Human Amnion/Chorion Membrane May Reduce Transient Recurrent Laryngeal Nerve Injury During Thyroid Surgery.

Recurrent laryngeal nerve (RLN) damage is a significant and prevalent complication of thyroid surgery. Based on the beneficial role of a human amnion/chorion membrane (HACM) allograft in wound management and nerve regeneration, we investigated whether placement of a commercially available HACM allograft on dissected RLN could reduce the occurrence and/or duration of RLN injury during thyroidectomy. Among 67 patients undergoing thyroidectomy, 100 at-risk nerves (exposure of at least 3 cm of RLN) received intraoperative placement of HACM; 205 at-risk RLNs without HACM in 134 matched patients served as controls. Patient-reported vocal analysis, physician-assessed vocal analysis, and laryngoscopic assessment of vocal-fold dysfunction were performed before and after surgery. At 24 h after surgery, 17 patients in the control group (12.5%) had documented voice changes; these changes persisted for at least 3 weeks in seven patients (5%). Only one patient (1.5%) in the HACM group had vocal changes at 24 h after surgery, which resolved within 1 week (P < 0.01). Intraoperative placement of the HACM allograft over at-risk RLNs during thyroidectomy may reduce the incidence, severity, and/or duration of intraoperative RLN injury, which could address a significant complication of head and neck surgery. A larger prospectively designed clinical study is warranted to further investigate a possible benefit of the HACM allograft in thyroid surgery and to begin to understand the mechanisms through which a clinical benefit might be mediated.

Comprehensive Genetic Characterization of Human Thyroid Cancer Cell Lines: A Validated Panel for Preclinical Studies.

PURPOSE: Thyroid cancer cell lines are valuable models but have been neglected in pancancer genomic studies. Moreover, their misidentification has been a significant problem. We aim to provide a validated dataset for thyroid cancer researchers. EXPERIMENTAL DESIGN: We performed next-generation sequencing (NGS) and analyzed the transcriptome of 60 authenticated thyroid cell lines and compared our findings with the known genomic defects in human thyroid cancers. RESULTS: Unsupervised transcriptomic analysis showed that 94% of thyroid cell lines clustered distinctly from other lineages. Thyroid cancer cell line mutations recapitulate those found in primary tumors (e.g., BRAF, RAS, or gene fusions). Mutations in the TERT promoter (83%) and TP53 (71%) were highly prevalent. There were frequent alterations in PTEN, PIK3CA, and of members of the SWI/SNF chromatin remodeling complex, mismatch repair, cell-cycle checkpoint, and histone methyl- and acetyltransferase functional groups. Copy number alterations (CNA) were more prevalent in cell lines derived from advanced versus differentiated cancers, as reported in primary tumors, although the precise CNAs were only partially recapitulated. Transcriptomic analysis showed that all cell lines were profoundly dedifferentiated, regardless of their derivation, making them good models for advanced disease. However, they maintained the BRAFV600E versus RAS-dependent consequences on MAPK transcriptional output, which correlated with differential sensitivity to MEK inhibitors. Paired primary tumor-cell line samples showed high concordance of mutations. Complete loss of p53 function in TP53 heterozygous tumors was the most prominent event selected during in vitro immortalization. CONCLUSIONS: This cell line resource will help inform future preclinical studies exploring tumor-specific dependencies.

Management of the central compartment in differentiated thyroid carcinoma.

Management of differentiated thyroid carcinoma (DTC) is gradually evolving with considerations of de-escalation of treatment and/or active surveillance in a significant proportion of patients on the basis of an improved understanding of the long-term disease and functional outcomes from both surgical and non-surgical approaches. This is fueled by improved risk stratification using clinicopathologic prognostic factors as determined through high resolution ultrasound and fine needle aspiration cytology. This paper discusses general recommendations for preoperative decision-making in the management of the central compartment in DTC with particular reference to micropapillary thyroid carcinoma and encapsulated follicular variant papillary thyroid carcinoma. Given the multitude of specific factors that must be considered for each patient, therapeutic decisions should occur in a multidisciplinary setting weighing the risks of treatment morbidity against the risks of disease progression or recurrence. Recurrent/persistent disease merits special attention with regard to pre-operative planning and surgical risk, and should be managed by high-volume thyroid surgeons.

