazard ratio for recurrence with almost twice the risk of recurrence (Adjusted Hazard Ratio /HR^A): 1.828, p-value = 0.019).

Conclusions

NLR can be considered a prognostic score with twice the risk of recurrence in low-risk DTC patients with NLR < 1.750.

Radioactive iodine does not improve overall survival for patients with aggressive variants of papillary thyroid carcinoma less than 2 cm

BACKGROUND

Tall cell and diffuse sclerosing variants of papillary thyroid cancer are associated with aggressive features. Radioactive iodine after total thyroidectomy is poorly studied.

METHODS

Patients ≥18 years in the National Cancer Data Base from 2004 to 2016 with classic papillary thyroid cancer, tall cell, or diffuse sclerosing 1 mm to 40 mm were identified. Logistic regression identified factors associated with aggressive features. Overall survival was assessed using Kaplan-Meier method and log-rank tests, after propensity score matching for clinicopathological and treatment variables.

RESULTS

A total of 155,940 classic papillary thyroid cancer patients, 4,011 tall cell, and 507 diffuse sclerosing were identified. Tall cell patients represented an increasing proportion of the study population during the analysis period, whereas diffuse sclerosing and classic papillary thyroid cancer patients showed a statistically significant decline. Extrathyroidal extension and nodal involvement were more prevalent among tall cell and diffuse sclerosing patients when compared to those diagnosed with classic papillary thyroid cancer (P < .01). Adjuvant radioactive iodine was less frequently used in patients with classic papillary thyroid cancer when compared to tall cell and diffuse sclerosing patients (42.6% vs 62.4%, 59.0%; P < .001, respectively). Aggressive variants receiving total thyroidectomy versus total thyroidectomy + radioactive iodine propensity score matched across clinicopathologic variables were analyzed. There was no difference in overall survival between the 2 treatment groups for tumors <2 cm (01-1.0 cm, 92.2% vs 84.8%; P = .98); (1.0-2.0 cm, 72.7% vs 88.1%; P = .82). However, overall survival was improved for total thyroidectomy + radioactive iodine propensity score matched patients with tumor sizes 21 to 40 mm versus total thyroidectomy (83.4% vs 70.0%, P = .004).

CONCLUSION

For aggressive tumor variants ≤2 cm treated with total thyroidectomy, there is no overall survival advantage provided by the addition of adjuvant radioactive iodine.

Selective Use of Radioactive Iodine Therapy for Papillary Thyroid Cancers With Low or Lower-Intermediate Recurrence Risk

CONTEXT

Current guidelines recommend a selective use of radioiodine treatment (RAI) for papillary thyroid cancer (PTC).

OBJECTIVE

This work aimed to determine how policy changes affect the use of RAI and the short-term outcomes of patients.

METHODS

A retrospective analysis of longitudinal data was conducted in an academic referral center of patients with nonaggressive PTC variants; no extrathyroidal invasion or limited to soft tissues, no distant metastases, and 5 or fewer central-compartment cervical lymph node metastases. In cohort 1, standard treatments were total thyroidectomy and RAI (May 2005-June 2011); in cohort 2 decisions on RAI were deferred for approximately 12 months after surgery (July 2011-December 2018). Propensity score matching was used to adjust for sex, age, tumor size, lymph node status, and extrathyroidal extension. Intervention included immediate RAI or deferred choice. Main outcome measures were responses to initial treatment during 3 or more years of follow-up.

RESULTS

In cohort 1, RAI was performed in 50 of 116 patients (51.7%), whereas in cohort 2, it was far less frequent: immediately in 10 of 156 (6.4%), and in 3 more patients after the first follow-up data. The frequencies of structural incomplete response were low (1%-3%), and there were no differences between the 2 cohorts at any follow-up visit. Cohort 2 patients had higher rates of "gray-zone responses" (biochemical incomplete or indeterminate response).

CONCLUSION

Selective use of RAI increases the rate of patients with "uncertain" status during early follow-up. The rate of structural incomplete responses remains low regardless of whether RAI is used immediately. Patients should be made aware of the advantages and drawbacks of omitting RAI.

Current practice in patients with differentiated thyroid cancer

Considerable changes have occurred in the management of differentiated thyroid cancer (DTC) during the past four decades, based on improved knowledge of the biology of DTC and on advances in therapy, including surgery, the use of radioactive iodine (radioiodine), thyroid hormone treatment and availability of recombinant human TSH. Improved diagnostic tools are available, including determining serum levels of thyroglobulin, neck ultrasonography, imaging (CT, MRI, SPECT-CT and PET-CT), and prognostic classifications have been improved. Patients with low-risk DTC, in whom the risk of thyroid cancer death is <1% and most recurrences can be cured, currently represent the majority of patients. By contrast, patients with high-risk DTC represent 5-10% of all patients. Most thyroid cancer-related deaths occur in this group of patients and recurrences are frequent. Patients with high-risk DTC require more aggressive treatment and follow-up than patients with low-risk DTC. Finally, the strategy for treating patients with intermediate-risk DTC is frequently defined on a case-by-case basis. Prospective trials are needed in well-selected patients with DTC to demonstrate the extent to which treatment and follow-up can be limited without increasing the risk of recurrence and thyroid cancer-related death.

