Risk factors contributing to a poor prognosis of papillary thyroid carcinoma: validity of UICC/AJCC TNM classification and stage grouping

Predictors of treatment response in lymphogenic metastasized papillary thyroid cancer: a histopathological study

BACKGROUND

Lymph node metastases in papillary thyroid cancer (PTC) increase the risk for persistent and recurrent disease. Data on the predictive value of histopathological features of lymph node metastases, however, are inconsistent. The aim of this study was to evaluate the prognostic significance of known and new histopathological features of lymph node metastases in a well-defined cohort of PTC patients with clinically evident lymph node metastases.

METHODS

A total of 1042 lymph node metastases, derived from 129 PTC patients, were reexamined according to a predefined protocol and evaluated for diameter, extranodal extension, cystic changes, necrosis, calcifications, and the proportion of the lymph node taken up by tumor cells. Predictors for a failure to achieve a complete biochemical and structural response to treatment were determined.

RESULTS

The presence of more than 5 lymph node metastases was the only independent predictor for a failure to achieve a complete response to treatment (odds ratio [OR] 3.39 [95% CI, 1.57-7.33], P < .05). Diameter nor any of the other evaluated lymph node features were significantly associated with the response to treatment.

CONCLUSIONS

Detailed reexamination of lymph nodes revealed that only the presence of more than 5 lymph node metastases was an independent predictor of failure to achieve a complete response to treatment. No predictive value was found for other histopathological features, including the diameter of the lymph node metastases. These findings have the potential to improve risk stratification in patients with PTC and clinically evident lymph node metastases.

BRAF V600E mutation co-existing with oncogenic mutations is associated with aggressive clinicopathologic features and poor prognosis in papillary thyroid carcinoma

BACKGROUND

The aim of this study was to evaluate the correlation among mutations in cancer-related genes, clinicopathologic features, and clinical outcome in classical papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

A total of 130 patients with classical PTC who underwent curative surgery between April 2012 and June 2023 at Hokuto Hospital were included. Mutations in targeted regions of 160 cancer-related genes were detected by next-generation sequencing (NGS)-based cancer panel testing.

RESULTS

The BRAF V600E mutation was detected in 108 (83.1%) of 130 PTC patients. Among the 108 patients with the BRAF V600E mutation, other co-existing oncogenic mutations were found in 12 (9.2%) patients. When we divided into 3 groups of no mutations, BRAF V600E mutation alone, and BRAF V600E and other oncogenic mutations, significant differences were observed in terms of tracheal invasion (P = 0.0024), and bilateral neck lymph node metastasis (P = 0.0047). Kaplan-Meier analysis of overall survival (OS) revealed patients with BRAF V600E and other oncogenic mutations had significantly poorer survival than those with BRAF V600E mutation alone (P = 0.0026). Multivariate cox proportional hazard analysis revealed BRAF V600E and other oncogenic mutations was an independent prognostic factor for OS (HR: 10.559; 95%CI: 1.007-110.656, P = 0.0493).

CONCLUSIONS

The BRAF V600E mutation co-existing with other oncogenic mutations but not the BRAF V600E mutation alone was associated with aggressive clinicopathologic features, resulting in poor prognosis in patients with classical PTC. Detection of oncogenic mutations using NGS-based cancer panel testing could enhance understanding of the clinical features of classical PTC.

Central lymph nodes in frozen sections can effectively guide extended lymph node resection for papillary thyroid carcinoma

OBJECTIVES

The scope of lateral neck lymph node dissection (LND) in papillary thyroid carcinoma (PTC) remains controversial. Our research aimed to explore the value of central lymph node metastasis (CLNM) in frozen sections for predicting neck lateral lymph node metastasis (NLLNM) and to guide clinical surgeons in performing surgical lymph node dissection.

PATIENTS

A total of 275 patients with PTC with suspected 'Cervical lymph node metastasis (LNM, including CLNM and NLLNM)' underwent unilateral or bilateral thyroidectomy and an intraoperative frozen diagnosis of central lymph nodes (LNs), as well as central and neck lateral LND. Validity indices and consistency of central LNs in frozen sections were calculated. In total, 216 patients then met the inclusion criteria and were enrolled in the follow-up study. The clinical and pathological data of the patients were retrospectively analyzed. The relationship between the number, metastatic diameter, and the ratio of CLNM to NLLNM was investigated.

RESULTS

CLNM in frozen and paraffin-embedded sections was associated with NLLNM. Univariate and multivariate analyses revealed the following risk factors for NLLNM metastasis: maximum diameter, total number, and ratio of metastatic LNs. A significant result was obtained when a cut-off value of 2.050 mm for the maximum metastatic diameter, 5.5 in the total number, and 0.5342 for the CLNM ratio level was used. Interaction term analyses showed that the association between the number of CLNM and NLLNM differed according to maximum diameter.

CONCLUSION

Central LNs in frozen sections accurately predicted NLLNM. In patients with PTC with >5 CLNMs, ≥2 and ≤5 CLNMs and maximum metastatic diameter > 2 mm, neck lateral LND should be considered. Our findings will facilitate the identification of patients who are likely to benefit from extended lateral neck LND.

Role of PET/Computed Tomography in Elderly Thyroid Cancer: Tumor Biology and Clinical Management

PET/computed tomography (CT) studies can be potentially useful in elderly thyroid carcinoma patients for exploring the disease biology, especially in metastatic setting and thereby directing appropriate therapeutic management on case-to-case basis, adopting nuclear theranostics, and disease prognostication. With the availability of multiple PET radiopharmaceuticals, it would be worthwhile to evolve and optimally use FDG and the other non-fluorodeoxyglucose and investigational PET/CT tracers as per the clinical situation and need and thereby define their utilities in a given case scenario. In this regard, (I) differentiated thyroid carcinoma (DTC) including radioiodine refractory disease, poorly differentiated thyroid cancer (PDTC) and TENIS, (II) medullary thyroid carcinoma (MTC), (III) anaplastic carcinoma and (IV) Primary thyroid lymphoma (PTL) should be viewed and dealt separately.

Predictive Factors of Recurrence of Papillary Thyroid Microcarcinomas: Analysis of 2,538 Patients

Introduction  The incidence of papillary thyroid microcarcinoma (PTMC) has increased, and its treatment remains controversial.

Objective  To identify the clinical and pathological factors predictive of tumor recurrence.

Methods  We retrospectively analyzed 2,538 consecutive patients treated for PTMC, most submitted to total thyroidectomy (98%) followed by radioactive iodine (RAI) ablation (51.7%) at a cancer center from 1996 to 2015. The patients were stratified according to the American Thyroid Association (ATA) risk categories (low, intermediate, or high), and the clinicopathological features were evaluated by multivariate Cox regression analysis to identify independent prognostic factors for recurrence.

Results  After a mean follow-up of 58 months (range: 3 to 236.5 months), tumor recurrence was diagnosed in 63 (2.5%) patients, mostly in the lymph nodes. Distant metastasis occurred in 2 (0.1%) patients. There were no cancer-related deaths. The multivariate analysis showed that age < 55 years ( p  = 0.049; hazard ratio [HR]: 2.54; 95% confidence interval [95%CI]: 0.95 to 0.99), multifocality ( p  = 0.032; HR: 1.76; 95%CI: 1.05 to 2.96), and the presence of lymph-node metastasis ( p  < 0.001; HR: 3.69; 95%CI: 2.07–6.57) were independent risk factors for recurrence. Recurrence was observed in 29 (1.5%) out of 1,940 low-risk patients, 32 (5.4%) out of 590 intermediate-risk patients, and in 2 (25%) out of 8 high-risk patients.

Conclusions  The prognosis of PTMC is excellent, favoring a conservative treatment for most patients. Age < 55 years, multifocality, and node metastasis at diagnosis, as well the ATA staging system effectively predict the risk of recurrence. The presence of these risk factors can help identify patients who should be considered for more aggressive management and more frequent follow-up.

Prognostic evaluation model for papillary thyroid cancer: a retrospective study of 660 cases

Background

Prognostic evaluation model for papillary thyroid cancer is very important for guiding the personalized treatment and follow-up strategy. There are imperfections in the system existed, and there is no suitable prognostic model for Chinese population.

Methods

This study was based on the clinic and follow-up data of 660 patients received surgical treatments in the Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center from 2000 to 2005. Cox univariate/multivariate analysis was used to explore the influence factors of prognosis, and nomogram model was performed to establish a prognostic prediction system.

