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

Clinical efficacy of radioactive iodine therapy in multifocal papillary thyroid microcarcinoma: a tertiary center experience

PURPOSE

In recent years, the increased incidence of differentiated thyroid cancers has largely been attributed to microcarcinomas. The aim of this study was to evaluate the impact of adjuvant radioactive iodine (RAI) therapy on recurrence in patients with multifocal papillary thyroid carcinoma (PTC) ≤ 1 cm.

METHODS

A total of 74 patients who were >18 years of age and diagnosed with multifocal PTC ≤ 1 cm at a tertiary referral center between July 2015 and December 2023 were retrospectively evaluated.

RESULTS

Of the 74 patients, 78.4% were female and 21.6% were male. The mean patient age was 45.6 ± 12.6 years, mean follow-up duration was 29.1 ± 22.8 months. Twenty two patients (29.7%) did not receive RAI [RAI (-)], whereas 52 patients (70.3%) received [RAI (+)]. Recurrence was observed in 6.7% (5/74) of patients. Four of the five recurrences occurred in patients initially managed without RAI. The recurrence rate was significantly higher in the RAI (-) group (18.2%, n = 4) compared to the RAI (+) group (1.9%, n = 1) (p> = 0.011). Patients without recurrence had a mean age of 46.8 ± 12.0 years, whereas those with recurrence had a mean age of 28.6 ± 8.7 years. The mean age of patients with recurrence was significantly lower (p < 0.01).

CONCLUSION

RAI ablation appears to improve disease-free survival in multifocal PTC ≤ 1 cm. These findings suggest that RAI therapy decisions in multifocal PTC ≤ 1 cm should be individualized based on tumor variant, invasion characteristics, and patient age.

MRI-based model to predict preoperative extrathyroidal extension in papillary thyroid carcinoma

OBJECTIVE

This study aimed to develop and validate a predictive model for preoperative extrathyroidal extension (ETE) in papillary thyroid carcinoma (PTC) using MRI features.

METHODS

We retrospectively analyzed 140 confirmed PTC cases, divided into training (n = 84) and validation (n = 56) groups. MRI features such as T2-weighted imaging, multiphase contrast-enhanced MRI, and diffusion-weighted imaging were evaluated along with clinical data. Univariate and multivariate logistic regression identified independent predictors of ETE and developed a predictive nomogram. We evaluated the nomogram's discrimination, calibration, and clinical utility, and performed subgroup analyses to explore the relationships between risk factors and baseline data. Predictive performance was assessed using ROC curves and DeLong tests.

RESULTS

Age, protrusion value, and apparent diffusion coefficient_Brightest_rate (ADC_Best_rate) were independent predictors of ETE. The nomogram effectively differentiated ETE from no-ETE, showing strong discrimination, clinical utility, and calibration in both the training (AUC = 0.826, Hosmer-Lemeshow p = 0.882) and validation cohorts (AUC = 0.805, Hosmer-Lemeshow p = 0.585). The model performed consistently across different MRI systems (1.5 T and 3.0 T) and gender subgroups. Notably, ADC_Best_rate (AUC = 0.742) outperformed ADC_mean_rate and ADC_minimum_rate. A significant interaction between ADC_Best_rate and gender (p = 0.02) showed that ADC_Best_rate predicted ETE in PTC more accurately in males (AUC = 0.897) compared to females (AUC = 0.644).

CONCLUSION

Our nomogram model, incorporating age, protrusion value, and ADC_Best_rate, effectively predicted preoperative ETE in PTC patients, aiding surgeons in optimizing therapeutic decision-making. ADC_Best_rate may be a promising potential indicator in MRI functional imaging.

KEY POINTS

Question This study addresses the challenge of accurately predicting extrathyroidal extension (ETE) in papillary thyroid carcinoma (PTC) to improve surgical decision-making. Findings A predictive nomogram incorporating age, protrusion value, and ADC_Best_rate effectively differentiates ETE from no-ETE, showing strong performance in both training and validation cohorts. Clinical relevance This nomogram aids surgeons in identifying patients at risk for ETE, enhancing therapeutic decision-making and potentially improving patient outcomes in PTC management.

