Performance of a Region of Interest-based Algorithm in Diagnosing International Society of Urological Pathology Grade Group ≥2 Prostate Cancer on the MRI-FIRST Database-CAD-FIRST Study

BACKGROUND AND OBJECTIVE

Prostate multiparametric magnetic resonance imaging (MRI) shows high sensitivity for International Society of Urological Pathology grade group (GG) ≥2 cancers. Many artificial intelligence algorithms have shown promising results in diagnosing clinically significant prostate cancer on MRI. To assess a region-of-interest-based machine-learning algorithm aimed at characterising GG ≥2 prostate cancer on multiparametric MRI.

METHODS

The lesions targeted at biopsy in the MRI-FIRST dataset were retrospectively delineated and assessed using a previously developed algorithm. The Prostate Imaging-Reporting and Data System version 2 (PI-RADSv2) score assigned prospectively before biopsy and the algorithm score calculated retrospectively in the regions of interest were compared for diagnosing GG ≥2 cancer, using the areas under the curve (AUCs), and sensitivities and specificities calculated with predefined thresholds (PIRADSv2 scores ≥3 and ≥4; algorithm scores yielding 90% sensitivity in the training database). Ten predefined biopsy strategies were assessed retrospectively.

KEY FINDINGS AND LIMITATIONS

After excluding 19 patients, we analysed 232 patients imaged on 16 different scanners; 85 had GG ≥2 cancer at biopsy. At patient level, AUCs of the algorithm and PI-RADSv2 were 77% (95% confidence interval [CI]: 70-82) and 80% (CI: 74-85; p = 0.36), respectively. The algorithm's sensitivity and specificity were 86% (CI: 76-93) and 65% (CI: 54-73), respectively. PI-RADSv2 sensitivities and specificities were 95% (CI: 89-100) and 38% (CI: 26-47), and 89% (CI: 79-96) and 47% (CI: 35-57) for thresholds of ≥3 and ≥4, respectively. Using the PI-RADSv2 score to trigger a biopsy would have avoided 26-34% of biopsies while missing 5-11% of GG ≥2 cancers. Combining prostate-specific antigen density, the PI-RADSv2 and algorithm's scores would have avoided 44-47% of biopsies while missing 6-9% of GG ≥2 cancers. Limitations include the retrospective nature of the study and a lack of PI-RADS version 2.1 assessment.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The algorithm provided robust results in the multicentre multiscanner MRI-FIRST database and could help select patients for biopsy.

PATIENT SUMMARY

An artificial intelligence-based algorithm aimed at diagnosing aggressive cancers on prostate magnetic resonance imaging showed results similar to expert human assessment in a prospectively acquired multicentre test database.

[Molecular and other ancillary tests proposed by The Bethesda system for reporting thyroid cytopathology 2023]

For the first time the 2023 version of The Bethesda System for Reporting Thyroid Cytology dedicates a whole chapter (chapter 14) to ancillary studies almost exclusively represented by molecular testing. The latest data reported bring some evidence that molecular testing could help to optimize the diagnostic performance of « indeterminate » categories (AUS and NF). Other studies suggest a promising role to guide the management of suspicious of malignancy and malignant categories. Indeed, the recognition of prognostic and predictive biomarkers analyzed on cytological samples, regardless of how it is collected, has progressed thanks to advances in our knowledge of molecular abnormalities of thyroid tumors. The chapter 14 is presented here highlighting the current and emerging roles of « in-house » and commercialized molecular testing as presented by TSBRTC.

[SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Interest and place of thyroid cytology]

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a symptom that is a frequent reason for consultation in endocrinology. Thyroid nodules are very common and mostly benign. Thyroid ultrasound and thyroid fine-needle aspiration biopsy (FNAB) are the reference tests for the analysis of these nodules. The aim of this article is to describe for the cytopathologist the key points of the SFE-AFCE-SFMN 2022 consensus involving thyroid cytology: the indications for thyroid FNAB, the technique and analysis, and the management (treatment, follow-up) following this cytological screening examination, a key element in the management of the thyroid nodule.

Role of gene sequencing in classifying struma ovarii: BRAF p.G469A mutation and TERT promoter alterations favour malignant struma ovarii

AIMS

Struma ovarii (SO) are rare, accounting for 0.3-1% of ovarian tumours, and include benign and malignant lesions. In most cases, histology is not predictive of clinical outcome and prognosis. The prognosis of histologically malignant thyroid-type carcinomas can indeed be excellent, while SO, composed of normal thyroid tissue, can recur and are designated highly differentiated follicular carcinoma of the ovary. Clearer diagnostic criteria are therefore required.

METHODS AND RESULTS

We retrospectively studied 31 SO using DNA and RNA sequencing with pan-cancer gene panels, including eight biologically malignant SO (BMSO) defined based on ovarian serosal or extra-ovarian dissemination at presentation or during follow-up, 10 stage IA histologically malignant SO (HMSO) with thyroid-type carcinoma morphology and 13 biologically and histologically benign SO (BSO), with none of the above-mentioned characteristics. Molecular alterations were observed in 87.5% of BMSO, 70% of HMSO and 7.7% of BSO (P < 0.001). All patients with a peritoneal dissemination at presentation or during follow-up had at least one gene alteration. BRAF mutations (44.5%) were only observed in malignant forms (HMSO and BMSO) and TERT promoter alterations (25%) only in cases of BMSO. The BRAF p.G469A mutation, which is extremely rare in thyroid carcinomas, was the molecular alteration most frequently associated with malignant SO (28.5%).

CONCLUSION

Our results highlight the clinical utility of molecular sequencing in SO, based on this limited number of cases. However, as malignant SO evolve slowly, more extensive molecular studies in SO with more than 10 years' follow-up are required to draw any conclusions on the prognostic value of the associated gene alterations.

Drug-induced inhibition of HMGA and EZH2 activity as a possible therapy for anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive and lethal neoplasms in humans, and just limited progresses have been made to extend patient survival and decrease ATC-associated mortality. Thus, the identification of novel therapeutic strategies for treating ATC is needed. Recently, our group has identified two proteins with oncogenic activity, namely HMGA1 and EZH2, with pivotal roles in ATC cancer progression. Therefore, we tested the ability of trabectedin, a HMGA1-targeting drug, and GSK126, an inhibitor of EZH2 enzymatic activity, to impair cell viability of four ATC-derived cell lines. In the present study, we first confirmed the overexpression of HMGA1 and EZH2 in all ATC-derived cell lines and tissues compared to the normal primary thyroid cells and tissues. Then, treatment of the ATC cell lines with trabectedin and GSK126 resulted in a drastic induction of apoptotic cell death, which increased when the ATC cell lines were treated with a combination of both drugs. Conversely, normal primary human thyroid cells did not show any significant reduction in their viability when exposed to the same drugs. Noteworthy, both drugs induced the deregulation of EZH2- and HMGA1-controlled genes. Altogether, these findings propose the combination of trabectedin and GSK126 as possible novel strategy for ATC therapy.