Results

Totally, 660 patients for initial treatment were included in our analysis with a median follow-up of 113.5 months. Five-, 10- and 15-year disease-free survival rate was 95.5%, 90.2% and 89.2%. Five-, 10- and 15-year overall survival rate was 99.7%, 99.2% and 99.1%. Residual tumor was associated with overall survival [hazard ratio (HR) 20.9, 95% confidence interval (CI): 2.3-187.6, P<0.05]. Age of onset (HR 2.00, 95% CI: 1.17-3.42, P<0.05) and the dimension of lymph nodes involved (0.2-3 cm: HR 3.67, 95% CI: 1.13-11.87, P<0.05; >3 cm: HR 5.20, 95% CI: 1.31-20.65, P<0.05) were independent influence factors of disease-free survival. The nomogram model for predicting prognosis of papillary thyroid cancer was established with a moderate predictive value (c-index 0.71, 95% CI: 0.57-0.84).

Conclusions

The prognosis of papillary thyroid cancer is very good after appropriate treatment. Age and the dimension of lymph nodes involved were independent influence factors of disease-free survival for papillary thyroid cancer. A prognostic prediction model for Chinese population was established with moderate predictive value. A study with larger samples and including more factors of prognosis is necessary to increase the predictive value of model.

Correlation between sonographic features and pathological findings of cervical lymph node metastasis of differentiated thyroid carcinoma

Background

The aim of this study is to evaluate the relationship between the sonographic features and pathological findings of cervical lymph node metastasis of differentiated thyroid carcinoma (DTC).

Methods

A total of 49 patients who had thyroid surgery and lateral or central cervical lymph node dissection from October to December 2019 in our hospital were selected. All the lymph nodes included in the dissection were examined by intraoperative ultrasound and were divided into 5 groups according to the sonographic characteristics (A: overall hyperechoic group; B: hypoechoic with punctate hyperechoic group; C: mass hyperechoic group; D: cystic degeneration group; E: hypoechoic group without punctate hyperecho). All samples were sent to the Pathology Department according to the area of origin and classified and numbered for comparative analysis of the microscopic pathology and the sonogram.

Results

A total of 120 suspicious metastatic lymph nodes were finally screened out by intraoperative ultrasound. The sonographic signs of these suspicious metastatic lymph nodes in the lateral and central regions of the neck were significantly different from the normal lymph nodes. Besides, the indicators including sensitivity, specificity, accuracy, positive predictive value and negative predictive value of intraoperative ultrasound for detecting lateral and central lymph nodes were 89.04% vs. 82.98%, 93.83% vs. 80.00%, 90.97% vs. 81.10%, 92.86% vs. 70.91%, and 90.48% vs. 88.89%, respectively. The pathological features of metastatic lymph nodes were shown as follows: group A, diffuse distribution of follicular structure; group C, focal distribution of follicular structure; group B and E, atypical follicular epithelial cells with or without papillary structure. Necrosis and liquefaction were observed in group D.

Conclusions

The relationship between sonographic features and follicular structure of metastatic lymph nodes are firmly related. A correct understanding of these features is practical to improve the diagnostic rate of conventional ultrasonography and reduce the incidences of misdiagnosis.

The Application of Ultrasound and Fine-Needle Aspiration in Low-Volume Lateral Lymph Nodes of Papillary Thyroid Carcinoma Patients

This research investigates the application of high-frequency ultrasound (US) examination and US-guided fine-needle aspiration (US-FNA) in diagnosing low-volume metastatic lateral lymph nodes (LLNs) from papillary thyroid carcinoma patients. This study reviewed the medical records of 996 LLNs from 858 patients with suspicious thyroid nodules or after thyroidectomy from January 2013 to January 2016. All patients took US-FNA. The US characteristics and the malignancy rate of LLNs classified into group A and group B based on size were analyzed and compared (group A, ≥6 mm; group B, <6 mm). Size was not an independent predictor for malignancy (P > 0.005) in multiple regression analysis, whereas the malignancy rate in the large LLNs (286/425; 67.3%) was slightly higher than that in the small LLNs (338/571; 59.2%) (P = 0.01). However, no significant difference was observed between the groups in terms of calcification, absence of hilum, and peripheral vascularization. The prevalence of malignant LLNs was slightly higher in the small LLNs than that in the large ones when there were less than 3 suspicious US features (P < 0.05), and there was no significant difference between the small and large LLNs when there were 3 or more suspicious US features (P > 0.05). The results indicate that metastases may occur in the lymph nodes even when they were small. Ultrasound and US-FNA showed excellent performance in the diagnosis of low-volume metastatic lateral lymph nodes from papillary thyroid carcinoma patients.

Rapid Growth and Early Metastasis of Papillary Thyroid Carcinoma in an Adolescent Girl with Graves' Disease

BACKGROUND

The risk factors for rapid growth and early metastasis of papillary thyroid carcinoma (PTC) and the role of coexisting Graves' disease in the clinical course of PTC remain uncertain in children.

CASE DESCRIPTION

We report on a Japanese girl, whose PTC rapidly grew and metastasized within 4 years. Graves' disease was diagnosed by the presence of serum TSH receptor antibodies at 8 years of age when thyroid ultrasonography detected no nodules. After 4 years of effective treatment with thiamazole, multifocal nodules - up to 47 mm in diameter - were detected on thyroid ultrasonography. Chest CT scan revealed multiple metastatic lesions in the lung. After total thyroidectomy, PTC was pathologically diagnosed. The patient underwent two courses of radioactive iodine (RAI) treatment, but the pulmonary metastatic lesions did not take up the RAI. Molecular analyses of the PTC tissue identified a TFG/NTRK1 chimeric gene and disclosed the preserved expression of TSHR and the reduced expression of SLC5A5 compared with non-tumor thyroid tissue.

CONCLUSIONS

Rapid growth and early metastasis of PTC with coexisting Graves' disease in this patient can be related to a combination of multiple factors including preserved TSHR expression, reduced SLC5A5 expression, and TFG/NTRK1 rearrangement.

Predictive value of LN metastasis detected by 18F-FDG PET/CT in patients with papillary thyroid cancer receiving iodine-131 radiotherapy

The aim of the present study was to predict the prognostic value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the metastatic lymph nodes (mLNs) of patients with papillary thyroid carcinoma (PTC) with a negative iodine-131 (¹³¹I) whole-body scan (WBS). The present retrospective study included 32 patients with PTC undergoing standard surgery and radioiodine treatment. All patients received ¹⁸F-FDG PET/CT imaging prior to and following therapy. All mLNs were divided into an effective treatment group (group A) and ineffective treatment group (group B) based on the PET Response Criteria in Solid Tumors 1.0 guidelines. All the patients were followed up for ≥9 months. A significant difference was identified in the peak standardized uptake value (SULpeak) between group B (7.85±3.20) and group A (5.36±2.19). A cut-off value of 5.85 was used to distinguish ineffective treatment of lesions from mLNs receiving radioactive ablation based on receiver operating characteristic (ROC) curve analysis with an area under the ROC curve of 0.755. Patients with a high SULpeak (P=0.003) and extrathyroidal extension (P=0.030), confirmed by pathology, more frequently exhibited a poor prognosis. In conclusion, tracer uptake of ¹⁸F-FDG for cervical metastatic nodes was revealed as a predictor for the clinical outcome of patients with PTC treated with radioiodine therapy. The present results also indicated that high SULpeak and extrathyroidal extension are poor predictors for patients with mLNs receiving ¹³¹I therapy.

BRAF V600E mutation and microRNAs are helpful in distinguishing papillary thyroid malignant lesions: Tissues and fine needle aspiration cytology cases

AIMS

Mutations of BRAF oncogene are considered to contribute in the invasiveness and poor clinicopathologic features of papillary thyroid cancer (PTC). As a step towards understanding the underlying molecular mechanisms of this contribution, we aimed to examine the association of four microRNAs' (miR-222, -137, -214, -181b) levels with BRAFV600E and clinicopathological features in PTC tissues and fine needle aspiration (FNA) specimens.

METHODS

In total, 56 PTC and 27 benign with multinodular goiter tissue samples, 95 FNA samples, and B-CPAP and HEK293 cell lines were examined. BRAFV600E mutation was examined in PTC tissues and FNA samples. Expression of microRNAs was assessed by real-time quantitative reverse transcription-PCR.

