Impact of degree of extrathyroidal extension of disease on papillary thyroid cancer outcome

Selective use of radioactive iodine (RAI) in thyroid cancer: No longer "one size fits all"

A remarkable, evidence-based trend toward de-escalation has reformed the practice of radioactive iodine (RAI) administration for thyroid cancer patients. Updated guidelines have supported both decreased RAI doses for select populations, as well as expanded definitions of low-risk and intermediate-risk patients that may not require RAI. Correspondingly, there is now increased flexibility for hemithyroidectomy without need for RAI, and relaxed TSH suppression targets for low-risk thyroidectomy patients. Clinical judgment remains indispensable where multiple risk factors co-exist that individually are not indications for RAI. This is especially salient in intermediate-risk patients with a less than excellent response to therapy, determined through thyroglobulin and ultrasound surveillance. Such judgment, however, may lead to patterns of inappropriate RAI practices or overuse with little benefit to the patient and unnecessary harm. A multidisciplinary, risk-adapted approach is ever more important and obliges the surgeon to understand the likelihood that their patients will receive RAI. The risks and benefits of RAI, its evolved role in contemporary guidelines, and current patterns of use among endocrinologists are reviewed, as well as the practical implications for thyroid surgeons.

Minimal extrathyroidal extension does not affect survival of well-differentiated thyroid cancer

Differentiated thyroid cancer (DTC) with minimal extrathyroidal extension (MEE) is classified as stage III regardless of the tumor size. In this study, we aim to examine the effect of MEE on the overall survival and management of this population. A retrospective cohort study was performed, which utilized the National Cancer Database (NCDB), 2004-2012. The study population included patients, aged ≥ 45 years, who underwent surgery for DTC (pT3N0M0) with MEE compared to that in patients with pT2N0M0. A total of 9556 patients were included. These were divided into four groups, 4410 patients with pT2N0M0 (Group 1: T ≤ 4 cm without MEE), 3274 with pT3N0M0 (Group 2: T ≤ 4 cm with MEE), 447 with pT3N0M0 (Group 3: T > 4 cm with MEE) and 1430 patients with pT3N0M0 without MEE (Group 4: T > 4 cm without MEE). Median follow-up time was 46.7 months (interquartile range: 27.8-72.1). Patients in Group 2 (T ≤ 4 cm with MEE) had no significant worse survival compared to patients in Group 1 (T ≤ 4 cm without MEE) (P = 0.85), whereas Groups 3 and 4 (T > 4 cm), both had significantly lower survival (P < 0.001) with no difference between the two groups. Total thyroidectomy was associated with improved overall survival compared to that in lobectomy in Group 4 (T > 4 cm without MEE). Radioiodine utilization was associated with improved survival only with tumors larger than 4 cm with or without MEE. In DTC patients aged older than 45 years of age with tumor size less than 4 cm, MEE has no survival significance. Tumor size is an independent prognostic marker regardless of MEE status. Our data support re-evaluation of the current staging system.

Extrathyroidal Extension Is Associated with Compromised Survival in Patients with Thyroid Cancer

BACKGROUND

Patients with thyroid cancer who have extrathyroidal extension (ETE) are considered to have more advanced tumors. However, data on the impact of ETE on patient outcomes remain limited. The purpose of this study was to evaluate the association between ETE and survival in patients with thyroid cancer.

METHODS

The National Cancer Database (1998-2012) was queried for all adult patients with differentiated thyroid cancer and medullary thyroid cancer. Patients were divided into three groups: no ETE (T1 and T2 tumors), minimal ETE (T3 tumors <4 cm), and extensive ETE (T4 tumors <4 cm). Patient demographic, clinical, and pathologic factors were evaluated for all patients. A Cox proportional hazards model was developed for each histology to identify factors associated with survival.