Thyroid nodules: diagnosis and management

Thyroid nodules, with a prevalence of almost 25% in the general population, are a common occurrence. Their prevalence varies considerably depending on demographics such as age and sex as well as the presence of risk factors. This article provides a comprehensive overview of the prevalence, risk stratification and current management strategies for thyroid nodules, with a particular focus on changes in diagnostic and therapeutic protocols that have occurred over the past 10 years. Several sonography-based stratification systems (such as Thyroid Imaging Reporting and Data Systems (TIRADS)) might help to predict the malignancy risk of nodules, potentially eliminating the need for biopsy in many instances. However, large or suspicious nodules necessitate cytological evaluation following fine-needle aspiration biopsy for accurate classification. In the case of cytology yielding indeterminate results, additional tools, such as molecular testing, can assist in guiding the management plan. Surgery is no longer the only treatment for symptomatic or malignant nodules: active surveillance or local ablative treatments might be beneficial for appropriately selected patients. To enhance clinician-patient interactions and discussions about diagnostic options, shared decision-making tools have been developed. A personalized, risk-based protocol promotes high-quality care while minimizing costs and unnecessary testing.

Nonoperative, Active Surveillance of Larger Malignant and Suspicious Thyroid Nodules

CONTEXT

Active surveillance for papillary thyroid cancer (PTC) meeting criteria for surgical resection is uncommon. Which patients may prove reasonable candidates for this approach is not well defined.

OBJECTIVE

This work aimed to examine the feasibility and safety of active surveillance for patients with known or suspected intrathyroidal PTC up to 4 cm in diameter.

METHODS

A retrospective review was conducted of all consecutive patients who underwent nonoperative active surveillance of suspicious or malignant thyroid nodules over a 20-year period from 2001 to 2021. We included patients with an initial ultrasound-fine-needle aspiration confirming either (a) Bethesda 5 or 6 cytology or (b) a "suspicious" Afirma molecular test. The primary outcomes and measures included the rate of adverse oncologic outcomes (mortality and recurrence), as well as the cumulative incidence of size/volume growth.

RESULTS

Sixty-nine patients were followed with active surveillance for 1 year or longer (average 55 months), with 26 patients (38%) having nodules 2 cm or larger. No patients were found to develop new-incident occurrence of lymph node or distant metastasis. One patient, however, demonstrated concern for progression to a dedifferentiated cancer on repeat core biopsy 17 years after initial start of nonoperative selection. A total of 21% of patients had an increase in maximum diameter more than 3 mm, while volume increase of 50% or greater was noted in 25% of patients. Thirteen patients ultimately underwent delayed (rescue) surgery, and no disease recurrence was noted after such treatment. Age and initial nodule size were not predictors of nodule growth.

CONCLUSION

These data expand consideration of active surveillance of PTC in select patients with intrathyroidal suspected malignancy greater than 1 cm in diameter. Rescue surgery, if required at a later time point, appears effective.

Initial versus Staged Thyroidectomy for Differentiated Thyroid Cancer: A Retrospective Multi-Dimensional Cohort Analysis of Effectiveness and Safety

