Feasibility of active surveillance in patients with clinically T1b papillary thyroid carcinoma ≤1.5 cm in preoperative ultrasonography: MASTER study

Objective

Active surveillance (AS) is generally accepted as an alternative to immediate surgery for papillary thyroid carcinoma (PTC) measuring ≤1.0 cm (cT1a) without risk factors. This study investigated the clinicopathologic characteristics of PTCs measuring ≤2.0 cm without cervical lymph node metastasis (cT1N0) by tumor size group to assess the feasibility of AS for PTCs between 1.0 cm and 1.5 cm (cT1b≤1.5).

Design

This study enrolled clinically T1N0 patients with preoperative ultrasonography information (n= 935) from a cohort of 1259 patients who underwent lobectomy and were finally diagnosed with PTC from June 2020 to March 2022.

Results

The cT1b≤1.5 group (n = 171; 18.3 %) exhibited more lymphatic invasion and occult central lymph node (LN) metastasis with a higher metastatic LN ratio than the cT1a group (n = 719; 76.9 %). However, among patients aged 55 years or older, there were no significant differences in occult central LN metastasis and metastatic LN ratio between the cT1a, cT1b≤1.5, and cT1b>1.5 groups. Multivariate regression analyses revealed that occult central LN metastasis was associated with age, sex, tumor size, extrathyroidal extension, and lymphatic invasion in patients under 55, while in those aged 55 or older, it was associated only with age and lymphatic invasion.

Conclusion

For PTC patients aged 55 years or older with cT1b≤1.5, AS could be a viable option due to the absence of a significant relationship between tumor size and occult central LN.

Clinical impact of coexistent chronic lymphocytic thyroiditis on central lymph node metastasis in low- to intermediate-risk papillary thyroid carcinoma: The MASTER study

BACKGROUND

The clinicopathological impact of chronic lymphocytic thyroiditis on patients with papillary thyroid carcinoma patients is still controversial. This study aimed to evaluate the clinicopathologic differences and risk factors for central lymph node metastasis based on the presence of coexistent chronic lymphocytic thyroiditis in patients with low- to intermediate-risk papillary thyroid carcinoma.

METHODS

The medical records of 1,022 patients with low- to intermediate-risk papillary thyroid carcinoma who underwent lobectomy and central neck dissection between June 2020 and March 2022 were reviewed. Differences in clinicopathological factors were analyzed in patients with papillary thyroid carcinoma with or without chronic lymphocytic thyroiditis. Furthermore, risk factors for central lymph node metastasis in patients with low- to intermediate-risk papillary thyroid carcinoma with or without chronic lymphocytic thyroiditis were evaluated.

RESULTS

Among the 1,022 patients with low to intermediate-risk papillary thyroid carcinoma, 102 (10.0%) had coexisting chronic lymphocytic thyroiditis. Female sex (odds ratio = 3.536, P = .001, 95% confidence interval 1.781-8.069), a multifocal tumor (odds ratio = 2.162, P = .001, 95% confidence interval 1.358-3.395), and angiolymphatic invasion (odds ratio = 0.365, P < .001, 95% confidence interval 0.203-0.625) were independent factors associated with patients who had coexisting chronic lymphocytic thyroiditis compared to those without chronic lymphocytic thyroiditis. There were 358 (35%) patients who had central lymph node metastasis. Multivariate analysis showed that younger age (odds ratio = 0.667, P = .013, 95% confidence interval 0.482-0.555), male sex (odds ratio = 0.549, P < .001, 95% confidence interval 0.402-0.751), tumor size >1 cm (odds ratio = 1.454, P = .022, 95% confidence interval 1.053-2.003), extrathyroidal extension (odds ratio = 1.874, P < .001, 95% confidence interval 1.414-2.486), and angiolymphatic invasion (odds ratio = 3.094, P < .001, 95% confidence interval 2.339-4.101) were risk factors for central lymph node metastasis. Angiolymphatic invasion (odds ratio = 11.184, P < .001, 95% confidence interval 3.277-46.199) was identified as the sole independent risk factor for central lymph node metastasis in patients with papillary thyroid carcinoma with coexisting chronic lymphocytic thyroiditis.

CONCLUSION

Our data suggest that patients with low to intermediate-risk papillary thyroid carcinoma with coexistent chronic lymphocytic thyroiditis exhibit different clinical features than patients with papillary thyroid carcinoma without chronic lymphocytic thyroiditis. Additionally, the presence of chronic lymphocytic thyroiditis may be considered a potential factor against central lymph node metastasis.

Optimal value of lymph node ratio and metastatic lymph node size to predict risk of recurrence in pediatric thyroid cancer with lateral neck metastasis

BACKGROUND

No specific guideline exists for risk stratification based on lymph node (LN) status in pediatric thyroid cancer. The purpose of our study is to identify optimal values of lymph node ratio (LNR) and largest metastatic LN size for predicting recurrent/persistent disease, especially in children with lateral neck metastasis (N1b).

METHODS

We conducted a retrospective study from January 1997 to June 2018 at Samsung Medical Center. A total of 50 papillary thyroid carcinoma (PTC) patients who underwent total thyroidectomy + both central neck dissection (CND) + modified radical neck dissection (MRND) (unilateral or bilateral) was enrolled.

RESULTS

The median follow-up duration was 60.8 months (range, 6.2-247 months). The mean age was 14.6 years, and the mean tumor size was 2.9 cm. Mean size of the largest metastatic LN was 1.5 cm. Mean value of central LNR was 0.6, and mean value of lateral LNR was 0.3. Largest metastatic LN size [HR = 2.0 (95% CI 1.0-4.0), p = 0.040] and lateral LNR [HR = 43.6 (95% CI 2.2-871.0), p = 0.014] were significant prognostic factors for recurrence. The optimal combination of lateral LNR and largest metastatic LN size to predict recurrence were 0.3 and 2.5 cm, respectively, with the largest AUC (AUC at 60 months = 77.4) and significant p-value (p = 0.009 and p = 0.021) (Table 3). Kaplan-Meier curves showed significant differences in recurrence-free survival (RFS) rates among four groups (Fig. 2A,2B).

CONCLUSIONS

In pediatric PTC patients with N1b, lateral LNR and largest metastatic LN size are significant predictors for recurrence. Children with lateral LNR > 0.3 or any metastatic lymph node > 2.5 cm in the largest dimension have higher risk for recurrence. Children are classified as extensive N1b if lateral LNR > 0.3 or pathologic N1 with largest LN size > 2.5 cm, and vice versa.

Frequency of TERT Promoter Mutations in Real-World Analysis of 2,092 Thyroid Carcinoma Patients

BACKGRUOUND

Telomerase reverse transcriptase (TERT) promoter mutations are associated with increased recurrence and mortality in patients with thyroid carcinoma. Previous studies on TERT promoter mutations were retrospectively conducted on a limited number of patients.

METHODS

We prospectively collected data on all consecutive patients who underwent thyroid carcinoma surgery between January 2019 and December 2020 at the Samsung Medical Center, Seoul, Korea. We included 2,092 patients with thyroid carcinoma.

RESULTS

Of 2,092 patients, 72 patients (3.4%) had TERT promoter mutations. However, the frequency of TERT promoter mutations was 0.5% in papillary thyroid microcarcinoma (PTMC) ≤1 cm and it was 5.8% in papillary thyroid carcinoma (PTC) >1 cm. The frequency of TERT promoter mutations was significantly associated with older age at diagnosis (odds ratio [OR], 1.12; P<0.001), larger primary tumor size (OR, 2.02; P<0.001), and aggressive histological type (OR, 7.78 in follicular thyroid carcinoma; OR, 10.33 in poorly differentiated thyroid carcinoma; OR, 45.92 in anaplastic thyroid carcinoma; P<0.001). Advanced T stage, advanced N stage, and distant metastasis at diagnosis were highly prevalent in mutated thyroid cancers. However, initial distant metastasis was not present in patients with TERT promoter mutations in PTMC. Although the C228T mutation was more highly detected than the C250T mutation (64 cases vs. 7 cases), there were no significant clinicopathological differences.

CONCLUSION

This study is the first attempt to investigate the frequency of TERT promoter mutations in a real-world setting. The frequency of TERT promoter mutations in PTC was lower than expected, and in PTMC, young patients, and female patients, the frequency was very low.

The clinical impact of extrathyroidal extensions on prognoses in pediatric differentiated thyroid cancers

BACKGROUND

The prognostic impact of extrathyroidal extensions (ETE) on clinical outcomes has not been well studied in pediatric thyroid cancers. The aim of this study was to analyze the clinicopathological characteristics and clinical outcomes according to the extent of ETE in pediatric and adolescent thyroid cancers.