KEY FINDINGS

The frequency of BRAFV600E in PTC tissues and FNA samples "suspicious for PTC" was 41.1 and 36.8%, respectively. MiR-222, -137, -214, and -181b were significantly upregulated in PTC tumors (P < 0.05) and in B-CPAP cell line (P < 0.001). In FNA, the expressions of miR-222, -181b and -214 were significantly elevated in patients suspected for PTC (P < 0.05), while there was no significant difference in miR-137. After adjustment for age and sex, miR-181b was associated with an increased risk of bearing BRAFV600E mutation (OR: 1.27; 95% CI: 1.01-1.61; P = 0.045) and risk of lymphovascular invasion (OR: 1.66; 95% CI: 1.01-2.72; P = 0.045); miR-137 was associated with the risk of larger tumor size (OR: 1.31; 95% CI: 1.04-1.65; P = 0.022); miR-222 was related to increase in extracapsular invasion (OR: 1.28; 95% CI: 1.04-1.57; P = 0.018).

SIGNIFICANCE

Upregulation of miR-222, -214 and -181b has been confirmed in PTC tumors, FNA samples and cell line. MiR-137 upregulation has been confirmed in PTC tumors and cell line, but not in FNA samples. MiR-222, -137 and -181b showed an association with the degree of malignancy in PTC tumors.

Identifying risk factors for recurrence of papillary thyroid cancer in patients who underwent modified radical neck dissection

Background

Papillary thyroid cancer (PTC) patients with ipsilateral neck metastatic lymph node (LN) and those with contralateral neck metastatic LN belong to N1b. Only a few studies have reported on comparisons with regard to laterality of metastatic lateral LN. The aim of this study was to evaluate predictive factors for contralateral neck LN metastasis and to determine prognostic factors for recurrence in PTC patients with N1b.

Methods

This retrospective study reviewed the medical records of 390 PTC patients who underwent total thyroidectomy and central LN dissection plus ipsilateral or bilateral modified radical neck dissection (MRND) between January 2004 and December 2012.

Results

During a median follow-up of 81 (range, 6–156) months, 84 patients had a recurrence in any lesion. Male gender, a main tumor of more than 2 cm, number of metastatic central LN, number of harvested and metastatic lateral LN, total LN ratio, multifocality, bilaterality, and gross ETE had significance in the patients who underwent bilateral MRND. In multivariate analysis according to recurrence, patients with LN ratio > 0.44 in the central compartment (hazard ratio [HR], 1.890; 95% confidence interval [CI], 1.124–3.178; p = 0.015), LN ratio > 0.29 in the lateral compartment (HR, 2.351; 95% CI, 1.477–3.743; p < 0.001), and multifocality (HR, 1.583; 95% CI, 1.030–2.431; p = 0.036) were associated with worse RFS. However, the type of MRND was statistically significant only in univariate analysis.

Conclusions

Recurrence in N1b PTC patients is predicted by central neck LN ratio > 0.44, lateral neck LN ratio > 0.29, and multifocality of tumors. We suggest that patients with these factors should receive short-term follow-up using image modalities like ultrasonography and computed tomography.

Survival in Differentiated Thyroid Cancer: Comparing the AJCC Cancer Staging Seventh and Eighth Editions

BACKGROUND

The American Joint Committee on Cancer Cancer Staging System for differentiated thyroid cancer has been recently revised. The purpose of this study was to compare survival prognostication between the seventh and eighth editions.

MATERIALS AND METHODS

We retrospectively reviewed 2579 differentiated thyroid cancer patients who underwent surgery at MD Anderson Cancer Center between 2000 and 2015. Disease-specific survival (DSS) and overall survival were estimated using the Kaplan-Meier method and compared using log rank test. The effect of potential predictor was estimated using Cox proportional hazards model. Power of survival prediction was estimated using Harrell's C concordance index (C-index), and predictive capacities for DSS were estimated using proportion of variance explained (PVE).

RESULTS

Revision of tumor-node-metastasis (TNM) categories, age cutoff, and stage reassignment in the 8^th edition caused reclassification of overall stage compared with the seventh edition. The proportion of patients in stage I and II increased from 62% to 83% and 5% to 12%, respectively, while the proportion of patients in stage III and IV decreased from 20% to 2% and 14% to 3%, respectively. Ten-year DSS for stages I-IV based on the seventh edition were 100%, 97.5%, 98.3%, and 82.6%, respectively, while 10-year DSS for the corresponding stage in the eighth edition were 99.8%, 88.3%, 72.4%, and 71.9%, respectively. In multivariate analysis for both seventh edition (C-index 0.94, PVE 4.6%) and eighth edition (C-index 0.94, PVE 4.8%), the factors predictive of worse outcome for DSS were older age, advanced tumor size category, and distant metastasis while cervical lymph node metastases did not predict worse survival. For the eighth edition, patients <55 years of age with stage II disease had significantly worse DSS (p < 0.001) than patients ≥55 years with stage II disease but appeared to be similar to patients ≥55 years with stage III (p = 0.742) and IV disease (p = 0.566). Patients ≥55 years old with T3a and T3b disease had 10-year DSS of 67% and 92%, respectively (p = 0.390).

CONCLUSION

The AJCC eighth edition is similar to the seventh edition in disease-specific survival prediction. Potential modifications that may improve disease-specific survival prediction in future renditions include reconsideration of T3b tumor category and upstaging classification of patients <55 years of age with distant metastases.

Prognostic Role of Metastatic Lymph Node Ratio in Papillary Thyroid Carcinoma

Background

The aim of this study is to elucidate the clinicopathological significances, including the prognostic role, of metastatic lymph node ratio (mLNR) and tumor deposit diameter in papillary thyroid carcinoma (PTC) through a retrospective review and meta-analysis.

Methods

We categorized the cases into high (≥ 0.44) and low mLNR (< 0.44) and investigated the correlations with clinicopathological parameters in 64 PTCs with neck level VI lymph node (LN) metastasis. In addition, meta-analysis of seven eligible studies was used to investigate the correlation between mLNR and survival.

Results

Among 64 PTCs with neck level VI LN metastasis, high mLNR was found in 34 PTCs (53.1%). High mLNR was significantly correlated with macrometastasis (tumor deposit diameter ≥ 0.2 cm), extracapsular spread, and number of metastatic LNs. Based on linear regression test, mLNR was significantly increased by the largest LN size but not the largest metastatic LN (mLN) size. High mLNR was not correlated with nuclear factor κB or cyclin D1 immunohistochemical expression, Ki-67 labeling index, or other pathological parameters of primary tumor. Based on meta-analysis, high mLNR significantly correlated with worse disease-free survival at the 5-year and 10-year follow-up (hazard ratio [HR], 4.866; 95% confidence interval [CI], 3.527 to 6.714 and HR, 5.769; 95% CI, 2.951 to 11.275, respectively).

Conclusions

Our data showed that high mLNR significantly correlated with worse survival, macrometastasis, and extracapsular spread of mLNs. Further cumulative studies for more detailed criteria of mLNR are needed before application in daily practice.

Eliminating the Age Cutoff in Staging of Differentiated Thyroid Cancer: The Safest Road?

BACKGROUND

Unlike virtually all other cancer types, thyroid cancer is unique in that patient age is a key component in its staging. Pathologists and clinicians worldwide have accepted an age cutoff of 45 years for staging; in 2018, this advances to age 55 years in the eighth edition of the American Joint Commission on Cancer staging system.

EVIDENCE ACQUISITION

Clinical and basic research studies, reviews, and previous editions of consensus statements regarding thyroid cancer staging were reviewed, with particular focus on the influence of age in thyroid cancer prognosis.

PURPOSE

This perspective briefly reviews the basis for this practice and challenges it as no more appropriate than for other malignancies.

EVIDENCE SYNTHESIS

The majority of findings report an association of age with thyroid cancer survival but do not support a specific age cutoff; rather, they suggest that outcome is affected by age as a continuous variable. Conceivably, other factors interact with age on a continuous basis over time, affecting prognosis. When identified, these factors could alter our current concept of the importance of an age cutoff in staging.

CONCLUSIONS

Among all cancers, age has an important role in only thyroid cancer staging. The consideration of age as a continuous variable and the search for age-associated prognostic variables could elucidate a more accurate staging system.

Heterogeneous Prognoses for pT3 Papillary Thyroid Carcinomas and Impact of Delayed Risk Stratification

BACKGROUND

Papillary thyroid carcinomas (PTC) in the pT3 category constitute a heterogeneous group of tumors with a variable risk of recurrence. The objectives of this study were (i) to estimate disease-free survival (DFS) and identify prognostic factors associated with recurrence in a cohort of pT3 PTC, and (ii) to evaluate the concept of delayed risk stratification in a cohort of pT3 tumors.