Prognostic value of programmed death ligand-1 and programmed death-1 expression in patients with upper tract urothelial carcinoma

OBJECTIVE

To evaluate the prognostic value of programmed death ligand-1 (PD-L1) and programmed death-1 (PD-1) expression in patients with upper tract urothelial carcinoma (UTUC).

PATIENTS AND METHODS

A retrospective multicentre study was conducted in 283 patients with UTUC treated with radical nephroureterectomy (RNU) between 2000 and 2015 at 10 French hospitals. Immunohistochemistry analyses were performed using 2 mm-core tissue microarrays with NAT105® and 28.8® antibodies at a 5% cut-off for positivity on tumour cells and tumour-infiltrating lymphocytes to evaluate PD-L1 and PD-1 expression, respectively. Multivariable Cox regression models were used to determine the independent predictors of recurrence-free (RFS), cancer-specific (CSS) and overall survival (OS).

RESULTS

Overall, 63 (22.3%) and 220 (77.7%) patients with UTUC had PD-L1-positive and -negative disease, respectively, while 91 (32.2%) and 192 (67.8%) had PD-1-positive and -negative disease, respectively. Patients who expressed PD-L1 or PD-1 were more likely to have pathological tumour stage ≥pT2 (68.3% vs 49.5%, P = 0.009; and 69.2% vs 46.4%, P < 0.001, respectively) and high-grade (90.5% vs 70.0%, P = 0.001; and 91.2% vs 66.7%, P < 0.001, respectively) disease with lymphovascular invasion (52.4% vs 17.3%, P < 0.001; and 39.6% vs 18.2%, P < 0.001, respectively) as compared to those who did not. In multivariable Cox regression analysis adjusting for each other, PD-L1 and PD-1 expression were significantly associated with decreased RFS (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.09-3.08, P = 0.023; and HR 1.59, 95% CI 1.01-2.54, P = 0.049; respectively), CSS (HR 2.73, 95% CI 1.48-5.04, P = 0.001; and HR 1.96, 95% CI 1.12-3.45, P = 0.019; respectively) and OS (HR 2.08, 95% CI 1.23-3.53, P = 0.006; and HR 1.71, 95% CI 1.05-2.78, P = 0.031; respectively). In addition, multivariable Cox regression analyses evaluating the four-tier combination of PD-L1 and PD-1 expression showed that only PD-L1/PD-1-positive patients (n = 38 [13.4%]) had significantly decreased RFS (HR 3.07, 95% CI 1.70-5.52; P < 0.001), CSS (HR 5.23, 95% CI 2.62-10.43; P < 0.001) and OS (HR 3.82, 95% CI 2.13-6.85; P < 0.001) as compared to those with PD-L1/PD-1-negative disease (n = 167 [59.0%]).

CONCLUSIONS

We observed that PD-L1 and PD-1 expression were both associated with adverse pathological features that translated into an independent and cumulative adverse prognostic value in UTUC patients treated with RNU.

CDK4 phosphorylation status and rational use for combining CDK4/6 and BRAF/MEK inhibition in advanced thyroid carcinomas

Background

CDK4/6 inhibitors (CDK4/6i) have been established as standard treatment against advanced Estrogen Receptor-positive breast cancers. These drugs are being tested against several cancers, including in combinations with other therapies. We identified the T172-phosphorylation of CDK4 as the step determining its activity, retinoblastoma protein (RB) inactivation, cell cycle commitment and sensitivity to CDK4/6i. Poorly differentiated (PDTC) and anaplastic (ATC) thyroid carcinomas, the latter considered one of the most lethal human malignancies, represent major clinical challenges. Several molecular evidence suggest that CDK4/6i could be considered for treating these advanced thyroid cancers.

Methods

We analyzed by two-dimensional gel electrophoresis the CDK4 modification profile and the presence of T172-phosphorylated CDK4 in a collection of 98 fresh-frozen tissues and in 21 cell lines. A sub-cohort of samples was characterized by RNA sequencing and immunohistochemistry. Sensitivity to CDK4/6i (palbociclib and abemaciclib) was assessed by BrdU incorporation/viability assays. Treatment of cell lines with CDK4/6i and combination with BRAF/MEK inhibitors (dabrafenib/trametinib) was comprehensively evaluated by western blot, characterization of immunoprecipitated CDK4 and CDK2 complexes and clonogenic assays.

Results

CDK4 phosphorylation was detected in all well-differentiated thyroid carcinomas (n=29), 19/20 PDTC, 16/23 ATC and 18/21 thyroid cancer cell lines, including 11 ATC-derived ones. Tumors and cell lines without phosphorylated CDK4 presented very high p16CDKN2A levels, which were associated with proliferative activity. Absence of CDK4 phosphorylation in cell lines was associated with CDK4/6i insensitivity. RB1 defects (the primary cause of intrinsic CDK4/6i resistance) were not found in 5/7 tumors without detectable phosphorylated CDK4. A previously developed 11-gene expression signature identified the likely unresponsive tumors, lacking CDK4 phosphorylation. In cell lines, palbociclib synergized with dabrafenib/trametinib by completely and permanently arresting proliferation. These combinations prevented resistance mechanisms induced by palbociclib, most notably Cyclin E1-CDK2 activation and a paradoxical stabilization of phosphorylated CDK4 complexes.

Conclusion

Our study supports further clinical evaluation of CDK4/6i and their combination with anti-BRAF/MEK therapies as a novel effective treatment against advanced thyroid tumors. Moreover, the complementary use of our 11 genes predictor with p16/KI67 evaluation could represent a prompt tool for recognizing the intrinsically CDK4/6i insensitive patients, who are potentially better candidates to immediate chemotherapy.

Factors Associated with Survival in Anaplastic Thyroid Carcinoma: A Multicenter Study from the ENDOCAN-TUTHYREF Network

Background: Anaplastic thyroid carcinoma (ATC) is a rare and frequently fatal type of thyroid cancer. The degree of heterogeneity in survival rates for ATC is incompletely studied. This study evaluated the factors associated with overall survival (OS) of patients with ATC using multicenter real-world data from a national tertiary care center network in France. Methods: In this multicenter, retrospective cohort study, all patients with ATC diagnosed between 2010 and 2020 were identified from the national database of the French ENDOCAN-TUTHYREF network. Factors associated with OS were examined in multivariable analyses using Cox proportional hazards models. Results: The study included 360 patients. Of these, 220 (61%) were female and the median age was 72 years (interquartile range: 62-80). The percentages of patients with pure and mixed (synchronously-transformed) ATC (p-ATC and st-ATC) were 62.5% and 26.7%, respectively. The median OS was 6.8 months [confidence interval, CI: 5.5-8.1]: not reached for stage IVa, 11.4 months [8.2-17.8] for IVb, and 4.6 months [3.5-5.7] for IVc. Surgery, radiation therapy to the neck, chemotherapy, and best supportive care were administered to 69 (19.2%), 214 (59.4%), 254 (70.6%), and 66 (18.3%) patients, respectively. In a multivariable analysis, including stage IVb-IVc patients, significantly higher OS was observed in patients with Eastern Cooperative Oncology Group performance-status of 0-1 (hazard ratio [HR], 0.6; [CI, 0.4-0.9], p < 0.02), stage IVb [HR, 0.5; CI, 0.4-0.8, p < 0.001], and multimodal treatment (surgery and chemoradiotherapy) [HR, 0.07; CI, 0.04-0.1, p < 0.001]. Variables associated with significantly worse OS included: p-ATC (vs. st-ATC) [HR, 1.83; CI, 1.33-2.51, p = 0.001] and a neutrophil-to-lymphocyte ratio (NLR) >5.05 [HR, 2.05, CI, 1.39-3.05, p < 0.001]. Conclusions: Factors independently associated with improved OS in ATC included: European Cooperative Oncology Group performance status, disease stage, multimodality treatment, synchronously transformed ATC, and lower NLR. Long-term OS was observed in selected patients with ATC who underwent multimodal treatment.