RESULTS

In total, 241,118 patients with differentiated thyroid cancer met the inclusion criteria; 86.9% had no ETE, 9.1% minimal ETE, and 4.0% extensive ETE. Compared with patients with no ETE, patients with minimal and extensive ETE were more likely to have larger tumors (1.4 cm vs. 1.8 cm and 2.0 cm, respectively), lymphovascular invasion (8.6% vs. 28.0% and 35.1%, respectively), positive margins after thyroidectomy (6.1% vs. 35.2% and 45.9%, respectively), and regional lymph node metastases (32.5% vs. 67.0% and 74.6%, respectively; all p < 0.01). After adjustment, minimal ETE (hazard ratio [HR] = 1.13; p < 0.01) and extensive ETE (HR = 1.74; p < 0.01) were associated with compromised survival for patients with differentiated thyroid cancer. In total, 3415 patients with medullary thyroid cancer met the inclusion criteria; 87.9% had no ETE, 7.1% minimal ETE, and 5.0% extensive ETE. Compared with patients with no ETE, patients with minimal and extensive ETE were more likely to have larger tumors (1.7 cm vs. 2.2 cm and 2.2 cm, respectively), lymphovascular invasion (19.2% vs. 68.9% and 79.3%, respectively), positive margins after thyroidectomy (5.8% vs. 44.1% and 51.9%, respectively), and regional lymph node metastases (39.0% vs. 90.5% and 94.4%, respectively; all p < 0.01). After adjustment, extensive ETE (HR = 1.63; p = 0.01) was associated with compromised survival for patients with medullary thyroid cancer.

CONCLUSION

In patients with differentiated and medullary thyroid cancers, ETE is associated with compromised survival. Given these findings, ETE should be included in the thyroid cancer treatment guidelines.

Updated guidelines on the preoperative staging of thyroid cancer

Recent studies have provided prognostic information and recommendations for staging thyroid cancers that have changed the staging and management guidelines for the disease. Consequently, minimal extrathyroidal extension (ETE) was removed from the T3 stage classification in the eighth edition of the TNM staging system by the American Joint Committee on Cancer. New T categories have been subsequently added, including T3a, defined as a tumor >4 cm in its greatest dimension, limited to the thyroid gland, and T3b, defined as a tumor of any size with gross ETE invading only the strap muscles. In this article, the author reviews the changes in the TNM staging system for thyroid cancer, with an emphasis on ultrasonography in preoperative staging.

Prognostic impact of minimal extrathyroidal extension in papillary thyroid carcinoma

BACKGROUND

It is widely accepted that maximal extrathyroidal extension (ETE) plays a vital role in the prognosis of papillary thyroid carcinoma (PTC). However, there is no consensus among researchers about the meaning of minimal ETE (mETE) in PTC. Herein, we conducted a systematic review and meta-analysis to examine the role of mETE in the prognosis of PTC.

METHODS

We searched PubMed, EMBASE, and Cochrane search trials databases in English to identify studies comparing data on disease recurrence in PTC patients with mETE and those with no ETE. To summarize the data related to mETE status, risk ratios and hazard ratios adjusted for potential confounders were used to assess the number of recurrence and time-dependent risks related to mETE status, respectively.

RESULTS

According to the inclusion criteria, a total of 7951 patients from 9 studies were included. The recurrence rate in patients with mETE is significantly higher when compared with those with no ETE (risk ratio = 1.70, 95% confidence interval: 1.26-2.28, I = 56%). According to the data summarized with hazard ratios, PTC patients with mETE showed a significantly increased risk of disease recurrence.

CONCLUSION

mETE is a risk factor for poor prognosis in patients with PTC. Our innovative classification of ETE has its value in assessing the prognosis of PTC.

Reappraisal of the indication for radioiodine thyroid ablation in differentiated thyroid cancer patients

Radioactive iodine therapy is administered to patients with differentiated thyroid cancer (DTC) for eradication of thyroid remnant after total thyroidectomy or, in patients with metastatic disease, for curative or palliative treatment. In past years, thyroid remnant ablation was indicated in almost every patient with a diagnosis of DTC. Nowadays, careful revision of patients' outcome has introduced the concept of risk-based selection of patients candidate to thyroid remnant ablation. The present review aims to underline the indications for thyroid remnant ablation and to address methodologies to be employed.

Differences in the Recurrence and Survival of Patients with Symptomatic and Asymptomatic Papillary Thyroid Carcinoma: An Observational Study of 11,265 Person-Years of Follow-Up

BACKGROUND

Papillary thyroid carcinoma (PTC) generally has an indolent course and favorable prognosis. However, an optimal treatment strategy for asymptomatic PTC is not clear. We compared the recurrence and survival outcomes of patients with asymptomatic and symptomatic PTC and identified the associated risk factors.