METHODS

A total of 560 patients with pT3 PTC, treated and followed at the authors' institution, were studied. They were divided into three groups: group 1, pT3 ≤10 mm; group 2, pT3 >10 mm with extrathyroidal invasion (ETI); and group 3, pT3 due to a tumor size >4 cm. DFS was estimated using the Kaplan-Meier method, and associated prognostic features were studied in univariate and multivariate Cox model-based analyses in each group. Then, DFS was studied for each group according to the six- to eight-month status (remission or not).

RESULTS

DFS at 10 years was 75% for the entire cohort and was 89%, 67%, and 82% in groups 1, 2, and 3, respectively (p < 0.0001). Multivariate analysis identified three factors significantly associated with reduced DFS: lymph node (LN) involvement, male sex, and group 2 (>1 cm with ETI). A trend toward a worse prognosis in patients with pT3 N0/Nx PTC >10 mm with ETI was found in comparison with the other pT3 N0/Nx patients. When the six- to eight-month checkup was normal, the DFS at 10 years increased to 98%, 96%, and 91% in groups 1-3, respectively. Furthermore, in this case, initial LN involvement no longer seemed to affect the prognosis in those groups.

CONCLUSION

PTC ≤10 mm with ETI and large tumors >4 cm without ETI both have a low-recurrence risk when there are no adverse associated prognostic features such as LN involvement. LN involvement, especially in the lateral compartment (N1b), is a strong prognostic factor of recurrence in pT3 PTC. Delayed risk stratification can be applied in pT3 PTC patients. Those cured at the first checkup, including those with limited LN involvement, have excellent outcomes, which should prompt clinicians to adapt subsequent management accordingly.

Identification of risk factors of central lymph node metastasis and evaluation of the effect of prophylactic central neck dissection on migration of staging and risk stratification in patients with clinically node-negative papillary thyroid microcarcinoma

OBJECTIVE

The first aim of this study was to explore the risk factors that were associated with central lymph node metastasis (CLNM) in patients with clinically node-negative papillary thyroid microcarcinoma (cN₀ PTMC) after prophylactic central neck dissection (PCND). The second aim was to evaluate the influence of PCND on migration of TNM staging and risk stratification (RS) in patients with cN₀ PTMC.

METHODS

A total of 295 cN₀ PTMC patients who underwent thyroidectomy with PCND in the Department of General Surgery at Guangdong General Hospital between March 2014 to December 2015 were assessed retrospectively. The relations of CLNM with clinicopathologic characteristics of cN₀ PTMC were analyzed by univariate and multivariate logistic regression. The effect of PCND on migration of TNM staging and RS was also observed.

RESULTS

The incidence of CLNM was 42.4% (125 of 295 cases) in patients with cN₀ PTMC. Univariate analysis showed that age (P=0.000), ultrasonographic tumor size (P=0.009), pathologic tumor size (P=0.005), and multifocality (P=0.031) were significantly associated with the incidence of CLNM. No significant correlations were found between the presence of CLNM and other variables such as gender (P=0.399), bilaterality (P=0.118), capsular invasion (P=0.111), lymphovascular invasion (P=0.184), extent of thyroidectomy (P=0.319) and lymphadenectomy (P=0.458). Multivariate logistic regression analysis revealed that age <45 years (P=0.000) and multifocality (P=0.033) were independent predictors of CLNM in patients with cN₀ PTMC. Because of the identification of CLNM in the implementation of PCND, 42 (14.2%) patients were upstaged, and 118 (40.0%) patients upgraded in RS.

CONCLUSIONS

CLNM is highly prevalent in cN₀ PTMC. Age <45 years and multifocality are independent risk factors of CLNM in cN₀ PTMC patients. PCND can identify CLNM, which allows more accurate TNM staging/RS and may have an important impact on postoperative treatment in cN₀ PTMC patients.

Locally invasive thyroid cancer: options for a treatment

Local invasion to neighbor organs by thyroid cancer is an important prognosticator and requires different therapeutic approach. Which one is the possible best treatment option and results are evaluated in this study. A single-institution experience in thyroid cancer invading the airway is evaluated retrospectively (1990-2016). Facts regarding patients' demographics, disease history, comorbidities, condition at first evaluation and reason for referral are analyzed. Hospital records and treatment details are extracted from charts and Institutional folders. Therapeutic indication and treatment option details are assessed. A total of 2203 thyroid cancer patients undergoing evaluation and treatment are found in the Institutional records. According to the current staging system, T4a cancers are 309. Airway has been compromised in 144 cases. All patients have been referred after receiving indicative workup imaging or airway-related symptoms. Well-differentiated histology is reported in 97; non-differentiated pattern is described in the remaining ones. Airway endoscopy is performed in all patients prior to every treatment planned. In 37 cases, the airway is found to get benefit from resection with curative intent; stenting has been indicated in 41 cases while tracheostomy has been performed in 44 cases as permanent treatment option. Rigid bronchoscopy is apparently a mandatory preliminary step for patients undergoing resection and reconstruction of a segmental airway tract. Tracheostomy is performed when the disease could not be submitted to exeresis or when the tumor biology shows a tumultuous disease. Forty patients had a stable symptoms relief after stenting. The rate of patients presenting with respiratory symptoms due to thyroid cancer infiltrating the airway is decreasing thank to screening programs and the greater attention to early detection. When possible, the segmental resection and reconstruction of the compromised airway produces good outcome and represents a surgical subspecialty requiring a multidisciplinary approach with specific technical competences. Stenting and tracheotomy are end-stage treatment with possible stable outcome for highly variable time span.

Anaplastic Thyroid Cancer in Sicily: The Role of Environmental Characteristics

BACKGROUND

Anaplastic thyroid cancer (ATC) is a rare but extremely aggressive cancer of the thyroid, contributing up to 30-40% of thyroid cancer-specific mortality. We analyzed ATC characteristics and survival rates in Sicily to evaluate the possible influence of environmental factors. With this aim, data regarding ATC incidences in urban/rural and industrial, iodine-deficient, and volcanic vs control areas were compared in Sicily as well as ATC data from Sicily and USA.

METHODS

Using the Sicilian Register of Thyroid Cancer (SRTC) database incidence, age, gender, tumor size and histotype, extrathyroidal extension, stage, and coexistence with pre-existing differentiated thyroid cancer (DTC) were evaluated in different areas of Sicily and also compared with Surveillance Epidemiology and End Results data in USA.

RESULTS

Forty-three ATCs were identified in Sicily in the period 2002-2009. In our series only age <70 years at diagnosis (p = 0.01), coexistence with DTC (p = 0.027) and tumor size ≤6 cm (p = 0.012) were significant factors for increased survival at univariate analysis (only age at multivariate analysis). No difference in ATC incidence was found in urban vs rural areas and in iodine-deficient and industrial vs control areas. By contrast, in the volcanic area of Sicily, where DTC incidence is doubled relative to the rest of the island, also ATC incidence was increased. ATC data in Sicily were similar to those reported in the same period in the USA where overall survival rate at 6 and 12 months, however, was smaller.

CONCLUSION

The similar ATC data observed in Sicily and USA (having different genetic background and lifestyle) and the increased ATC incidence in the volcanic area of Sicily paralleling the increased incidence of papillary thyroid cancer are compatible with the possibility that casual additional mutations, more frequent in a background of increased cell replication like DCT, are the major causes of ATC rather than genetic background and/or direct environmental influences.

Risk factors analyses for lateral lymph node metastases in papillary thyroid carcinomas: a retrospective study of 356 patients

Objective

The aim of this study was to investigate the incidence and risk factors for lateral lymph node metastasis (LLNM) in patients with papillary thyroid carcinoma (PTC).

Subjects and methods

356 patients diagnosed with PTC who underwent total thyroidectomy and central lymph node dissection and lateral lymph node dissection between January 2005 and December 2011 were enrolled. The relation between LLNM and clinicopathological features such as gender, age, tumor size, tumor spread, psammoma bodies, tumor multifocality, extrathyroidal extension (ETE), unilateral or bilateral disease, tumor primary location and central lymph node metastases (CLNM) was analyzed.

Results

The rate of LLNM was 75.0%. In the univariate analysis, it was significantly associated with age, tumor size, tumor spread, extrathyroidal extension, primary tumor location and central lymph node metastasis (p < 0.05). In contrast, in the multivariate analysis, it was significantly associated with primary tumor location, central lymph node metastasis (p < 0.05) and tumor size > 1.5 cm with p = 0.05 but was unrelated to the other factors.