[French recommendations for malignant pheochromocytomas and paragangliomas by the national ENDOCAN-COMETE network]

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors, developed respectively in the adrenal medulla and in extra-adrenal locations. Their malignancy is defined by the presence of distant metastases. Forty percent of them are inherited and can be part of different hereditary syndromes. Their management is ensured in France by the multidisciplinary expert centers of the ENDOCAN-COMETE national network "Cancers of the Adrenal gland", certified by the National Cancer Institute and discussed within multidisciplinary team meetings. The diagnostic and therapeutic work-up must be standardized, based on an expert analysis of clinical symptoms, hormonal biological secretions, genetics, morphological and specific metabolic imaging. In the context of a heterogeneous survival sometimes beyond seven to ten years, therapeutic intervention must be justified. This is multidisciplinary and relies on surgery, interventional radiology, external or internal radiotherapy and medical treatments such as sunitinib or dacarbazine and temodal chemotherapy. The personalized approach based on functional imaging fixation status and genetics is progressing despite the extreme rarity of this disease.

Correction: Sepe et al. The Long Non-Coding RNA RP5-1024C24.1 and Its Associated-Gene MPPED2 Are Down-Regulated in Human Thyroid Neoplasias and Act as Tumour Suppressors. Cancers 2018, 10, 146

In the original publication [...].

The lncRNA RMST is drastically downregulated in anaplastic thyroid carcinomas where exerts a tumor suppressor activity impairing epithelial-mesenchymal transition and stemness

Thyroid cancer is the most prevalent endocrine malignancy and comprises a wide range of lesions subdivided into differentiated (DTC) and undifferentiated thyroid cancer (UTC), mainly represented by the anaplastic thyroid carcinoma (ATC). This is one of the most lethal malignancies in humankind leading invariably to patient death in few months. Then, a better comprehension of the mechanisms underlying the development of ATC is required to set up new therapeutic approaches. Long non-coding RNAs (lncRNAs) are transcripts over 200 nucleotides in length that do not code for proteins. They show a strong regulatory function at both transcriptional and post-transcriptional level and are emerging as key players in regulating developmental processes. Their aberrant expression has been linked to several biological processes, including cancer, making them potential diagnostic and prognostic markers. We have recently analyzed the lncRNA expression profile in ATC through a microarray technique and have identified rhabdomyosarcoma 2-associated transcript (RMST) as one of the most downregulated lncRNA in ATC. RMST has been reported to be deregulated in a series of human cancers, to play an anti-oncogenic role in triple-negative breast cancer, and to modulate neurogenesis by interacting with SOX2. Therefore, these findings prompted us to investigate the role of RMST in ATC development. In this study we show that RMST levels are strongly decreased in ATC, but only slightly in DTC, indicating that the loss of this lncRNA could be related to the loss of the differentiation and high aggressiveness. We also report a concomitant increase of SOX2 levels in the same subset of ATC, that inversely correlated with RMST levels, further supporting the RMST/SOX2 relationship. Finally, functional studies demonstrate that the restoration of RMST in ATC cells reduces cell growth, migration and the stemness properties of ATC stem cells. In conclusion, these findings support a critical role of RMST downregulation in ATC development.

[Guidelines of the French National ENDOCAN-COMETE, Association of Endocrine Surgery, Society of Urology for the management of adrenocortical carcinoma]

The adrenocortical carcinoma (ACC) is a primary malignant tumor developed from the adrenal cortex, defined by a Weiss score≥3. Its prognosis is poor and depends mainly on the stage of the disease at diagnosis. Care is organized in France by the multidisciplinary expert centers of the national ENDOCAN-COMETE "Adrenal Cancers" network, certified by the National Cancer Institute. This document updates the guidelines for the management of ACC in adults based on the most robust data in the literature. It's divided into 11 chapters: (1) circumstances of discovery; (2) pre-therapeutic assessment; (3) diagnosis of ACC; (4) oncogenetics; (5) prognostic classifications; (6) treatment of hormonal hypersecretion; (7) treatment of localized forms; (8) treatment of relapses; (9) treatment of advanced forms; (10) follow-up; (11) the particular case of ACC and pregnancy. R0 resection of all localized ACC remains an unmet need and it must be performed in expert centers. Flow-charts for the therapeutic management of localized ACC, relapse or advanced ACC are provided. It was written by the experts from the national ENDOCAN-COMETE network and validated by all French Societies involved in the management of these patients (endocrinology, medical oncology, endocrine surgery, urology, pathology, genetics, nuclear medicine, radiology, interventional radiology).

Primary thyroid rhabdomyosarcoma in an adult: A challenging case with histomolecular diagnosis and literature review

INTRODUCTION AND IMPORTANCE

Primary thyroid sarcomas are very rare tumours, accounting for less than 1 % of all thyroid malignancies. We present the fifth case in the literature of primary thyroid rhabdomyosarcoma and the third in adults with, for the first time, an extensive molecular analysis.

CASE PRESENTATION

A 61-year-old woman presented with a rapidly progressive neck mass with extensive local invasion of the tumour.

CLINICAL DISCUSSION

Histologically, the neoplasm was composed of sheets of pleomorphic or spindle-shaped cells with eosinophilic cytoplasm and few large and very pleomorphic cells admixed with the spindle cell proliferation, without any thyroid epithelial component. Immunohistochemically, the tumour cells were positive for muscular markers and negative for epithelial and thyroid differentiation markers. Molecular tests revealed the presence of NF1, PTEN and TERT pathogenic mutations. Classifying undifferentiated neoplasm with muscular differentiation into the thyroid is challenging as many more common differential diagnoses could be favoured including anaplastic thyroid carcinoma with rhabdoid phenotype, leiomyosarcoma, and other rare sarcomas.

CONCLUSION

Primary thyroid rhabdomyosarcoma is extremely rare and can be diagnostically challenging. We emphasize the histological, immunohistochemical and molecular criteria in order to make an accurate diagnosis.