MATERIALS AND METHODS

Patients with previously untreated PTC of size ≤2 cm and who underwent curative surgery were included in this analysis. Asymptomatic PTC was defined as a tumor detected only by ultrasonography, computed tomography (CT), magnetic resonance imaging, and/or ¹⁸F-fluorodeoxyglucose positron emission tomography/CT. Clinical factors, operative and pathologic findings, and posttreatment outcomes were compared between the aforementioned two groups. Univariate and multivariate analyses were performed to identify the factors associated with recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Out of 1419 patients, 1259 patients (88.7%) were asymptomatic. Patients with symptomatic PTC had significantly larger tumor size, palpability, extrathyroidal extension, high tumor and node stages, and were more likely to undergo treatment with radioactive iodine therapy compared with patients with asymptomatic PTC (p < 0.05 each). Recurrence was significantly higher in the symptomatic PTC group than in the asymptomatic group (p < 0.001). Asymptomatic PTC was an independent predictor of RFS and OS and had higher five-year rates than those associated with symptomatic tumors: 97.3% and 90.6% for RFS (p < 0.001) and 99.4% and 96.9% for OS (p < 0.001), respectively.

CONCLUSION

Symptomatic PTC is associated with higher recurrence and lower overall survival rates than asymptomatic PTC. Symptomatic PTC may require total thyroidectomy and close posttreatment surveillance.

Current Guidelines for Postoperative Treatment and Follow-Up of Well-Differentiated Thyroid Cancer

Well-differentiated thyroid cancer is increasing in incidence but the disease-specific mortality remains very low. The only effective adjuvant treatment is radioactive iodine ablation. Guidelines regarding the use and dosage of radioactive iodine depend on pathologic features of the primary and metastatic tumor that define risk. Long-term treatment includes thyroid-stimulating hormone suppression and surveillance with serum thyroglobulin and radiologic assessment for nodal recurrence.

Risk prediction and clinical model building for lymph node metastasis in papillary thyroid microcarcinoma

The surgical management of papillary thyroid microcarcinoma (PTMC), especially regarding the necessity of central/lateral lymph node dissection, remains controversial. This study investigated the clinicopathologic factors predictive of lymph node metastasis (LNM) in patients diagnosed with PTMC. Multivariate logistic regression analysis was used for PTMC patients identified from the Surveillance, Epidemiology, and End Results database who were treated by surgery between 2002 and 2012, to determine the association of clinicopathologic factors with LNM. According to the results, a total of 31,017 patients met the inclusion criteria of the study. Final histology confirmed 2,135 (6.9%) cases of N1a disease and 1,684 cases (5.4%) of N1b disease. Our multivariate logistic regression analysis identified variables associated with both central LNM and lateral lymph node metastasis (LLNM), including a younger age (<45 years), male sex, non-Hispanic white and other race, classical papillary histology, larger tumor size, multifocality, and extrathyroidal extension; distant metastasis was also significantly associated with LLNM. The significant predictors identified from multivariable logistic regression were integrated into a statistical model that showed that extrathyroidal extension had maximum weight in the predictive role for LNM. LLNM was validated to be a significant risk factor for cancer-specific death in Cox regression analyses, whereas central LNM failed to predict a worse cancer-specific survival according to our data. Therefore, we suggested that central lymph node dissection could be performed in certain patients with risk factors. Given the prevalence of LLNM in PTMC, a thorough inspection of the lateral compartment is recommended in PTMC patients with risk factors for precise staging; from the viewpoint of a radical treatment for tumors, prophylactic lateral lymph node dissection that aims to remove the occult lateral lymph nodes may be an option for PTMC with risk factors. Multicenter studies with long-term follow-up are recommended to better understand the risk factors and surgical management for cervical nodes in PTMC.

Overexpression of long non-coding RNA NR_036575.1 contributes to the proliferation and migration of papillary thyroid cancer