METHODS

This study retrospectively reviewed 89 papillary thyroid carcinoma (PTC) patients less than 19 years of age who underwent total thyroidectomy with central neck dissections (CND) between 1997 and 2018. We compared the clinicopathological features among three groups: no ETE, microscopic ETE, and gross ETE.

RESULTS

The median follow-up time was 111 months. The mean age was 15.3 years and the mean tumor size was 2.4 cm. Tumor sizes larger than 2 cm (OR = 9.2, p = 0.001), exhibited bilaterality (OR = 4.3, p = 0.006), were an aggressive variant (OR = 5.8, p = 0.006), and exhibited central lymph node metastasis (OR = 1.3, p = 0.018), lateral lymph node metastasis (OR = 9.2, p = 0.001), recurrence (OR = 3.9, p = 0.038), and distant metastasis (OR = 4.4, p = 0.016) were associated with gross ETE. There was no remarkable difference in clinicopathological characteristics between the no ETE group and microscopic ETE group, except for aggressive variants (OR = 5.5, p = 0.008). There was a significant difference in recurrence-free survival (RFS) rates according to the extent of ETE (p = 0.025). Furthermore, the distant metastasis-free survival curve presented a significant difference among the three groups (p = 0.018). Both microscopic ETE and gross ETE were significantly associated with worse prognoses in pediatric thyroid cancers.

CONCLUSIONS

We recommend that microscopic ETE should be included in the intermediate risk category and that gross ETE should be stratified in the high risk group in future revisions of ATA pediatric guidelines.

Is total thyroidectomy with bilateral central neck dissection the only surgery for papillary thyroid carcinoma patients with clinically involved central nodes?

Background

In clinical practice, we often observed that patients who underwent total thyroidectomy due to clinically involved nodal disease (cN1a) actually had less extensive CLNM on final pathology. This study investigates whether total thyroidectomy and therapeutic bilateral CND are necessary for all PTC patients with cN1a.

Methods

This study retrospectively reviewed 899 PTC patients who underwent total thyroidectomy with bilateral CND from January 2012 to June 2017. The patients were divided into two groups according to pre-operative central lymph node (CLN) status: cN0, no suspicious CLNM; cN1a, suspicious CLNM. We compared the clinicopathological features of these two groups.

Results

There was no significant difference in recurrence between cN0 and cN1a groups after a mean follow-up time of 59.1 months. Unilateral cN1a was related to the largest central LN size ≥ 2 mm (OR = 3.67, p < 0.001) and number of CLNM > 5(OR = 2.24, p = 0.006). On the other hand, unilateral cN1a was not associated with an increased risk of contralateral lobe involvement (OR = 1.35, p = 0.364) and contralateral CLNM (OR = 1.31, p = 0.359). Among 106 unilateral cN1a patients, 33 (31.1%) were found to be pN0 or had ≤ 5 metastatic CLNs with the largest node smaller than 2 mm.

Conclusions

Most cN1a patients were in an intermediate risk group for recurrence and required total thyroidectomy. However, lobectomy with CND should have performed in approximately 30% of the cN1a patients. Pre-operative clinical examination, meticulous radiologic evaluation, and intra-operative frozen sections to check the nodal status are prerequisites for this approach.

Total thyroidectomy can be overtreatment in cN1a papillary thyroid carcinoma patients whose tumor is smaller than 1 cm

BACKGROUND

The 2015 American Thyroid Association (ATA) guidelines recommend pursuing total thyroidectomy with therapeutic central lymph-node dissection (CND) in patients with clinically apparent nodal disease (cN1a), regardless of tumor size. The aim of this study was to investigate whether total thyroidectomy is necessary for thyroid papillary microcarcinoma (PTMC) patients with preoperative unilateral cN1a.

METHODS

This study included 295 papillary thyroid microcarcinoma patients who underwent total thyroidectomy with bilateral CND from January 2012 to June 2015.

RESULTS

The median follow-up time was 42.5 months. Locoregional recurrence (LRR) was observed in only two (0.9%) patients. Among 70 cN1a patients, only 19 (27.1%) were at intermediate risk for disease recurrence and required total thyroidectomy per the ATA guidelines. Lobectomy can be considered as a treatment option for the remaining patients (72.9%).

CONCLUSIONS

Our study showed that more than two-thirds of PTMC patients with clinical nodal disease who underwent total thyroidectomy and CND were actually lobectomy candidates. Total thyroidectomy as the first surgical option for cN1a, especially in PTMC patients, should be reconsidered.

Changes in Thyrotropin Receptor Antibody Levels Following Total Thyroidectomy or Radioiodine Therapy in Patients with Refractory Graves' Disease

Background: The actions of thyrotropin-binding inhibitory immunoglobulins (TBIIs) against thyrotropin receptors in thyroid follicular cells have been studied as important etiological factors in Graves' disease (GD). The purpose of this study was to investigate changes in the TBII levels of patients undergoing total thyroidectomy (TTx) or radioactive iodine (RAI) therapy for GD refractory to antithyroid drugs (ATDs). Methods: We enrolled patients who underwent TTx or RAI for GD with previous ATD use between January 2011 and December 2017 at the Samsung Medical Center in Seoul, Korea. Thorough retrospective reviews of medical records were performed in 130 patients. Results: Patients with goiter, ophthalmopathy, high levels of TBIIs, and high doses of ATDs received TTx. Elderly patients with arrhythmia received RAI. We observed that TBII levels continued to decrease after TTx. On the contrary, TBIIs initially increased for 138 days (estimated median time) and then decreased slowly after RAI. A faster decline in TBII levels was observed in the TTx group than in the RAI group (p < 0.001). The estimated median time for TBIIs to decrease below 4.5 IU (3 × upper normal limit, which is known to be a risk factor for fetal hyperthyroidism) was 318 days in the TTx group and 659 days in the RAI group, respectively. In the RAI group, high levels of TBII (>4.5 IU/L) were present in 70 (82%) at 6 months, 57 (67%) at 1 year, and 3 (3%) at 2 years. In the TTx group, rapid decreases in TBII levels were observed in younger patients and those with lower baseline TBII levels. In the RAI group, smaller thyroid volume was correlated with more rapid decrease in TBII levels. Conclusions: The changes in TBII levels following TTx or RAI were different in patients with refractory GD. When deciding on TTx or RAI, this difference should be considered with patient age, severity of hyperthyroidism, goiter, ophthalmopathy, and future pregnancy plans (for young female patients).

Feasibility of lateral sentinel lymph node biopsy in medullary thyroid cancer: A surrogate tool for determining prophylactic lateral neck dissection-A pilot study

BACKGROUNDS

This study aimed to evaluate usefulness of lateral sentinel lymph node biopsy (SLNB) in determining lateral neck dissection (LND) of patients with medullary thyroid cancer (MTC).

METHODS

Sixteen patients with MTC were enrolled in the study from January 2013 to June 2019. Intratumoral injection of technetium (Tc)-99m phytate followed by lymphoscintigraphy was performed preoperatively. Lateral sentinel lymph nodes were detected by a collimated gamma probe and underwent frozen analysis. Ipsilateral LND was performed in all patients to assess lateral LN status.

RESULTS

The identification rate of sentinel lymph nodes (SLNs) detected by radioisotope was 87.5% (14 of 16 patients). The sensitivity, specificity, positive predictive value, and negative predictive value of frozen analyses were 66.7%, 100%, 100%, and 91.6%, respectively. Based on final histopathology, however, the diagnostic values of lateral SLNB were all 100%.

CONCLUSIONS

This study showed that lateral SLNB can be a promising surgical tool for decisions on LND in patients with MTC.

Surgeon Volume and Long-Term Oncologic Outcomes in Patients with Medullary Thyroid Carcinoma

BACKGROUND

Surgery is the most important curative treatment for medullary thyroid carcinoma (MTC). The relationship between surgeon volume (the number of surgeries performed) and short-term surgical outcomes, such as increased postoperative complication or costs, is well established. This study evaluated whether surgeon volume influenced long-term oncologic outcomes.

METHODS

We retrospectively reviewed 246 patients diagnosed with MTC after initial thyroid surgery from 1995 to 2019. After exclusion, 194 patients were eligible for inclusion in the study. Surgeons were categorized as low/intermediate volume (fewer than 100 operations per year) or high volume (at least 100 operations per year).