Thyroid liposarcoma: a case report

Objectives

Thyroid liposarcoma is a rare tumor. Its low prevalence accounts for the scarcity of data in the literature, which consists mostly of small studies and case reports.

Case presentation

We present the case of a 60 years old male with no past medical or past surgical history and presented with neck discomfort and a large left thyroid nodule. Thyroid ultrasound and CT scan were performed and confirmed the existence of a thyroid nodule most probably inside the left inferior thyroid lobe. In the posterior mediastinum, two fatty formations were found. To complete, an MRI was performed, showing a mixed lesion, of the lower neck and upper chest. The patient underwent an extended resection which consisted of an en bloc resection of the lesion (left thyroid lobectomy and isthmus resection) by an anterior transverse cervical incision and a sternotomy. Tracheal and laryngeal shaving and esophageal shaving with resection of the esophageal muscularis was performed as well. The pathological evaluation of the specimen showed a grade II dedifferentiated liposarcoma with an inflammatory component.

Conclusions

Thyroid liposarcoma is a rare lesion of the thyroid. Its management requires an exhaustive workup followed by an en bloc resection of the lesion. Depending on the histology, postoperative radiation therapy may or may not be necessary.

SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Synthesis and algorithms

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid with benign and non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies, the French Society of Endocrinology (SFE), the French Association of Endocrine Surgery (AFCE) and the French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This specific text is a summary chapter taking up the recommendations from specific sections and presenting algorithms for the exploration and management of thyroid nodules.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules : Recommendations in thyroid cytology: from technique to interpretation

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the technique and interpretation of thyroid fine-needle aspiration biopsy (FNAB), a reference test for the analysis of thyroid nodules.

Embryonated Chicken Tumor Xenografts Derived from Circulating Tumor Cells as a Relevant Model to Study Metastatic Dissemination: A Proof of Concept

Simple Summary

Circulating Tumor Cells (CTCs) are heterogeneous and rare in the bloodstream, but responsible for cancer metastasis. Their in vitro or in vivo expansion remains a major challenge. The chicken Chorioallantoic Membrane (CAM) assay has proven to be a reliable alternative to the murine model, notably for tumor xenografts. We have developed a promising model of CTC-derived xenografts in the chicken CAM and demonstrated the feasibility of Next Generation Sequencing (NGS) analysis in this assay, with a genomic concordance between the in ovo tumor and the original patient’s tumor. We also evidenced metastatic dissemination from the xenograft in the chicken embryo’s distant organs. Further characterization of the in ovo tumors and metastases may provide new insights into the mechanisms of tumor dissemination. The development of a xenograft from a given patient’s CTCs, in a time frame compatible with managing the patient’s treatment, could also be a step forward towards personalized medicine.

Abstract

Patient-Derived Xenografts (PDXs) in the Chorioallantoic Membrane (CAM) are a representative model for studying human tumors. Circulating Tumor Cells (CTCs) are involved in cancer dissemination and treatment resistance mechanisms. To facilitate research and deep analysis of these few cells, significant efforts were made to expand them. We evaluated here whether the isolation of fresh CTCs from patients with metastatic cancers could provide a reliable tumor model after a CAM xenograft. We enrolled 35 patients, with breast, prostate, or lung metastatic cancers. We performed microfluidic-based CTC enrichment. After 48–72 h of culture, the CTCs were engrafted onto the CAM of embryonated chicken eggs at day 9 of embryonic development (EDD9). The tumors were resected 9 days after engraftment and histopathological, immunochemical, and genomic analyses were performed. We obtained in ovo tumors for 61% of the patients. Dedifferentiated small tumors with spindle-shaped cells were observed. The epithelial-to-mesenchymal transition of CTCs could explain this phenotype. Beyond the feasibility of NGS in this model, we have highlighted a genomic concordance between the in ovo tumor and the original patient’s tumor for constitutional polymorphism and somatic alteration in one patient. Alu DNA sequences were detected in the chicken embryo’s distant organs, supporting the idea of dedifferentiated cells with aggressive behavior. To our knowledge, we performed the first chicken CAM CTC-derived xenografts with NGS analysis and evidence of CTC dissemination in the chicken embryo.

Her2 Expression in Circulating Tumor Cells Is Associated with Poor Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer

HER2-dependent signaling may support the development of metastatic castration-resistant prostate cancer (mCRPC) by activating androgen receptor signaling through ligand-independent mechanisms. From 41 mCRPC patients (including 31 treated with Androgen Receptor Signaling Inhibitors [ARSI]), Circulating Tumor Cells (CTCs) were prospectively enriched with AdnaTest platform and analyzed with a multiplexed assay for HER2 and AR-V7 mRNA expression. Then, we evaluated the impact of HER2 expression on PSA-response, Progression Free Survival (PFS) and Overall Survival (OS). HER2 expression was detected in CTCs of 26 patients (63%). Although PSA response was similar regardless of HER2 status, patients with HER2 positive CTCs had shorter PSA-PFS (median: 6.2 months versus 13.0 months, p = 0.034) and radiological-PFS (6.8 months versus 25.6 months, p = 0.022) than patients without HER2 expression. HER2 expression was also associated with a shorter OS (22.7 months versus not reached, p = 0.05). In patients treated with ARSI, multivariate analyses revealed that the prognostic impact of HER2 status on PSA-PFS was independent of AR-V7 expression and of the detection of CTCs by an AdnaTest. We showed for the first time the poor prognostic value of HER2 expression in CTCs from patients with mCRPC. The therapeutic interest of targeting this actionable pathway remains to be explored.

Long-Term Outcome of Lobectomy for Thyroid Cancer

INTRODUCTION

Recent guidelines of the American Thyroid Association (ATA) suggest that a lobectomy may be sufficient to treat low- to intermediate-risk patients with thyroid tumors ≤40 mm, without extrathyroidal extension or lymph node metastases. The present study aimed to evaluate long-term recurrence after lobectomy for differentiated thyroid cancer and to analyze factors associated with recurrence.

METHODS

In this retrospective cohort study, patients who underwent a lobectomy for thyroid cancer in a tertiary center between 1970 and 2010 were included. The outcome was the proportion of pathology-confirmed thyroid cancer recurrence, assessed in the whole cohort or in subgroups according to tumor size (≤ or >40 mm).