Pros and cons of hemi-thyroidectomy for low-risk differentiated thyroid cancer

The debate regarding the surgical management of low-risk differentiated thyroid cancer (DTC) is ongoing. The recommended extent of surgery in DTC is based on an assessment of the predicted risk of recurrence and recent guidelines reflect an evolving philosophy of de-escalation of surgical management, informed by a growing understanding of the determinants of tumour biology and important prognostic factors. However, our current clinical and pathological risk stratification processes are imperfect and hence there is significant variation in clinical practice. Surgeons face the challenge of finding the balance between avoiding overtreatment, minimizing complications and providing adequate oncological management. This article discusses the nuances of the current management guidelines as well as the important considerations in preoperative decision making.

Does the ATA Risk Stratification Apply to Patients with Papillary Thyroid Microcarcinoma?

BACKGROUND

The incidence of papillary thyroid microcarcinoma (PTMC) has increased over the past decade. The American Thyroid Association (ATA) suggests that these patients may undergo either thyroid lobectomy or active surveillance. It remains unclear whether there exists a subgroup of PTMC patients who may benefit from more aggressive treatment due to increased risk of recurrence.

METHODS

We retrospectively reviewed 357 patients with PTMC who underwent surgery at a single institution from 2004 to 2016. Patients were classified according to 2015 ATA risk stratification for structural disease recurrence. Demographic, oncologic, and clinicopathologic data were compared between groups.

RESULTS

Out of 357 patients, 246 were classified as low-risk PTMC, 93 were intermediate-risk, and 18 were high-risk. There were more male patients in the high-risk group (38.9%) than the intermediate- (31.2%) or low-risk groups (15.4%) (p < 0.001). Patients with low-risk microcarcinomas were more likely to have an incidental PTMC when compared to intermediate- or high-risk groups (98[39.8%], 15[16.1%], 1[5.6%], respectively, p < 0.001). Patients with high-risk PTMCs, compared to those with intermediate- and low-risk PTMCs, were more likely to have rising postoperative thyroglobulin levels after total thyroidectomy (6[40.0%], 4[5.1%], 9[5.7%], respectively, p = 0.001) and structural recurrence after lobectomy or total thyroidectomy (3[16.7%], 0[0%], 0[0%], respectively, p < 0.001). The median follow-up time was 17.5 (IQR 3-55) months.

CONCLUSIONS

Patients with high-risk PTMC have an increased risk of recurrence when compared to low- and intermediate-risk microcarcinomas, whereas intermediate-risk PTMC may behave similarly to low-risk tumors. ATA risk stratification may inform clinical decision making for patients with PTMC.

Pediatric differentiated thyroid carcinoma: An update from the APSA Cancer Committee

BACKGROUND

Differentiated thyroid carcinomas (DTCs) are rare in young children but represent almost 10% of all malignancies diagnosed in older adolescents.

METHODS

This article reviews the recent literature describing surgical therapeutic approaches to pediatric DTC, associated complications, and long-term recurrence and survival outcomes.

RESULTS

Similar to adult thyroid cancers, pediatric DTCs are more common in females and are associated with thyroid nodules, family history of thyroid cancer, radiation exposure, iodine deficiency, autoimmune thyroid disease, and genetic syndromes. Management of thyroid cancers in children involves ultrasound imaging, fine needle aspiration, and surgical resection with treatment decisions based on clinical and radiological features, cytology and risk assessment.

CONCLUSIONS

Total thyroidectomy and compartment based resection of clinically involved lymph node basins form the cornerstone of treatment of DTC. There is an evolving literature regarding the use of molecular genetics to inform treatment strategies and the use of targeted therapies to treat iodine refractory and surgically unresectable progressive disease.

TYPE OF STUDY

Summary review.

LEVEL OF EVIDENCE

This is a review article of previously published Level 1-5 articles that includes expert opinion (Level 5).

Ultrasonography surveillance in papillary thyroid carcinoma patients after total thyroidectomy according to dynamic risk stratification

PURPOSE

To investigate the role of neck US surveillance in patients with papillary thyroid carcinoma (PTC) after total thyroidectomy according to dynamic risk stratification (DRS) based on response to initial therapy.

METHODS

This retrospective study included 812 patients with PTC who underwent total thyroidectomy with prophylactic central neck dissection from January 2003 through February 2007. The relative risk of recurrence/persistence according to DRS was evaluated with the multivariable Cox regression proportional hazard model.