RESULTS

Of the 194 included patients, 60 (30.9%) developed disease recurrence, and 9 (4.6%) died of MTC during the median follow-up of 92.5 months. Having a low/intermediate-volume surgeon was associated with high disease recurrence (log-rank test, p < 0.001). After adjustment for age, sex, tumor type (sporadic versus hereditary), primary tumor size, presence of central lymph node metastasis (LNM), presence of lateral LNM, extrathyroidal extension, and positive resection margin, surgeon volume was a significant factor for disease recurrence (hazard ratio 2.28, p = 0.004); however, cancer-specific survival was not affected by surgeon volume (hazard ratio 4.16, p = 0.115).

CONCLUSIONS

Surgeon volume is associated with long-term oncologic outcome. MTC patients will be able to make the best decisions for their treatment based on the results of this study.

Prognostic Value of the Neutrophil-to-Lymphocyte Ratio before and after Radiotherapy for Anaplastic Thyroid Carcinoma

Simple Summary

Systemic hematologic markers such as the neutrophil–lymphocyte ratio (NLR) are attracting attention in a simple blood test predicting survival and treatment outcomes in various solid cancers. In our study including 40 patients with anaplastic thyroid cancer (ATC) who underwent radiotherapy, we found that high NLR before and after radiotherapy was associated with poor survival. This study result means that host immunity has an important role in patients with ATC, which can be important information for designing future investigations on the impact of immune system modulating therapy in ATC.

Abstract

The neutrophil–lymphocyte ratio (NLR) is a marker of systemic inflammation, and its elevation has recently been associated with poor survival in many solid cancers. Leukocyte elevation and lymphocyte reduction are associated with a poor response to radiotherapy (RT). This study aimed to assess the prognostic value of NLR before and after RT for anaplastic thyroid carcinoma (ATC). This retrospective study analyzed 40 patients with ATC who received RT with available complete blood cell count data from November 1995 through May 2020 at Samsung Medical Center (Seoul, Korea). Patients were classified into two groups according to the NLR before and after RT. The median overall survival (OS) was 8.9 months (range, 3.5–18.2) in the low NLR group (<3.47) and 5.2 months (range, 2.7–7.5) months in the high NLR group (≥3.47). The association between NLR and OS was also observed in multivariable Cox regression analysis (hazard ratio, 3.18; 95% confidence interval, 1.15–8.85; p = 0.026). The OS curves differed significantly according to post-RT NLR (p = 0.036). A high NLR before and after RT may be significantly associated with poor OS in patients with ATC who receive RT.

Occult contralateral central neck metastasis in papillary thyroid carcinoma with preoperatively documented ipsilateral lateral neck metastasis

BACKGROUND

This study was conducted to evaluate risk factors and long-term prognosis of contralateral central neck metastasis (CCNM) in papillary thyroid cancer (PTC) patients with ipsilateral lateral neck metastasis. We present clinical evidence to aid in surgical decision-making regarding the extent of central neck dissection (CND), focusing on separation between ipsilateral and contralateral sides.

METHODS

A total of 379 PTC patients who underwent total thyroidectomy and concomitant bilateral central neck dissection with ipsilateral lateral neck dissection (LND) at a single institution was retrospectively included between January 1997 and December 2015.

RESULTS

The median follow-up time was 83.2 months, the mean age was 44.3 years, and the mean tumor size was 1.5 cm. Among the study sample, 266 patients were female (70.2%) and 113 (29.8%) were male. Of 379 patients, CCNM was present in 34.6%. In multivariate analysis, male sex (adjusted OR = 2.46, p = 0.002), bilaterality (adjusted OR = 2.58, p = 0.004), number of metastatic ipsilateral central lymph nodes (adjusted OR = 1.15, p = 0.002), number of metastatic lateral lymph nodes (adjusted OR = 1.48, p < 0.001), and three-level metastasis (adjusted OR = 2.46, p = 0.012) were identified as risk factors of CCNM. Overall recurrence occurred in 6.0% and 11.5% of patients in the CCNM (-) group and CCNM (+) group, respectively. In addition, contralateral recurrence was observed in 1.2% patients and 0.8% patients in the CCNM (-) group and CCNM (+) group, respectively. However, CCNM did not significantly increase risk of recurrence (adjusted HR = 1.01, p = 0.981).

CONCLUSIONS

Although the probability of pathological CCNM is not negligible, CCNM was not associated with higher risk of recurrence. This study suggest that central neck dissection may be limited to the ipsilateral side, and the result regarding prognosis of CCNM may help to avoid bilateral CND so that it could have potential to minimize unnecessary surgery-related complications such as recurrent laryngeal nerve(RLN) injury or hypoparathyroidism.

Highly Sensitive and Specific Molecular Test for Mutations in the Diagnosis of Thyroid Nodules: A Prospective Study of BRAF-Prevalent Population

Molecular testing offers more objective information in the diagnosis and personalized decision making for thyroid nodules. In Korea, as the BRAF V600E mutation is detected in 70–80% of thyroid cancer specimens, its testing in fine-needle aspiration (FNA) cytology specimens alone has been used for the differential diagnosis of thyroid nodules until now. Thus, we aimed to develop a mutation panel to detect not only BRAF V600E, but also other common genetic alterations in thyroid cancer and to evaluate the diagnostic accuracy of the mutation panel for thyroid nodules in Korea. For this prospective study, FNA specimens of 430 nodules were obtained from patients who underwent thyroid surgery for thyroid nodules. A molecular test was devised using real-time PCR to detect common genetic alterations in thyroid cancer, including BRAF, N-, H-, and K-RAS mutations and rearrangements of RET/PTC and PAX8/PPARr. Positive results for the mutation panel were confirmed by sequencing. Among the 430 FNA specimens, genetic alterations were detected in 293 cases (68%). BRAF V600E (240 of 347 cases, 69%) was the most prevalent mutation in thyroid cancer. The RAS mutation was most prevalently detected for indeterminate cytology. Among the 293 mutation-positive cases, 287 (98%) were diagnosed as cancer. The combination of molecular testing and cytology improved sensitivity from 72% (cytology alone) to 89% (combination), with a specificity of 93%. We verified the excellent diagnostic performance of the mutation panel applicable for clinical practice in Korea. A plan has been devised to validate its performance using independent FNA specimens.

Preoperative Serum Thyroglobulin and Its Correlation with the Burden and Extent of Differentiated Thyroid Cancer

Lymph node metastasis (LNM) in differentiated thyroid cancer (DTC) is usually detected with preoperative ultrasonography; however, this has limited sensitivity for small metastases, and there is currently no predictive biomarker that can help to inform the extent of surgery required. We evaluated whether preoperative serum thyroglobulin levels can predict tumor burden and extent. We retrospectively reviewed the clinical records of 4029 DTC cases diagnosed and treated at a Samsung Medical Center between 1994 and 2016. We reviewed primary tumor size, number and location of LNM, and presence of distant metastases to reveal relationships between tumor burden and extent and preoperative serum thyroglobulin levels. We found a linear association between increasing preoperative thyroglobulin levels, the size of the primary tumor, and the number of LNM (r = 0.34, p < 0.001, r = 0.20, p < 0.001, respectively). Tumor extent also increased with each decile of increasing preoperative thyroglobulin level (r = 0.18, p < 0.001). Preoperative thyroglobulin levels of 13.15 ng/mL, 30.05 ng/mL, and 62.9 ng/mL were associated with the presence of ipsilateral lateral LNM, contralateral lateral LNM, and distant metastasis, respectively. Our results suggest that preoperative measurement of serum thyroglobulin may help to predict LNM and help to tailor surgery.

Prediction of lateral neck lymph node metastasis according to preoperative calcitonin level and tumor size for medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) accounts up to 10% of all thyroid cancers, but is responsible for a disproportionate number of deaths. While surgery is the only curative treatment for MTC, indications for lateral neck lymph node (LLN) dissection are controversial. We performed a retrospective review to describe clinical outcomes in 93 MTC patients from July 1995 to March 2015. We analyzed their clinicopathologic factors, and cut-off values of tumor size and calcitonin levels were calculated using a receiver operating characteristic curve. Using the instances of lymph node metastases, the tumor size cut-off value was 0.95 cm (area under curve, AUC = 0.697) in patients with ipsilateral central lymph node (CLN) metastases, 2.25 cm (AUC = 0.793) in contralateral CLN metastases, and 1.75 cm (AUC = 0.753) in ipsilateral LLN metastases. The cut-off values of preoperative calcitonin levels were 226.6 pg/mL (AUC = 0.746) in ipsilateral CLN, 755.0 pg/mL (AUC = 0.840) in contralateral CLN metastases, and 237.0 pg/mL (AUC = 0.775) in ipsilateral LLN metastases. This study supports the notion that ipsilateral LLN metastases occur before contralateral CLN metastases. Therefore, ipsilateral LLN dissection should be considered in patients with contralateral CLN metastases. The extent of surgery should be based on the status of LN metastases, preoperative basal calcitonin level, and tumor size to help individualize the extent of surgery.