RESULTS

A total of 295 patients were included, and these were followed-up for a mean (standard deviation, SD) 19.1 (7.8) years (5,649 patient-years); 61 (20.7%) were male and the mean (SD) age at diagnosis was 39.7 (12) years. Histological subtype was papillary in 263 (89.2%) patients and mean cancer size was 22.9 (16.9) mm. According to the 2015 ATA guidelines, 271 (91.9%) cancers had a low risk of recurrence and 24 (8.1%) an intermediate risk. A reoperation was performed in 54 patients (18.3%) and recurrence was confirmed in 40 (13.6%), diagnosed for 55% of cases more than 10 years after their initial surgery. Among recurrent patients, 14 (4.8% of the cohort) were operated for a contralateral papillary thyroid microcarcinoma and 26 (8.8% of the cohort) for a locoregional or metastatic recurrence. Non-suspicious nodular recurrences were monitored without reoperation in 53 (18.0%) patients. At the end of follow-up, 282 (95.6%) patients were in remission. Tumors with locoregional or metastatic recurrence were more frequent among tumors with aggressive histology (19.2 vs. 4.1%, p = 0.015) and of intermediate risk category (28.6 vs. 7.1%, p = 0.018). Tumors >40 mm, which would have been treated by thyroidectomy according to the 2015 ATA guidelines criteria, were found in 34 (11.5%) patients and were associated with a higher frequency of recurrence (20.6 vs. 7.3%, p = 0.024) and less remission (85.3 vs. 96.9%, p = 0.001).

CONCLUSION

The outcome of thyroid cancer treated by lobectomy is very good, particularly for cancer ≤40 mm. A prolonged follow-up is required due to the risk of late recurrence.

Feasibility and performance of the Idylla™ NRAS/BRAF cartridge mutation assay on thyroid liquid-based fine-needle aspiration

BACKGROUND

Thyroid nodules with indeterminate cytology represent up to 30% of cases. Molecular testing is now highly recommended to improve management. This study aimed to evaluate the use of the Idylla™ NRAS/BRAF mutation test, a rapid and automated polymerase chain reaction (PCR) assay validated for fixed paraffin-embedded use, on residual thyroid liquid-based fine-needle aspiration (LB-FNA).

METHODS

Concordance between mutations detected by the Idylla™ assay and the gold-standard qPCR was assessed by splitting in two aliquots 31 BRAF or RAS mutated and 5 non-mutated LB-FNA samples. Samples were obtained either from simulated FNA after thyroidectomy or from FNA obtained during routine care. A third aliquot was used to assess the limit of detection of Idylla™ for five mutated samples.

RESULTS

The Idylla™ assay showed a sensitivity of 97% and a specificity of 83% as results were concordant for 34 out of 36 samples. One discordant sample concerned a BRAF p.K601E-mutation which is not detected by the Idylla™ cartridge. The other showed a false-positive NRAS p.A146T detection and a weak BRAF p.V600E detection. The limit of detection of the Idylla™ assay was not reached by the dilution assay.

CONCLUSION

Idylla™ NRAS/BRAF mutation testing can be performed on residual thyroid LB-FNA, using low DNA quantity input, thus not requiring a dedicated sample. The Idylla™ NRAS/BRAF assay offers a quick and easy first step for analyzing the main molecular alterations in indeterminate thyroid nodules, hence improving diagnostic management.

Programmed death ligand-1 (PD-L1) immunohistochemical assessment using the QR1 clone in muscle-invasive urothelial carcinomas: a comparison with reference clones 22C3 and SP263

Programmed death ligand-1 (PD-L1) immunohistochemical (IHC) status is used to predict which patients with metastatic urothelial carcinoma (UC) will respond to immunotherapy. We aimed to compare QR1(Quartett), 22C3 (Dako), and SP263 (Ventana) detection of PD-L1 expression in muscle-invasive UCs and determine the best scoring algorithm for assessment of PD-L1 expression when using the QR1 clone. Our study included 69 UCs. For SP263 and 22C3, PD-L1-positive tumor cell (TC) and/or immune cell (IC) percentages (TC%/IC%) and the Combined Positive Score (CPS) were assessed, respectively (positivity cut-offs of ≥ 25% and ≥ 10). For QR1, both interpretation systems were evaluated. The concordances between assays were calculated. PD-L1 IHC staining characteristics were comparable between QR1, 22C3, and SP263 in both conventional and variant histology UCs. We demonstrated strong or very strong correlations between clones; the strongest correlation for TCs was between QR1 and SP263 (r = 0.92; p = 0.001) and for ICs was between QR1 and 22C3 (r = 0.85; p = 0.001). Our comparative analysis of the scoring algorithms revealed very good concordances among the three assays (range 0.791-0.878); the highest concordance was between QR1 and SP263 when CPS was used as the scoring algorithm for QR1 (0.878; p < 0.001). Our study is the first to demonstrate that the QR1 clone can be used to evaluate PD-L1 status in UCs, with a very good agreement rate with the reference clones. QR1 appeared to be more similar to the SP263 clone. With regard to the scoring algorithm, when evaluating PD-L1 expression using QR1 clone, CPS performed better compared with the TC%/IC% score.

[Molecular genotyping in refractory thyroid cancers in 2021: When, how and why? A review from the TUTHYREF network]

Refractory thyroid cancers include radio-iodine-refractory cancers, metastatic or locally advanced unresectable medullary and anaplastic thyroid cancers. Their management has been based for several years on the use of multi-target kinase inhibitors, with anti-angiogenic action, with the exception of anaplastic cancers usually treated with chemo- and radiotherapy. The situation has recently evolved due to the availability of molecular genotyping techniques allowing the discovery of rare but targetable molecular abnormalities. New treatment options have become available, more effective and less toxic than the previously available multi-target kinase inhibitors. The management of refractory thyroid cancers is therefore becoming more complex both at a diagnosis level with the need to know when, how and why to look for these molecular abnormalities but also at a therapeutic level, innovative treatments being hardly accessible. The cost of molecular analyzes and the access to treatments need also to be homogenized because disparities could lead to inequality of care at a national or international level. Finally, the strategy of identifying molecular alterations and treating these rare tumors reinforces the importance of a discussion in a multidisciplinary consultation meeting.

RBM10-TFE3 fusions: A FISH-concealed anomaly in adult renal cell carcinomas displaying a variety of morphological and genomic features: Comprehensive study of six novel cases

The accurate diagnosis of Xp11-translocation renal cell carcinoma (RCC) in adults is challenging. TFE3 (located on chromosome X) fuses with a partner gene generally located on another chromosome. In rare cases TFE3 may fuse with a neighboring gene: RBM10. Because TFE3 false-positive immunostaining is a common pitfall in many laboratories, demonstration of the chromosomal rearrangement is required in order to ascertain the diagnosis. Fluorescence in situ hybridization (FISH)-that has been considered as the gold standard method-reaches its limits for detecting small Xp11 paracentric inversions. We performed a comprehensive clinical, histological and genomic study of six novel cases of RCC with RBM10-TFE3 fusion. Using FISH, TFE3 rearrangement was equivocal in one case and negative in others. RBM10-TFE3 fusion was discovered using targeted RNA sequencing (RNASeq). As all the previously reported cases (mean age: 50), the six patients were adults (mean age: 42), suggesting an epidemiologic difference between RBM10-TFE3 RCC and tumors harboring some other partner genes, such as ASPSCR1 that rather occur in children. Array-comparative genomic hybridization showed several alterations, notably a gain of 17q in four cases with papillary features and loss of 3p in one case with clear cells. Our study demonstrates that, though rare among adult cases of RCC, RBM10-TFE3 fusion is not exceptional and warrants appropriate molecular detection. Notably, it would be worthy to systemically investigate by RNASeq challenging RCC with type-2 papillary features and 17q gain.