The optimal surgical approach for differentiated thyroid cancer remains controversial, with debate regarding the comparative risks of upfront total thyroidectomy versus staged completion thyroidectomy following the initial lobectomy. This study aimed to assess the complication rates associated with these two strategies and identify the optimal timing for completion thyroidectomy using a multi-dimensional analysis of four cohorts: an institutional series (n = 148), the National Surgical Quality Improvement Program (NSQIP) database (n = 39,992), the TriNetX repository (n > 30,000), and a pooled literature review (10 studies, n = 6015). Institutional data revealed higher overall complication rates with total thyroidectomy (18.3%) compared to completion thyroidectomy (6.8%), primarily due to increased temporary hypocalcemia (10% vs. 0%, p = 0.004). The NSQIP analysis demonstrated that total thyroidectomy was associated with a 72% increased risk of transient hypocalcemia (p < 0.001) and a 25% increased risk of permanent hypocalcemia (p < 0.001). TriNetX data confirmed these findings and identified obesity and concurrent neck dissection as risk factors for complications. A meta-analysis showed that total thyroidectomy increased the rates of transient (RR = 1.63) and permanent (RR = 1.23) hypocalcemia (p < 0.001). Institutional and TriNetX data suggested that performing completion thyroidectomy between 1 and 6 months after the initial lobectomy minimized permanent complication rates compared to delays beyond 6 months. In conclusion, for differentiated thyroid cancer, total thyroidectomy is associated with higher risks of transient and permanent hypocalcemia compared to staged completion thyroidectomy. However, performing completion thyroidectomy within 1-6 months of the initial lobectomy may mitigate the risk of permanent complications. These findings can inform personalized surgical decision-making for patients with differentiated thyroid cancer.

Analyzing circulating tumor cells and epithelial-mesenchymal transition status of papillary thyroid carcinoma patients following thyroidectomy: a prospective cohort study

BACKGROUND

This study investigated the prevalence and subtype distribution of circulating tumor cells (CTCs) in patients with papillary thyroid cancer (PTC) before and after thyroidectomy to determine the potential of CTC count as a noninvasive marker of the efficacy of surgical treatment in PTC.

MATERIALS AND METHODS

Between January 2021 and January 2022, 62 PTC patients who underwent thyroidectomy at Seoul National University Bundang Hospital were prospectively evaluated. Peripheral blood samples (7.5 ml) were collected from each patient for CTC analysis before surgery and at 2 weeks and 3 months after surgery. CTC count and the distribution of CTC subtypes, including epithelial, epithelial-mesenchymal, and mesenchymal phenotypes, were analyzed using the negative selection method and immunofluorescence staining. The relationship between CTC count and clinicopathological characteristics was analyzed before and after surgery.

RESULTS

Before surgery, CTCs were detected in 87% (54/62) of patients; the mean CTC count was 8.0 and the median was 5.0 in 7.5 ml of peripheral blood. The mesenchymal or epithelial-mesenchymal phenotypes were predominant. After thyroidectomy, the mean and median CTC count values decreased to 5.3 and 2.5, respectively, at 2 weeks and to 4.3 and 3.0, respectively, at 3 months. This postoperative reduction in CTCs was more pronounced in patients with lymphatic invasion, lymph node metastasis, or BRAF V600E mutation.

CONCLUSION

CTCs were detected in patients with PTC with a predominance of cells undergoing epithelial-mesenchymal transition. The CTC count decreased postoperatively, suggesting that liquid biopsy with CTC detection could be a valuable noninvasive tool for monitoring the efficacy of surgery in PTC.

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.

Transoral endoscopic and robotic thyroidectomy for thyroid cancer: the mid-term oncological outcome

BACKGROUND

Traditional open thyroidectomy is the surgical standard for thyroid cancer; however, it inevitably leaves a visible scar on the neck and affects the patient's quality of life. Therefore, to avoid making a neck incision, the transoral endoscopic thyroidectomy vestibular approach (TOETVA) and transoral robotic thyroidectomy (TORT) have been developed recently, and the surgical outcomes of these techniques are as favorable as open surgery for benign disease. Additionally, positive short-term surgical outcomes have also been achieved in a few patients with thyroid cancer. However, no data on the mid-to-long-term recurrence and survival rates of transoral thyroidectomy in thyroid cancer are available. Therefore, in this study, we analyzed the surgical outcomes and mid-term oncological results of the TOETVA and TORT in patients with thyroid cancer.

METHODS

We reviewed patients who had received TOETVA or TORT between July 2017 and November 2021 and followed up on their oncological outcomes until December 2022. Perioperative surgical and mid-term oncological outcomes were analyzed.