Evaluation of a Novel Collagen Hemostatic Matrix: Comparison of Two Hemostatic Matrices in a Rabbits Jejunal Artery Injury Model

BACKGROUND

We evaluated the hemostatic efficacy and immunogenicity of CollaStat compared with FloSeal in a rabbit jejunal artery injury model.

METHODS

A total of 27 experimental rabbits were used in the study. For each hemostatic agent, an injury was created in one of the right angles of the jejunal arteries originating from the vascular arcs. Time to hemostasis was determined after applying manual compression to the wound for 30 s, which was repeated a maximum of three times in cases of persistent bleeding. On postoperative day 7, the concentration of serum antithrombin antibody was measured among agent-treated and nontreated control groups.

RESULTS

The mean time to hemostasis for CollaStat was significantly shorter than for FloSeal (64.0 ± 5.0 versus 84.0 ± 7.8 s; P = 0.040). There were no significant differences in rabbit serum mean anti-thrombin Ab concentration between CollaStat-treated, FloSeal -treated, and the control groups (8.43 ± 0.44 versus 8.18 ± 7.8 versus 9.58 ± 1.11 ng/mL; P = 0.065).

CONCLUSIONS

According to our study, CollaStat was more efficient in achieving hemostasis in a rabbit jejunal artery injury and exhibited nonsignificant immunogenicity compared with FloSeal. These findings suggest that CollaStat has acceptable hemostatic potential for controlling significant arterial bleeding.

Clinical Validation of the Prognostic Stage Groups of the Eighth-Edition TNM Staging for Medullary Thyroid Carcinoma

CONTEXT

Despite advances in thyroid cancer staging systems, considerable controversy about the current staging system for medullary thyroid carcinoma (MTC) continues.

OBJECTIVE

We aimed to evaluate the prognostic performance of the current eighth edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control TNM staging system (TNM-8) and the alternative proposed prognostic stage groups based on recursive partitioning analysis (TNM-RPA).

DESIGN, SETTING, AND PATIENTS

We retrospectively analyzed 182 patients with MTC treated at a single tertiary Korean hospital between 1995 and 2015.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Survival analysis was conducted according to TNM-8 and TNM-RPA. The area under the receiver-operating characteristic curve (AUC), the proportion of variation explained (PVE), and the Harrell concordance index (C-index) were used to evaluate predictive performance.

RESULTS

Under TNM-8, only two (1.1%) patients were downstaged compared with the seventh edition of the AJCC TNM staging system (TNM-7). The AUC at 10 years, PVE, and C-index were 0.679, 8.7%, and 0.744 for TNM-7 and 0.681, 8.9%, and 0.747 for TNM-8, respectively. Under TNM-RPA, 104 (57.14%) patients were downstaged compared with TNM-8. TNM-RPA had better prognostic performance with respect to cancer-specific survival (AUC at 10 years, 0.750; PVE, 20.9%; C-index, 0.881).

CONCLUSIONS

The predictive performance of the revised TNM-8 in patients with MTC has not changed despite its modification from TNM-7. The proposed changes in TNM-RPA were statistically valid and may present a more reproducible system that better estimates cancer-specific survival of individual patients.

Low versus high activity radioiodine remnant ablation for differentiated thyroid carcinoma with gross extrathyroidal extension invading only strap muscles

OBJECTIVES

The efficacy of radioiodine remnant ablation (RRA) for patients with differentiated thyroid carcinoma (DTC) with gross extrathyroidal extension (ETE) is well described in observational studies. However, its role in gross ETE invading only strap muscles, T3b category in the newly proposed eighth edition of the TNM staging system, is currently unknown.

METHODS

This study retrospectively analyzed 260 DTC patients with ETE invading only strap muscles who underwent thyroidectomy at a tertiary Korean hospital between 1994 and 2005. Cancer-specific survival (CSS) and recurrence-free survival (RFS) in the no RRA (n = 13), low RRA activity (<3.7 GBq, n = 80), and high RRA activity (≥3.7 GBq, n = 167) groups were studied.

RESULTS

No significant differences were observed between low and high activity RRA groups in terms of 10-year CSS (97.3% versus 99.3%; HR 0.23, 95% CI 0.02-2.57; p = .235) and RFS (86.8% versus 88.8%; 0.90, 0.40-2.03; p = .804). In the no RRA group, no patients died of cancer, and only one developed structural recurrence. In Cox regression analyses with inverse probability of treatment weighting adjusted for clinicopathologic risk factors, high activity RRA was not related to recurrence outcomes compared to low activity (HR 0.60, 95% CI 0.26-1.35; p = .214).

CONCLUSIONS

Long term oncologic outcomes did not significantly differ between low versus high activity RRA groups, which suggests that low activity RRA might be sufficient in patients with DTC with gross ETE invading only strap muscles. Further studies are needed to clarify the optimal activity of RRA in these patients.

Nanoconfinement effects of chemically reduced graphene oxide nanoribbons on poly(vinyl chloride)

Polymeric nanocomposites with graphene-based nanocarbons (GNCs) have been extensively studied with emphasis on the percolation of nanofillers toward electrical, rheological, and mechanical reinforcement. In this study, we report an unusual indirect reinforcing phenomenon of highly defective GNCs dispersed in the poly(vinyl chloride) (PVC) matrix via densification of the polymer packing originating from nanoscale confinement. Herein, chemically reduced graphene oxide nanoribbons (C-rGONRs) are employed as a nanofiller. The inclusion of defective and oxygen-functionalized C-rGONRs resulted in a dramatic densification of the PVC host with extremely low C-rGONR loading, largely exceeding the theoretical calculation from a rule of mixture. Along with the densification, the glass transition temperature of PVC also increased by 28.6 °C at 0.1 wt% filler loading. Remarkably, the oxygen barrier property and mechanical toughness under tension for the PVC/C-rGONR nanocomposite were the maximum when the greatest densification occurred. The structure-property relationship of the nanocomposites has been discussed with an emphasis on the nanoscale confinement phenomenon.

Faucial Pillar Perforation by Glidescope Intubation with Incorrectly Placed Stylet

Glidescope GVL® is frequently used in intubation of difficult airway. We report a case of right side of faucial pillar perforation during intubation with Glidescope®. A rigid stylet can facilitate placing of endotracheal tube quickly but it may also penetrate the soft tissue to cause injuries.

Preoperative serum thyroglobulin predicts initial distant metastasis in patients with differentiated thyroid cancer

Differentiated thyroid cancer (DTC) generally has a favorable prognosis. However, a small percentage of patients suffer from initial distant metastasis (DM). To date, there is no effective predictor for the presence of initial DM. The aim of this study was to determine if preoperative serum thyroglobulin (Tg) level could predict initial DM in DTC. We reviewed an institutional thyroid cancer database from October 1994 to February 2016. To determine the Tg cutoff for predicting initial DM, 4,735 patients who were diagnosed with DTC were included in this study. Fifty-seven patients (1.2%) were identified as having DTC with initial DM. Median preoperative Tg level was 328.4 ng/ml in the initial DM group and 10.0 ng/ml in the non-DM group. Initial DM was the most important factor affecting serum Tg level (β = 2,049.32 ± 103.40; P < 0.001). The Tg cutoff level that distinguished overall DM with the greatest accuracy was 63.4 ng/ml [area under the ROC curve 0.914, sensitivity 84.2%, specificity 90.6%, negative likelihood ratio (LR) 0.17, and positive LR 8.97]. Preoperative Tg levels were useful for predicting initial DM of DTC. Measurement of serum Tg in patients with DTC may guide preoperative staging evaluation and initial treatment.

Restratification of survival prognosis of N1b papillary thyroid cancer by lateral lymph node ratio and largest lymph node size

The current 7th TNM staging stratifies N1b papillary thyroid cancer (PTC) patients without distant metastasis into either stage I or stage IV merely by an age threshold (45 years). To date, no studies have adequately quantified the mortality risk of PTC patients with N1b disease. We hypothesized that incorporating lymph node (LN) factors into the staging system would better predict cancer-specific mortality (CSM). A total of 745 nonmetastatic PTC patients with N1b disease were enrolled. We identified factors related to LNs and cut-points using Cox regression and time-dependent ROC analysis. New prognostic groupings were derived based on minimal hazard differences for CSM among the groups stratified by LN risk and age, and prediction of CSM was assessed. Lateral lymph node ratio (LNR) and largest LN size were significant prognostic LN factors at cut-points of 0.3 and 3 cm. Without LN risk (lateral LNR >0.3 or largest LN size >3 cm), stage IV patients had prognosis [adjusted HR 1.10 (98% CI 0.19-6.20); P = 0.906] similar to stage I patients with LN risk. Patients were restratified into three prognostic groups: Group 1, <45 years without LN risk; Group 2, <45 years with LN risk or ≥45 years without LN risk; and Group 3, ≥45 with LN risk. This system had a lower log-rank P-value (<0.001 vs. 0.002) and higher C-statistics (0.80 vs. 0.71) than the 7th TNM. New prognostic grouping using lateral LNR and largest LN size predicts CSM accurately and distinguishes N1b patients with different prognosis.