Current evidence suggests that the human genome produces a large number of non-coding RNAs, including microRNAs and long non-coding RNAs (lncRNAs). Generally, lncRNAs are defined as RNA transcripts longer than 200 nucleotides that are not transcribed into proteins. In recent years, lncRNAs have been reported to play oncogenic roles in tumourigenesis. However, minimal research has been performed on the expression and clinicopathological significance of lncRNAs in papillary thyroid cancer (PTC). In the present study, we investigated not only the expression and clinicopathological significance of a novel lncRNA, NR_036575.1, in PTC tissues and adjacent non-cancerous tissues but also its potential function in TPC1 cells. The expression levels of the lncRNA NR_036575.1 in 83 pairs of PTC tissues and adjacent non-cancerous tissues were detected via quantitative real-time polymerase chain reaction. The relationships between the expression levels and clinicopathological characteristics of the lncRNA NR_036575.1 were analysed. In addition, we established two receiver operating characteristic (ROC) curves to assess the diagnostic value of NR_036575.1 expression. Cell Counting Kit-8 and transwell assays were used to assess cell proliferation and migration, respectively. The expression levels of the lncRNA NR_036575.1 were significantly higher in PTC tissues than in adjacent non-cancerous tissues. High NR_036575.1 expression was associated with extrathyroidal extension (ETE) (P = 0.011) and tumour size (P = 0.006). The ROC curves indicated that NR_036575.1 could potentially serve as a biomarker for identifying PTC and related, non-cancerous diseases (sensitivity, 80.7 %; specificity, 88 %), as well as for differentiating between PTC with or without ETE (sensitivity, 57.8 %; specificity, 86.7 %). NR_036575.1 knock-down significantly inhibited the proliferation and migration of TPC1 cells. Our findings are the first to describe lncRNA NR_036575.1 overexpression in PTC. NR_036575.1 expression was associated with both ETE and tumour size. In addition, NR_036575.1 modulation could regulate TPC1 cell proliferation and migration. The results of our study suggest that NR_036575.1 could be applied as a potential biomarker and a novel therapeutic target for PTC patients.

Predicting Extrathyroidal Extension in Patients With Papillary Thyroid Microcarcinoma According to a BRAF Mutation

Objectives

The aim of this study was to evaluate the association between preoperative parameters and extrathyroidal extension (ETE) of papillary thyroid microcarcinoma (PTMC) according to the BRAF mutation and to evaluate the preoperative predictability of ETE.

Methods

We analyzed the medical records of 332 patients with PTMC (140 in the BRAF– group and 192 in the BRAF+ group). The presence of ETE was subjected to a correlation analysis with age, sex, tumor size, clinical nodal status, and ultrasonography (US) findings. Among the US findings, the correlation between tumors and the thyroid capsule was categorized into four groups; US group A, intraparechymal; US group B, tumor abutting the capsule <50% of diameter; US group C, tumor abutting >50% of diameter; and US group D, tumor destroyed the capsule. The predictive value of ETE, including sensitivity, specificity, and positive and negative predictive values were evaluated.

Results

Tumor size and US group were significantly correlated with gross ETE in the BRAF– and BRAF+ groups. Tumor size of 0.5 cm and US groups B and C in the BRAF– group were cutoff values for gross ETE, with a negative predictive value of 100%, whereas tumor size of 0.7 cm and US groups A and B in the BRAF+ group had negative predictive values of 92.4% and 100%, respectively.

Conclusion

Excluding of ETE by US was categorized according to tumor size and US findings. A different categorization to exclude ETE is needed according to the BRAF mutation.

Ultrasonography Diagnosis and Imaging-Based Management of Thyroid Nodules: Revised Korean Society of Thyroid Radiology Consensus Statement and Recommendations

The rate of detection of thyroid nodules and carcinomas has increased with the widespread use of ultrasonography (US), which is the mainstay for the detection and risk stratification of thyroid nodules as well as for providing guidance for their biopsy and nonsurgical treatment. The Korean Society of Thyroid Radiology (KSThR) published their first recommendations for the US-based diagnosis and management of thyroid nodules in 2011. These recommendations have been used as the standard guidelines for the past several years in Korea. Lately, the application of US has been further emphasized for the personalized management of patients with thyroid nodules. The Task Force on Thyroid Nodules of the KSThR has revised the recommendations for the ultrasound diagnosis and imaging-based management of thyroid nodules. The review and recommendations in this report have been based on a comprehensive analysis of the current literature and the consensus of experts.

Noninferior response in BRAF(V600E) mutant nonmetastatic papillary thyroid carcinoma to radioiodine therapy

PURPOSE

As the most frequent and specific genetic alteration in papillary thyroid carcinoma (PTC), BRAF(V600E) has an intimate relationship with more invasive tumour and higher postoperative recurrence risk in PTC patients. We investigate the effect of radioactive iodine (RAI) therapy on the clinical outcome in PTC patients with the BRAF(V600E) mutation without distant metastases.

