Corrigendum: Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal - U-PIK Project.

[This corrects the article DOI: 10.3389/fmolb.2023.1082915.].

TERTmonitor-qPCR Detection of TERTp Mutations in Glioma.

Telomerase promoter (TERTp) mutations are frequently observed in various types of tumours and commonly characterised by two specific hotspots located at positions -124 and -146 upstream of the start codon. They enhance TERTp activity, resulting in increased TERT expression. In central nervous system (CNS) tumours, they are integrated as biomarkers, aiding in the diagnosis and with a role in prognosis, where, in some settings, they are associated with aggressive behaviour. In this study, we evaluated the performance of TERTmonitor for TERTp genotyping in a series of 185 gliomas in comparison to the traditional method, Sanger sequencing. Against the gold-standard Sanger method, TERTmonitor performed with a 97.8% accuracy. Inaccuracy was mainly due to the over-detection of variants in negative cases (by Sanger) and the presence of variants that can modify the chemistry of the probe detection. The distribution of the mutations was comparable to other series, with the -124 being the most represented (38.92% for Sanger and TERTmonitor) and more prevalent in the higher-grade tumours, gliosarcoma (50.00%) and glioblastoma (52.6%). The non-matched cases are debatable, as we may be dealing with the reduced sensitivity of Sanger in detecting rare alleles, which strengthens the use of the TERTmonitor. With this study, we present a reliable and rapid potential tool for TERTp genotyping in gliomas.

Using a Dual CRISPR/Cas9 Approach to Gain Insight into the Role of LRP1B in Glioblastoma.

LRP1B remains one of the most altered genes in cancer, although its relevance in cancer biology is still unclear. Recent advances in gene editing techniques, particularly CRISPR/Cas9 systems, offer new opportunities to evaluate the function of large genes, such as LRP1B. Using a dual sgRNA CRISPR/Cas9 gene editing approach, this study aimed to assess the impact of disrupting LRP1B in glioblastoma cell biology. Four sgRNAs were designed for the dual targeting of two LRP1B exons (1 and 85). The U87 glioblastoma (GB) cell line was transfected with CRISPR/Cas9 PX459 vectors. To assess LRP1B-gene-induced alterations and expression, PCR, Sanger DNA sequencing, and qRT-PCR were carried out. Three clones (clones B9, E6, and H7) were further evaluated. All clones presented altered cellular morphology, increased cellular and nuclear size, and changes in ploidy. Two clones (E6 and H7) showed a significant decrease in cell growth, both in vitro and in the in vivo CAM assay. Proteomic analysis of the clones' secretome identified differentially expressed proteins that had not been previously associated with LRP1B alterations. This study demonstrates that the dual sgRNA CRISPR/Cas9 strategy can effectively edit LRP1B in GB cells, providing new insights into the impact of LRP1B deletions in GBM biology.

Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal - U-PIK Project.

Background: Around 40% of ER+/HER2-breast carcinomas (BC) present mutations in the PIK3CA gene. Assessment of PIK3CA mutational status is required to identify patients eligible for treatment with PI3Kα inhibitors, with alpelisib currently the only approved tyrosine kinase inhibitor in this setting. U-PIK project aimed to conduct a ring trial to validate and implement the PIK3CA mutation testing in several Portuguese centers, decentralizing it and optimizing its quality at national level. Methods: Eight Tester centers selected two samples of patients with advanced ER+/HER2- BC and generated eight replicates of each (n = 16). PIK3CA mutational status was assessed in two rounds. Six centers used the cobas® PIK3CA mutation test, and two used PCR and Sanger sequencing. In parallel, two reference centers (IPATIMUP and the Portuguese Institute of Oncology [IPO]-Porto) performed PIK3CA mutation testing by NGS in the two rounds. The quality of molecular reports describing the results was also assessed. Testing results and molecular reports were received and analyzed by U-PIK coordinators: IPATIMUP, IPO-Porto, and IPO-Lisboa. Results: Overall, five centers achieved a concordance rate with NGS results (allele frequency [AF] ≥5%) of 100%, one of 94%, one of 93%, and one of 87.5%, considering the overall performance in the two testing rounds. NGS reassessment of discrepancies in the results of the methods used by the Tester centers and the reference centers identified one probable false positive and two mutations with low AF (1-3%, at the analytical sensitivity threshold), interpreted as subclonal variants with heterogeneous representation in the tissue sections processed by the respective centers. The analysis of molecular reports revealed the need to implement the use of appropriate sequence variant nomenclature with the identification of reference sequences (HGVS-nomenclature) and to state the tumor cell content in each sample. Conclusion: The concordance rates between the method used by each tester center and NGS validate the use of the PIK3CA mutational status test performed at these centers in clinical practice in patients with advanced ER+/HER2- BC.