Predictive Factors of Lymph Node Metastasis in Follicular Variant of Papillary Thyroid Carcinoma

BACKGROUND

Compared with conventional papillary thyroid carcinoma (PTC), follicular variant of PTC (FV-PTC) shows less aggressive behavior and better prognosis. Nonetheless, regional lymph node (LN) metastasis was found in 22.8% of FV-PTC patients. Because LN metastasis is a proven predictor of recurrence in PTC, it is important to assess LN metastasis in FV-PTC patients.

METHODS

We retrospectively reviewed 134 FV-PTC patients who underwent thyroidectomy with neck dissection.

RESULTS

Central LN metastasis (CLNM) and lateral LN metastasis (LLNM) were found in 50 (37.3%) and 16 (11.9%) patients, respectively. In the multivariate analysis for CLNM, male sex (adjusted OR 4.735, p = 0.001), nonencapsulated form (adjusted OR 2.863, p = 0.022), and tumor size >1.0 cm (adjusted OR 3.157, p = 0.008) were independent predictors of high prevalence of CLNM in FV-PTC patients. In the multivariate analysis for LLNM, microscopic extrathyroidal extension (ETE) (adjusted OR 3.939, p = 0.041) and CLNM (adjusted OR 13.340, p = 0.001) were independent predictors of high prevalence of LLNM in FV-PTC patients.

CONCLUSIONS

Meticulous perioperative evaluation and prophylactic central neck dissection may be beneficial for FV-PTC patients with male sex, nonencapsulated form, and tumor size >1.0 cm. Moreover, cautious perioperative evaluation of lateral neck LN may be mandatory for FV-PTC patients with microscopic ETE and CLNM.

Patterns of Initial Recurrence in Completely Resected Papillary Thyroid Carcinoma

BACKGROUND

Despite improvements in the surgical and medical treatment of papillary thyroid carcinoma (PTC), subsets of patients suffer from structural recurrence after initial treatment. This study evaluated the timing and patterns of recurrence in completely resected PTC patients.

METHODS

A retrospective review of a prospectively maintained thyroid cancer database was performed. The timing and patterns of recurrence were reviewed in 2250 patients with PTC >1 cm who achieved complete remission after total thyroidectomy and/or radioactive iodine treatment. Univariate and multivariate analyses were performed to identify factors predictive of recurrence patterns.

RESULTS

During 8.1 years of mean follow-up, 68 (3.0%) patients developed structural recurrences: 53 lymph node recurrences (LNR), 11 local soft tissue recurrences (LR), and four distant recurrences (DR). Two patients died of DR. Younger patients had a higher proportion of LNR, and older patients had a tendency toward LR/DR. LNR showed a peak incidence between one and three years after remission, but LR/DR showed a delayed peak incidence between two and four years. The factors that significantly increased the risk of LNR were multifocal tumor and lymph node metastasis (central/lateral). The factors that increased the risk of LR/DR were old age, large tumor size (>2 cm), and lateral lymph node metastasis. In addition, central neck dissection significantly reduced subsequent LR/DR.

CONCLUSION

Patterns of recurrence after complete PTC resection are variable and associated with specific clinicopathologic factors. Understanding the timing and patterns of recurrence may lead to more effective adjuvant treatment and improved long-term follow-up strategies.

Prognostic value of the eighth edition AJCC TNM classification for differentiated thyroid carcinoma

BACKGROUND

The prognostic value of the proposed eighth edition of the American Joint Committee on Cancer (AJCC) tumor, node, and metastasis (TNM) classification is currently unclear. The aim of the study was to evaluate the prognostic value of the eighth edition of the AJCC TNM classification.

METHODS

We retrospectively assessed 3176 patients with differentiated thyroid carcinoma (DTC) who underwent thyroidectomy at a tertiary Korean hospital from 1996 to 2005. Cancer-specific survival (CSS) was analyzed using the Kaplan-Meier method and compared using the log-rank test. Performance of the eighth edition TNM with respect to prediction of CSS was assessed against the current seventh edition.

RESULTS

Upon reclassification according to the eighth edition, 37.6% of patients were down-staged. The proportions of stage I and II tumors increased from 61.9% to 81.1% and from 1.7% to 16.0%, respectively, whereas those of stage III and IVB (formerly IVC in the seventh edition) decreased from 27.6% to 2.3% and 0.8% to 0.5%, respectively. The proportions of variance explained (PVEs) for the ability of the eighth and the seventh edition to predict CSS were 3.9% and 2.9%, respectively. The C-index values were 0.765 (95% confidence interval 0.764-0.766) for the eighth edition and 0.736 (0.735-0.737) for the seventh edition.

CONCLUSION

Our results demonstrate that the eighth edition TNM more accurately predicts CSS for patients with DTC than does the seventh edition.

Refining Dynamic Risk Stratification and Prognostic Groups for Differentiated Thyroid Cancer With TERT Promoter Mutations

CONTEXT

Currently, no recurrence or mortality risk systems consider molecular testing when predicting thyroid cancer outcomes.

OBJECTIVE

We developed an integrative prognostic system that incorporates telomerase reverse transcription (TERT) promoter mutations into the recently proposed risk reclassification system after initial therapy [dynamic risk stratification (DRS)] to better categorize and predict outcomes.

DESIGN

A total of 357 differentiated thyroid cancer (DTC) patients without initial distant metastasis were enrolled. Among patients with mutated TERT and wild-type, recurrence-free survival (RFS) was compared according to DRS grouping. Cox regression was used to calculate adjusted hazard ratios (AHRs) to derive AHR groups. Performance of the AHR grouping system with respect to prediction of structural recurrence and cancer-specific survival (CSS) was assessed against the current DRS system and the tumor/node/metastasis (TNM) classification.

RESULTS

Among 357 patients, there were 90 recurrences and 15 cancer-related deaths during a median of 14 years of follow-up. Patients in higher AHR groups were at higher risk of recurrence (10-year RFS for AHR 1, 2, 3, and 4: 94.9%, 82.7%, 50.2%, and 23.1%; P < 0.001) and cancer-related death (10-year CSS: 100.0%. 98.7%, 94.2%, and 76.9%; P < 0.001). The proportions of variance explained (PVEs) for the ability of AHR and DRS grouping to predict recurrence were 22.4% and 18.5%. PVEs of AHR and TNM system to predict cancer-related deaths were 11.5% and 7.4%.

CONCLUSIONS

The AHR grouping system, a simple two-dimensional prognostic system, is as effective as DRS at predicting structural recurrence and provides clinical implication for long-term CSS in patients with nonmetastatic DTC.

Erratum: Validation of a Web-Based Tool to Predict the Ipsilateral Breast Tumor Recurrence (IBTR! 2.0) after Breast-Conserving Therapy for Korean Patients

[This corrects the article on p. 97 in vol. 16, PMID: 23593089.].

Patterns, Predictive Factors, and Prognostic Impact of Contralateral Lateral Lymph Node Metastasis in N1b Papillary Thyroid Carcinoma

BACKGROUND

Although the incidence among patients with bilateral lateral lymph node metastasis (LLNM) in N1b papillary thyroid carcinoma (PTC) is reported to be as high as 40%, only a few reports have addressed the characteristics of contralateral LLNM. Therefore, this study aimed to investigate the characteristics of patients with contralateral LLNM in N1b PTC.

METHODS

This study retrospectively reviewed 834 patients with N1b PTC who underwent modified radical neck dissection between January 1997 and June 2015.

RESULTS

Of the 834 N1b PTC patients, unilateral LLNM was found in 728 patients (87.3%) and bilateral LLNM in 106 patients (12.7%). The independent predictors of contralateral LLNM in N1b PTC patients were male sex (adjusted odds ratio [OR], 1.647; p = 0.039), tumor larger than 4 cm (adjusted OR, 6.700; p < 0.001), multiplicity (adjusted OR, 1.754; p = 0.040), bilobar involvement (adjusted OR, 1.971; p = 0.010), and bilateral central LN metastasis (CLNM) (adjusted OR, 2.829; p = 0.025). Moreover, contralateral LLNM significantly increased the risk of overall (adjusted hazard ratio [HR], 1.943; p = 0.016) and lateral neck (adjusted HR, 2.246; p = 0.015) locoregional recurrence.