Conclusion

Patients with PTC, with the primary tumor located in the upper part of the lobe and positive central compartment lymph node metastasis with a tumor size > 1.5 cm diameter are more likely to have LLNM. Therefore, more meticulous evaluations including the lateral lymph nodes should be performed before surgery.

Predictors for papillary thyroid cancer persistence and recurrence: a retrospective analysis with a 10-year follow-up cohort study

OBJECTIVE

We aimed to determine outcome predictors of papillary thyroid cancer (PTC) persistence and recurrence, separately.

CONTEXT

The factors contributing to either persistence or recurrence of PTC are poorly defined, as both outcomes are usually evaluated together.

DESIGN AND PATIENTS

In this 10-year follow-up cohort study, 190 PTC patients were evaluated (18-85 years old; registered from 1 January 1990 to31 December 1999 at a Brazilian Cancer Care referral Hospital). After initial surgery, we examined persistence (disease detected up to 1 year), recurrence (disease detected after 1 year) and PTC-free status (disease absence during follow-up).

MEASUREMENTS

Outcome predictors were modelled using multinomial logit regression analysis.

RESULTS

The univariate analysis showed that persistence and recurrence were significantly associated with lymph node metastasis (OR = 12·33; OR = 2·84, respectively), local aggressiveness (OR = 5·22; OR = 3·35) and extrathyroidal extension (OR = 5·07; OR = 7·11). Persistence was associated with male sex (OR = 3·49), age above 45 years old at diagnosis (OR = 1·03), macroscopic lymph node metastasis (OR = 5·85), local aggressiveness (OR = 5·22), each 1-cm tumour size increase (OR = 1·34), a cancer care referral hospital as the place of initial surgery (OR = 2·3), thyroidectomy or near total thyroidectomy(OR = 3·03) and neck dissection (OR = 3·19). Recurrence was associated with the time of radioactive iodine ((131) I) therapy (OR = 3·71). After data modelling, persistence was associated with macroscopic lymph node metastasis (OR = 6·17), 1-cm increases in tumour size (OR = 1·30) and thyroidectomy or near total thyroidectomy (OR = 3·82), while recurrence was associated with surgery at referral hospital (OR = 3·79).

CONCLUSIONS

The best predictors of persistence were tumour size and macroscopic lymph node metastasis; when the initial surgery is of quality, the recurrence depends more on tumour's biology aspects.

Metastatic Lymph Node Ratio of Central Neck Compartment Has Predictive Values for Locoregional Recurrence in Papillary Thyroid Microcarcinoma

OBJECTIVES

This study aimed to evaluate the significance of metastatic lymph node ratio (the ratio between the metastatic lymph node and the harvested lymph nodes; MLNR) in the central neck for the prediction of locoregional recurrence in patients with papillary thyroid microcarcinoma.

METHODS

After reviewing medical records of papillary thyroid microcarcinoma patients who received total thyroidectomy with central neck node dissection, 573 consecutive adult patients were enrolled in this study, with a follow-up period of more than 36 months. Regarding the risk of recurrence, multivariate analyses were performed with the following variables; sex, age, multiplicity of the primary tumor, presence of pathological extrathyroidal extension, the level of postoperative stimulated serum thyroglobulin, the number of harvested lymph nodes, the number of lymph node metastasis and MLNR.

RESULTS

The MLNR showed a predictive significance for the locoregional recurrence (P<0.05). Most recurrences were occurred in the lateral neck (n=12, 80%) with a median interval of 20 months. The lowest cutoff value of the MLNR for a meaningful separation of disease recurrence was 0.44 (hazard ratio, 8.86; 95% confidence interval, 1.49 to 52.58; P=0.001).

CONCLUSION

When the MLNR is higher than 0.44, there is an increased risk of locoregional recurrence mostly in the lateral neck. Therefore, MLNR of the central neck in a permanent or frozen biopsy may be helpful in decision making in the extent of thyroidectomy and/or the need for contralateral central neck lymph nodes dissection.

Bilaterality weighs more than unilateral multifocality in predicting prognosis in papillary thyroid cancer

Papillary thyroid cancer (PTC) often presents as multifocal tumor;, however, whether multifocality is associated with poor prognosis remains controversial. The aims of this retrospective study were to identify the characteristics of PTC with multifocal tumors and evaluate the association between the location and prognosis. We reviewed the medical records of 496 patients who underwent total thyroidectomy for PTC. Patients were classified as three groups: N1 (solitary tumor), N2 (2 or more foci within unilateral lobe of thyroid), and N3 (bilateral tumors, at least one tumor focus for each lobe of thyroid). We analyzed the differences of clinicopathologic features and clinical outcomes among the three groups. Cox regression model was used to assess the relation between the different locations of multifocal tumors and prognosis. Although the differences of clinicopathologic features such as the size of tumor, extrathyroidal extension, and cervical lymph node metastasis were not significant among the three groups, the bilateral-multifocality was proved to be an independent risk factor for neck recurrence (hazard ratio (HR) = 4.052, 95 % confidence interval (CI) 2.070-7.933), distant metastasis (HR = 3.860, 95 % CI 1.507-9.884), and cancer death (HR = 7.252, 95 % 2.189-24.025). In addition, extrathyroidal extension (HR = 2.291, 95 % CI 1.185-4.427) and older age >45 years (HR = 6.721, 95 % CI 2.300-19.637) were also significant predictors for neck recurrence and cancer death, respectively. Therefore, bilateral-multifocality as an indicator for more extensive tumor location could be used to assess the risk of recurrence and mortality in PTC. Given the poor prognosis associated with bilateral-multifocality and other risk factors, aggressive therapy and intensive follow-up were recommended for PTC patients with them.

Downregulation of long noncoding RNA NONHSAT037832 in papillary thyroid carcinoma and its clinical significance

Long noncoding RNA (lncRNA) is a kind of RNA that is longer than 200 nucleotides with limited or no protein-coding potential. Studies have proved that lncRNAs play important regulatory roles in gene expression and contribute to oncogenesis and cancer metastasis. However, the expression level of lncRNAs and their clinicopathologic significance in papillary thyroid carcinoma (PTC) have not been well studied. In this study, we investigated the expression level of a novel lncRNA NONHSAT037832 in PTC and paired noncancerous thyroid tissues as well as some cell lines by quantitative real-time polymerase chain reaction. The association between the expression level of NONHSAT037832 and clinicopathologic characteristics of patients with PTC was further analyzed. Three receiver operating characteristic curves (ROCs) were established to evaluate the diagnostic value of NONHSAT037832. The results suggested that the expression level of NONHSAT037832 was significantly decreased in PTC compared with paired noncancerous tissues (P < 0.01). And, NONHSAT037832 was also significantly downregulated in two PTC cell lines (K1 and IHH-4) compared to normal thyroid follicular epithelial cell line Nthy-ori 3-1 (P < 0.01). Downregulated NONHSAT037832 was significantly associated with lymph node metastasis (P = 0.015) and tumor size (P = 0.032). The ROCs revealed that NONHSAT037832 had a high diagnostic value for differentiating between PTC and noncancerous diseases as well as identifying PTC with lymph node metastasis and larger tumors (≥3 cm). The area under curve was up to 0.897 (95%CI = 0.852-0.942, P = 0.000), 0.641 (95%CI = 0.519-0.762, P = 0.033), and 0.702 (95%CI = 0.567-0.827, P = 0.008), respectively. This study indicated that NONHSAT037832 might serve as a potential biomarker of PTC.

A Meta-analysis of Central Lymph Node Metastasis for Predicting Lateral Involvement in Papillary Thyroid Carcinoma

OBJECTIVE

Whether central lymph node metastasis is a reliable indicator of lateral lymph node metastasis in papillary thyroid carcinoma remains obscure. To investigate the value of central lymph node metastasis for predicting lateral compartment involvement, we performed a meta-analysis of published studies.

DATA SOURCES

A systematic literature search of PubMed, EMBASE, and Chinese National Knowledge Infrastructure databases was completed, and the reference lists of the identified articles and prior relevant reviews were examined.

REVIEW METHODS

Two reviewers extracted data and assessed the quality of eligible studies independently. Odds ratios and 95% confidence intervals were pooled through a random effects meta-analysis model.

RESULTS

Twenty-one studies were eligible and further analyzed in this meta-analysis. The risk of lateral lymph node metastasis was significantly higher in the central lymph node-positive group than in the negative group (odds ratio = 7.64, 95% confidence interval: 5.59-10.44), with moderate heterogeneity across studies (P = .007, I(2) = 48.6%). Subgroup analyses and sensitivity analysis suggested that the results were consistent and credible. However, Begg's funnel plot and Egger linear regression test revealed a likelihood of publication bias (P = .000).