Management of the lateral neck compartment in patients with sporadic medullary thyroid cancer.

BACKGROUND: The purpose of this retrospective analysis was to evaluate the benefits of an elective lateral neck dissection (ELND) in patients with medullary thyroid cancer (MTC) without radiographically apparent lateral neck metastases. METHODS: Patients with sporadic MTC without radiographic evidence of lateral neck metastasis who underwent definitive surgery were divided into 2 groups based on surgical approach: no ELND (the observation group) and ipsilateral or bilateral ELND (the ELND group). Primary outcomes were biochemical cure, locoregional recurrence, distant metastasis, and overall survival (OS). RESULTS: Sixty-six patients met inclusion criteria: 44 patients (67%) in the observation group and 22 patients (33%) in the ELND group. Two of 44 patients (5%) in the observation group developed subsequent (ipsilateral) lateral neck disease. At last follow-up, locoregional disease control rates among the observation and ELND groups were 98% and 100% (P > .999), respectively, whereas biochemical cure rates were 82% and 85% (P > .999), respectively, and 5-year OSs were 84% and 100% (P = .156), respectively. CONCLUSION: Patients with MTC without lateral neck metastasis have similar biochemical cure rates with observation or elective dissection of lateral neck compartments.

Long-Term Outcomes of Lateral Neck Dissection in Patients with Recurrent or Persistent Well-Differentiated Thyroid Cancer.

BACKGROUND: Well-differentiated thyroid carcinoma (WDTC) has a high predilection for regional metastatic spread. Rates for WDTC lateral neck recurrence are reported to be as high as 24% in patients after initial thyroidectomy, lateral neck surgery, and adjuvant radioactive (RAI) iodine treatment. The objective of the study was to evaluate the efficacy, safety, and long-term outcome of comprehensive lateral neck dissection (LND) of levels II-V for recurrent or persistent WDTC in a tertiary referral center. METHODS: This study retrospectively analyzed the standardized approach of LND for recurrent WDTC in the lateral neck compartment. Survival was analyzed by Cox regression analysis. RESULTS: Three hundred and seven patients underwent 429 LND for cytopathology-confirmed lateral neck recurrent WDTC at the University of Texas MD Anderson Cancer Center between 1994 and 2012. The vast majority (90%) of patients were originally treated elsewhere. Multilevel lateral neck dissection had been originally performed in 80% of patients, with 17% having undergone at least two previous operations. Two hundred and sixty-seven (87%) patients had previous RAI. The most common levels of recurrence were levels III and IV (33% and 33%, respectively). Postoperative complications were seen in 7% of patients. Median follow-up was 7.2 years. In-field lateral neck control was 96% at 10 years. Overall lateral neck regional control, overall survival (OS), and disease-specific survival (DSS) at 10 years was 88%, 78%, and 91%, respectively. When stratifying by age (<24 years, 24-50 years, and >50 years), OS and DSS was significantly better in patients <50 years (OS: p < 0.001; DSS: p < 0.001). However, there was worse overall lateral neck control in the younger group (<24 years; p = 0.04). Regional recurrence after salvage LND occurred within a median time interval of 20.0 months (2.9-121.3 months), of which 2% (8/429) developed in-field lateral neck recurrences. Of those with any lateral neck recurrence after salvage LND, 24/30 (80%) patients successfully underwent another LND, resulting in an ultimate 98% lateral neck regional control rate. CONCLUSIONS: Expert comprehensive LND of levels II-V is associated with few perioperative complications and results in very high in-field regional control rate and ultimate lateral neck control in recurrent/persistent WDTC.

Sonographic Evaluation of Intrathyroid Metastases.