CONCLUSIONS

In the preoperative period, the meticulous evaluation of contralateral lateral neck may be required for male N1b PTC patients with tumor larger than 4 cm, multiplicity, bilobar involvement, and/or bilateral CLNM. In the postoperative period, N1b PTC patients may be re-stratified according to the contralateral LLNM, and meticulous follow-up assessment is required for N1b PTC patients with contralateral LLNM.

Comprehensive screening for PD-L1 expression in thyroid cancer

PD-L1 expression is being considered a potential biomarker for response of anti-PD-1 or anti-PD-L1 agents in various tumors. The reported frequency of PD-L1 positivity varies in thyroid carcinomas, and multiple factors may contribute to the variability in PD-L1 positivity. We evaluated the PD-L1 expression in various thyroid cancers on a large scale. A total of 407 primary thyroid cancers with a median 13.7-year of follow-up were included. We evaluated the frequency of PD-L1 expression using a rabbit monoclonal antibody (clone SP142). In addition, we analyzed the relationships between PD-L1 expression and clinicopathologic factors, including TERT promoter, BRAF status and disease progression. Tumoral PD-L1 was expressed in 6.1% of papillary thyroid carcinomas, 7.6% of follicular thyroid carcinomas and 22.2% of anaplastic thyroid carcinomas. The distribution of PD-L1 positivity was different according to cancer histology types (P < 0.001). All PD-L1-positive cases of follicular thyroid carcinoma and anaplastic thyroid carcinoma showed strong intensity. The proportions of positivity in PD-L1 positive anaplastic thyroid carcinomas were more than 80%. PD-L1 in immune cells was positive in 28.5% of papillary thyroid carcinoma, 9.1% of follicular thyroid carcinomas and 11.1% of anaplastic thyroid carcinomas. There was no significant association between clinicopathologic variables, disease progression, oncogenic mutation and PD-L1 expression. PD-L1 was highly expressed in a subset of patients with advanced thyroid cancer, such as follicular and anaplastic thyroid carcinoma. Identification of PD-L1 expression may have direct therapeutic relevance to patients with refractory thyroid cancer.

Predicting Factors for Bilaterality in Papillary Thyroid Carcinoma with Tumor Size <4 cm

BACKGROUND

In the 2015 American Thyroid Association guidelines, either lobectomy or total thyroidectomy was recommended for thyroid cancer <4 cm without extrathyroidal extension (ETE) and lymph node (LN) metastasis. Therefore, the purpose of this study was to investigate factors predictive of bilaterality in papillary thyroid carcinoma (PTC) patients with tumor size <4 cm.

METHODS

This study retrospectively reviewed 3296 conventional PTC patients who underwent total thyroidectomy with central neck dissection and/or lateral neck dissection between January 2008 and June 2015.

RESULTS

In overall conventional PTC patients, per 10-year age increment (adjusted odds ratio [OR] = 1.153, p < 0.001), BRAF mutation positivity (adjusted OR = 1.447, p = 0.002) and multifocality (adjusted OR = 3.895, p < 0.001) were independent predictors for bilaterality. In conventional PTC patients with tumor size 1-4 cm, per 10-year age increment (adjusted OR = 1.289, p < 0.001), BRAF mutation positivity (adjusted OR = 1.560, p = 0.012), multifocality (adjusted OR = 4.220, p < 0.001), and N1b (adjusted OR = 1.570, p = 0.007) were independent predictors for bilaterality. In conventional PTC patients with tumor size <1 cm, BRAF mutation positivity (adjusted OR = 1.327, p = 0.042) and multifocality (adjusted OR = 3.530, p < 0.001) were found to be independent predictors for bilaterality.

CONCLUSIONS

When multifocality and BRAF mutation positivity are observed in PTC patients with tumor size <4 cm, total thyroidectomy may be considered. If lobectomy is performed in PTC patients with multifocality and BRAF mutation positivity, meticulous follow-up is needed to detect hidden malignancies in the contralateral lobe.

Should Level V Be Routinely Dissected in N1b Papillary Thyroid Carcinoma?

BACKGROUND

For N1b papillary thyroid carcinoma (PTC) patients, modified radical neck dissection (MRND) encompassing levels II-V is generally recommended. However, routine level V dissection is controversial because of the low incidence of metastasis/recurrence in level V and the increased morbidities associated with level V dissection.

METHODS

This study retrospectively reviewed 646 N1b PTC patients who underwent unilateral MRND between January 1997 and June 2015. Specifically, to assess surgery-related outcomes of level V dissection, outcomes from N1b PTC patients who underwent unilateral MRND (levels II-V) were compared with those who underwent unilateral selective neck dissection (SND; levels II-IV) using propensity score matching.

RESULTS

Overall and occult level V metastases were observed in 13.9% and 8.6% of patients, respectively. Level V recurrences were observed in only 2.26 (7.7%) recurred N1b PTC patients who underwent unilateral MRND. In multivariate analysis, three-level (II, III, and IV) simultaneous metastasis (adjusted odds ratio = 3.079, p = 0.003) was an independent predictor for level V metastasis. Under a matched condition, "shoulder syndrome" encompassing shoulder dysfunction and pain (9.1% vs. 2.7%, p = 0.002) was significantly more frequent in the MRND group than it was in the SND group.

CONCLUSIONS

Because of the low incidence of metastasis/recurrence in level V and the clear evidence of increased morbidities, level V dissection in N1b PTC patients may be reserved for those with three-level simultaneous metastasis or clinically/radiologically evident level V metastasis.

Propensity score-matched analysis of robotic versus endoscopic bilateral axillo-breast approach (BABA) thyroidectomy in papillary thyroid carcinoma

PURPOSE

The da Vinci surgical robot system was developed to overcome the weaknesses of endoscopic surgery. However, whether robotic surgery is superior to endoscopic surgery remains uncertain. Therefore, the purpose of this study was to compare the surgical and oncologic outcomes between endoscopic and robotic thyroidectomy using bilateral axillo-breast approach (BABA).

METHODS

Between January 2008 and June 2015, papillary thyroid carcinoma patients who underwent thyroidectomy with central neck dissection using endoscopic (n = 480) or robotic (n = 705) BABA were primarily reviewed. We performed 1:1 propensity score matching and 289 matched pairs were yielded.

RESULTS

Operation time was significantly longer in the robotic thyroidectomy than in the endoscopic thyroidectomy (184.9 vs. 128.9 min, P < 0.001). A significantly higher number of central lymph nodes (CLNs) were resected in the robotic thyroidectomy than in the endoscopic thyroidectomy (5.3 vs. 4.4, P = 0.003). However, the incidence of other outcomes including hospital stay, postoperative duration, thyroglobulin level, radioactive iodine ablation, hemorrhage, chyle leakage, wound infection, recurrent laryngeal nerve injury, and loco-regional recurrence did not significantly differ between the endoscopic thyroidectomy and the robotic thyroidectomy.

CONCLUSIONS

Endoscopic thyroidectomy is comparable with robotic thyroidectomy in view of surgical complications and LRR. Because robotic thyroidectomy resected a larger number of CLNs than did endoscopic thyroidectomy, further long-term follow-up studies will be required to clarify the possible prognostic benefits of robotic thyroidectomy.

TERT promoter mutations and long-term survival in patients with thyroid cancer

TERT promoter mutations are emerging prognostic biomarkers in multiple cancers and are found in highly aggressive thyroid cancer. Our aim is to investigate the prognostic value of these mutations for the outcome of thyroid cancer-related mortality in a large cohort of thyroid cancer patients. This was a retrospective study of 409 patients (393 with differentiated thyroid cancer) with a median age of 44 years (range 16-81 years) and median follow-up of 13 years (interquartile range 11-16 years). Analyses of associations between mutational status and various clinicopathological variables were performed. TERT promoter mutations were identified in 32 (9.8%) papillary, 11 (16.7%) follicular and seven (43.8%) poorly differentiated/anaplastic thyroid cancer patients. The presence of TERT promoter mutations was associated with factors such as increased age (P < 0.001), extrathyroidal invasion (P = 0.01), increased stage at diagnosis (P < 0.001) and dedifferentiated histological type (P = 0.001). A TERT promoter mutation was independently associated with poorer overall survival in patients with differentiated thyroid cancer (10-year survival rate, 66.2% vs 98.3% for wild type; adjusted HR, 7.18; 95% CI: 2.77-18.59) and in patients with papillary cancer (74.2% vs 99.3%; 14.20; 3.03-66.68). Concomitant TERT and BRAF mutations worsened the survival rate of patients with papillary cancer (82.6% vs 99.4% for exclusively BRAF mutation alone; 5.62; 1.85-17.09). In conclusion, the presence of TERT promoter mutations is independently associated with increased mortality in patients with differentiated thyroid cancer. The results suggest that inclusion of TERT promoter mutation analysis with conventional clinicopathological evaluation can lead to better prognostication and management for individual patients.