Estado nutricional e consumo alimentar de produtores rurais em um assentamento de Minas Gerais / Nutritional status and food consumption of rural producers in a settlement in Minas Gerais / Estado nutricional y consumo de alimentos de productores rurales de un asentamiento en Minas Gerais

Objetivo:avaliar o estado nutricional e consumo alimentar dos trabalhadores rurais de um assentamento em Minas Gerais. Método: estudo transversal, descritivo, comparativo e observacional realizado com produtores rurais, no período de junho a outubro de 2018. Todos os participantes responderam um recordatório de 24 horas através da técnica de múltiplos passos e foram submetidos a avaliação antropométrica e pesquisa socioeconômica. Realizou-se análise descritiva dos dados Resultados:participaram dos estudos 31 trabalhadores rurais. A média dos valores do IMC foi de 26,79kg/m2. Observou-se carências nutricionais diretamente relacionadas ao tipo de alimento consumido, para as vitaminas A e C, com 254,69 RE e 67,30mg respectivamente. O consumo defibras ficou em média 8g abaixo do recomendado; e o consumo de colesterol acima, sendo 501,20mg (±1271,20). Estas inadequações são fatores de risco para desenvolvimento de doenças crônicas não transmissíveis relacionadas aos hábitos de vida, como diabetese hipertensão arterial. Conclusão:os produtores rurais apresentaram alto índice de sobrepeso e obesidade, e comorbidades associadas aos estados nutricionais, consequência da má nutrição associada a falta de atenção do Estado em assistir populações em situação de vulnerabilidade alimentar de maneira suficiente e satisfatória.

Objective: to evaluate the nutritional status and food consumption of rural workers in a settlement in Minas Gerais.Method: a cross-sectional, descriptive, comparative and observational study carried out with rural producers, from June to October 2018. All participants answered a 24-hour recall using the multiple-step technique and underwent anthropometric assessment and socioeconomic research. A descriptive analysis of the data was performed.Results: thirty-one rural workers participated in the study. The mean BMI values were 26.79kg/m2. Nutritional deficiencies directly related to the type of food consumed were observed, for vitamins A and C, there are 254.69 RE and 67.30mg respectively. Fiber consumption was on average 8g below the recommended level; and the cholesterol consumption above being 501.20mg (±1271.20). Theseinadequacies are risk factors for the development of chronic non-communicable diseases related to life habits, such as diabetes and high blood pressure.Conclusion: rural producers had a high rate of overweight and obesity, and comorbidities associated with nutritional status, a consequence of malnutrition associated with the lack of attention of the State in assisting populations in situations of food vulnerability in a sufficient and satisfactory way.