MiR-7-5p inhibits thyroid cell proliferation by targeting the EGFR/MAPK and IRS2/PI3K signaling pathways

The aberrant expression of miRNAs is often correlated to tumor development. MiR-7-5p is a recently discovered downregulated miRNA in thyroid papillary carcinoma (PTC). The goal of this project was to characterize its functional role in thyroid tumorigenesis and to identify the targeted modulated pathways. MiR-7-5p overexpression following transfection in TPC1 and HT-ori3 cells decreased proliferation of the two thyroid cell lines. Analysis of global transcriptome modifications showed that miR-7-5p inhibits thyroid cell proliferation by modulating the MAPK and PI3K signaling pathways which are both necessary for normal thyroid proliferation and play central roles in PTC tumorigenesis. Several effectors of these pathways are indeed targets of miR-7-5p, among which EGFR and IRS2, two upstream activators. We confirmed the upregulation of IRS2 and EGFR in human PTC and showed the existence of a negative correlation between the decreased expression of miR-7-5p and the increased expression of IRS2 or EGFR. Our results thus support a tumor-suppressor activity of miR-7-5p. The decreased expression of miR-7-5p during PTC tumorigenesis might give the cells a proliferative advantage and delivery of miR-7-5p may represent an innovative approach for therapy.

[Adenomatoid tumor of the adrenal gland: Clinicopathologic characteristics and differential diagnosis on two tumors of exceptional adrenal location]

Adenomatoid tumors are benign tumors from mesothelial origin, usually occurring in the genital tract. Extragenital locations, especially in the adrenal gland are extremely rare. Here we are reporting two cases of a 28-year-old and 50-year-old men with an adenomatoid tumor of the right adrenal gland. Usual morphological aspects join scattered and microcystic pattern with epithelioid or signet-ring cells. According to the morphological features, main differential diagnoses are adenocarcinoma metastasis, vascular tumors or mesotheliomas. Immunohistochemistry provides precious help to confirm the mesothelial origin thanks to positivity of epithelial markers (CK7, AE1-AE3, CK5/6) coupled to mesothelial markers (D2-40, Calretinin, WT1). On the other hand, there is no loss of BAP1 by immunohistochemistry and usually a surexpression of P16. Adrenal gland adenomatoid tumor is a benign tumor, which can be promoted by iatrogenous or constitutive immunodepression.

Standardizing immunohistochemistry methodology for evaluation of PD-1 and PDL-1 expression in upper tract urothelial carcinoma

INTRODUCTION

Controversy regarding the prognostic and/or predictive role of PD-1 and PD-L1 expression for upper tract urothelial carcinoma (UTUC) could partly be explained by inconsistencies in the immunohistochemistry (IHC) methodology. Objective is to standardize the methodology for routine evaluation of PD-1 and PD-L1 expression in UTUC patients.

MATERIALS AND METHODS

Twenty-two cases treated with radical nephroureterectomy between 1996 and 2015 at 11 French hospitals were randomly selected to compare different methodologies for evaluation of PD-1 and PD-L1 expression. IHC was carried out on whole tissue sections and 0.6 mm- or 2 mm-core tissue micro-arrays (TMAs) using PD-1 NAT105 and PD-L1 28.8 or E1L3N on both tumor cells and tumor-infiltrating immune cells (TILs). Results obtained with whole tissue sections (WTS) were compared to those obtained with 0.6 mm- and 2 mm-core TMAs. Concordance was evaluated using Kappa coefficient.

RESULTS

For evaluation of PD-1 and PD-L1 expression, the best concordance with WTS was observed using the PD-1 NAT105 and PD-L1 28.8 antibody on 2 mm-core TMAs, with 5% cut off for positivity on TILs and tumor cells, respectively (Kappa = 0.8).

CONCLUSIONS

The most accurate methodology for routine evaluation of PD-1 and PD-L1 expression in UTUC may be based on 2 mm-core TMAs using NAT105 and 28.8 antibodies with a 5% cut off for positivity on TILs and tumor cells, respectively.

PD-L1 Expression in Muscle Invasive Urothelial Carcinomas as Assessed via Immunohistochemistry: Correlations with Specific Clinical and Pathological Features, with Emphasis on Prognosis after Radical Cystectomy

In the present study, we analyzed Programmed Death Ligand-1 (PD-L1) expression in radical cystectomy (RC) specimens from patients with muscle-invasive urothelial carcinoma (UC), in order to assess any correlations with specific clinicopathological features and its potential prognostic value. A multi-institutional study was performed within the departments of urology and pathology at the Mureș County Hospital, Romania, and Centre Hospitalier Lyon Sud, France. Sixty-nine patients with MIBC were included, for whom tumor histology (conventional versus histological variant/differentiation), tumor extension (T), lymph node involvement (N), and distant metastases (M) were recorded. PD-L1 immunostaining was performed using the 22C3 clone and was interpreted using the combined positive score (CPS) as recommended (Dako Agilent, Santa Clara, CA, USA). Positive PD-L1 immunostaining was more prevalent among UCs with squamous differentiation compared to conventional UCs and trended towards an improved OS (p = 0.366). We found the T stage to be a risk factor for poor survival in PD-L1-positive patients (HR 2.9, p = 0.021), along with the N stage in PD-L1-negative patients (HR 1.98, p = 0.007). No other clinicopathological factor was found to be significantly associated with PD-L1 positivity. Thus, we confirm the need for PD-L1 immunostaining prior to initiating immune checkpoint inhibitor therapy for a more accurate assessment of the patients’ chances of responding to treatment.

[Myxoid variant of adrenocortical carcinoma]

We report two cases of patients presenting myxoid variant of adrenocortical carcinoma (ACC). This very rare variant is characterized by a tumoral proliferation organized in trabeculae, cords or even pseudo-glands within an acellular myxoid materiel stained by Alcian Blue and negative for PAS. Tumor cells have a small to medium size and have little atypia. Their immunohistochemical profil (positivity of Synaptophysin, SF1, Melan A, Vimentin and Inhibin, with a weak or negative pancytokeratin expression) eliminate the main differential diagnoses (metastasis of a myxoid adenocarcinoma and soft tissue myxoid tumor). Many scoring systems have been proposed in order to evaluate the risk of malignancy of these lesions: the Weiss score seems less efficient to evaluate malignancy in this variant than the reticulinic algorithm or the Helsinki score. Prognosis of myxoid variant of ACC seems worse than classical ACC.

Prognostic Impact of pT3 Subclassification in a Multicentre Cohort of Patients with Urothelial Carcinoma of the Renal Pelvicalyceal System Undergoing Radical Nephroureterectomy: A Propensity Score-weighted Analysis After Central Pathology Review

BACKGROUND

The current pathological tumour-node-metastasis (pTNM) classification for upper tract urothelial carcinoma (UTUC) does not include any risk stratification of pT3 renal pelvicalyceal tumours.