OBJECTIVES: Intrathyroid metastases from extrathyroid primary tumors are rare. Clinical findings may be subtle, but detection of intrathyroid metastases has improved with sonography. The objective of this study was to evaluate the sonographic appearance of intrathyroid metastases. METHODS: Patients with thyroid masses with cytopathologic features matching those of an extrathyroid primary tumor were retrospectively identified. The appearances of intrathyroid metastases on sonography were reviewed for the following features: size, margin regularity, echogenicity, echotexture, vascularity on power or color Doppler ultrasonography, and the presence or absence of any associated cervical adenopathy. RESULTS: The study included 52 patients. The most frequent primary tumor sites were lung, head and neck, and breast. Intrathyroid metastases presented as a discrete nodule in 34 patients and as diffuse infiltration of the gland in 18 patients. The discrete nodules ranged in size from 1.1 to 5.6 cm (mean ± SD, 2.5 ± 1.2 cm). Thirty-three lesions (63%) had irregular margins, and 19 (37%) had well-defined margins. Most of the lesions were heterogeneously hypoechoic (n = 50, 96%). Vascularity was present in 32 of 50 measured lesions (64%) that were evaluated with Doppler sonography. Cervical adenopathy was present in 37 patients (71%). CONCLUSIONS: Intrathyroid metastases have sonographic characteristics similar to those described for both benign and malignant thyroid diseases. In patients with a previous or current extrathyroid malignancy, thyroid nodules or diffuse infiltration of the thyroid gland on sonography should be viewed as a potential intrathyroid metastasis and evaluated via ultrasound-guided fine-needle aspiration regardless of the site of the primary tumor.

Well-differentiated thyroid cancer with aerodigestive tract invasion: Long-term control and functional outcomes.

BACKGROUND: Well-differentiated thyroid cancer (WDTC) invading the aerodigestive tract is an uncommon entity associated with significant morbidity and reduced survival. METHODS: We reviewed the surgical treatment, oncologic control, and functional outcomes of 69 consecutive patients with WDTC invading the upper aerodigestive tract. RESULTS: Complete tumor excision with negative margins was achieved in 62% of patients. Tracheostomy dependence (27%) and permanent hypoparathyroidism (49%) were present or the result of surgery. Seventy-one percent of patients ate a regular diet, 59% had normal speech, and the majority (62%) reported normal activities of daily living. The local, regional, and distant recurrence was 1%, 14%, and 23%, respectively. The 5-year overall survival (OS) and disease-free survival (DFS) was 71% and 45%, respectively. CONCLUSION: Surgical resection and appropriate adjuvant treatment can achieve excellent locoregional control while preserving function and quality of life. Long-term survival is limited by the high incidence of distant metastasis.

Association of TERT Promoter Mutation, But Not BRAF Mutation, With Increased Mortality in PTC.

CONTEXT: Papillary thyroid carcinoma (PTC) carrying the BRAF mutation has been reported to be associated with high recurrence and potentially increased mortality. PTC carrying the TERT promoter mutation has been associated with older age, recurrence, and aggressive disease. OBJECTIVE: The objective of this study was to determine the association of BRAF and TERT promoter gene alterations with recurrence and survival in a high-risk population. DESIGN: Genomic DNA was analyzed for the BRAF mutation from 256 persistent/recurrent PTC (p/rPTC; 202 new, 54 previously reported) and for the TERT promoter mutation and polymorphism (242 p/rPTC). Two-tailed Fisher exact tests or the Pearson χ(2) test were performed for the associations between mutations and other variables. Overall and disease-free survivals were compared by log rank tests on Kaplan-Meier plots and by Cox regression analysis. TERT promoter constructs were tested in PTC cell lines to determine their activities in these cells. RESULTS: BRAF V600E mutation was identified in 235 of 256 (91.8%), TERT promoter mutation at -124 was detected in 77 of 242 (31.8%), and TERT promoter polymorphism at -245 was found in 113 of 242 (46.7%) p/rPTC patients. A significant difference in survival was found in p/rPTC patients with the TERT promoter mutation, which also displayed increased activity in vitro as compared to the nonmutated promoter sequence. No association was noted between the BRAF mutation or TERT promoter polymorphism and recurrence or survival. A drawback of our study could be the limited number of patients with nonmutated BRAF (21 of 256 [8.2%]). CONCLUSIONS: Mutation in the TERT promoter, but not in BRAF, was associated with decreased survival in 19 (24.7%) p/rPTC patients who died of disease and in 38 (49.4%) p/rPTC patients who died at last contact. The presence or absence of the BRAF mutation and TERT promoter polymorphism, however, was not significantly correlated with survival.

Management of recurrent/persistent nodal disease in patients with differentiated thyroid cancer: a critical review of the risks and benefits of surgical intervention versus active surveillance.

