Christine J. O'Neill

Association Between BRAF V600E Mutation and Recurrence of Papillary Thyroid Cancer

PURPOSE To investigate the prognostic value of BRAF V600E mutation for the recurrence of papillary thyroid cancer (PTC). PATIENTS AND METHODS This was a retrospective multicenter study of the relationship between BRAF V600E mutation and recurrence of PTC in 2,099 patients (1,615 women and 484 men), with a median age of 45 years (interquartile range [IQR], 34 to 58 years) and a median follow-up time of 36 months (IQR, 14 to 75 months). RESULTS The overall BRAF V600E mutation prevalence was 48.5% (1,017 of 2,099). PTC recurrence occurred in 20.9% (213 of 1,017) of BRAF V600E mutation-positive and 11.6% (125 of 1,082) of BRAF V600E mutation-negative patients. Recurrence rates were 47.71 (95% CI, 41.72 to 54.57) versus 26.03 (95% CI, 21.85 to 31.02) per 1,000 person-years in BRAF mutation-positive versus -negative patients (P < .001), with a hazard ratio (HR) of 1.82 (95% CI, 1.46 to 2.28), which remained significant in a multivariable model adjusting for patient sex and age at diagnosis, medical center, and various conventional pathologic factors. Significant association between BRAF mutation and PTC recurrence was also found in patients with conventionally low-risk disease stage I or II and micro-PTC and within various subtypes of PTC. For example, in BRAF mutation-positive versus -negative follicular-variant PTC, recurrence occurred in 21.3% (19 of 89) and 7.0% (24 of 342) of patients, respectively, with recurrence rates of 53.84 (95% CI, 34.34 to 84.40) versus 19.47 (95% CI, 13.05 to 29.04) per 1,000 person-years (P < .001) and an HR of 3.20 (95% CI, 1.46 to 7.02) after adjustment for clinicopathologic factors. BRAF mutation was associated with poorer recurrence-free probability in Kaplan-Meier survival analyses in various clinicopathologic categories. CONCLUSION This large multicenter study demonstrates an independent prognostic value of BRAF V600E mutation for PTC recurrence in various clinicopathologic categories.

Differential Clinicopathological Risk and Prognosis of Major Papillary Thyroid Cancer Variants

CONTEXT Individualized management, incorporating papillary thyroid cancer (PTC) variant-specific risk, is conceivably a useful treatment strategy for PTC, which awaits comprehensive data demonstrating differential risks of PTC variants to support. OBJECTIVE This study sought to establish the differential clinicopathological risk of major PTC variants: conventional PTC (CPTC), follicular-variant PTC (FVPTC), and tall-cell PTC (TCPTC). METHODS This was a retrospective study of clinicopathological outcomes of 6282 PTC patients (4799 females and 1483 males) from 26 centers and The Cancer Genome Atlas in 14 countries with a median age of 44 years (interquartile range, 33-56 y) and median follow-up time of 37 months (interquartile range, 15-82 mo). RESULTS The cohort consisted of 4702 (74.8%) patients with CPTC, 1126 (17.9%) with FVPTC, and 239 (3.8%) with TCPTC. The prevalence of high-risk parameters was significantly different among the three variants, including extrathyroidal invasion, lymph node metastasis, stages III/IV, disease recurrence, mortality, and the use (need) of radioiodine treatment (all P < .001), being highest in TCPTC, lowest in FVPTC, and intermediate in CPTC, following an order of TCPTC > CPTC ≫ FVPTC. Recurrence and mortality in TCPTC, CPTC, and FVPTC were 27.3 and 6.7%, 16.1 and 2.5%, and 9.1 and 0.6%, corresponding to events per 1000 person-years (95% confidence interval [CI]) of 92.47 (64.66-132.26) and 24.61 (12.31-49.21), 34.46 (30.71-38.66), and 5.87 (4.37-7.88), and 24.73 (18.34-33.35) and 1.68 (0.54-5.21), respectively. Mortality hazard ratios of CPTC and TCPTC over FVPTC were 3.44 (95% CI, 1.07-11.11) and 14.96 (95% CI, 3.93-56.89), respectively. Kaplan-Meier survival analyses showed the best prognosis in FVPTC, worst in TCPTC, and intermediate in CPTC in disease recurrence-free probability and disease-specific patient survival. This was particularly the case in patients at least 45 years old. CONCLUSION This large multicenter study demonstrates differential prognostic risks of the three major PTC variants and establishes a unique risk order of TCPTC > CPTC ≫ FVPTC, providing important clinical implications for specific variant-based management of PTC.