CONCLUSION

This meta-analysis suggests that central lymph node metastasis is valuable for predicting lateral compartment involvement in patients with papillary thyroid carcinoma. For those patients with central lymph node metastasis, additional attention should be paid to the lateral neck, as the risk of lateral lymph node metastasis was significantly higher in the central lymph node-positive group than in the negative group. Further studies regarding appropriate management for patients with high risk of lateral involvement are needed.

The total number of prelaryngeal and pretracheal lymph node metastases: is it a reliable predictor of contralateral central lymph node metastasis in papillary thyroid carcinoma?

BACKGROUND

Central lymph node (CLN) metastasis in papillary thyroid carcinoma (PTC) is common and being able to predict CLN metastasis helps surgeons determine individualized therapy. However, the relationship between contralateral CLN metastasis and the total number of positive lymph nodes (LNs) in the combined prelaryngeal and pretracheal region remains unclear. This study aimed to investigate whether the total number of positive LNs in the combined prelaryngeal and pretracheal region has clinical significance as a predictor for contralateral CLN metastasis.

METHODS

We prospectively enrolled 153 consecutive patients with unifocal PTC >1.0 cm without ultrasonographic evidence of nodal metastasis who underwent total thyroidectomy and prophylactic bilateral CLN dissection from July 2011-May 2013. Patients were divided into three groups according to the total number of positive LNs in the combined prelaryngeal and pretracheal region.

RESULTS

Rates of metastasis to ipsilateral and contralateral central compartments in PTC >1.0 cm were 84.3% and 24.2%, respectively. Multivariate analysis showed that ≥3 positive LNs in the combined prelaryngeal and pretracheal region were an independent predictive factor of contralateral CLN metastasis (P < 0.001; odds ratio, 8.585). After a mean follow-up of 24.1 mo, none of these patients had a recurrence in the central or lateral compartment.

CONCLUSIONS

Occult metastasis is highly prevalent in the ipsilateral central neck of patients with PTC >1.0 cm, and the total number of prelaryngeal and pretracheal LNs metastases may be a useful indicator to predict contralateral CLN metastasis in patients with unifocal PTC.

Variants of papillary thyroid carcinoma: association with histopathological prognostic factors

Papillary carcinoma is the most common thyroid malignancy. Many variants of this tumor have been described, with different morphological and molecular characteristics. Although most cases have excellent prognosis, the relationship between tumor architecture and its biological behavior remains controversial.

Objective

To present the experience of a single center on the prevalence of thyroid papillary carcinoma variants and their relationship with other histopathological prognostic factors.

Method

Retrospective study of all the cases submitted to thyroidectomy for papillary carcinoma in the same institution over 11 years.

Results

We included 517 patients, 81.9% of them were women. The average age was 47.2 years. The variants recognized to have higher aggressiveness potential corresponded to 5.6% of the sample. We found an association of tumor subtypes with greater lesion diameter, T staging, lymphovascular and gland capsule invasion.

Conclusion

A small percentage of papillary carcinoma cases is represented by variants recognized by their greater potential for aggression. There are associations between these variants and several other histopathological factors already recognized for their prognostic value, which may, by themselves, influence the outcome of these cases.

Level 7 disease does not confer worse outcome than level 6 disease in differentiated thyroid cancer

BACKGROUND

Level 7 nodal disease increases patients from N1a to N1b in the American Joint Committee on Cancer (AJCC) TNM classification of differentiated thyroid cancers (DTCs). This results in upstaging of patients older than 45 years of age from stage III to IV. Our objective was to determine if patients with level 7 disease had poorer outcome in comparison to patients with isolated level 6 disease.

METHODS

A total of 599 patients with DTC limited to the central neck (level 6 and 7) were identified from an institutional database. Patients with N1b disease due to lateral compartment (level 1-5) involvement or M1 disease were excluded. Fifty-seven patients had positive level 7 disease, and 542 patients had nodal disease limited to level 6. Disease-specific survival (DSS) and recurrence-free survival (RFS) were calculated for each group.

RESULTS

Median age was 41 years (range 12-91) and follow-up was 61 months (range 1-330). There were no disease-specific deaths at 5 years. Among patients with level 6 disease at presentation, there were 42 nodal recurrences, and among patients with level 7 disease, there were two recurrences. There were no differences in overall RFS between patients with level 6 or 7 disease (5-year RFS 90.7 vs. 98.2 %, respectively; p = 0.096).

CONCLUSIONS

Our results suggest that N1b disease due to level 7 disease does not confer worse DSS or RFS compared with patients with level 6 disease only. Classifying all central neck disease (levels 6 and 7) into the N1a category, and reserving the N1b classification only for patients with lateral neck disease may be more reflective of prognosis.

Pathologic reporting of lymph node metastases in differentiated thyroid cancer: a call to action for the College of American Pathologists

Lymph nodes in differentiated thyroid cancer have many different histomorphologic features. The current AJCC staging system does not distinguish between different lymph node characteristics and is based entirely on the presence of metastatic disease to upstage pN0 to pN1. However, clinicians involved in the management of thyroid cancer recognize that there is a difference in the clinical significance of finding macroscopic versus microscopic nodes. There appears to be a difference in disease biology that allows lymph nodes to reach different sizes and to manifest disease extension outside the capsule, which has led clinicians, and even clinical practice guidelines, to stratify nodal metastases on the basis of these features. The inherent presumption is that all lymph node metastases in differentiated thyroid cancer do not have the same clinical significance with respect to the risk of recurrence and the risk of death. However, the College of American Pathology (CAP) has not mandated that pathologists include these findings as part of their standard reporting protocol in thyroid cancer. In order to arm clinicians with the tools to design clinical trials and to make important patient management decisions in the presence of lymph node metastases, it is imperative that the CAP adopt a strategy for more detailed reporting that is similar to the protocol currently utilized in breast cancer pathologic reporting.

Validation of the QTNM staging system for cancer-specific survival in patients with differentiated thyroid cancer

An Australian state database was used to test the validity of the Quantitative tumor/node/metastasis (QTNM) staging system for assessing prognosis of differentiated thyroid cancer (DTC) on the basis of four variables quantified at diagnosis (histopathology, age, node involvement, and tumor size). Using the Queensland Cancer Registry (QCR), we identified 788 cases of DTC diagnosed from 1982 to 2006 with complete staging information. Causes of death were ascertained by linking the QCR database with the Australian National Death Index. Subjects were staged according to AJCC TNM 7th edition and QTNM, and cancer-specific survival (CSS) was calculated by the Kaplan-Meier method. Cancer-specific mortality was observed in 22 (2.8 %) patients, with 10-year CSS for the cohort of 97.0 % at a median follow-up of 262.8 months. QTNM stage specific cancer survival at 10 years was 99.6, 97.0, and 78.6 % for low-, intermediate-, and high-risk groups, respectively. This was comparable to the original US dataset in which the QTNM was initially studied, and it fared better at discriminating survival than the standard TNM system, where there was overlap in survival between stages. The current study validates the QTNM system in an Australian cohort and shows at least equivalent discriminatory capacity to the current TNM staging system. The QTNM utilized prognostic variables of significance to produce an optimal three-stage stratification scheme. Given, its advantage in clearly discriminating between prognostic groups, clinical relevance and simplicity of use, we recommend that TNM be replaced with QTNM for risk stratification for both recurrence and CSS.

No significant difference in the prognostic value of the 5th and 7th editions of AJCC staging for differentiated thyroid cancer

OBJECTIVE

The seventh edition of the American Joint Committee on Cancer (AJCC) has more detailed staging categories for differentiated thyroid cancer (DTC) than the fifth edition. The aim was to compare potential alterations in the disease-specific (DSS), event-free (EFS) and overall survival (OS), after reclassification from the fifth to the seventh edition.

METHODS

Data of 2460 patients with DTC referred to our centre were reclassified from the fifth to the seventh edition of AJCC. DSS, EFS and OS were calculated using the Kaplan-Meier method and compared by the log-rank test. The relative abilities of each edition to predict survival were calculated by the proportion of variance explained (PVE).

RESULTS

After reclassification to the seventh edition, there was an increase in stage I and IV patients from 58·1% to 65·0% and from 6·2% to 10·1%, respectively, and a corresponding decrease in stage II and III patients from 22·4% to 12·5% and 13·3% to 12·4%, respectively. As to DSS, the seventh edition had only a marginally higher PVE value than the fifth edition. With respect to EFS, the predictability of the seventh edition was even inferior to that of the fifth edition. Similarly, with regard to OS, the PVE value was slightly better for the older edition. Furthermore, a comparison only for those patients affected by the reclassification revealed no differences for DSS, EFS or OS between classifications.