RESULTS

There were 132 men and 680 women. The mean age at surgery was 45.2 years. Postoperative US was used for DRS. According to DRS, 676 patients had excellent response, 78 indeterminate response, 40 biochemical incomplete response, and 18 structural incomplete response to initial therapy. Neck US was performed during follow-up and detected locoregional recurrences in 21 patients (2.6%): 12 with excellent response, 2 with biochemical incomplete response, and 7 with structural incomplete response according to DRS. Only 1 patient (0.1%) with excellent response had a locoregional recurrence that exceeded 8 mm in its shortest diameter, which is the size cut-off for diagnostic US fine-needle aspiration in suspicious lymph nodes. This patient did not develop biochemical abnormalities during follow-up.

CONCLUSIONS

Postoperative neck US surveillance after total thyroidectomy with prophylactic central neck dissection is not essential in PTC patients who show excellent response to initial therapy. Future studies are needed to verify the role of US surveillance in patients who receive variable degrees of treatments.

Thyroglobulin Changes are Highly Dependent on TSH in Low-risk DTC Patients not Treated with Radioiodine

INTRODUCTION

Low-risk differentiated thyroid cancer (DTC) is currently rarely treated with radioiodine (131I) to ablate the postoperative remnant. Therefore, the interpretation of the serum thyroglobulin (Tg) values should be reconsidered. The aim of our study was to evaluate the changes in Tg values during follow-up with regard to the changing values in thyroid stimulating hormone (TSH).

MATERIALS AND METHODS

We evaluated 271 low-risk DTC patients, treated with total thyroidectomy but not 131I. To be included, patients had to be negative for Tg antibodies and have at least 3 evaluations in our department. All patients were on levothyroxine (L-T4) therapy.

RESULTS

After a median follow-up of 73 months, the overall Tg values were stable, while TSH values slightly increased. Therefore, we pooled data of Tg and TSH from all evaluations and a significant positive correlation was demonstrated (R = 0.2; P < 0.01), and was also demonstrated when we performed the analysis using time-weighted values (R = 0.14; P = 0.02). Moreover, when dividing patients into 3 groups according to first postoperative Tg (Group A [Tg < 0.2 ng/ml], Group B [Tg 0.2-1 ng/ml], and Group C [Tg > 1 ng/ml]) most patients showed stable values of Tg at the end of follow-up but TSH variations had a clear impact on the changes in Tg among the groups.

CONCLUSION

We demonstrated that in low-risk DTC not treated with 131I, serum Tg remains substantially stable over time, and the variations observed were correlated with the concomitant variations of TSH levels, mainly due to the modification of LT-4 therapy performed according to the ongoing risk stratification.

Management and follow-up of differentiated thyroid cancer not submitted to radioiodine treatment: a systematic review

INTRODUCTION

The treatment of differentiated thyroid cancer (DTC) has been changing. In low (LR) and intermediate (IR) risk DTC, surgery is becoming more conservative and the usefulness of radioiodine (¹³¹I) has been questioned. An increasing number of patients are treated with lobectomy or total thyroidectomy (TTx), but without ¹³¹I. Consequently, the management and the follow-up of these patients need to be revised.

EVIDENCE ACQUISITION

We reviewed the available data about the management of these growing categories of patients. We focused on the emerging roles of the conventional tools in the follow-up [thyroglobulin (Tg), thyroglobulin antibodies (TgAb) and neck ultrasound (US)]. Moreover, we evaluated the changes in the use of levothyroxine (L-T4) therapy, and the role of the ongoing risk re-stratification.

EVIDENCE SYNTHESIS

Tg, TgAb and neck US continue to represent the cornerstone of the follow-up, however, a change in their interpretation is needed. In particular, the absolute value of Tg and TgAb lost their clinical meaning, while their trend over time acquired a greater value. At variance, the diagnostic role of neck US is becoming very relevant for the early identification of the local recurrences. In addition, L-T4 therapy should be personalized according with the type of surgery, the age of patients and their comorbidities.

CONCLUSIONS

Management of DTC treated with lobectomy or TTx but without ¹³¹I is worldwide changing. The evidences suggest that in this setting of patients with LR or IR of recurrences, a relaxed surveillance could represent the most reasonable choice.

Thyroid cancer histological subtypes based on tumor size: National perspective

BACKGROUND

Thyroid tumor size is an important prognostic factor. The aim of this study is to examine the histological subtypes and management of thyroid cancer based on tumor size (≤4 cm vs >4 cm).

METHODS

Retrospective cohort study utilizing the National Cancer Database, 2004-2014.

RESULTS

A total of 152 387 patients were included, 13 614 (8.9%) of whom had a tumor size >4 cm. Histological subtypes of tumors >4 cm were: 69.6% papillary thyroid carcinoma, 17.5% FTC, 7.9% HCC, and 2.8% medullary thyroid carcinoma (MTC). High-volume hospitals for thyroid surgery were less likely to perform two-stage thyroidectomy, particularly for tumors ≤4 cm. Low-volume hospitals had a higher risk of staged thyroidectomy for MTC ≤4 cm (19.8%) compared with high-volume hospitals (8.7%) (P < .001).