Objetivo: evaluar el estado nutricional y el consumo de alimentos de trabajadores rurales en un asentamiento de Minas Gerais.Método: estudio transversal, descriptivo, comparativo y observacional realizado con productores rurales, de junio a octubre de 2018. Todos los participantes respondieron un recordatorio de 24 horas mediante la técnica de pasos múltiples y fueron sometidos a evaluación antropométrica e investigación socioeconómica. Se realizó un análisis descriptivo de los datos. Resultados: participaron del estudio 31 trabajadores rurales, los valores medios del IMC fueron de 26,79kg/m2. Se observaron deficiencias nutricionales directamente relacionadas con el tipo de alimento consumido, para las vitaminas A y C se encuentran 254.69 RE y 67.30mg respectivamente. El consumo de fibra estuvo en promedio 8g por debajo del nivel recomendado; y el consumo de colesterol por encima de 501,20mg (±1271,20). Estasinsuficiencias son factores de riesgo para el desarrollo de enfermedades crónicas no transmisibles relacionadas con el estilo de vida, como la diabetes y la hipertensión arterial.Conclusión: los productores rurales presentaban un alto índice de sobrepeso y obesidade, y comorbilidades asociadas al estado nutricional, consecuencia de la desnutrición asociada a la falta de atención del Estado en atender de manera suficiente y satisfactoria a las poblaciones en situación de vulnerabilidad alimentaria.

Resistance to endocrine therapy in HR + and/or HER2 + breast cancer: the most promising predictive biomarkers.

Breast cancer is the most common cancer in women. It is a heterogeneous disease, encompassing different biological subtypes that differ in histological features, outcomes, clinical behaviour and different molecular subtypes. Therapy has progressed substantially over the past years with a reduction both for locoregional and systemic therapy. Endocrine therapies have considerably reduced cancer recurrence and mortality. Despite the major diagnostic and therapeutic innovations, resistance to therapy has become a main challenge, especially in metastatic breast cancer, and became a major factor limiting the use of endocrine therapeutic agents in ER positive breast cancers. Approximately 50% of patients with ER positive metastatic disease achieve a complete or partial response with endocrine therapy. However, in the remaining patients, the benefit is limited due to resistance, intrinsic or acquired, resulting in disease progression and poor outcome.Tumour heterogeneity as well as acquired genetic changes and therapeutics pressure have been involved in the endocrine therapy resistance. Nowadays, targeted sequencing of genes involved in cancer has provided insights about genomic tumour evolution throughout treatment and resistance driver mutations. Several studies have described multiple alterations in receptor tyrosine kinases, signalling pathways such as Phosphoinositide-3-kinase-protein kinase B/Akt/mTOR (PI3K/Akt/mTOR) and Mitogen-activated protein kinase (MAPK), cell cycle machinery and their implications in endocrine treatment failure.One of the current concern in cancer is personalized therapy. The focus has been the discovery of new potentially predictive biomarkers capable to identify reliably the most appropriate therapy regimen and which patients will experience disease relapse. The major concern is also to avoid overtreatment/undertreatment and development of resistance.This review focuses on the most promising predictive biomarkers of resistance in estrogen receptor-positive breast cancer and the emerging role of circulating free-DNA as a powerful tool for longitudinal monitoring of tumour molecular profile throughout treatment.

LRP1B Expression as a Putative Predictor of Response to Pegylated Liposomal Doxorubicin Treatment in Ovarian Cancer.

BACKGROUND: Pegylated liposomal doxorubicin (PLD) is among the most active therapies for recurrent/progressive ovarian cancer (OC). Low-density lipoprotein receptor-related protein 1B (LRP1B) is one of the 10 most significantly deleted genes in human cancers. It mediates endocytosis of several factors from the cellular environment including liposomes. Although the LRP1B role in cancer has not been fully disclosed, its contribution to resistance to liposomal therapies has been hypothesized. This study aimed to evaluate the impact of LRP1B protein as a possible marker of response to PLD in patients with OC. METHODS: LRP1B expression and response to PLD were analyzed in OC cell lines by qRT-PCR and PrestoBlue viability assay, respectively. LRP1B protein expression was evaluated for the first time, in tumor samples from PLD-treated patients and controls (other chemotherapies) by immunohistochemistry. Association of LRP1B staining score (determined based on intensity and percentage of positively stained cells) with clinicopathological features, response to therapy and survival outcomes was evaluated. RESULTS: OC cells with increased expression of LRP1B were more sensitive to PLD. LRP1B staining score was associated with clinicopathological features, response to therapy, and survival outcomes. Higher LRP1B levels were associated with prolonged progression-free survival. This association was more evident in patients treated with PLD and in responders to PLD. CONCLUSION: Our results support a possible role of LRP1B as a predictor of response to PLD in patients with OC.