BACKGROUND: The primary goals of this interdisciplinary consensus statement are to define the eligibility criteria for management of recurrent and persistent cervical nodal disease in patients with differentiated thyroid cancer (DTC) and to review the risks and benefits of surgical intervention versus active surveillance. METHODS: A writing group was convened by the Surgical Affairs Committee of the American Thyroid Association and was tasked with identifying the important clinical elements to consider when managing recurrent/persistent nodal disease in patients with DTC based on the available evidence in the literature and the group's collective experience. SUMMARY: The decision on how best to manage individual patients with suspected recurrent/persistent nodal disease is challenging and requires the consideration of a significant number of variables outlined by the members of the interdisciplinary team. Here we report on the consensus opinions that were reached by the writing group regarding the technical and clinical issues encountered in this patient population. CONCLUSIONS: Identification of recurrent/persistent disease requires a team decision-making process that includes the patient and physicians as to what, if any, intervention should be performed to best control the disease while minimizing morbidity. Several management principles and variables involved in the decision making for surgery versus active surveillance were developed that should be taken into account when deciding how best to manage a patient with DTC and suspected recurrent or persistent cervical nodal disease.

Development and characterization of six new human papillary thyroid carcinoma cell lines.

CONTEXT: Cell lines are a widely used tool in cancer research. However, despite the relatively high incidence of papillary thyroid carcinoma (PTC), there are only four PTC cell lines available for international research audience. OBJECTIVE: The objective of this study was to establish and characterize new PTC cell lines that represent primary tumor biology. Surgical specimens were obtained to generate PTC cell lines. Short tandem repeat profiling was used to confirm the uniqueness of the cell lines against databases of known cell lines and mutations were assessed using Sequenom. The expression of thyroid-specific genes was examined using real-time PCR. Tumorigenicity was determined using an orthotopic thyroid xenograft tumor mouse model. RESULTS: Six PTC cell lines (five conventional PTCs and one follicular variant of PTC) were generated and found to be unique when compared by short tandem repeat profiling against databases of all existing cell lines. The five conventional PTC cell lines carry the BRAF V600E mutation and the follicular variant of PTC cell line had an NRAS mutation. Five of the six cell lines had a mutation in the promoter of the human telomerase reverse transcriptase gene. None of the cell lines have RET/PTC rearrangements. Three cell lines were tumorigenic in the orthotopic thyroid xenograft tumor mouse model. CONCLUSIONS: These five characterized conventional PTC cell lines and the unique follicular variant of PTC cell line should be valuable reagents for thyroid cancer research. The three tumorigenic cell lines can be used for in vivo testing of targeted therapeutic and novel agents.

Mutational landscape of aggressive cutaneous squamous cell carcinoma.

PURPOSE: Aggressive cutaneous squamous cell carcinoma (cSCC) is often a disfiguring and lethal disease. Very little is currently known about the mutations that drive aggressive cSCC. EXPERIMENTAL DESIGN: Whole-exome sequencing was performed on 39 cases of aggressive cSCC to identify driver genes and novel therapeutic targets. Significantly, mutated genes were identified with MutSig or complementary methods developed to specifically identify candidate tumor suppressors based upon their inactivating mutation bias. RESULTS: Despite the very high-mutational background caused by UV exposure, 23 candidate drivers were identified, including the well-known cancer-associated genes TP53, CDKN2A, NOTCH1, AJUBA, HRAS, CASP8, FAT1, and KMT2C (MLL3). Three novel candidate tumor suppressors with putative links to cancer or differentiation, NOTCH2, PARD3, and RASA1, were also identified as possible drivers in cSCC. KMT2C mutations were associated with poor outcome and increased bone invasion. CONCLUSIONS: The mutational spectrum of cSCC is similar to that of head and neck squamous cell carcinoma and dominated by tumor-suppressor genes. These results improve the foundation for understanding this disease and should aid in identifying and treating aggressive cSCC.

Measuring the extent of total thyroidectomy for differentiated thyroid carcinoma using radioactive iodine imaging: relationship with serum thyroglobulin and clinical outcomes.