OBJECTIVE

To assess the prognostic impact of pT3 subclassification in a multicentre cohort of patients with UTUC of the renal pelvicalyceal system undergoing radical nephroureterectomy (RNU).

DESIGN, SETTING, AND PARTICIPANTS

Data from all consecutive patients treated with RNU for pT3 renal pelvicalyceal UTUC at 14 French centres from 1995 to 2013 were reviewed retrospectively.

INTERVENTION

A central pathology review (CPR) was used to stratify pT3 patients into those with infiltration of the renal parenchyma on a microscopic level (pT3a) versus those with infiltration of the renal parenchyma visible on gross inspection of the resection specimen and/or invasion of peripelvic fat (pT3b).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Inverse probability weighting (IPW)-adjusted Cox regression analyses were used to compare recurrence-free survival (RFS) and cancer-specific survival (CSS) between pT3a and pT3b patients.

RESULTS AND LIMITATIONS

Overall, 202 patients were included and further stratified into pT3a (n = 98; 48.5%) and pT3b (n = 104; 51.5%) subgroups. Median time to follow-up in the weighted population was 68 (interquartile range, 50-95) mo. In IPW-adjusted Cox regression analyses, pT3b versus pT3a substage was associated with a significant adverse effect on RFS (hazard ratio [HR] = 2.02; 95% confidence interval [CI] = [1.36-3.01]; p < 0.001) and CSS (HR = 1.84; 95% CI = [1.20-2.82]; p = 0.005). The study is limited by its retrospective design.

CONCLUSIONS

Using IPW-adjusted analyses after the CPR, we observed that RNU patients with pT3b renal pelvicalyceal UTUC had adverse prognosis as compared with those with pT3a disease. As such, this subclassification could help refine the current pTNM system for UTUC.

PATIENT SUMMARY

In this report, we looked at the prognostic interest of stratifying patients with pT3 renal pelvicalyceal upper tract urothelial carcinoma based on the extent of local invasion. We found that those with extensive infiltration (pT3b) had adverse prognosis as compared with those with limited infiltration (pT3a). This information could be provided on pathology reports to further guide clinical decision making.

Cytological features and nuclear scores: Diagnostic tools in preoperative fine needle aspiration of indeterminate thyroid nodules with RAS or BRAF K601E mutations?

INTRODUCTION

The cytological diagnosis of follicular-patterned thyroid lesions is challenging, especially since the World Health Organisation classification has recognised non-invasive follicular thyroid neoplasm with papillary-like features. These entities are often classified as indeterminate on cytology. Molecular testing has been proposed to help classify indeterminate nodules. RAS and K601E BRAF mutations are mostly encountered in follicular-patterned lesions, but their diagnostic value is not well established. Nuclear scores have also been proposed to help classify indeterminate lesions.

OBJECTIVE

To investigate the correlation between cytological features and histology and to assess nuclear scores in a series of indeterminate RAS or BRAF K601E positive thyroid nodules.

METHODS

The cytological parameters of 69 indeterminate RAS or BRAF K601E-positive thyroid nodules were evaluated. The Strickland and Maletta scores and a new nuclear score were assessed. Diagnosis of malignant, benign or indolent neoplasms was confirmed in each case by histology. Malignant and indolent nodules were considered surgical nodules, and adenomas non-surgical nodule.

RESULTS

Surgical nodules were associated with the presence of ground glass nuclei (P = .001), grooves (P < .001) or irregular nuclear membranes (P = .01) on cytology. Nuclear scores were more often ≥2 in surgical nodules compared to benign ones (P < .001), with high sensitivity, but a low negative predictive value.

CONCLUSIONS

Analysis of nuclear features is useful to distinguish non-surgical from surgical nodules in indeterminate FNAs. Although nuclear scores are not ideal rule-out tests for indeterminate RAS or BRAF K601E positive nodules, they seem useful to screen non-molecular tested or non-mutated indeterminate FNAs. This work shows that meticulous analysis of nuclear features on cytological specimens can be useful to distinguish non-surgical nodules (adenoma) from surgical nodules in indeterminate FNAs. Although nuclear scores are not rule-out tests for indeterminate RAS or BRAF K601E positive nodules, they are useful in screening non-molecular tested or non-mutated indeterminate FNAs for surgery.

Poorly differentiated thyroid carcinoma with pleomorphic giant cells-a case report

Poorly differentiated thyroid carcinoma (PDTC) refers to a malignant tumour that displays an intermediate prognosis between well-differentiated carcinomas and anaplastic thyroid carcinomas (ATC). In the thyroid, pleomorphic giant cells are observed in ATC or in some non-neoplastic thyroid diseases. We described the case of a 43-year-old woman with a 34-mm nodule in her thyroid right lobe. Microscopic examination revealed an encapsulated tumour with a main solid growth pattern and extensive capsular invasion. Multiple images of angioinvasion were observed. There was neither necrosis nor inflammation. Most of the tumour cells were medium-sized and intermingled with pleomorphic giant tumour cells with bizarre features. The immunoprofile (keratins +, TTF1+, Pax 8+) proved their thyroid origin. By NGS, no molecular alteration was identified. The patient was treated by surgery and radioiodine therapy and she has no recurrence after a follow-up of 24 months. Our case meets all the histological criteria of the Turin proposal for PDTC but with pleomorphic giant cells and is very different from ATC according to clinical, histological and immunohistochemical features. Pleomorphic tumour giant cells in thyroid carcinomas could be present in PDTC and do not always represent dedifferentiation and more aggressive carcinoma, thyroid neoplasm.

[Hereditary predispositions to follicular thyroid tumors]

Familial thyroid cancers of follicular origin are rare and include syndromic and non-syndromic tumours. In familial adenomatous polyposis, the prevalence of papillary thyroid cancer is 2-12% and in 20-40% of cases it is a cribriform-morular papillary thyroid carcinoma. Morules and cribriform pattern are the two main typical criteria, associated with a nuclear and cytoplasmic immunopositivity for beta catenin. DICER1 syndrome is associated with pleuropneumoblastoma, ovarian tumors and thyroid pathology (multinodular goiter and less frequently a well-differentiated thyroid cancer without microscopic particularity). Cowden syndrome is characterized by multiple hamartomas and two-thirds of patients develop thyroid pathology, including multinodular goiter (50-67%) and cancer (35%), the latter being one of the major diagnostic criteria of the syndrome. Classic triad of Carney complex associates lentiginosis, myxoid tumors, and various endocrine abnormalities; thyroid pathology occurs in 10% of cases and may be benign or malignant. In Werner's syndrome, thyroid cancer is present in 18% of cases. McCune-Albright syndrome is characterized by fibrous dysplasia, café-au-lait spots and various endocrinopathies including hyperthyroidism and nodular hyperplasia. Non-syndromic thyroid cancers, which represent the majority of familial cancers, are most often papillary carcinomas. In daily practice, in the presence of multiple benign thyroid nodules and/or thyroid cancer in a young person, or with family thyroid diseases, the pathologist should be aware about hereditary predispositions to propose an oncogenetic consultation.