CONCLUSION

When comparing the stages of the seventh with the fifth edition of the AJCC for DTC, there was no significant difference in predicting DSS, EFS and OS.

Risk factors for recurrence after therapeutic lateral neck dissection for primary papillary thyroid cancer

BACKGROUND

Lateral lymph node metastasis is an important prognostic factor and is predictive of tumor recurrence and cause-specific survival in patients with papillary thyroid cancer (PTC). However, the factors predicting recurrence and clinical outcomes after therapeutic lateral neck dissection are not well established. The aims of this study were to evaluate the incidence, pattern, and factors predictive of PTC recurrence after therapeutic lateral neck dissection.

MATERIALS AND METHODS

The records of 126 consecutive patients who underwent total thyroidectomy with therapeutic lateral neck dissection for primary PTC at the National Cancer Center were retrospectively reviewed. The factors predictive of recurrence were determined using both univariate and multivariate analyses considering several clinicopathologic variables.

RESULTS

The median follow-up period was 61.2 months, during which 22 patients (17.5 %) experienced recurrence with 1 death (0.8 %) due to disease. Locoregional recurrence and distant metastasis were found in 20 cases (15.9 %) and 2 cases (1.6 %), respectively. Male gender, aggressive histology, number of lymph node metastases, initial level of T4-off Tg per ng/mL, and ATA risk categories (high risk) were independent risk factors for recurrence. Of note, initial T4-off Tg levels greater than 4.2 ng/mL showed highest sensitivity and specificity in predicting recurrence.

CONCLUSIONS

These results provide useful information regarding the clinical outcomes after therapeutic lateral neck dissection for primary PTC and can be used to identify at-risk patients who need aggressive treatment and intensive surveillance for postoperative recurrence.

Prognostic values of clinical lymph node metastasis and macroscopic extrathyroid extension in papillary thyroid carcinoma

In papillary thyroid carcinoma (PTC), macroscopic extrathyroid extension (Ex) and clinical node metastasis (N) are prominent prognostic factors. Ex is divided into two grades in the UICC TNM classification: minimal and massive Ex. Massive Ex significantly affects patients' prognoses, whereas minimal Ex has little prognostic value. N is also divided into two grades in the TNM classification: N1a and N1b, depending on the location of metastasis, with N1b graded higher than N1a. However, massive Ex and/or N-positive PTC includes patients with a wide range of biological characteristics and prognoses, depending on their degrees of Ex and N. Other clinicopathological features such as age, gender, and tumor size also influence the prognosis. In evaluations of the biological characteristics of PTC patients with Ex and/or N, we should consider the degrees and relationships of Ex and N with other clinicopathological features.

Is minimal residual lymph node disease in papillary thyroid cancer of prognostic impact? An analysis of the epithelial cell adhesion molecule EpCAM in lymph nodes of 40 pN0 patients

This study was aimed to assess the extend of nodal microdissemination in patients with pN0 papillary thyroid carcinoma (PTC) using immunohistochemical analysis. In early stage PTC both, systematic lymphadenectomy as well as radio iodine treatment, aimed to eliminate occult nodal tumor involvement, are under controversial debate, since little is known about the extend of lymphatic microdissemination in these patients. Formalin embedded samples of the resected lymph nodes were systematically screened for the presence of disseminated tumor cells using immunohistochemistry (monoclonal antibody Ber-EP4). Clinical and histopathological parameters as well as the post-operative course were recorded. Survival data were analysed by the Kaplan-Meier method and the log rank test. Overall 321 lymph nodes of 40 patients were screened immunohistochemically. In 12.5% of the patients disseminated occult tumor cells were diagnosed. In addition to tumor resection 90% of the patients underwent adjuvant radio-iodine treatment. The mean observation period in our collective was 72 months. The detection of disseminated tumor cells did not correlate with clinicopathologic risk parameters and did not have significant influence on the prognosis of these patients. Immunohistochemical analysis enables the detection of disseminated tumor cells in patients with pN0 PTC. This finding seems to support the application of adjuvant radio iodine, even in early tumor stages.

Poorly differentiated thyroid carcinoma presenting with gross extrathyroidal extension: 1986-2009 Memorial Sloan-Kettering Cancer Center experience

PURPOSE

To describe the outcome of patients with poorly differentiated thyroid cancer (PDTC) presenting with gross extrathyroidal extension (ETE).

MATERIALS AND METHODS

After obtaining Institutional Review Board approval, we performed a retrospective review of a consecutive series of thyroid cancer patients treated by primary surgical resection with or without adjuvant therapy at Memorial Sloan-Kettering Cancer Center from 1986 to 2009. Out of 91 PDTC patients, 27 (30%) had gross ETE (T4a), and they formed the basis of our study. Of 27 patients, 52% were women. The median age was 70 years (range 27-87 years). Ten patients (37%) presented with distant metastases; four to bone, three to lung, and three to both bone and lung. All patients had extended total thyroidectomy, except two who had subtotal thyroidectomy. Twenty patients (74%) had central compartment neck dissection and 11 also had lateral neck dissection. Four patients had pN0, six (30%) pN1a, and 10 (50%) pN1b neck disease. Twenty-one patients (77%) had adjuvant therapy: 15 (55%) radioactive iodine (RAI) only, three (11%) postoperative external beam radiation (EBRT) only, and three (11%) had both RAI and EBRT. Overall survival (OS), disease-specific survival (DSS), local recurrence-free survival (LRFS), and regional recurrence-free survival (RRFS) were calculated by the Kaplan Meier method.

RESULTS

The median follow-up time was 57 months (range 1-197 months). The 5 year OS and DSS were 47% and 49%, respectively. This poor outcome was due to distant metastatic disease; 10 patients had distant metastases at presentation and a further six developed distant metastases during follow-up. Locoregional control was good with 5-year LRFS and RRFS of 70% and 62%, respectively. Overall, eight patients (30%) had recurrences: two had distant alone, two regional, two regional and distant, one local and distant, and one had local, regional, and distant recurrence.

CONCLUSION

Aggressive surgery in patients with PDTC showing gross ETE resulted in satisfactory locoregional control. Due to the small proportion of patients who received EBRT (22%), it is not possible to analyze its benefit on locoregional control. Of significance is the observation that the majority of patients (60%) who presented with or subsequently developed distant metastases eventually died of distant disease. New systemic therapies to target distant metastatic disease are required for improvements in outcome.

Clinical characteristics of papillary thyroid microcarcinoma less than or equal to 5 mm on ultrasonography

Management of papillary thyroid microcarcinoma sized ≤5 mm identified on ultrasonography is controversial. In this study, we evaluated the clinical characteristics of papillary thyroid microcarcinoma sized ≤5 mm on ultrasonography in comparison to those >5 mm and sought to present rationales for optimal management in papillary thyroid microcarcinoma ≤5 mm. The medical records of 396 patients who underwent surgery for papillary thyroid carcinoma between 2009 and 2011 were retrospectively analyzed. The patients were grouped into A (≤5 mm, n = 132) or B (>5 mm, n = 264) and the clinicopathologic characteristics of the patients were reviewed and compared between the two groups. Tumor capsular invasion (45.5 vs. 59.8 %, p = 0.007) and cervical lymph node metastasis (18.2 vs. 29.2 %, p = 0.018) were more frequent in group B. Nonetheless, group A presented lymph node metastasis in 42.3 % of multifocal cases showing no difference to that of group B (41.5 %, p = 0.946) and also included five cases (3.8 %) of lateral neck metastasis. Multifocality was the only predictive factor for lymph node metastasis in group A (p < 0.001). Over half (55.3 %) of the patients of group A were diagnosed with papillary carcinoma in private clinics; however, only 5.5 % of these patients underwent assessment of lateral neck lymph nodes initially. In conclusion, higher risk of cervical lymph node metastasis should be considered in evaluation and surgical decision of papillary thyroid microcarcinoma ≤5 mm identified on ultrasonography with multifocality. Evaluation of the cervical lymph nodes including the lateral neck should not be overlooked when suspicious thyroid nodule suggesting malignancy sized ≤5 mm shows multifocal lesions.