CONCLUSIONS

This study describes the prevalence of thyroid cancer subtypes. In the era of a conservative approach to differentiated thyroid carcinoma, there could be a potential increase in the risk of staged thyroidectomy.

Referral Practice for Radioactive Iodine Ablation (RAI) after ATA guidelines 2015: results from a Tertiary Cancer Care Centre

INTRODUCTION

The ATA guidelines for differentiated thyroid cancer (DTC) are one of the most widely referred to. Their 2015 edition proposed a new risk stratification system and modified the indications for radioactive iodine (RAI) ablation especially for the low risk category. We attempted to analyze whether the new guidelines altered referral practices for RAI ablation at our institute.

METHODOLOGY

Patients who underwent total or completion thyroidectomy for DTC during 2016-2017 were included. Relevant demographical and pathological data was tabulated. Patients were classified as per the new stratification system and referral practice for RAI ablation documented.

RESULTS

238 patients were included. Of these 20.6% were low risk, 44.1% were intermediate and 35.3% were high risk as per modified guidelines. All patients within the intermediate and high-risk group and 77.8% of the low risk group were referred for RAI ablation. Analysis of risk factors revealed that within the low risk group there were three patients with < 5 metastatic nodes, all within 3 cm in size-a category that the ATA failed to stratify appropriately. Among those labeled as Intermediate risk due to microscopic extra thyroidal extension (ETE), 85% had no other risk factors and were upstaged solely due to microscopic ETE, which is interestingly no longer included in the TNM staging.

CONCLUSION

Majority of low risk patients continue to receive RAI ablation due to persistent belief emanating from literature that remnant ablation improves outcomes and aids in follow up. The issue of RAI ablation for low risk group and prognostic implications of microscopic ETE and limited nodal disease need to be revisited.

Dynamics of serum antithyroglobulin antibodies in patients with differentiated thyroid cancer

PURPOSE

Serum antithyroglobulin antibodies (sTgAb) affect the reliability of Tg measurement in patients with thyroid cancer. We compared the outcome of patients with detectable and undetectable sTgAb, stratified according to the initial risk of recurrence (RR); also the response to treatment in patients with detectable sTgAb treated with total thyroidectomy (TT) with and without radioiodine remnant ablation (RA) and the sTgAb trend in the long-term follow-up according to the initial response.

METHODS

We included 432 patients submitted to TT, with or without RA; 106 patients had detectable sTgAb levels. Median follow-up was 53 months.

RESULTS

There were no statistically significant differences considering presentation between negative or positive sTgAb subjects. The frequency of structural incomplete response (SIR) in low, intermediate, and high RR was similar. Undetectable sTgAb in patients was achieved in a median of 16 months in ablated patients compared with 11 months in those without RA (p = 0.0232). Patients without RA had a higher rate of undetectable sTgAb during the first 12 months. A SIR was observed in 3% of patients with declining sTgAb, in 19% of those with stable levels, and in 43% with increasing sTgAb (p = 0.004). The status of no evidence of disease was achieved more frequently in patients with initial sTgAb levels < 200 mUI/l, independently of the initial RR.

CONCLUSIONS

There was no impact of sTgAb on the initial clinical presentation and the response to therapy in low-risk patients treated with or without RA. sTgAb trend is more useful than an absolute value to predict a SIR.

Contemporary Debates in Adult Papillary Thyroid Cancer Management

An ever-increasing population of patients with papillary thyroid cancer is engaging with health care systems around the world. Numerous questions about optimal management have arisen that challenge conventional paradigms. This is particularly the case for patients with low-risk disease, who comprise most new patients. At the same time, new therapies for patients with advanced disease are also being introduced, which may have the potential to prolong life. This review discusses selected controversial issues in adult papillary thyroid cancer management at both ends of the disease spectrum. These topics include: (i) the role of active surveillance for small papillary cancers; (ii) the extent of surgery in low-risk disease (lobectomy vs total thyroidectomy); (iii) the role of postoperative remnant ablation with radioiodine; (iv) optimal follow-up strategies in patients, especially those who have only undergone lobectomy; and (v) new therapies for advanced disease. Although our current management is hampered by the lack of large randomized controlled trials, we are fortunate that data from ongoing trials will be available within the next few years. This information should provide additional evidence that will decrease morbidity in low-risk patients and improve outcomes in those with distant metastatic disease.

Thyroid Cancer Patients With No Evidence of Disease: The Need for Repeat Neck Ultrasound

CONTEXT

Ultrasonography (US) is considered the most sensitive tool for imaging persistent or recurrent papillary thyroid cancer (PTC) in the neck.

OBJECTIVE

To clarify the usefulness of routine neck US in low- and intermediate-risk patients with PTC with no evidence of disease 1 year after thyroidectomy.