LRP1B: A Giant Lost in Cancer Translation.

Low-density lipoprotein receptor-related protein 1B (LRP1B) is a giant member of the LDLR protein family, which includes several structurally homologous cell surface receptors with a wide range of biological functions from cargo transport to cell signaling. LRP1B is among the most altered genes in human cancer overall. Found frequently inactivated by several genetic and epigenetic mechanisms, it has mostly been regarded as a putative tumor suppressor. Still, limitations in LRP1B studies exist, in particular associated with its huge size. Therefore, LRP1B expression and function in cancer remains to be fully unveiled. This review addresses the current understanding of LRP1B and the studies that shed a light on the LRP1B structure and ligands. It goes further in presenting increasing knowledge brought by technical and methodological advances that allow to better manipulate LRP1B expression in cells and to more thoroughly explore its expression and mutation status. New evidence is pushing towards the increased relevance of LRP1B in cancer as a potential target or translational prognosis and response to therapy biomarker.

Clinical Validation of a Urine Test (Uromonitor-V2®) for the Surveillance of Non-Muscle-Invasive Bladder Cancer Patients.

The costly and burdensome nature of the current follow-up methods in non-muscle-invasive bladder cancer (NMIBC) drives the development of new methods that may alternate with regular cystoscopy and urine cytology. The Uromonitor-V2® is a new urine-based assay in the detection of hotspot mutations in three genes (TERT, FGFR3, and KRAS) for evaluation of disease recurrence. The aim of this study was to investigate the Uromonitor-V2®'s performance in detecting NMIBC recurrence and compare it with urine cytology. From February 2018 to September 2019 patients were enrolled. All subjects underwent a standard-of-care (SOC) cystoscopy, either as part of their follow-up for NMIBC or for a nonmalignant urological pathology. Urine cytology was performed in NMIBC patients. Out of the 105 patients enrolled, 97 were eligible for the study. Twenty patients presented nonmalignant lesions, 29 had a history of NMIBC with disease recurrence, and 49 had a history of NMIBC without recurrence. In NMIBC, the Uromonitor-V2® displayed a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 93.1%, 85.4%, 79.4%, and 95.3%, respectively. Urine cytology was available for 52 patients, and the sensitivity, specificity, PPV, and NPV were 26.3%, 90.9%, 62.5%, and 68.2%, respectively. With its high NPV of 95.3%, the Uromonitor-V2® revealed promising properties for the follow-up of patients with NMIBC.

Predictive Biomarkers and Patient Outcome in Platinum-Resistant (PLD-Treated) Ovarian Cancer.

Identification of predictive biomarkers for ovarian cancer (OC) treatment, particularly in the platinum-resistant/refractory setting, is highly relevant for clinical management. E-cadherin, vimentin, and osteopontin (OPN) are proteins associated with tumor microenvironment (TME) remodelling that play key roles in cancer. This study aimed to evaluate the association between the staining patterns of these proteins with survival outcomes in a series of OC patients, namely in patients with platinum-resistant/refractory disease. Low E-cadherin expression and high vimentin expression in all patient groups (as well as for E-cadherin in the platinum-resistant arm) were significantly associated with longer overall survival (OS). Low cytoplasmic OPN expression (and cytoplasmic and membrane OPN in the platinum-resistant arm) were significantly associated with longer OS. In patients that responded to treatment (pegylated liposomal doxorubicin (PLD) or other), low cytoplasmic OPN expression was also associated with longer progression-free survival (PFS). In the other hand, high nuclear OPN-c expression in patients that respond to treatment was associated with longer OS and longer PFS. Longer PFS was also associated with high expression of both nuclear and cytoplasm OPN-c, in platinum-resistant patients and in those that responded to PLD. Our study indicates that the expression of E-cadherin, vimentin, and OPN may have prognostic implications. Nuclear OPN-c and cytoplasm OPN expression are putative predictive markers in platinum-resistant (PLD treated) ovarian cancer patients.