RESULTS

The 115 patients underwent 122 operations (57 TOETVAs and 65 TORTs), including seven complete thyroidectomies for differentiated thyroid cancer (DTC), Stage I-II, including T1-T3, N0-N1a, and initial low- to high-risk groups. There was no conversion from transoral to open surgery. TORT required a longer operating time (median [interquartile range]) than TOETVA (lobectomy: 279 [250, 318] vs. 196 [173, 253] min, p < 0.001; bilateral total thyroidectomy: 375 [309, 433] vs. 279 [238, 312] min, p < 0.001); however, no difference was found between the two groups regarding perioperative complications. Complete thyroidectomy with a second transoral approach was safe. TOETVA and TORT achieved favorable oncological outcomes with 100% survival and 98.2% acceptable response (excellent and indeterminate response) during a mean 37.88 ± 12.42 months mid-term follow-up.

CONCLUSIONS

Transoral endoscopic and robotic thyroidectomy was safe and achieved favorable mid-term oncological outcomes in a selected cohort of patients with early-stage DTC.

Preoperative identification of low-risk medullary thyroid carcinoma: potential application to reduce total thyroidectomy

Current guidelines recommend total thyroidectomy with central lymph node dissection (CND) for patients with medullary thyroid carcinoma (MTC). This study aimed to identify low-risk MTC patients who may be candidates for lobectomy. We retrospectively reviewed MTC patients who underwent primary surgery at a tertiary referral center from 1998 to 2019. Eighty-five MTC patients were enrolled, excluding patients with primary tumor size > 2.0 cm. Among them, one (1.2%) patient had bilateral tumors. During a median follow-up of 84 months, 12 of the 85 patients experienced structural recurrence. 13 patients had occult lymph node metastasis, and structural recurrence occurred in 2 patients. Factors that significantly affected disease-free survival were clinical N stage (cN0 vs. cN1, log-rank P < 0.001), pathological N stage (pN0 vs. pN1, P < 0.001), and preoperative calcitonin levels (≤ 250 vs. > 250 pg/mL, P = 0.017). After categorizing patients into four groups, patients with preoperative calcitonin levels > 250 pg/mL and cN1 or pN1 had a significantly worse prognosis. Patients with a primary tumor size of 2 cm or less, cN0, and preoperative calcitonin of 250 pg/mL or less can be classified as low-risk MTC patients. We used preoperative clinical information to identify low-risk MTC patients. Lobectomy with prophylactic CND may be a potential therapeutic approach.

Association between surgical extent and recurrence in unilateral intermediate- to high-risk papillary thyroid cancer

BACKGROUND

Guidelines recommend total thyroidectomy (TT) to facilitate radioactive ablation and serological follow-up for intermediate- to high-risk papillary thyroid carcinoma (PTC). However, the association between surgical extent and tumor recurrence in these patients has not been well validated. We aimed to examine the association between the extent of surgery and recurrence in patients with completely resected unilateral intermediate- to high-risk PTC.

METHODS

Patients with completely resected unilateral PTC from 2000 to 2017 in a single institute were reviewed. Those who had extrathyroidal extension (ETE) or lymph node metastasis (LNM, cN1 or pN1 > 5 lymph nodes involved) were included for analysis. Cox proportional hazards models were applied to measure the association between surgical extent and recurrence-free survival (RFS) while adjusting for patient demographic, clinicopathological and treatment variables.

RESULTS

A total of 4550 patients (mean[SD] age, 43.0[11.7] years; 3379 women[74.3%]) were included. Of these patients, 2262(49.7%), 656(14.4%), 1032(22.7%), and 600 (13.2%) underwent lobectomy, TT, lobectomy + neck dissection (ND) and TT + ND, respectively. With a median follow-up period of 68 months, after multivariate adjustment, lobectomy was associated with a compromised RFS compared with other surgical extents (HR[95%CI], TT 0.537[0.333-0.866], P = 0.011, lobectomy + ND 0.531[0.392-0.720] P < 0.0001, TT + ND 0.446[0.286-0.697] P < 0.0001). RFS was similar between the two extents with ND (lobectomy + ND, HR [95%CI], 1.196 [0.759-1.885], P = 0.440).