Total thyroidectomy versus lobectomy in conventional papillary thyroid microcarcinoma: Analysis of 8,676 patients at a single institution

BACKGROUND

Because there is a controversy regarding the management of papillary thyroid microcarcinoma, the purpose of this study was to compare lobectomy with total thyroidectomy as a primary operative treatment for papillary thyroid microcarcinoma. Loco-regional recurrence in the contralateral remnant lobe can be managed safely by completion thyroidectomy via the previous scar. However, reoperation for operation bed (thyroidectomy site) or regional lymph node (central or lateral) recurrence generally is associated with morbidity. Therefore, we analyzed overall loco-regional recurrence and loco-regional recurrence outside of the contralateral remnant lobe separately.

METHODS

We retrospectively reviewed 8,676 conventional patients with papillary thyroid microcarcinoma who underwent thyroidectomy.

RESULTS

Lobectomy was performed in 3,289 (37.9%) patients, and total thyroidectomy was performed in 5,387 (62.1%) patients. Total thyroidectomy significantly decreased the risk of overall loco-regional recurrence (adjusted hazard ratio 0.398, P < .001). However, total thyroidectomy did not significantly decrease the risk of loco-regional recurrence outside of the contralateral remnant lobe (adjusted hazard ratio 0.880, P = .640). Particularly in conventional papillary thyroid microcarcinoma patients with multifocality, total thyroidectomy significantly decreased the risk of overall loco-regional recurrence (adjusted hazard ratio 0.284, P = .002) and loco-regional recurrence outside of the contralateral remnant lobe (adjusted hazard ratio 0.342, P = .020).

CONCLUSION

Although lobectomy is associated with contralateral remnant lobe recurrence, lobectomy did not increase the risk of loco-regional recurrence outside of the contralateral remnant lobe in patients with papillary thyroid microcarcinoma, except in those with multifocality. Because recurrence in the contralateral remnant lobe can be managed safely by completion thyroidectomy, lobectomy may be a safe operative option for select patients with papillary thyroid microcarcinoma without multifocality.

Follicular and Diffuse Sclerosing Variant Papillary Thyroid Carcinomas as Independent Predictive Factors of Loco-Regional Recurrence: A Comparison Study Using Propensity Score Matching

BACKGROUND

Only about half of papillary thyroid carcinoma (PTC) cases are classified as conventional PTC (CV-PTC), whereas various histologic variants constitute the remaining cases. Since controversies about the clinical behavior and outcomes of PTC variants continue, the purpose of this study was to compare the outcomes of patients with PTC variants who were treated at a large tertiary referral center in Korea.

METHODS

The medical records for 15,598 CV-PTCs, 435 follicular variants of PTC (FV-PTCs), and 66 diffuse sclerosing variants of PTC (DSV-PTCs) were retrospectively reviewed. Loco-regional recurrences (LRR) among PTC variants were compared using propensity score matching.

RESULTS

Analysis I compared CV-PTC with FV-PTC. After rigorous matching, 367 pairs were established. Recurrence-free survival (RFS) rates in CV-PTC were 96.1% at 5 years, 92.2% at 10 years, and 92.2% at 15 years, while those for FV-PTC were 98.8% at 5 years, 98.8% at 10 years, and 98.8% at 15 years (p = 0.026). Analysis II compared CV-PTC with DSV-PTC. Rigorous matching yielded 56 pairs. RFS rates for CV-PTC were 87.4% at 5 years, 87.4% at 10 years, and 87.4% at 15 years, while those for DSV-PTC were 68.9% at 5 years, 57.5% at 10 years, and were not available at 15 years (p = 0.013).

CONCLUSIONS

Compared with CV-PTC, FV-PTC showed less aggressive behaviors and more favorable outcomes. However, DSV-PTC showed more aggressive behaviors and a less favorable outcome than CV-PTC did. Therefore, the management strategy and follow-up plan for PTC should be differentiated according to the histologic variant.

Radioactive iodine ablation may not decrease the risk of recurrence in intermediate-risk papillary thyroid carcinoma

The use of radioactive iodine (RAI) ablation in patients with intermediate-risk papillary thyroid carcinoma (PTC) who show microscopic extrathyroidal extension (ETE), regional lymph node (LN) metastasis, tumors with aggressive histology, or vascular invasion has been debated due to the lack of data regarding long-term prognosis in this risk group. Therefore, the purpose of this study was to resolve the controversy surrounding the prognostic benefit of RAI ablation, especially in intermediate-risk PTC patients. We retrospectively reviewed the medical records of 8297 intermediate-risk PTC patients who underwent primary total thyroidectomy with or without neck dissection at the Thyroid Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea, between January 1997 and June 2015. Of these 8297 patients, 7483 (90.2%) received RAI ablation. After adjusting for clinicopathological characteristics, RAI ablation did not significantly decrease the risk of loco-regional recurrence (LRR) (adjusted hazard ratio (HR) 0.852, P 0.413). Moreover, RAI ablation did not decrease the risk of LRR even in intermediate-risk PTC patients with aggressive features such as BRAF positivity (adjusted HR 0.729, P 0.137), tumor size >1 cm (adjusted HR 0.762, P 0.228), multifocality (adjusted HR 1.032, P 0.926), ETE (adjusted HR 0.870, P 0.541), and regional LN metastasis (adjusted HR 0.804, P 0.349). Furthermore, high-dose RAI ablation (>100 mCi) did not significantly decrease the risk of LRR (adjusted HR 0.942, P 0.843). Therefore, RAI ablation in intermediate-risk PTC patients should be considered on the basis of tailored risk restratification.

Influence of Body Mass Index and Body Surface Area on the Behavior of Papillary Thyroid Carcinoma

BACKGROUND

Previous studies have examined the relationship between body mass index (BMI) and the behavior of papillary thyroid carcinomas (PTC). However, the results are inconsistent. The purpose of this study was to clarify the association between PTC behavior and anthropometric parameters including BMI and body surface area (BSA).

METHODS

This study retrospectively reviewed 5081 PTC patients who underwent total thyroidectomy with bilateral central neck dissection between January 2002 and June 2015. Because of sexual dimorphism in obesity, analyses were conducted separately for men and women. The World Health Organization BMI classification was used to classify patients as normal (18.5 ≤ BMI <25 kg/m(2)), overweight (25 ≤ BMI <30 kg/m(2)), or obese (BMI ≥30 kg/m(2)). Since no consensus for BSA categorization exists, enrolled patients were grouped into BSA quartiles by sex: women BSA1 (BSA <1.52 m(2)), BSA2 (1.52 ≤ BSA <1.59 m(2)), BSA3 (1.59 ≤ BSA <1.67 m(2)), and BSA4 (BSA ≥1.67 m(2)); and men BSA1 (BSA <1.77 m(2)), BSA2 (1.77 ≤ BSA <1.86 m(2)), BSA3 (1.86 ≤ BSA <1.96 m(2)), and BSA4 (BSA ≥1.96 m(2)).

RESULTS

In women, overweight (adjusted odds ratio [OR] = 1.187, p = 0.042) and obese (adjusted OR = 2.231, p < 0.001) were independent predictors for multiplicity. Furthermore, overweight (adjusted OR = 1.237, p = 0.012) and obese (adjusted OR = 1.789, p = 0.005) were independent predictors for extrathyroidal extension (ETE). However, higher BMI was not an independent predictor for bilaterality or central lymph node metastasis (CLNM). In addition, higher BSA-BSA3 (adjusted OR = 1.205, p = 0.049) and BSA4 (adjusted OR = 1.524, p < 0.001)-was an independent predictor for multiplicity. However, higher BSA was not a predictor for bilaterality, ETE, or CLNM. In men, higher BMI and BSA were not predictors for multiplicity, bilaterality, ETE, or CLNM.

CONCLUSIONS

In women with PTC, higher BMI was an independent predictor for multiplicity and ETE. Furthermore, higher BSA was an independent predictor for multiplicity. However, BMI and BSA were not predictors for the PTC behavior in men.

Predictive Factors for Lymph Node Metastasis in Papillary Thyroid Microcarcinoma

BACKGROUND

Because lymph node (LN) metastasis has been proven to be a predictor for locoregional recurrence (LRR) in papillary thyroid microcarcinoma (PTMC), better knowledge about the predictors for LN metastasis in PTMC is required.