DESIGN

Retrospective analysis of prospectively recorded data.

SETTING

Academic center.

PATIENTS

Two hundred twenty-six patients with PTC with sonographically normal neck lymph nodes and unstimulated serum thyroglobulin (Tg) levels that were either undetectable (<0.20 ng/mL) or low (0.21 to 0.99 ng/mL) at the 1-year evaluation.

INTERVENTIONS

Yearly assessment: unstimulated serum Tg level, anti-Tg-antibody (TgAb) titer, TSH levels, and ultrasound examination of neck lymph nodes.

MAIN OUTCOME MEASURES

Rates of ultrasonographic lymph node abnormalities at the 3-year and last follow-up visits.

RESULTS

In patients with an undetectable Tg level at the 1-year evaluation, sonographically suspicious neck lymph nodes were found in 1.2% of patients at 3 years and in 1.8% at the last visit [negative predictive values (NPVs) of 1-year Tg < 0.2 ng/mL: 98.8% (95% CI 95.8% to 99.9%) and 98.2% (95% to 99.6%), respectively]. Similar NPVs emerged for low detectable 1-year Tg levels [98.2% (90.3% to 99.9%) and 94.5% (84.9% to 98.9%) at the 3-year and last visits, respectively]. Seventy-five percent of the nodal lesions were likely false positive; none required treatment.

CONCLUSIONS

Low- and intermediate-risk patients with PTC with negative ultrasound findings and unstimulated Tg levels <1 ng/mL at the 1-year evaluation can be safely followed with clinical assessments and unstimulated serum Tg determinations. Neck US might be repeated if TgAb titers rise, or unstimulated Tg levels exceed 1 ng/mL.

Lobectomy in patients with differentiated thyroid cancer: indications and follow-up

The extent of thyroid surgery for patients with low- and intermediate-risk differentiated thyroid carcinoma (DTC), with a primary tumour <4 cm and no extrathyroidal extension (ETE) or lymph node (LN) metastases, has shifted in a more conservative direction. However, clinicopathological risk factors, including microscopic ETE, aggressive histology, vascular invasion in papillary thyroid carcinoma (PTC) and intermediate volume of LN metastases, can only be identified after completing thyroid lobectomy. It is controversial whether patients with these risk factors should immediately undergo complete thyroidectomy and/or radioactive iodine remnant ablation or should be monitored without further treatments. Data are conflicting about the prognostic impact of these risk factors on clinical DTC outcomes. Notably, the recurrence rate in patients who underwent thyroid lobectomy is low and the few recurrences that develop during long-term follow-up can readily be detected by neck ultrasonography and treated by salvage surgery with no impact on survival. These findings suggest that a more conservative approach may be a preferred management strategy over immediate completion surgery, despite a slightly higher risk of structural recurrence. Regarding follow-up of post-lobectomy DTC patients, it is reasonable that an initial risk stratification system based on clinicohistological findings be used to guide the short-term follow-up prior to evaluating the response to initial therapy and that the dynamic risk stratification system based on the response to initial therapy be used to guide long-term follow-up.

Long-Term Outcome after Hemithyroidectomy for Papillary Thyroid Cancer: A Comparative Study and Review of the Literature

Background: The extent of surgery for differentiated thyroid cancer (DTC) remains a controversial issue. Since a less aggressive approach is becoming more predominant, we aim here to study the short- and long-term outcomes of DTC patients after hemithyroidectomy. Methods: From a total of 1252 consecutive papillary thyroid cancer (PTC) patients, 109 treated with hemithyroidectomy and 50 with total thyroidectomy but no I¹³¹ were included. Persistent or recurrent disease was defined based on histopathology, imaging studies, and thyroglobulin levels. Results: Our hemithyroidectomy cohort included females (84.4%), microcarcinomas (81.9%), TNM stage I (95.4%), and a low American Thyroid Association (ATA) recurrence risk (94.5%). At one-year post-treatment, 3.7% had persistent disease (all female, median age 55 years, tumor size 7.5 mm). Recurrent disease was detected in 7.5% of those with excellent response at 1-year. With a follow-up of 8.6 years (1–48), all 109 patients were disease free at last visit, including the 11 patients (10.1%) who received additional treatment. Also, when comparing the hemi- and total thyroidectomy groups no significant differences were found in the rate of persistent and recurrent disease, overall mortality, and disease status at last visit. Conclusions: For properly selected low-risk PTC patients, hemithyroidectomy is a safe treatment option with a favorable long-term outcome.

Thyroid cancer burden and economic impact on the Brazilian public health system

OBJECTIVE

Recent data indicates an increasing incidence of thyroid cancer not accompanied by a proportional increase in mortality, suggesting overdiagnosis, which may represent a big public health problem, particularly where resources are scarce. This article aims to describe and evaluate the procedures related to investigation of thyroid nodules and treatment and follow-up of thyroid cancer and the costs for the Brazilian public health system between 2008 and 2015.

