Clara Ugolini

BRAF(V600E) mutation and outcome of patients with papillary thyroid carcinoma: a 15-year median follow-up study.

BACKGROUND The BRAF(V600E) mutation is the most frequent genetic alteration in papillary thyroid carcinoma (PTC). The role of BRAF(V600E) mutation as a poor prognostic factor has been controversially reported in series with short-term follow-ups. In this study we verified the prognostic value of the BRAF(V600E) mutation in PTC patients with a long-term follow-up. METHODS We studied 102 PTC patients with a median follow-up of 15 yr. The BRAF(V600E) mutation was analyzed by PCR-single-strand conformational polymorphism and sequencing. The correlation between the presence/absence of the BRAF(V600E) mutation, clinicopathological features, and outcome of PTC patients were evaluated. RESULTS The BRAF(V600E) mutation was found in 38 of 102 (37.3%) PTC patients, and was significantly more frequent in patients older than 60 yr (P = 0.02), in advanced stages (P = 0.03), and in cases with vascular invasion (P = 0.02). At univariate analysis the worst outcome for PTC patients was significantly correlated with clinicopathological features (i.e. age, tumor size, extrathyroid extension, lymph node and distant metastases, advanced stage, vascular endothelial growth factor expression, and vascular invasion) and the BRAF(V600E) mutation (P < 0.002). However, at multivariate analysis only the BRAF(V600E) mutation showed an independent correlation with the worst outcome (P = 0.03). Moreover, the survival curves of PTC patients showed a lower percentage of survivors in the BRAF(V600E)-mutated group (P = 0.015). CONCLUSIONS In this study the BRAF(V600E) mutation correlated with the worst outcome for PTC patients, who were not only at a higher risk not to be cured but also for death. In particular, the BRAF(V600E) mutation was demonstrated to be a poor prognostic factor independent from other clinicopathological features.

Lower levels of TSH are associated with a lower risk of papillary thyroid cancer in patients with thyroid nodular disease: thyroid autonomy may play a protective role.

Higher TSH values, even within normal ranges, have been associated with a greater risk of thyroid malignancy. The relationship between TSH and papillary thyroid cancer (PTC) has been analyzed in 10 178 patients submitted to fine needle aspiration of thyroid nodules with a cytology of PTC (n=497) or benign thyroid nodular disease (BTND, n=9681). In 942 patients, submitted to surgery (521 from BTND and 421 from PTC), the histological diagnosis confirmed an elevated specificity (99.6%) and sensitivity (98.1%) of cytology. TSH levels were significantly higher in PTC than in BTND both in the cytological and histological series and also in patients with a clinical diagnosis of multinodular goiter (MNG) and single/isolate nodule (S/I). A significant age-dependent development of thyroid autonomy (TSH <0.4 microU/ml) was observed in patients with benign thyroid disease, but not in those with PTC, diagnosed both on cytology and histology. In patients with MNG, the frequency of thyroid autonomy was higher and the risk of PTC was lower compared to those with S/I. In all patients, the presence of thyroid auto-antibodies (TAb) was associated with a significant increase of TSH. However, both in TAb positive and TAb negative patients TSH levels were significantly higher in PTC than in BTND. Our data confirm a direct relationship between TSH levels and risk of PTC in patients with nodular thyroid diseases. Thyroid autonomy conceivably protects against the risk of PTC, while thyroid autoimmunity does not play a significant role.

The BRAF(V600E) mutation is an independent, poor prognostic factor for the outcome of patients with low-risk intrathyroid papillary thyroid carcinoma: single-institution results from a large cohort study

BACKGROUND The BRAF(V600E) mutation, the most frequent genetic alteration in papillary thyroid carcinoma (PTC), was demonstrated to be a poor prognostic factor. The aim of this study was to evaluate its prognostic significance in a large cohort of low-risk intrathyroid PTC. METHODS Among the 431 consecutive PTC patients, we selected 319 patients with an intrathyroid tumor and no metastases (T1-T2, N0, M0). The BRAF(V600E) mutation was analyzed by PCR-single-strand conformation polymorphism analysis and direct genomic sequencing. The correlation between the presence/absence of the mutation, the clinical-pathological features, and the outcome of the PTC patients was investigated. RESULTS The BRAF(V600E) mutation was present in 106 of 319 PTC patients (33.2%). Its prevalence was also the same in subgroups identified according to the level of risk. The BRAF(V600E) mutation correlated with multifocality, aggressive variant, absence, or infiltration of the tumoral capsule. BRAF(V600E)-mutated PTC also required a higher number of radioiodine courses to obtain disease-free status. The BRAF(V600E) mutation was the only prognostic factor predicting the persistence of the disease in these patients after 5 yr of follow-up. CONCLUSIONS The BRAF(V600E) mutation was demonstrated to be a poor prognostic factor for the persistence of the disease independent from other clinical-pathological features in low-risk intrathyroid PTC patients. It could be useful to search for the BRAF(V600E) mutation in the workup of low-risk PTC patients to distinguish those who require less or more aggressive treatments. In particular, the high negative predictive value of the BRAF(V600E) mutation could be useful to identify, among low-risk PTC patients, those who could avoid 131-I treatment.