METHODS

This retrospective study included PTC 228 patients without distant metastases who underwent total or near-total thyroidectomy and RAI treatment in our hospital from January 2011 to July 2014. The BRAF(V600E) status of the primary lesions was determined and the patients were divided into two groups according to the presence of the mutation. Serological and imaging data were collected at a median follow-up of 2.34 years after RAI administration. Suppressed and stimulated thyroglobulin (Tg), Tg antibody, diagnostic whole-body scintigraphy, and other imaging examinations were used to assess clinical outcome, which was defined as excellent response, indeterminate response, biochemical incomplete response and structural incomplete response.

RESULTS

The BRAF(V600E) mutation was observed in 153 of the 228 patients (67.1 %). The clinicopathological features did not differ between the BRAF(V600E) mutatation and wild-type groups except age at diagnosis (P = 0.000), tumour size (P = 0.023) and TNM stage (P = 0.003). Older age and more advanced TNM stage were prevalent in the BRAF(V600E) mutatation group, whereas tumours were slightly larger in the BRAF(V600E) wild-type group. The response to RAI therapy was evaluated in both the entire series and the patients with a high recurrence risk, and no significant difference in response was found between the BRAF(V600E) mutatation and the wild-type groups (P = 0.881 and P = 0.851, respectively).

CONCLUSION

The clinical response to timely postsurgical RAI therapy is not inferior in BRAF(V600E) mutation PTC patients without distant metastases, which suggests that RAI therapy might improve the general clinical outcome in this patient group.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

External-beam radiotherapy for differentiated thyroid cancer locoregional control: A statement of the American Head and Neck Society

The use of external-beam radiotherapy (EBRT) in differentiated thyroid cancer (DTC) is debated because of a lack of prospective clinical data, but recent retrospective studies have reported benefits in selected patients. The Endocrine Surgery Committee of the American Head and Neck Society provides 4 recommendations regarding EBRT for locoregional control in DTC, based on review of literature and expert opinion of the authors. (1) EBRT is recommended for patients with gross residual or unresectable locoregional disease, except for patients <45 years old with limited gross disease that is radioactive iodine (RAI)-avid. (2) EBRT should not be routinely used as adjuvant therapy after complete resection of gross disease. (3) After complete resection, EBRT may be considered in select patients >45 years old with high likelihood of microscopic residual disease and low likelihood of responding to RAI. (4) Cervical lymph node involvement alone should not be an indication for adjuvant EBRT.

Patients Treated at Low-Volume Centers have Higher Rates of Incomplete Resection and Compromised Outcomes: Analysis of 31,129 Patients with Papillary Thyroid Cancer

BACKGROUND

Data on the importance of margin status after total thyroidectomy for papillary thyroid cancer (PTC) remain limited. This study sought to identify factors associated with positive margins and to determine the impact of positive margins on survival for patients with PTC.

METHODS

The National Cancer Data Base (1998-2006) was queried for patients with PTC who had undergone total thyroidectomy. The patients were divided into three groups based on margin status (negative, microscopically positive, and macroscopically positive). Patient demographic, clinical, and pathologic features were evaluated. A binary logistic regression model was developed to identify factors associated with positive margins. A Cox proportional hazards model was developed to identify factors associated with survival.

RESULTS

Of the 31,129 patients enrolled in the study, 91.3 % had negative margins, 8.1 % had microscopically positive margins, and 0.6 % had macroscopically positive margins. The patients with negative margins were younger and more likely to be female, white, covered by private insurance, and treated at an academic or high-volume center (p < 0.05). They had smaller tumors and were less likely to have advanced-stage disease. After multivariable adjustment, increasing patient age [odds ratio (OR) = 1.02; p < 0.01], government insurance (OR = 1.20; p < 0.01), and no insurance (OR = 1.34; p = 0.01) were associated with positive margins. Reception of surgery at a high-volume facility (OR = 0.72; p < 0.01) was protective. After multivariable adjustment, both microscopically [hazard ratio (HR), 1.49; p < 0.01] and macroscopically positive margins (HR = 2.38; p < 0.01) were associated with compromised survival.

CONCLUSIONS

Several vulnerable patient populations have a higher risk of incomplete resection after thyroidectomy for PTC. High-risk thyroid cancer patients should be referred to high-volume centers to optimize outcomes.

High metabolic tumor volume and total lesion glycolysis are associated with lateral lymph node metastasis in patients with incidentally detected thyroid carcinoma

OBJECTIVE

The objective of this study was to investigate whether total lesion glycolysis (TLG) and metabolic tumor volume (MTV) measured by ¹⁸F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) could predict the aggressiveness and lymph node metastasis (LNM) in patients with incidentally detected differentiated thyroid carcinoma.