IMPORTANCE Despite performing total thyroidectomy (TT), postoperative radioactive iodine (RAI) imaging often demonstrates the presence of residual thyroid tissue within the operative bed. OBJECTIVE To measure the extent of TT using postoperative RAI imaging and assessing serum thyroglobulin (Tg) level for patients with differentiated thyroid carcinoma (DTC). DESIGN, SETTING, AND PARTICIPANTS We evaluated 245 patients undergoing TT for clinically staged cT1-3N0M0 DTC, who underwent diagnostic postoperative RAI imaging. INTERVENTIONS Total thyroidectomy. MAIN OUTCOMES AND MEASURES On the basis of quantitative measurements, RAI uptake (RAIU) in the thyroid bed of 0.2% of administered activity was selected as the cutpoint to determine the presence or absence of thyroid remnant. RESULTS By postoperative RAI imaging, TT in 106 patients (43%) resulted in RAIU of less than 0.2%. In the remaining 139 patients (57%), there was measurable iodine-avid thyroid tissue and/or tumor in the thyroid bed (n = 117 [84%]), the neck (n = 4 [3%]), or both (n = 18 [13%]). For the entire study population, mean 24-hour RAIU was 0.62%. Stimulated serum Tg levels were obtained in 232 of 245 patients (95%). Measurable stimulated Tg level (≥1 ng/mL) (to convert to micrograms per liter, multiply by 1) was found in 26 of 102 patients (25%) without thyroid remnant and in 87of 133 patients (65%) with thyroid remnant (P < .001). CONCLUSIONS AND RELEVANCE A goal of postthyroidectomy RAIU of less than 0.2% helps maximize the likelihood of an unmeasurable postoperative Tg level, potentially simplifying follow-up evaluation and reducing the use of postoperative RAI in order to facilitate surveillance.

Use of transoral sonography with an endocavitary transducer in diagnosis, fine-needle aspiration biopsy, and intraoperative localization of retropharyngeal masses.

OBJECTIVE: The purpose of this article is to describe the use of transoral sonography in the diagnosis, fine-needle aspiration (FNA) biopsy, and intraoperative localization of retropharyngeal masses. MATERIALS AND METHODS: We reviewed images and data for eight patients with a retropharyngeal mass identified on CT, MRI, or PET/CT as being suspicious for a metastatic Rouviere node. Transoral ultrasound was performed using a commercially available endorectal or endovaginal transducer. Transoral ultrasound-guided FNA biopsy was performed using a needle guide attached to the transducer shaft. Color and power Doppler imaging were used to identify the internal carotid artery and jugular vein and to plan the safest path to the targeted mass. The mass was intraoperatively localized by marking the mucosa with a permanent marker or by injecting methylene blue. RESULTS: There were six patients with a history of thyroid cancer (five papillary cancers and one medullary cancer), one patient with a history of esthesioneuroblastoma, and one patient with no history of cancer. Transoral ultrasound imaging was successful in all eight patients. Transoral ultrasound-guided FNA biopsy was performed in four patients, and a satisfactory cytologic diagnosis was obtained in all cases, although in one of those four cases, an additional core biopsy with an 18-gauge needle was performed to completely rule out lymphoma. Six patients underwent a transoral resection of the lesion. In three of them, the lesion was localized intraoperatively by making a mark on the mucosa and in one case by adding transoral ultrasound-guided injection of methylene blue. CONCLUSION: Transoral ultrasound can be used to visualize, sample, and localize abnormal masses in the retropharyngeal space, such as metastatic Rouviere nodes in patients with a history of head and neck cancer.

Detection of thyroid cancer stem cells in papillary thyroid carcinoma.

CONTEXT: Special populations of cells that can efficiently initiate tumor growth have been characterized, and this feature supports the cancer stem cell theory. These cancer stem cell populations have been identified with CD44 and POU5F1. Most cancer stem cells express high levels of CD44 and low levels of CD24. In thyroid lesions, cancer stem cells have been detected in anaplastic carcinoma. However, little is known about the presence of cancer stem cells in papillary thyroid carcinoma (PTC), especially in recurrent PTC. OBJECTIVE AND DESIGN: PTC cells were labeled and sorted by flow cytometry to obtain two populations. Total RNA was prepared from cells with high CD44 and CD24 expressions (CD44+CD24+) and from cells with high CD44 and low CD24 expressions (CD44+CD24-). The expressions of the stem cell marker POU5F1 and several differentiated thyroid markers were measured via real-time PCR. RESULTS: CD44+CD24- cells were present in all PTCs tested, and the percentage of these cells was higher in clinically aggressive recurrent PTC than in less aggressive primary PTCs. Higher expression of POU5F1 was found in CD44+CD24- cells compared with that of CD44+CD24+ cells. The expression of POU5F1 was higher in thyrospheroids grown in serum-free condition than in cells grown in the presence of serum from the same patient, and the tumor was initiated in mice using thyrospheroids. CONCLUSIONS: The percentage of CD44+CD24- cells varied from tumor to tumor. Our findings suggest that cancer stem cells are present in PTC.