CONCLUSION

Lobectomy alone is associated with an elevated recurrence risk in patients with unilateral intermediate- to high-risk PTC compared with larger surgical extents. However, lobectomy and ND may provide similar tumor control compared with the conventional approach of TT and ND.

Ultrasound-based Nomogram for Predicting the Pathological Nodal Negativity of Unilateral Clinical N1a Papillary Thyroid Carcinoma in Adolescents and Young Adults

RATIONALE AND OBJECTIVES

To develop and validate a nomogram incorporating clinical and ultrasound (US) characteristics for predicting the pathological nodal negativity of unilateral clinically N1a (cN1a) papillary thyroid carcinoma (PTC) among adolescents and young adults.

MATERIALS AND METHODS

From December 2016 to August 2021, 278 patients aged ≤ 30 years from two medical centers were enrolled and randomly assigned to the training and validation cohorts at a ratio of 2:1. After performing univariate and multivariate analyses, a nomogram combining all independent predictive factors was constructed and applied to the validation cohort. The performance of the nomogram was evaluated using receiver operating characteristic curves, calibration curves, and decision curve analysis .

RESULTS

Multivariate logistic regression analysis showed that unilateral cN1a PTC in young patients with Hashimoto's thyroiditis, T1 stage, no intra-tumoral microcalcification, and tumors located in the upper third of the thyroid gland was more likely to be free of central lymph node metastases. The nomogram revealed good calibration and discrimination in both cohorts, with areas under the receiver operating characteristic curve of 0.764 (95% confidence interval [CI]: 0.684-0.843) and 0.728 (95% CI: 0.602-0.853) in the training and validation cohorts, respectively. The clinical application of the nomogram was further confirmed using decision curve analysis.

CONCLUSION

This US-based nomogram may assist the assessment of central cervical lymph nodes in young patients with unilateral cN1a PTC, enabling improved risk stratification and optimal treatment management in clinical practice.

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

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

Long-Term Outcomes After Lobectomy for Patients with High-Risk Papillary Thyroid Carcinoma

BACKGROUND

Guidelines universally recommend total thyroidectomy for high-risk papillary thyroid carcinoma (PTC). However, in Japan, thyroid-conserving surgery had been widely applied for such patients until recently. We investigated long-term outcomes for this strategy.

METHODS

A prospectively recorded database was retrospectively analyzed for 368 patients who had undergone curative surgery for high-risk PTC without distant metastasis between 1993 and 2013. High-risk PTC was defined for tumors showing tumor size > 4 cm, extrathyroidal extension, or large nodal metastasis ≥ 3 cm.

RESULTS

Median age was 59 years and 243 patients were female. Mean duration of follow-up was 12.7 years. Lobectomy was conducted for 207 patients (LT group) and total or near-total thyroidectomy for 161 patients (TT group). The frequency of massive extrathyroidal invasion and large nodal metastasis was lower in the LT group than in the TT group. After propensity score matching, no significant differences were seen between groups for overall survival, cause-specific survival or distant recurrence-free survival. In the overall cohort, multivariate analysis identified age ≥ 55 years, large nodal metastasis, tumor size > 4 cm and massive extrathyroidal invasion as significantly associated with cause-specific survival, whereas extent of thyroidectomy was not.

CONCLUSIONS

For patients with high-risk PTC without distant metastasis, curative surgery with lobectomy showed almost identical oncological outcomes compared to total thyroidectomy. The benefits of total thyroidectomy for high-risk PTC should be reevaluated in the future prospective studies.

The role of neck ultrasound in the follow-up of low- and intermediate- risk papillary thyroid cancer

Introduction

The optimal time for a neck ultrasound (US) in the follow-up of papillary thyroid cancer (PTC) after the first year is undetermined. We aimed to verify the utility of routine neck US in the surveillance of patients diagnosed with low- and intermediate-risk PTC with no evidence of disease at the one-year assessment.