MATERIALS AND METHODS

Data on procedures related to investigation of thyroid nodules and treatment/follow-up of thyroid cancer between 2008 and 2015 in Brazil were collected from the Department of Informatics of the Brazilian Unified Health System (Datasus) website.

RESULTS

A statistically significant increase in the use of procedures related to thyroid nodules investigation and thyroid cancer treatment and follow-up was observed in Brazil, though a reduction was noted for procedures related to the treatment of more aggressive thyroid cancer, such as total thyroidectomy with neck dissection and higher radioiodine activities such as 200 and 250 milicuries (mCi). The procedures related to thyroid nodules investigation costs increased by 91% for thyroid ultrasound (p = 0.0003) and 128% in thyroid nodule biopsy (p < 0.001). Costs related to treatment and follow-up related-procedures increased by 120%.

CONCLUSION

The increase in the incidence of thyroid cancer in Brazil is directly associated with an increased use of diagnostic tools for thyroid nodules, which leads to an upsurge in thyroid cancer treatment and followup-related procedures. These data suggest that substantial resources are being used for diagnosis, treatment and follow-up of a potentially indolent condition.

IS IT WORTH SUPPRESSING TSH IN LOW- AND INTERMEDIATE-RISK PAPILLARY THYROID CANCER PATIENTS BEFORE THE FIRST DISEASE ASSESSMENT?

OBJECTIVE

Guidelines recommend thyroid-stimulating hormone (TSH) suppression before the first response to treatment assessment in papillary thyroid cancer (PTC) patients. The aim of this study was to assess the rate of structural disease (SD) in low- and intermediate-risk PTC patients according to TSH levels measured 1 year after primary treatment.

METHODS

A consecutive, prospective series of low- and intermediate-risk PTC patients with 3-years follow-up was collected. TSH, thyroglobulin (Tg), antithyroglobulin antibodies (TgAb), and neck ultrasonography (US) 1 and 3 years after primary treatment were analyzed. Recurrence risk and disease status at 1 year were defined according to the American Thyroid Association (ATA) guidelines and as the presence or absence of SD after 3 years. Patients were grouped according to TSH level at 1 year: group 1, TSH <0.1 μUI/mL; group 2, TSH 0.1 to 0.5 μUI/mL; group 3, 0.5 to 2 μUI/mL; and group 4 >2 μUI/mL.

RESULTS

This study included 263 patients (70.9% female, median age 47.2 years) of whom the risk of recurrence was low in 170 (65%), intermediate-low in 63 (24%), and intermediate-high in 30 (11%). The response to initial treatment at 1 year was excellent in 149 (57%), biochemical incomplete in 18 (7%), indeterminate in 84 (32%), and structural incomplete in 12 (4%). Group 1 consisted of 53 (20%) patients, group 2 of 85 (32%), group 3 of 61 (23%), and group 4 of 64 (24%). The rate of SD at 1 and 3 years from primary treatment was not significantly different between TSH groups.

CONCLUSION

TSH suppression before the first response to treatment assessment does not appear to influence the rate of SD evaluated 1 and 3 years after primary treatment.

ABBREVIATIONS

ATA = American Thyroid Association; DTC = differentiated thyroid cancer; FTC = follicular thyroid cancer; LT4 = levothyroxine; PTC = papillary thyroid cancer; SD = structural disease; Tg = thyroglobulin; TgAb = antithyroglobulin antibodies; TSH = thyroid-stimulating hormone; US = ultrasonography.

Comparison of short-term oncologic outcome of robotic thyroid surgery using dynamic risk stratification: A propensity score-matched comparison study

BACKGROUND

The long-term oncologic outcome of robotic surgery for thyroid cancer is not well established. The aim of this study was to predict the long-term oncologic outcome of robotic surgery by using dynamic risk stratification in classic papillary thyroid carcinoma.

METHODS

A total of 444 propensity score-matched pairs of patients with papillary thyroid carcinoma treated with robotic surgery and conventional open surgery were classified into 4 response-to-therapy categories. The results were compared between the robotic surgery and open surgery groups.

RESULTS

The median follow-up duration was 60 months. After propensity score matching, the robotic surgery group showed less extensive thyroid surgery and lymph node dissection and a higher proportion of patients who underwent radioactive iodine remnant ablation than the open surgery group; however, the dynamic risk stratification did not differ between the 2 groups (P = .086).

CONCLUSION

The long-term oncologic outcome of robotic surgery is expected to be comparable with that of open surgery based on the dynamic risk stratification.