BRAF mutation in papillary thyroid carcinoma: predictive value for long-term prognosis and radioiodine sensitivity

OBJECTIVES

BRAF pV600E mutation is the most common oncogenic event and the most specific mutation for papillary thyroid carcinoma (PTC). Many studies over the last decade have shown a direct relationship between BRAF mutation and aggressive tumour characteristics, resulting in poor prognosis. However, several recent studies have suggested that BRAF mutation is not associated with poor prognosis of PTC. The present study was designed to evaluate the association between BRAF mutation with clinicopathological factors and tumour recurrence.

MATERIAL AND METHODS

In this retrospective study, BRAF mutation status was examined by direct sequencing on paraffin-embedded tumour specimens from 46 patients undergoing surgery for PTC in our institution from 1985 to 2000. The relationship between BRAF mutation and gender, advanced age, extrathyroid extension, multifocal tumour, cervical lymph node metastasis, tumour size and advanced pT stage of PTC and its predictive role for the risk of tumour recurrence were investigated with a median follow-up of 10.1 (±6.5)years.

RESULTS

BRAF mutation was detected in 20 of the 46 patients (43.5%) included in the study. No statistically significant correlation was demonstrated between the presence of BRAF mutation and the various clinicopathological factors studied. No significant difference in tumour recurrence rate or radioiodine sensitivity was observed between the two subgroups: mutant BRAF and wild-type BRAF.

CONCLUSION

Although BRAF mutation appears to play a role in local tumour progression, it is not a risk factor for poor prognosis or tumour recurrence in PTC.

Not the number but the location of lymph nodes matters for recurrence rate and disease-free survival in patients with differentiated thyroid cancer

Background

Several Japanese studies have focused on identifying prognostic factors in patients with positive lymph nodes to predict recurrence rate and disease-free survival (DFS). However, different treatment protocol is followed in Japan compared with the European and American approach. This study was designed to investigate whether the number and/or location of lymph nodes predicts prognosis in patients with DTC treated with total thyroidectomy, lymph node dissection, and postoperative radioactive iodine ablation.

Methods

All 402 patients who were treated at the Department of Nuclear Medicine between 1998 and 2010 for DTC were reviewed. Patients were treated with (near) total thyroidectomy, lymph node dissection on indication, and postoperative I-131 ablation. Median follow-up was 49 (range, 10–240) months. Outcome measures were recurrence rate, disease-free survival, and mean time to recurrence.

Results

Ninety-seven patients had proven lymph node metastases. Recurrence rate was significantly higher in patients with positive lymph nodes in the lateral compartment vs. patients with lymph node metastasis in the central compartment (60 vs. 30%, p = 0.007). Disease-free survival and mean time to recurrence also were significantly shorter (30 vs. 52 months, p = 0.035 and 7 vs. 44 months, p = 0.004, respectively). The number of lymph nodes and extranodal growth were not significantly associated with the outcome measures used.

Conclusions

The location of positive lymph nodes was significantly correlated with the risk of recurrence and a shorter DFS. Hence, the TNM criteria are useful in subdividing patients based on risk of recurrence and DFS.

Prognostic factors for recurrence of papillary thyroid carcinoma in the lymph nodes, lung, and bone: analysis of 5,768 patients with average 10-year follow-up

BACKGROUND

Papillary thyroid carcinoma (PTC) frequently recurs to the lymph nodes, which may not be fatal immediately but is a stressor for physicians and patients. Recurrence to the distant organs, although less frequent, is often life-threatening, and the lung and bone are organs to which PTC is likely to recur. In the present study we investigated factors predicting recurrence of PTC to the lymph nodes, lung, and bone in a large number of patients undergoing long-term follow-up.

METHODS

A total of 5,768 PTC patients (608 males and 5,159 females) without distant metastasis at diagnosis who underwent initial surgery between 1987 and 2004 in Kuma Hospital were enrolled in this study. The postoperative follow-up ranged from 12 to 280 months, and was 129 months (10.8 years) on average.

RESULTS

To date, node, lung, and bone recurrences have been detected in 389 (7%), 118 (2%), and 33 patients (0.6%), respectively, and 57 patients (1%) have died of PTC. We examined the prognostic significance of the tumor size (T), extrathyroid extension (Ex), age 55 years or older (Age), male gender (Gender), clinical node metastasis (N), and extranodal tumor extension (LN-Ex) for each outcome on multivariate analysis. Age, Gender, T > 2 cm, N, and Ex were independent predictors of lymph node recurrence. Age, Ex, T > 2 cm, and N were independent prognostic factors for lung recurrence. Ex, T > 4 cm, and N independently predicted bone recurrence. Of these, N ≥ 3 cm had the strongest prognostic value for lymph node, lung, and bone recurrences. In contrast, Age was the strongest predictor for carcinoma death. LN-Ex also had a prognostic value for carcinoma death, although it was not a predictor of carcinoma recurrence. Ex, N ≥ 3 cm, and T > 2 cm also had a prognostic impact on carcinoma death.

CONCLUSIONS

Large lymph node metastasis showed a strong prognostic impact on carcinoma recurrence not only to the lymph nodes but also to the lung and bone, and carcinoma death. Extrathyroid extension also independently predicted these recurrences and carcinoma death, although hazard ratios were lower than for large node metastasis. Age 55 years or older, in contrast, was the strongest predictor of carcinoma death. Extranodal tumor extension did not independently affect recurrence, but it had prognostic significance for carcinoma death. These findings suggest that recurring PTC lesions of older patients and/or extranodal tumor extensions are difficult to control and very progressive.

Lateral cervical lymph node metastases in papillary thyroid cancer: a systematic review of imaging-guided and prophylactic removal of the lateral compartment

BACKGROUND

Papillary thyroid cancer (PTC) is a common endocrine cancer and frequently presents with lymph node (LN) metastases. The frequency of LN metastases in the lateral compartment and their surgical removal are poorly defined. There are no prospective randomised controlled trials addressing an eventual outcome difference relating to the extent of the initial surgical approach. The aim of this study was to define the extent of lateral LN involvement and the role of imaging in identification of these metastatic LN.

DESIGN AND METHODS

A systematic review of studies of patients with PTC undergoing either prophylactic or therapeutic lymphadenectomy of the lateral cervical compartment. Studies involving imaging modalities in the detection of lateral cervical LNs in PTC were also analysed.

RESULTS

Systematic review on the frequency of lateral LN metastases and their detection using various imaging tools identified 19 studies containing data on 5587 patients undergoing prophylactic or imaging-guided removal of the lateral compartment. Imaging-guided surgery retrieved cancerous lateral LNs in 446/3178 or 14% of eligible patients, whilst prophylactic lateral neck dissection yielded histopathological proof of cancer in 1177/204 or 57·5% of patients. The frequency of lateral compartment metastases increased with T stage. The sensitivity of ultrasound and CT was poor as low as 27% when accurately calculated.

CONCLUSION

Metastatic cervical LNs were found in more than half of patients when prophylactic lateral LN dissection was performed. Use of conventional imaging for the selection of the surgical approach to the lateral cervical compartment may commonly identify stage N1a instead of N1b and thus lead to false stage assignment as stage III rather than stage IV, concealing the severe prognostic implications of this stage progression in individual patients.

American Thyroid Association consensus review and statement regarding the anatomy, terminology, and rationale for lateral neck dissection in differentiated thyroid cancer

BACKGROUND

Cervical lymph node metastases from differentiated thyroid cancer (DTC) are common. Thirty to eighty percent of patients with papillary thyroid cancer harbor lymph node metastases, with the central neck being the most common compartment involved. The goals of this study were to: (1) identify appropriate methods for determining metastatic DTC in the lateral neck and (2) address the extent of lymph node dissection for the lateral neck necessary to control nodal disease balanced against known risks of surgery.

METHODS

A literature review followed by formulation of a consensus statement was performed.

RESULTS

Four proposals regarding management of the lateral neck are made for consideration by organizations developing management guidelines for patients with thyroid nodules and DTC including the next iteration of management guidelines developed by the American Thyroid Association (ATA). Metastases to lateral neck nodes must be considered in the evaluation of the newly diagnosed thyroid cancer patient and for surveillance of the previously treated DTC patient.

CONCLUSIONS

Lateral neck lymph nodes are a significant consideration in the surgical management of patients with DTC. When current guidelines formulated by the ATA and by other international medical societies are followed, initial evaluation of the DTC patient with ultrasound (or other modalities when indicated) will help to identify lateral neck lymph nodes of concern. These findings should be addressed using fine-needle aspiration biopsy. A comprehensive neck dissection of at least nodal levels IIa, III, IV, and Vb should be performed when indicated to optimize disease control.