Src inhibitors in suppression of papillary thyroid carcinoma growth.

BACKGROUND: Papillary thyroid carcinoma is the most common thyroid malignancy. Most papillary thyroid carcinomas contain BRAF mutations or RET/PTC rearrangements, thus providing targets for biologic therapy. Our previous studies had suggested papillary thyroid carcinomas (PTCs) with a BRAF mutation and the RET/PTC1 rearrangement have different sensitivities to MEK1/2 inhibitors, suggesting different signaling transduction pathways were involved. METHODS: Src signaling transduction pathway in PTC cells was examined using Src inhibitors (PP2, SU6656, or dasatinib) and si-Src RNA in vitro by Western blot analysis and proliferation analysis. An orthotopic xenograft mouse model was used for the in vivo studies using dasatinib. RESULTS: In PTC cells, Src inhibitors suppressed p-Src and p-FAK and inhibited cell growth. In addition, significant suppression and extension of the p-ERK1/2 dephosphorylation were detected in RET/PTC1-rearranged cells in combination with an MEK inhibitor (CI-1040). The Src family kinase/ABL inhibitor, dasatinib, significantly decreased tumor volume in mice inoculated with PTC cells carrying the RET/PTC1 rearrangement. In BRAF-mutated PTC cells, Src inhibitors effectively suppressed p-Src expression and dasatinib significantly decreased tumor volume with twice daily treatment. CONCLUSION: Src inhibitors effectively inhibited the Src signaling transduction pathway in PTC cells in vitro and dasatinib suppressed tumor growth in vivo. These results suggested that Src signaling transduction pathway plays an important role in regulating growth in PTC cells. Combination of Src and MEK1/2 inhibitors extended the dephosphorylation of extracellular signal-regulated kinase (ERK)1/2 in PTCs carrying the RET/PTC1 rearrangement suggesting that combination therapy with complementary inhibitors of other signaling transduction pathways may be needed to effectively suppress growth and induce apoptosis in these cells.

Long-term follow-up data may help manage patient and parent expectations for pediatric patients undergoing thyroidectomy.

BACKGROUND: We investigated the incidence and impact of postoperative complications in children who underwent total thyroidectomy (TTx). METHODS: The records of all pediatric patients undergoing TTx (2001-2011) at our institution were retrospectively reviewed for the occurrence of biochemical hypothyroidism (thyroid-stimulating hormone >10 mIU/mL), laboratory assessments, and medication nonadherence. RESULTS: The 74 patients (median age, 12.5 years) had thyroid cancer (differentiated, n = 39; medullary, n = 16) or benign pathology (n = 19; 16 with multiple endocrine neoplasia type 2A). The median postoperative follow-up was 3.2 years; 46 patients (62%) had ≥ 1 year follow-up. Forty-one percent had ≥ 1 period of medication nonadherence; this was not associated with age at TTx (P = .30). Non-treatment-related hypothyroidism occurred in 33% of patients during postoperative year (POY) 1. The number of POY1 laboratory assessments among the 30% of patients with parathyroid dysfunction was more than twice that among patients with normal parathyroid function (median assessments per year 8 vs 3; P < .0001). Forty-four percent of patients/families reported behavioral or physiologic changes; 40% were concomitant with abnormal thyroid function. CONCLUSION: More than 40% of pediatric patients were unable to fully adhere to postoperative medication regimens, and non-treatment-related hypothyroidism was common. Postoperative hypoparathyroidism doubled the number of laboratory assessments obtained. These data may help families better prepare for TTx sequelae.