Subjects and methods

We conducted a retrospective longitudinal study of patients with low- and intermediate-risk PTC with normal neck US, unstimulated serum thyroglobulin (Tg) < 1 ng/mL and negative anti-Tg antibodies at the one-year follow-up. Patients were divided into group 1 [undetectable Tg (<0.20 ng/mL)] and group 2 [detectable Tg but < 1 ng/mL]. The negative predictive value (NPV) of the one-year unstimulated Tg at the five-year and last follow-up visits was calculated.

Results

We included n = 88 patients in group 1 and n = 8 patients in group 2. No patient from group 1 presented suspicious US findings at the five-year evaluation [NPV: 100.0% (95% confidence interval (CI): 95.5%-100.0%)], and at the last visit, only one patient had developed a lymph node classified as suspicious [NPV: 98.8% (95% CI: 93.2%-100.0%); mean follow-up: 6.7 years]. In group 2, two patients' USs presented suspicious findings at the five-year evaluation [NPV: 75.0% (95% CI: 34.9%-96.8%)]. At the last visit, only one patient persisted with suspicious findings in the US [NPV: 87.5% (95% CI: 47.4%-99.7%); mean follow-up: 6.5 years].

Conclusion

Low- and intermediaterisk PTC with an excellent response to treatment at the one-year assessment can be safely monitored with regular unstimulated Tg assessments. Conclusions should not be drawn for Tg levels between 0.20-0.99 ng/mL.

Optimal cutoff values of primary tumour size to better predict long-term outcomes in patients with papillary thyroid carcinoma undergoing total thyroidectomy: A preliminary study using restricted cubic spline analysis

OBJECTIVE

Primary tumour size (PTS) is known to be a significant prognostic factor in patients with papillary thyroid carcinoma (PTC) undergoing thyroidectomy. Although cutoff values of 2 and 4 cm are widely used in surgical extent decision and long-term outcomes predictions, the effectiveness of arbitrary cutoff values in stratifying patients for target outcomes is questionable. This study aimed to determine new optimal cutoffs of PTS.

DESIGN, PATIENT AND MEASUREMENTS

Patients (n = 529) with PTC who underwent total thyroidectomy were retrospectively reviewed. After risk factor analysis for structural recurrence, the optimal cutoffs of PTS were automatically calculated using restricted cubic spline analysis and X-tile software. Subgroups were classified based on the newly determined cutoff values. Both the recurrence-free survival (RFS) and the proportion of patients in each response-to-therapy category, using the dynamic risk stratification system (DRS), were compared between the subgroups.

RESULTS

PTS was confirmed as an independent risk factor for structural recurrence. The optimal cutoff values were calculated as 1.4 and 3.0 cm. The subgroups stratified using these newly determined cutoffs showed significantly different RFS and DRS based on the response to initial therapy, but the subgroups classified using the cutoffs of 2 and 4 cm did not.

CONCLUSIONS

The newly determined cutoff values of PTS may be useful in better stratifying patients with PTC undergoing thyroidectomy for target outcomes and can be considered as a new definition in staging and risk stratification systems.

Restratification of Patients with Intermediate-Risk Papillary Thyroid Carcinoma

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Prevalence and predictor for malignancy of contralateral thyroid nodules in patients with unilateral PTMC: a systematic review and meta-analysis

BACKGROUND

The presence of clinically negative nodules on the contralateral lobe is common in patients with unilateral papillary thyroid microcarcinoma (PTMC). The appropriate operational strategies of contralateral thyroid nodules remain controversial. In this study, we analyzed clinical features that could be predictors for malignancy of contralateral thyroid nodules coexisting with diagnosed unilateral PTMC.

METHODS

The literatures published from January 2000 to December 2019 were searched in PubMed, Cochrane Library, Embase, Web of Science, CNKI, and Wan Fang database. Odds ratio (OR) with 95% CI was used to describe categorical variables. Heterogeneity among studies was examined by the Q test and I2 test; potential publication bias was detected by Harbord test and 'trim and fill' method.