Biomarkers for Bladder Cancer Diagnosis and Surveillance: A Comprehensive Review.

Bladder cancer (BC) ranks as the sixth most prevalent cancer in the world, with a steady rise in its incidence and prevalence, and is accompanied by a high morbidity and mortality. BC is a complex disease with several molecular and pathological pathways, thus reflecting different behaviors depending on the clinical staging of the tumor and molecular type. Diagnosis and monitoring of BC is mainly performed by invasive tests, namely periodic cystoscopies; this procedure, although a reliable method, is highly uncomfortable for the patient and it is not exempt of comorbidities. Currently, there is no formal indication for the use of molecular biomarkers in clinical practice, even though there are several tests available. There is an imperative need for a clinical non-invasive testing for early detection, disease monitoring, and treatment response in BC. In this review, we aim to assess and compare different tests based on molecular biomarkers and evaluate their potential role as new molecules for bladder cancer diagnosis, follow-up, and treatment response monitoring.

Validation of a Novel, Sensitive, and Specific Urine-Based Test for Recurrence Surveillance of Patients With Non-Muscle-Invasive Bladder Cancer in a Comprehensive Multicenter Study.

Bladder cancer (BC), the most frequent malignancy of the urinary system, is ranked the sixth most prevalent cancer worldwide. Of all newly diagnosed patients with BC, 70-75% will present disease confined to the mucosa or submucosa, the non-muscle-invasive BC (NMIBC) subtype. Of those, approximately 70% will recur after transurethral resection (TUR). Due to high rate of recurrence, patients are submitted to an intensive follow-up program maintained throughout many years, or even throughout life, resulting in an expensive follow-up, with cystoscopy being the most cost-effective procedure for NMIBC screening. Currently, the gold standard procedure for detection and follow-up of NMIBC is based on the association of cystoscopy and urine cytology. As cystoscopy is a very invasive approach, over the years, many different noninvasive assays (both based in serum and urine samples) have been developed in order to search genetic and protein alterations related to the development, progression, and recurrence of BC. TERT promoter mutations and FGFR3 hotspot mutations are the most frequent somatic alterations in BC and constitute the most reliable biomarkers for BC. Based on these, we developed an ultra-sensitive, urine-based assay called Uromonitor®, capable of detecting trace amounts of TERT promoter (c.1-124C > T and c.1-146C > T) and FGFR3 (p.R248C and p.S249C) hotspot mutations, in tumor cells exfoliated to urine samples. Cells present in urine were concentrated by the filtration of urine through filters where tumor cells are trapped and stored until analysis, presenting long-term stability. Detection of the alterations was achieved through a custom-made, robust, and highly sensitive multiplex competitive allele-specific discrimination PCR allowing clear interpretation of results. In this study, we validate a test for NMIBC recurrence detection, using for technical validation a total of 331 urine samples and 41 formalin-fixed paraffin-embedded tissues of the primary tumor and recurrence lesions from a large cluster of urology centers. In the clinical validation, we used 185 samples to assess sensitivity/specificity in the detection of NMIBC recurrence vs. cystoscopy/cytology and in a smaller cohort its potential as a primary diagnostic tool for NMIBC. Our results show this test to be highly sensitive (73.5%) and specific (93.2%) in detecting recurrence of BC in patients under surveillance of NMIBC.

Liposomal therapies in oncology: does one size fit all?

Liposomal therapies opened the chapter of nanomedicine, in 1995, with the approval of liposomal doxorubicin (Doxil®) for the treatment of numerous types of cancer. For the first time, liposomes permitted the employment of potent chemotherapeutic agents with improved pharmacokinetic and pharmacodynamic profiles, with less undesired side effects. Liposomal therapies allow the drug encapsulation and more selective delivery in the tumor bed, particularly due to the enhanced permeation and retention effect. These unique characteristics explain why liposomal therapies are being increasingly considered as alternatives in cancer therapy and represent an important research field with the recent approval for clinical use and emergent formulations in clinical trials. Even so, the response rate of liposomal therapies varies between 5 and 71%, and they are still indistinguishably given to every patient. As already well-demonstrated for conventional chemotherapies and targeted therapies, there is also the need for predictive biomarkers that allow a better use of liposomal drugs, with higher patient quality of life. Our aim in this review was to address the approved liposomal therapies and to summarize the information concerning possible predictive markers of response in their various clinical applications, to personalize each patient treatment and maximize its efficacy.