Follow-up of differentiated thyroid cancer - what should (and what should not) be done

The treatment paradigm for thyroid cancer has shifted from a one-size-fits-all approach to more personalized protocols that range from active surveillance to total thyroidectomy followed by radioiodine remnant ablation. Accurate surveillance tools are available, but follow-up protocols vary widely between centres and clinicians, owing to the lack of clear, straightforward recommendations on the instruments and assessment schedule that health-care professionals should adopt. For most patients (that is, those who have had an excellent response to the initial treatment and have a low or intermediate risk of tumour recurrence), an infrequent assessment schedule is sufficient (such as a yearly determination of serum levels of TSH and thyroglobulin). Select patients will benefit from second-line imaging and more frequent assessments. This Review discusses the strengths and weaknesses of the surveillance tools and follow-up strategies that clinicians use as a function of the initial treatment and each patient's risk of recurrence.

Changes in Serum Thyroglobulin Levels After Lobectomy in Patients with Low-Risk Papillary Thyroid Cancer

BACKGROUND

Low-risk patients with differentiated thyroid cancer can be treated with thyroid lobectomy. Serial measurements of serum thyroglobulin (Tg) are recommended for surveillance, but the cutoff values indicating recurrence are not known. This study documented the natural course of serum Tg levels during follow-up after lobectomy for low-risk papillary thyroid carcinoma (PTC) and evaluated whether changes in serum Tg levels predict disease recurrence.

METHODS

This historical cohort study included 208 patients with low-risk PTC who underwent lobectomy but did not require hormone replacement. Postoperative serum Tg levels and Tg/thyrotropin (TSH) ratios and neck ultrasound were evaluated during a follow-up period with a median of 6.9 years.

RESULTS

The serum Tg levels increased gradually, and the proportion of patients with levels >10 ng/dL increased annually by 13.9%, 18.8%, 22.1%, 21.9%, 28.4%, and 28.9% during the six-year follow-up period (β = 0.574, p = 0.027). The relative serum Tg levels increased by 10% annually (β = 0.105, p < 0.001), and the levels of Tg and Tg/TSH ratios in 19 patients with recurrent disease did not differ significantly (β = 0.150, p = 0.090). Patients without recurrent disease were more likely to have serum Tg levels increased by >20% (p = 0.022). There were no significant differences in the proportions of patients with serum Tg levels increased by ≥50% or ≥100% in terms of the disease recurrence.

CONCLUSIONS

Serum Tg levels and the Tg/TSH ratio increased gradually after lobectomy in patients with and without recurrences, without any significant differences. Periodic measurements of serum Tg levels seem to have limited value in predicting recurrent PTCs after lobectomy.

Outcome after ablation in patients with low-risk thyroid cancer (ESTIMABL1): 5-year follow-up results of a randomised, phase 3, equivalence trial

BACKGROUND

In ESTIMABL1, a randomised phase 3 trial of radioactive iodine (131I) administration after complete surgical resection in patients with low-risk thyroid cancer, 92% of patients had complete thyroid ablation at 6-10 months, defined as a recombinant human thyroid-stimulating hormone (rhTSH)-stimulated serum thyroglobulin concentration of 1 ng/mL or less and normal findings on neck ultrasonography. Equivalence was shown between low-activity (1·1 GBq) and high-activity (3·7 GBq) radioactive iodine and also between the use of rhTSH injections and thyroid hormone withdrawal. Here, we report outcomes after 5 years of follow-up.

METHODS

This multicentre, randomised, open-label, equivalence trial was done at 24 centres in France. Between March 28, 2007, and Feb 25, 2010, we randomly assigned (1:1:1:1) adults with low-risk differentiated thyroid carcinoma who had undergone total thyroidectomy to one of four strategies, each combining one of two methods of thyrotropin stimulation (rhTSH or thyroid hormone withdrawal) and one of two radioactive iodine activities (1·1 GBq or 3·7 GBq). Randomisation was by computer-generated sequence, with variable block size. Follow-up consisted of a yearly serum thyroglobulin measurement on levothyroxine treatment. Measurement of rhTSH-stimulated thyroglobulin and neck ultrasonography were done at the discretion of the treating physician. No evidence of disease was defined as serum thyroglobulin of 1 ng/mL or less on levothyroxine treatment and normal results on neck ultrasonography, when performed. This study was registered with ClinicalTrials.gov, number NCT00435851.

FINDINGS

726 patients (97% of the 752 patients originally randomised) were followed up. At a median follow-up since randomisation of 5·4 years (range 0·5-9·2), 715 (98%) had no evidence of disease. The other 11 had either structural disease (n=4), raised serum thyroglobulin concentration (n=5), or indeterminate findings on neck ultrasonography (n=2). At ablation, six of these patients had received 1·1 GBq radioactive iodine (five after rhTSH and one after withdrawal) and five had received 3·7 GBq (two after rhTSH and three after withdrawal). TSH-stimulated (either after rhTSH injections or thyroid hormone withdrawal according to the treatment group) thyroglobulin concentration measured at the time of ablation was prognostic for structural disease status at ablation, ablation status at 6-10 months, and the final outcome.

INTERPRETATION

Our findings suggest that disease recurrence was not related to the strategy used for ablation. These data validate the use of 1·1 GBq radioactive iodine after rhTSH for postoperative ablation in patients with low-risk thyroid cancer.