METHODS

We retrospectively reviewed 5656 PTMC patients who underwent total thyroidectomy and central neck dissection and/or lateral neck dissection between January 1997 and June 2015.

RESULTS

Male gender (adjusted odds ratio [OR] 2.332), conventional variant (adjusted OR 4.266), tumor size >0.5 cm (adjusted OR 1.753), multiplicity (adjusted OR 1.168), bilaterality (adjusted OR 1.177), and extrathyroidal extension (ETE) (adjusted OR 1.448) were independent predictors for high prevalence of central LN metastasis (CLNM), whereas per 10-year age increment (adjusted OR 0.760) and chronic lymphocytic thyroiditis (adjusted OR 0.791) were independent predictors for low prevalence of CLNM. In addition, male gender (adjusted OR 1.489), tumor size >0.5 cm (adjusted OR 1.295), multiplicity (adjusted OR 1.801), ETE (adjusted OR 1.659), and CLNM (adjusted OR 4.359) were independent predictors for high prevalence of lateral LN metastasis (LLNM), whereas per 10-year age increment (adjusted OR 0.838) was an independent predictor for low prevalence of LLNM. There was a statistically significant difference in LRR with regard to nodal stage (p < 0.001).

CONCLUSIONS

Meticulous perioperative evaluation of LN metastasis is required for PTMC patients with the above predictors.

Clinical outcomes of patients with hypercalcitoninemia after initial treatment for medullary thyroid cancer and postoperative serum calcitonin cutoffs for predicting structural recurrence

BACKGROUND

Persistent hypercalcitoninemia is reported in 40% to 60% of patients with medullary thyroid cancer (MTC) after initial therapy, but their clinical outcomes have not been clearly studied. We evaluated the outcomes of MTC with hypercalcitoninemia and assessed the cutoffs of postoperative serum calcitonin for predicting structural recurrence.

METHODS

A dynamic risk assessment system was used to categorize clinical outcomes in this retrospective study. Receiver operating characteristic (ROC) curve analysis was used to calculate the calcitonin cutoffs for predicting structural recurrence.

RESULTS

Among 120 patients operated on, 30 (25%) had persistent hypercalcitoninemia. Of that group, 18 (60%) had biochemical persistent disease and 11 (37%) developed structural identified disease, including 1 death (3%). Postoperative calcitonin <29 pg/mL predicted structural disease with 100% sensitivity, 90.5% specificity, and 100% negative predictive value.

CONCLUSION

One third of the patients with MTC with hypercalcitoninemia experienced structural recurrence, and postoperative basal serum calcitonin might be a simple tumor marker to predict structural recurrence. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-1508, 2016.

Prophylactic Central Neck Dissection Might Not Be Necessary in Papillary Thyroid Carcinoma: Analysis of 11,569 Cases from a Single Institution

BACKGROUND

The benefits of prophylactic central neck dissection (pCND) remain controversial in clinically node-negative (cN0) papillary thyroid carcinoma (PTC). The purpose of this study was to investigate the clinical impact of pCND with a large group of cN0 PTC patients.

STUDY DESIGN

A total of 11,569 cN0 PTC patients who underwent thyroidectomy between January 1997 and June 2015 were investigated. Using Cox multivariate analysis, the prognostic impact of pCND was assessed using subset analyses according to various clinicopathologic conditions. Using propensity score matching, various surgical morbidities were assessed under adjusted conditions.

RESULTS

Of 11,569 cN0 PTC patients, 8,735 (75.5%) underwent pCND. Prophylactic CND did not significantly decrease the risk of locoregional recurrence in cN0 PTC patients (adjusted hazard ratio [HR] = 0.874; p = 0.392). In addition, pCND did not significantly decrease the risk of locoregional recurrence in various surgical extents (lobectomy and ipsilateral pCND [adjusted HR = 0.636; p = 0.131], total thyroidectomy and ipsilateral pCND [adjusted HR = 0.775; p = 0.164], and total thyroidectomy and bilateral pCND [adjusted HR = 1.041; p = 0.821]). However, surgical morbidities, such as temporary vocal cord palsy (5.6% vs 2.5%; p = 0.001), temporary hypoparathyroidism (30.8% vs 16.7%; p < 0.001), and permanent hypoparathyroidism (3.5% vs 1.7%; p < 0.001) were significantly more frequent in the pCND(+) group.

CONCLUSIONS

Given the lack of proven benefits and the clear evidence of morbidities, pCND cannot be recommended as a routine procedure. We suggest that CND be reserved for therapeutic situations.

Chronic lymphocytic thyroiditis and BRAF V600E in papillary thyroid carcinoma

It has been reported that papillary thyroid carcinoma (PTC) with chronic lymphocytic thyroiditis (CLT) is less associated with extrathyroidal extension (ETE), advanced tumor stage and lymph node (LN) metastasis. Other studies have suggested that concurrent CLT could antagonize PTC progression, even in BRAF-positive patients. Since the clinical significance of the BRAF mutation has been particularly associated with conventional PTC, the purpose of this study was to determine the clinical significance of CLT according to BRAF mutation status in conventional PTC patients. We retrospectively reviewed the medical records of 3332 conventional PTC patients who underwent total thyroidectomy with bilateral central neck dissection at the Thyroid Cancer Center of Samsung Medical Center between January 2008 and June 2015. In this study, the prevalence of BRAF mutation was significantly less frequent in conventional PTC patients with CLT (76.9% vs 86.6%). CLT was an independent predictor for low prevalence of ETE in both BRAF-negative (OR=0.662, P=0.023) and BRAF-positive (OR=0.817, P=0.027) conventional PTC patients. In addition, CLT was an independent predictor for low prevalence of CLNM in both BRAF-negative (OR=0.675, P=0.044) and BRAF-positive (OR=0.817, P=0.030) conventional PTC patients. In conclusion, BRAF mutation was significantly less frequent in conventional PTC patients with CLT. However, CLT was an independent predictor for less aggressiveness in conventional PTC patients regardless of BRAF mutation status.

Influence of thyroid gland status on the thyroglobulin cutoff level in washout fluid from cervical lymph nodes of patients with recurrent/metastatic papillary thyroid cancer

BACKGROUND

The influence of serum thyroglobulin (Tg) and thyroidectomy status on Tg in fine-needle aspiration cytology (FNAC) washout fluid is unclear.

METHODS

A total of 282 lymph nodes were prospectively subjected to FNAC, fine-needle aspiration (FNA)-Tg measurement, and frozen and permanent biopsies. We evaluated the diagnostic performance of several predetermined FNA-Tg cutoff values for recurrence/metastasis in lymph nodes according to thyroidectomy status.

RESULTS

The diagnostic performance of FNA-Tg varied according to thyroidectomy status. The optimized cutoff value of FNA-Tg was 2.2 ng/mL. However, among FNAC-negative lymph nodes, the FNA-Tg cutoff value of 0.9 ng/mL showed better diagnostic performance in patients with a thyroid gland. An FNA-Tg/serum-Tg cutoff ratio of 1 showed the best diagnostic performance in patients without a thyroid gland.

CONCLUSION

Applying the optimal cutoff values of FNA-Tg according to thyroid gland status and serum Tg level facilitates the diagnostic evaluation of neck lymph node recurrences/metastases in patients with papillary thyroid carcinoma (PTC). © 2015 Wiley Periodicals, Inc. Head Neck 38: E1705-E1712, 2016.

BRAF V600E mutation: Differential impact on central lymph node metastasis by tumor size in papillary thyroid carcinoma

BACKGROUND

The necessity of prophylactic central neck dissection is one of debating issues in the treatment of papillary thyroid carcinoma (PTC). In a previous study, the predictive value of BRAF mutation for lymph node metastasis was only significant in 0.5 to 1.0 cm PTC. Thus, we assess the predictive value of BRAF mutation for central lymph node metastasis according to tumor size.

METHODS

Medical records of 3107 patients with PTC who underwent thyroidectomy with central neck dissection were retrospectively reviewed.

RESULTS

BRAF mutation was a predictor for central lymph node metastasis in 2.0 to 4.0 cm PTC (odds ratio [OR] = 3.494; p = .002). Although BRAF mutation was associated with central lymph node metastasis in 0.5 to 1.0 cm PTC in univariate analysis (OR = 1.334; p = .047), this significance was not observed in multivariate analysis (OR = 1.232; p = .163). BRAF mutation was not associated with central lymph node metastasis in other tumor sizes.

CONCLUSION

Prophylactic central neck dissection could be considered in 2.0 to 4.0 cm PTC with positive BRAF mutation. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1203-E1209, 2016.