A Cell Proliferation and Chromosomal Instability Signature in Anaplastic Thyroid Carcinoma

Here, we show that the anaplastic thyroid carcinoma (ATC) features the up-regulation of a set of genes involved in the control of cell cycle progression and chromosome segregation. This phenotype differentiates ATC from normal tissue and from well-differentiated papillary thyroid carcinoma. Transcriptional promoters of the ATC up-regulated genes are characterized by a modular organization featuring binding sites for E2F and NF-Y transcription factors and cell cycle-dependent element (CDE)/cell cycle gene homology region (CHR) cis-regulatory elements. Two protein kinases involved in cell cycle regulation, namely, Polo-like kinase 1 (PLK1) and T cell tyrosine kinase (TTK), are part of the gene set that is up-regulated in ATC. Adoptive overexpression of p53, p21 (CIP1/WAF1), and E2F4 down-regulated transcription from the PLK1 and TTK promoters in ATC cells, suggesting that these genes might be under the negative control of tumor suppressors of the p53 and pRB families. ATC, but not normal thyroid, cells depended on PLK1 for survival. RNAi-mediated PLK1 knockdown caused cell cycle arrest associated with 4N DNA content and massive mitotic cell death. Thus, thyroid cell anaplastic transformation is accompanied by the overexpression of a cell proliferation/genetic instability-related gene cluster that includes PLK1 kinase, which is a potential molecular target for ATC treatment.

Minimally Invasive Video-Assisted Thyroidectomy for Benign Thyroid Disease: An Evidence-Based Review

BackgroundA decade after nearly all surgical disciplines developed minimally invasive techniques, the first report of a single case of minimally invasive thyroidectomy was published. Minimally invasive video-assisted thyroidectomy (MIVAT) is now considered the most widely practiced and most easily reproducible minimally invasive procedure for thyroidectomy. The aim of this review was to analyze the treatment of benign thyroid diseases by MIVAT.MethodsA systematic evidence-based literature review focusing on three questions was carried out. Additional data were obtained on the basis of our personal experience. (1) Are minimally invasive procedures indicated in the treatment of thyroid diseases? (2) Is MIVAT a safe technique and what are the demonstrated advantages? (3) Since different thyroid diseases may be treated by MIVAT, is it of any value in the treatment of benign thyroid diseases?ResultsMIVAT can be considered an appropriate treatment of some thyroid diseases; it represents a safe procedure with the same incidence of complications as traditional surgery, and also has advantages in terms of both cosmetic result and postoperative distress.ConclusionsIn spite of an increasing trend toward performing more extensive procedures other than thyroidectomy alone during videoscopic procedures, the current literature seems to reaffirm that the main and safest indication for MIVAT is benign disease.

Evidence of a Low Prevalence of RAS Mutations in a Large Medullary Thyroid Cancer Series

BACKGROUND Approximately 60% of sporadic medullary thyroid carcinomas (sMTC) remain orphan of a recognized genetic cause. Recently, a high percentage of RAS point mutations have been described in RET-negative sMTC. The aim of this study was to assess the prevalence of RAS point mutations in a large series of MTC collected in four Italian centers. METHODS For this purpose, we studied codons 12, 13, and 61 of H-, K-, and N-RAS genes in 188 MTC samples, either hereditary or sporadic, by direct sequencing. Correlations between the RAS mutational status and the clinical-pathological features of MTC patients as well as a meta-analysis of all published data were performed. RESULTS The prevalence of RAS mutations in the present series of MTC was 10.1%, and 17.6% when considering only RET-negative cases. RAS mutations were found in MTC tumoral tissue, but not in peripheral blood indicating their somatic origin. A novel mutation in codon 72 (M72I) was found, but with a low or null transforming potential. No association was found between the presence of RAS mutations and the clinical-pathological features of the patients. Although not statistically significant, a positive association between the presence of RAS mutations and a better outcome was observed. The meta-analysis of all published studies confirmed a prevalence of 8.8% for RAS mutations in MTC. CONCLUSIONS The prevalence of RAS mutations in our MTC series was relatively low and consistent with the meta-analysis data. Only somatic RAS mutations were found and only in RET-negative sMTC. Likewise, MTCs that harbor a RAS mutation identify a subgroup of tumors with less aggressive behavior. To our knowledge, this is the largest series of MTCs studied for the presence of mutations in RAS genes and the first meta-analysis on this specific topic.