WT1, MSH6, GATA5 and PAX5 as epigenetic oral squamous cell carcinoma biomarkers - a short report.

PURPOSE: Oral squamous cell carcinoma (OSCC) is a frequently occurring aggressive malignancy with a heterogeneous clinical behavior. Based on the paucity of specific early diagnostic and prognostic biomarkers, which hampers the appropriate treatment and, ultimately the development of novel targeted therapies, we aimed at identifying such biomarkers through a genetic and epigenetic analysis of these tumors. METHODS: 93 primary OSCCs were subjected to DNA copy number alteration (CNA) and methylation status analyses using methylation-specific multiplex ligation-dependent probe amplification (MS-MPLA). The genetic and epigenetic OSCC profiles obtained were associated with the patients' clinic-pathological features. RESULTS: We found that WT1 gene promoter methylation is a predictor of a better prognosis and that MSH6 and GATA5 gene promoter methylation serve as predictors of a worse prognosis. GATA5 gene promoter methylation was found to be significantly associated with a shorter survival rate. In addition, we found that PAX5 gene promoter methylation was significantly associated with tongue tumors. To the best of our knowledge, this is the first study that highlights this specific set of genes as epigenetic diagnostic and prognostic biomarkers in OSCC. CONCLUSIONS: Our data highlight the importance of epigenetically assessing OSCCs to identify key genes that may serve as diagnostic and prognostic biomarkers and, potentially, as candidate therapeutic targets.

Corrigendum to "How to Treat a Signal? Current Basis for RET-Genotype-Oriented Choice of Kinase Inhibitors for the Treatment of Medullary Thyroid Cancer".

[This corrects the article DOI: 10.4061/2011/678357.].

Osteopontin expression is correlated with differentiation and good prognosis in medullary thyroid carcinoma.

BACKGROUND: Osteopontin (OPN) or secreted phosphoprotein 1 (SPP1) is a matricellular glycoprotein whose expression is elevated in various types of cancer and has been shown to be involved in tumourigenesis and metastasis in many malignancies, including follicular cell-derived thyroid carcinomas. Its role in C-cell-derived thyroid lesions and tumours remains to be established. OBJECTIVE: The objective of this study is to clarify the role of OPN expression in the development of medullary thyroid carcinoma (MTC). METHODS: OPN expression was analysed in a series of 116 MTCs by immunohistochemistry and by qPCR mRNA quantification of the 3 OPN isoforms (OPNa, OPNb and OPNc) in six cases from which fresh frozen tissue was available. Statistical tests were used to evaluate the relationship of OPN expression and the clinicopathological and molecular characteristics of patients and tumours. RESULTS: OPN expression was detected in 91 of 116 (78.4%) of the MTC. We also observed high OPN expression in C-cell hyperplasia as well as in C-cells scattered in the thyroid parenchyma adjacent to the tumours. OPN expression was significantly associated with smaller tumour size, PTEN nuclear expression and RAS status, and suggestively associated with non-invasive tumours. OPNa isoform was expressed significantly at higher levels in tumours than in non-tumour samples. OPNb and OPNc presented similar levels of expression in all samples. Furthermore, OPNa isoform overexpression was significantly associated with reduced growth and viability in the MTC-derived cell line (TT). CONCLUSION: The expression of OPN in normal C-cells and C-cell hyperplasia suggests that OPN is a differentiation marker of C-cells, rather than a marker of biological aggressiveness in this setting. At variance with other cancers, OPN expression is associated with good prognostic features in MTC.

mTOR activation in medullary thyroid carcinoma with RAS mutation.