Association of FOXE1 Polyalanine Repeat Region with Papillary Thyroid Cancer

CONTEXT Polyalanine tract variations in transcription factors have been identified for a wide spectrum of developmental disorders. The thyroid transcription factor forkhead factor E1 (FOXE1) contains a polymorphic polyalanine tract with 12-22 alanines. Single-nucleotide polymorphisms (SNP) close to this locus are associated with papillary thyroid cancer (PTC), and a strong linkage disequilibrium block extends across this region. OBJECTIVE The objective of the study was to assess whether the FOXE1 polyalanine repeat region was associated with PTC and to assess the effect of polyalanine repeat region variants on protein expression, DNA binding, and transcriptional function on FOXE1-responsive promoters. DESIGN This was a case-control study. SETTING The study was conducted at a tertiary referral hospital. PATIENTS AND METHODS The FOXE1 polyalanine repeat region and tag SNP were genotyped in 70 PTC, with a replication in a further 92 PTC, and compared with genotypes in 5767 healthy controls (including 5667 samples from the Wellcome Trust Case Control Consortium). In vitro studies were performed to examine the protein expression, DNA binding, and transcriptional function for FOXE1 variants of different polyalanine tract lengths. RESULTS All the genotyped SNP were in tight linkage disequilibrium, including the FOXE1 polyalanine repeat region. We confirmed the strong association of rs1867277 with PTC (overall P = 1 × 10(-7), odds ratio 1.84, confidence interval 1.31-2.57). rs1867277 was in tight linkage disequilibrium with the FOXE1 polyalanine repeat region (r(2) = 0.95). FOXE1(16Ala) was associated with PTC with an odds ratio of 2.23 (confidence interval 1.42-3.50; P = 0.0005). Functional studies in vitro showed that FOXE1(16Ala) was transcriptionally impaired compared with FOXE1(14Ala), which was not due to differences in protein expression or DNA binding. CONCLUSIONS We have confirmed the previous association of FOXE1 with PTC. Our data suggest that the coding polyalanine expansion in FOXE1 may be responsible for the observed association between FOXE1 and PTC.

Standard and Emerging Therapies for Metastatic Differentiated Thyroid Cancer

Differentiated thyroid cancer accounts for >90% of cases of thyroid cancer, with most patients having an excellent prognosis. Distant metastases occur in 10%-15% of patients, decreasing the overall 10-year survival rate in this group to 40%. Radioactive iodine has been the mainstay of treatment for distant metastases, with good results when lesions retain the ability to take up iodine. For patients with metastatic disease resistant to radioactive iodine, treatment options are few and survival is poor. Chemotherapy and external beam radiotherapy have been used in these patients, but with disappointing results. In recent years, our understanding of the molecular pathways involved in thyroid cancer has increased and a number of molecular targets have been identified. These targets include the proto-oncogenes BRAF and RET, known to be common mutations in thyroid cancer; vascular endothelial growth factor receptor and platelet-derived growth factor receptor, associated with angiogenesis; and the sodium-iodide symporter, with the aim of restoring its expression and hence radioactive iodine uptake. There are now multiple trials of tyrosine kinase inhibitors, angiogenesis inhibitors, and other novel agents available to patients with metastatic thyroid cancer. This review discusses both traditional and novel treatments for metastatic differentiated thyroid cancer with a particular focus on emerging treatments for patients with radioactive iodine-refractory disease.

Sutureless total thyroidectomy: a safe and cost-effective alternative

Background:  Advanced vessel sealing devices provide an alternative to conventional ligation techniques for thyroidectomy. To date, most studies have been inadequately powered to explore differences in the infrequent post‐operative complications following thyroidectomy. This study is designed to compare the outcomes of sutureless thyroidectomy and conventional thyroidectomy for recurrent laryngeal nerve (RLN) injury, permanent hypoparathyroidism, and haematoma formation.

Adrenal incidentalomas: risk of adrenocortical carcinoma and clinical outcomes.

The number of incidentally discovered adrenal lesions is increasing due to the widespread use of abdominal imaging. Although most incidentalomas are benign, larger suspicious lesions will require adrenalectomy. The aim of this study is to determine the risk of malignancy in patients undergoing surgery for adrenal incidentaloma; and to compare clinical outcomes in those with adrenocortical carcinoma (ACC) based on the mode of presentation.

Sutureless thyroidectomy: surgical technique

The technique of thyroid surgery has continued to evolve over the last 200 years. Sutureless thyroidectomy is one of the recent developments in surgical technique and is made possible by the use of vessel sealing devices. The most frequently used devices include a bipolar coagulation device (Ligasure Precise) and ultrasonic dissecting shears (Harmonic Scalpel FOCUS). The use of this technology is safe with minimal morbidity and has been shown in numerous studies to significantly decrease operative time. Over 3000 thyroid and parathyroid procedures, both open and minimally invasive, have been performed with vessel sealing devices within the University of Sydney Endocrine Surgery Unit since the technology was introduced in 2005. This manuscript discusses the technique of sutureless thyroidectomy focusing on points of difference in comparison with conventional thyroidectomy using ligatures or clips.

Parathyroid carcinoma: increasing incidence and changing presentation

Background:  Parathyroid carcinoma has been regarded as an exceedingly rare disease worldwide, responsible for less than 1% of cases of primary hyperparathyroidism. However, there have been anecdotal reports recently of an increasing number of patients presenting with parathyroid carcinoma. The aim of this study was to examine the changing incidence and presentation of parathyroid cancer within a single centre.

TERT promoter mutations are a major indicator of recurrence and death due to papillary thyroid carcinomas.

TERT promoter mutations have been associated with adverse prognosis in papillary thyroid carcinomas (PTCs).

Disease outcomes and nodal recurrence in patients with papillary thyroid cancer and lateral neck nodal metastases

The prognostic influence of lateral neck nodal metastases present at the time of diagnosis of papillary thyroid cancer (PTC) remains controversial. This study aims to document disease outcomes and nodal recurrence rates in such patients.