The Timing of Total Thyroidectomy in RET Gene Mutation Carriers Could Be Personalized and Safely Planned on the Basis of Serum Calcitonin: 18 Years Experience at One Single Center

BACKGROUND Medullary thyroid carcinoma (MTC) is a calcitonin (CT)-producing C-cell tumor. In hereditary cases, a germline RET mutation is found in 98% of families. Because MTC is cured only if intrathyroidal, prophylactic thyroidectomy is recommended in the gene carrier (GC). AIMS The aim was to determine whether thyroidectomy performed when stimulated CT becomes detectable is as safe as prophylactic thyroidectomy and to identify the serum CT cutoff able to distinguish intrathyroidal from extrathyroidal MTC. PATIENTS Eighty-four GC were prospectively enrolled; 53 of the 84 underwent total thyroidectomy, one refused surgery, and 30 with normal basal and stimulated CT were under surveillance. The follow-up ranged from 2 to 18 yr. RESULTS GC operated on for elevated stimulated CT included 27 GC with a positive peak CT at the screening and four cases who became positive after 4 yr. All of them had intrathyroidal MTC and no node metastases; all were cured after a mean follow-up of 7.5 yr. Among those operated on for detectable basal CT, intrathyroidal tumors were found when CT was below 60 pg/ml, whereas either node metastases or larger tumors were observed when CT was above 60 pg/ml. No correlation among serum CT, age, and type of RET mutation was observed. Thirty GC were still biochemically negative at the annual control. CONCLUSIONS The time of thyroidectomy in GC with negative CT could be personalized and safely planned when stimulated CT becomes positive, independent of the type of RET mutation and patients age. In this series, a basal CT below 60 pg/ml was always associated to an intrathyroidal localization of MTC.

RET genetic screening of sporadic medullary thyroid cancer (MTC) allows the preclinical diagnosis of unsuspected gene carriers and the identification of a relevant percentage of hidden familial MTC (FMTC)

Objective  This study was aimed to demonstrate the clinical benefits of rearranged during transfection (RET) genetic screening in patients with apparently sporadic medullary thyroid cancer (MTC) not only to identify the hereditary nature of the disease in the index case but also to discover family members harbouring the same germline mutations (i.e. gene carriers) who are unaware of their condition.

Clinical features of thyroid autoimmunity are associated with thyroiditis on histology and are not predictive of malignancy in 570 patients with indeterminate nodules on cytology who had a thyroidectomy

Background  The relationship between thyroid autoimmunity and cancer is still uncertain.

L-thyroxine-treated patients with nodular goiter have lower serum TSH and lower frequency of papillary thyroid cancer: results of a cross-sectional study on 27 914 patients

The risk of papillary thyroid cancer (PTC) is related to serum TSH, and the development of thyroid autonomy by reducing TSH levels decreases the frequency of PTC in patients with nodular goiter. Our aim was to investigate the effect of L-thyroxine (LT(4)) on the frequency of PTC diagnosed by cytology in a large series of patients with nodular goiter untreated (n=20 055) or treated with L-T(4) (n=7859). L-T(4)-treated patients with respect to untreated patients presented significantly lower serum TSH (median, interquartile range: 0.30 muU/ml, 0.08-0.62 microU/ml versus 0.70 muU/ml, 0.38-1.14 muU/ml; P<0.0001) and prevalence of PTC (3.2 vs 5.1%; P<0.0001). The frequency of PTC was closely related to serum TSH, with it being lowest in patients with TSH below the normal range (<0.4 muU/ml; 189/10 059, 1.9%) and highest in patients with TSH above the normal range (>3.4 muU/ml; 21/127, 16.5%), also showing a progressive increase from the lower to the upper quartile of normal range. A significantly higher proportion of L-T(4)-treated patients (6650/7859, 84.6%) had serum TSH below the median (0.90 muU/ml) with respect to untreated patients (12,599/20,055, 62.8%; chi(2) P value <0.0001), with it being included in the range of TSH associated with a lower frequency of PTC. The relationship between serum TSH and frequency of PTC was unrelated to the type of nodularity (solitary versus multinodular) and was not age dependent. In conclusion, patients with nodular goiter, treatment with L-T(4) is responsible for the reduction of serum TSH and is associated with a decreased frequency of PTC.