OBJECTIVE: Rearranged during transfection (RET) mutations are well-known genetic events in sporadic and familial medullary thyroid carcinoma (FMTC). The presence of RAS mutations in sporadic cases, challenging the RET paradigm in these tumors, has been recently reported. We intend to evaluate mTOR pathway activation in RET- and RAS-mutated MTC. MATERIALS AND METHODS: In this study, we analysed the presence of RET, H-RAS, and K-RAS mutations in a series of 87 MTCs (82 apparently sporadic and five FMTCs; five apparently sporadic MTCs were eventually found to be familial). We also evaluated mTOR activation--using the expression of its downstream effector phospho-S6 ribosomal protein (p-S6) and the expression of the mTOR inhibitor, phosphatase and tensin homologue deleted on chromosome 10 (PTEN)--by immunohistochemistry. RESULTS: Our results revealed that RET mutations were present in 52.9% of the cases (46/87) and RAS mutations in 12.6% (11/87) of the whole series of MTCs and 14.3% of the 77 sporadic MTCs. The presence of RET and RAS mutations was mutually exclusive. RAS mutations were significantly associated with higher intensity of p-S6 expression (P=0.007), suggesting that the mTOR pathway is activated in such MTCs. We observed also an increased expression of p-S6 in invasive tumors (P=0.042) and in MTCs with lymph node metastases (P=0.046). Cytoplasmic PTEN expression was detected in 58.8% of the cases; cases WT for RAS showed a significantly lower expression of PTEN (P=0.045). CONCLUSIONS: We confirmed the presence of RAS mutation in 14.3% of sporadic MTCs and report, for the first time, an association between such mutations and the activation of the mTOR pathway. The evaluation of the mTOR activation by pS6 expression may serve as an indicator of invasive MTC.

TERT promoter mutations are a major indicator of poor outcome in differentiated thyroid carcinomas.

CONTEXT: Telomerase promoter mutations (TERT) were recently described in follicular cell-derived thyroid carcinomas (FCDTC) and seem to be more prevalent in aggressive cancers. OBJECTIVES: We aimed to evaluate the frequency of TERT promoter mutations in thyroid lesions and to investigate the prognostic significance of such mutations in a large cohort of patients with differentiated thyroid carcinomas (DTCs). DESIGN: This was a retrospective observational study. SETTING AND PATIENTS: We studied 647 tumors and tumor-like lesions. A total of 469 patients with FCDTC treated and followed in five university hospitals were included. Mean follow-up (±SD) was 7.8 ± 5.8 years. MAIN OUTCOME MEASURES: Predictive value of TERT promoter mutations for distant metastasization, disease persistence at the end of follow-up, and disease-specific mortality. RESULTS: TERT promoter mutations were found in 7.5% of papillary carcinomas (PTCs), 17.1% of follicular carcinomas, 29.0% of poorly differentiated carcinomas, and 33.3% of anaplastic thyroid carcinomas. Patients with TERT-mutated tumors were older (P < .001) and had larger tumors (P = .002). In DTCs, TERT promoter mutations were significantly associated with distant metastases (P < .001) and higher stage (P < .001). Patients with DTC harboring TERT promoter mutations were submitted to more radioiodine treatments (P = .009) with higher cumulative dose (P = .004) and to more treatment modalities (P = .001). At the end of follow-up, patients with TERT-mutated DTCs were more prone to have persistent disease (P = .001). TERT promoter mutations were significantly associated with disease-specific mortality [in the whole FCDTC (P < .001)] in DTCs (P < .001), PTCs (P = .001), and follicular carcinomas (P < .001). After adjusting for age at diagnosis and gender, the hazard ratio was 10.35 (95% confidence interval 2.01-53.24; P = .005) in DTC and 23.81 (95% confidence interval 1.36-415.76; P = .03) in PTCs. CONCLUSIONS: TERT promoter mutations are an indicator of clinically aggressive tumors, being correlated with worse outcome and disease-specific mortality in DTC. TERT promoter mutations have an independent prognostic value in DTC and, notably, in PTC.