RESULTS

In this meta-analysis, 2541 studies were searched and 8 studies were finally included. The results showed that the rate of carcinoma in contralateral nodules was 23% (OR = 0.23, 95% CI = 0.18-0.29). The pooled data indicated that contralateral malignancy was not associated with age, gender, primary lesion size, ipsilateral central lymph node metastasis and multifocality of contralateral lesion. The following variables have correlations with an increased risk of contralateral malignancy: multifocality of primary carcinomas (OR = 3.93, 95% CI = 2.70-5.73, P < 0.0001), capsular invasion (OR = 1.61, 95% CI = 1.10-2.36, P = 0.01), and Hashimoto's thyroiditis (OR = 1.57, 95% CI = 1.13-2.20, P = 0.008).

CONCLUSIONS

Based on our meta-analysis, the rate at which contralateral malignancies are preoperatively misdiagnosed as benign is 23%. The risk factors for contralateral malignancy in unilateral PTMC patients with contralateral clinical negative nodules include multifocality of primary carcinomas, capsular invasion, and Hashimoto's thyroiditis.

Dual-energy computed tomography could reliably differentiate metastatic from non-metastatic lymph nodes of less than 0.5 cm in patients with papillary thyroid carcinoma

BACKGROUND

Dual-energy computed tomography (DECT) has been widely applied to detect lymph node (LN) and lymph node metastasis (LNM) in various cancers, including papillary thyroid carcinoma (PTC). This study aimed to quantitatively evaluate metastatic cervical lymph nodes (LNs) <0.5 cm in patients with PTC using DECT, which has not been done in previous studies.

METHODS

Preoperative DECT data of patients with pathologically confirmed PTC were retrospectively collected and analyzed between May 2016 and June 2018. A total of 359 LNs from 52 patients were included. Diameter, iodine concentration (IC), normalized iodine concentration (NIC), and the slope of the energy spectrum curve (λHU) of LNs in the arterial and the venous phases were compared between metastatic and non-metastatic LNs. The optimal parameters were obtained from the receiver operating characteristic (ROC) curves. The generalized estimation equation (GEE) model was used to evaluate independent diagnostic factors for LNM.

RESULTS

A total of 139 metastatic and 220 non-metastatic LNs were analyzed. There were statistical differences of quantitative parameters between the two groups (P value 0.000-0.007). The optimal parameter for diagnosing LNM was IC in the arterial phase, and its area under the curve (AUC), sensitivity, and specificity were 0.775, 71.9%, and 73.6%, respectively. When the three parameters of diameter, IC in the arterial phase, and NIC in the venous phase were combined, the prediction efficiency was better, and the AUC was 0.819. The GEE results showed that LNs located in level VIa [odds ratio (OR) 2.030, 95% confidence interval (CI): 1.134-3.634, P=0.017], VIb (OR 2.836, 95% CI: 1.597-5.038, P=0.000), diameter (OR 2.023, 95% CI: 1.158-3.532, P=0.013), IC in the arterial phase (OR 4.444, 95% CI: 2.808-7.035, P=0.000), and IC in the venous phase (OR 5.387, 95% CI: 3.449-8.413, P=0.000) were independent risk factors for LNM in patients with PTC.

CONCLUSIONS

DECT had good diagnostic performance in the differentiation of cervical metastatic LNs <0.5 cm in patients with PTC.