FUNDING

French National Cancer Institute (INCa), French Ministry of Health, and Sanofi Genzyme.

Changing Trend of Thyroglobulin Antibodies in Patients With Differentiated Thyroid Cancer Treated With Total Thyroidectomy Without 131I Ablation

BACKGROUND

Thyroglobulin (Tg) antibodies (TgAb) can interfere with Tg measurement and can be used as "Tg surrogate" in patients with differentiated thyroid cancer (DTC) treated with total thyroidectomy (TTx) and radioiodine remnant ablation (RRA). In contrast, few data, and in patients usually followed for a short-term follow-up, have been reported about the changes of TgAb levels in patients treated with TTx but without RRA. The aims of this study were to evaluate the changes of TgAb levels in DTC patients treated with TTx but not RRA and to identify the factors that influence these changes.

METHODS

The change in TgAb levels in 107 DTC (<1 cm) patients submitted to TTx but not RRA was evaluated. Patients were followed for a median of 6.3 years, and all had at least three determinations of TgAb and neck ultrasound (nUS).

RESULTS

TgAb levels showed a progressive decrease during follow-up. Initial TgAb levels and degree of lymphocytic infiltration influenced the time but not the rate of TgAb disappearance. No influence on time and rate of the decrease in TgAb was observed when the association with thyroperoxidase antibodies (TPOAb) levels were considered. A TgAb cutoff value of 61.9 IU/mL at first postoperative evaluation was a good indicator for disappearance of the TgAb within six years. No tumor recurrence was observed in the series. In one case, the progressive increase in TgAb anticipated the reappearance of benign thyroid tissue with lymphocytic infiltration.

CONCLUSIONS

TgAb levels decline in the majority of DTC patients treated with TTx but not ablated with radioiodine. The levels decrease rapidly after the surgical treatment and continue to decrease over time. The time of disappearance is influenced by the initial TgAb levels and the degree of lymphocytic infiltration. No influence of the actual TPOAb levels has been observed. An increase in TgAb levels should not be overlooked, since it can indicate the presence or reappearance of either normal thyroid tissue or tumor recurrence.

Dynamic risk stratification system in post-lobectomy low-risk and intermediate-risk papillary thyroid carcinoma patients

OBJECTIVE

The dynamic risk stratification (DRS) and its current definition of each response-to-therapy category in post-lobectomy papillary thyroid carcinoma (PTC) patients have not been well studied. This study aimed to validate the DRS system and to investigate useful thyroglobulin (Tg) or anti-Tg antibody (Ab)-related parameters in defining each response-to-therapy category.

DESIGN

Retrospective observational study.

PATIENTS

This historical cohort study included 619 patients with PTC treated by thyroid lobectomy.

MEASUREMENTS

All enrolled participants were stratified according to the American Thyroid Association (ATA) initial risk stratification system and DRS system, respectively. The association between these stratifications and structural recurrence was evaluated.

RESULTS

The median follow-up period was 103 months. Structural recurrence occurred in 1.6% of the patients with excellent response, 3.8% of those with indeterminate response, 2.9% of those with biochemical incomplete response, and all patients with structural incomplete response. Five (1.5%) of the low-risk patients and 14 (5.0%) of the intermediate-risk patients had structural recurrence. The disease-free survival curves showed significant differences according to the DRS (P < .001) and ATA initial risk stratification (P = .012), respectively. The proportion of variance explained the DRS system and ATA risk stratification system for structural recurrence was 32.4% and 29.4%, respectively. A thyroid-stimulating hormone (TSH) level >2.75 μU/mL at 1 year after the initial operation (P < .001) was the only valuable risk factor for structural recurrence identified in this study.

CONCLUSION

The long-term postoperative management of PTC patients treated with thyroid lobectomy could be guided based on the DRS.

Italian consensus on diagnosis and treatment of differentiated thyroid cancer: joint statements of six Italian societies

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent.

METHODS

Six scientific Italian societies entitled to cure thyroid cancer patients (the Italian Thyroid Association, the Medical Endocrinology Association, the Italian Society of Endocrinology, the Italian Association of Nuclear Medicine and Molecular Imaging, the Italian Society of Unified Endocrine Surgery and the Italian Society of Anatomic Pathology and Diagnostic Cytology) felt the need to develop a consensus report based on significant scientific advances occurred in the field.

OBJECTIVE

The document includes recommendations regarding initial evaluation of thyroid nodules, clinical and ultrasound criteria for fine-needle aspiration biopsy, initial management of thyroid cancer including staging and risk assessment, surgical management, radioiodine remnant ablation, and levothyroxine therapy, short-term and long-term follow-up strategies, and management of recurrent and metastatic disease. The objective of this consensus is to inform clinicians, patients, researchers, and health policy makers about the best strategies (and their limitations) relating to the diagnosis and treatment of differentiated thyroid cancer.