METHODS

A total 358 patients with focal FDG-avid thyroid incidentaloma during cancer evaluation were enrolled. Among 235 patients in whom fine-needle aspiration biopsy was performed, 51 patients underwent total thyroidectomy with LN dissection. We analyzed the relationship between volume-based parameters and clinicopathologic characteristics.

RESULTS

The mean age and tumor size were 57.1 ± 11.3 years and 1.15 ± 0.81 cm, respectively. The prevalence of malignancy was 21.7 % (51/235). When SUV(max) > 5.91, MTV2.5 > 2.05 cm³, and TLG2.5 > 9.09 were used as cutoff points, sensitivity, specificity, and area under curve (AUC) for prediction of lateral LNM were 77.9, 69.1 %, 0.716 (P = 0.047), 77.8, 88.1 %, 0.839 (P < 0.001), 77.8, 85.1 %, and 0.815 (P = 0.002), respectively. However, MTV and TLG had no value in prediction of central LNM, extrathyroidal extension, and multifocality. On comparison ROC curve analysis, the MTV and TLG showed the statistical differences for the prediction of lateral LNM compared with SUV(max) (all P's < 0.05).

CONCLUSIONS

This study has shown for the first time that volume-based PET functional parameters had a significant value for the prediction of lateral LNM in incidentally detected PTC. These results suggest that higher MTV and TLG can be potential new risk factors for preoperative risk stratification. The usefulness of TLG and MTV in preoperative risk stratification in patients with PTC needs to be confirmed in further large studies.

Characteristics and significance of minimal and maximal extrathyroidal extension in papillary thyroid carcinoma

OBJECTIVES

Maximal extrathyroidal extension (ETE) is known to be an important prognostic factor in papillary thyroid carcinoma (PTC). However, the significance of minimal ETE is controversial. The aim of this study was to investigate the clinicopathologic characteristics and prognostic significance of minimal vs maximal ETE in PTC.

MATERIALS AND METHODS

A group of 967 patients who underwent thyroidectomy for PTC in a tertiary hospital between January 2000 and December 2011 were studied retrospectively. Patients were classified into three groups: absence of ETE, and minimal and maximal ETE. The minimal ETE group was further categorized into two subgroups according to invasion of strap muscles or no invasion (STI+ and STI-).

RESULTS

Gender did not differ between the three groups of patients. The mean age of the patients with maximal ETE was significantly higher than in those belonging to the other groups. Tumor size, bilaterality, lymph node metastasis and stage increased significantly according to the degree of ETE. Recurrence and survival rates did not differ between the absence and minimal ETE groups, or between the STI- and STI+ subgroups of minimal ETE. However, the maximal ETE group had significantly higher recurrence and lower survival rates than the other groups (P<0.001).

CONCLUSION

Maximal ETE is a significant factor for poor prognosis. However, minimal ETE is not associated with increased recurrence or decreased survival in patients with PTC.

E-selectin expression and BRAF status in papillary thyroid carcinomas: Correlation with clinicopathologic features

BACKGROUND

Cell adhesion molecules, represented by the immunoglobulin family and selectins, play an important role in the progression of cancer. A correlation between selectins and tumor aggressiveness has been demonstrated in several reports.

METHODS

Eighty-eight patients (mean age, 41.0 ± 14 years) with papillary thyroid carcinoma (conventional variant and sized approximately 20 mm) were divided in 2 groups: 41 with encapsulated tumors and 47 with tumors with extrathyroidal extension. E-selectin expression was evaluated by immunohistochemical staining and semiquantitative real-time reverse-transcription polymerase chain reaction and normalized by calculating the z-score (positive: value above the population mean; negative: below the mean).

RESULTS

Lymph node metastasis (LNM) was found in 2 of 41 encapsulated tumors (4.8%) and in 19 of 47 tumors (40.4%) with extrathyroidal extension. BRAF mutation was present in 21 encapsulated tumors (51.2%) and in 31 tumors with extrathyroidal extension (65.9%). The mean E-selectin z-score was -0.32 for encapsulated tumors and 0.28 for tumors with extrathyroidal extension. E-selectin expression correlates with neoplastic infiltration (P = .04), the American Joint Commission on Cancer stage (P = .02), and BRAF mutation (P = .03).

CONCLUSION

E-selectin overexpression in association with BRAF mutation status could promote a more aggressive phenotype in papillary thyroid carcinoma.