The Ongoing Debate Regarding Completion Thyroidectomy Versus Primary Thyroid Surgery for Low and Intermediate Differentiated Thyroid Carcinoma: A Meta-Analysis

Lobectomy is increasingly performed for low-risk differentiated thyroid cancer (DTC) and papillary thyroid microcarcinoma (PTMC). However, there is a continuous controversy about completion thyroidectomy (CT) following lobectomy. The current meta-analysis aimed to assess the outcomes of the initial surgical procedure versus CT performed for low/intermediate-risk thyroid carcinoma. Six hundred and sixty-one articles were retrieved, and only 15 full texts fulfilled the inclusion and exclusion criteria. There were 15 studies, including 17,143 patients; twelve were retrospective, two prospective studies, and a controlled trial. Seven articles were from Asia, four from the USA, two from Europe, while two were published in Canada. The studies showed no difference between lobectomy and primary thyroid surgery regarding post-surgery complications. CT was not different from the initial surgical procedure in terms of complications for DTC. The study was limited by the retrospective studies included, the outcomes assessed were not uniform, and significant heterogeneity was observed. Further, well-controlled, more specific trials are needed.

The extent of surgery for low-risk 1-4 cm papillary thyroid carcinoma: a catch-22 situation. A retrospective analysis of 497 patients based on the 2015 ATA Guidelines recommendation 35

PURPOSE

The adequate extent of surgery for 1-4 cm low-risk papillary thyroid carcinoma (PTC) is unclear. Our objective was to analyze the applicability of the 2015 ATA Guidelines recommendation 35B (R35) for the management low-risk PTC.

METHODS

This multicentre study included patients with low-risk PTC who had undergone total thyroidectomy (TT). Retrospectively we selected those who met the R35 criteria for the performance of a thyroid lobectomy (TL). The aim was to identify the proportion of low-risk PTC patients treated using TT who would have required reintervention had they had a TL in accordance with R35.

RESULTS

We identified 497 patients (400 female; 80.5%). Median tumor size (mm): 21.2 (11-40). A tumor size ≥2 cm was found in 252 (50.7%). Most of them, 320 (64.4%), were in Stage I (AJCC 7th Edition). Following R35, 286 (57.5%) would have needed TT. Thus, they would have required a second surgery had they undergone TL. The indications for reintervention would have included lymph node involvement (35%), extrathyroidal extension (22.9%), aggressive subtype (8%), or vascular invasion (22.5%). No presurgical clinical data predict TT.

CONCLUSIONS

The appropriate management of low-risk PTC is unclear. Adherence to ATA R35 could lead to a huge increase in reinterventions when a TL is performed, though the need for them would be questionable. In our sample, more than half of patients (57.5%) who may undergo a TL for a seemingly low-risk PTC would have required a second operation to satisfy international guidelines, until better preoperative diagnostic tools become available.

Extent of thyroid surgery for clinically node-negative papillary thyroid carcinoma with confirmed nodal metastases after prophylactic central neck dissection: a 15-year experience in a single center

PURPOSE

The use of prophylactic central neck dissection (PCND) and the extent of thyroid surgery in clinically node-negative (cN0) papillary thyroid carcinoma (PTC) are controversial. This study aimed to investigate whether the extent of thyroid surgery influences the prognosis of patients with PTC with central lymph node metastasis (N1a), which was cN0 but pathologically confirmed after PCND.

METHODS

This was a single-center retrospective study using medical records. Patients who underwent thyroid surgery with PCND for the treatment of PTC between 2004 and 2019 were included. Predictive factors and local recurrence rates were analyzed.

RESULTS

Of 2,274 patients with cN0 PTC, 436 were confirmed to have pathologic N1a disease after PCND. Among them, 340 patients (78.0%) underwent total thyroidectomy (TT) and 96 patients (22.0%) underwent less than TT. Of the 374 patients who were followed up for >6 months, 5 (1.3%) experienced recurrence. The 15-year recurrence-free survival (RFS) rate was 98.2%. No clinicopathologic factor was predictive of tumor recurrence. RFS tended to be lower in patients who underwent less than TT than in those who underwent TT; however, the difference was not statistically significant.

CONCLUSION

Our study showed low recurrence rates in patients with cN0 PTC pathologically confirmed as N1a after PCND. The RFS did not differ according to the extent of thyroid surgery. Considering the low recurrence rate and the surgical morbidity associated with thyroid surgery, less than TT with PCND may be considered for patients with cN0 unilateral PTC even with a pathologic staging of N1a after PCND.

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.