The Long Non-Coding RNA Prader Willi/Angelman Region RNA5 (PAR5) Is Downregulated in Anaplastic Thyroid Carcinomas Where It Acts as a Tumor Suppressor by Reducing EZH2 Activity

Anaplastic thyroid carcinoma (ATC) represents one the most aggressive neoplasias in humans, and, nowadays, limited advances have been made to extend the survival and reduce the mortality of ATC. Thus, the identification of molecular mechanism underlying its progression is needed. Here, we evaluated the long non-coding RNA (lncRNA) expression profile of nine ATC in comparison with five normal thyroid tissues by a lncRNA microarray. By this analysis, we identified 19 upregulated and 28 downregulated lncRNAs with a fold change >1.1 or <−1.1 and p-value < 0.05, in ATC samples. Some of them were subsequently validated by qRT-PCR. Then, we investigated the role of the lncRNA Prader Willi/Angelman region RNA5 (PAR5), drastically and specifically downregulated in ATC. The restoration of PAR5 reduces proliferation and migration rates of ATC-derived cell lines indicating that its downregulation contributes to thyroid cancer progression. Our results suggest that PAR5 exerts its anti-oncogenic role by impairing Enhancer of Zeste Homolog 2 (EZH2) oncogenic activity since we demonstrated that PAR5 interacts with it in thyroid cancer cell lines, reducing EZH2 protein levels and its binding on the E-cadherin promoter, relieving E-cadherin from the negative regulation by EZH2. Consistently, EZH2 is overexpressed in ATC, but not in differentiated thyroid carcinomas. The results reported here define a tumor suppressor role for PAR5 in undifferentiated thyroid neoplasias, further highlighting the pivotal role of lncRNAs in thyroid carcinogenesis.

Improved Androgen Receptor Splice Variant 7 Detection Using a Highly Sensitive Assay to Predict Resistance to Abiraterone or Enzalutamide in Metastatic Prostate Cancer Patients

BACKGROUND

In metastatic castration-resistant prostate cancer (mCRPC), androgen receptor splice variant 7 (AR-V7) expression is associated with a low response to androgen receptor signaling (ARS) inhibitors such as abiraterone or enzalutamide.

OBJECTIVE

To perform a highly sensitive assay for detecting AR-V7 (hsAR-V7) in circulating tumor cells (CTCs) and evaluate its ability to predict response to ARS inhibitors.

DESIGN, SETTING, AND PARTICIPANTS

From 41 mCRPC patients, CTCs were prospectively enriched using AdnaTest platform and analyzed for AR-V7 with and without the highly sensitive assay.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The first objective of the study was to compare AR-V7 detection rates with and without the highly sensitive assay. Next, we investigated how AR-V7 (detected without the highly sensitive assay) and hsAR-V7 status influenced prostate-specific antigen (PSA) response and long-term clinical outcomes (PSA progression-free survival [PFS] and radiological PFS) after ARS-inhibitor treatment. Finally, discriminatory abilities of the assays were assessed by C-index to compare their impact on long-term clinical outcomes.

RESULTS AND LIMITATIONS

AR-V7 detection rates increased from 22% to 56% when the highly sensitive assay was used. The discriminatory abilities of hsAR-V7 for PSA PFS (C-index, 0.74; 95% confidence interval [CI], 0.60-0.88) and radiological PFS (0.70; 95% CI, 0.55-0.85) were higher than those of AR-V7 detected without the highly sensitive assay (0.60, 0.51-0.72, and 0.56, 0.44-0.67, respectively). After ARS-inhibitor treatment, PSA response was lower in hsAR-V7⁺ (53%) than in hsAR-V7^- (93%) patients (p = 0.016). AR-V7⁺ patients had shorter median PSA PFS (3.0 vs 10.6 mo, p = 0.032) and nonsignificantly shorter median radiological PFS (6.0 vs 14.8 mo, p = 0.24) compared with AR-V7^- patients. The hsAR-V7⁺ status was associated with shorter median PSA PFS (3.0 mo vs not reached, p = 0.0001) and radiological PFS (median, 6.0 mo vs not reached, p = 0.0026).

CONCLUSIONS

The hsAR-V7 assay achieved the highest AR-V7 detection rates among those reported in mCRPC. Discriminatory abilities for long-term clinical outcomes were better with hsAR-V7 assay.

PATIENT SUMMARY

We prospectively analyzed circulating tumor cells from men with metastatic castration-resistant prostate cancer for androgen receptor splice variant 7 (AR-V7) status using a highly sensitive assay. It yielded higher AR-V7 detection rates and predicted resistance to androgen receptor signaling inhibitors with better discriminatory abilities for long-term clinical outcomes.

A ceRNA Circuitry Involving the Long Noncoding RNA Klhl14-AS, Pax8, and Bcl2 Drives Thyroid Carcinogenesis

Klhl14-AS is a long noncoding RNA expressed since early specification of thyroid bud and is the most enriched gene in the mouse thyroid primordium at E10.5. Here, we studied its involvement in thyroid carcinogenesis by analyzing its expression in cancer tissues and different models of neoplastic transformation. Compared with normal thyroid tissue and cells, Klhl14-AS was significantly downregulated in human thyroid carcinoma tissue specimens, particularly the anaplastic histotype, thyroid cancer cell lines, and rodent models of thyroid cancer. Downregulating the expression of Klhl14-AS in normal thyroid cells decreased the expression of thyroid differentiation markers and cell death and increased cell viability. These effects were mediated by the binding of Klhl14-AS to two miRNAs, Mir182-5p and Mir20a-5p, which silenced Pax8 and Bcl2, both essential players of thyroid differentiation. MIR182-5p and MIR20a-5p were upregulated in human thyroid cancer and thyroid cancer experimental models and their effects on Pax8 and Bcl2 were rescued by Klhl14-AS overexpression, confirming Klhl14-AS as a ceRNA for both Pax8 and Bcl2. This work connects deregulation of differentiation with increased proliferation and survival in thyroid neoplastic cells and highlights a novel ceRNA circuitry involving key regulators of thyroid physiology. SIGNIFICANCE: This study describes a new ceRNA with potential tumor suppression activity and helps us better understand the regulatory mechanisms during thyroid differentiation and carcinogenesis.

TERT promoter mutations identify a high-risk group in metastasis-free advanced thyroid carcinoma

BACKGROUND

TERT promoter mutations are associated with adverse clinicopathological characteristics in thyroid carcinomas and considered as a major indicator of poor outcomes. Nevertheless, most studies have pooled heterogeneous types of thyroid carcinomas and have been conducted retrospectively. We investigated the association between TERT promoter mutations and recurrence in a prospective series of 173 intermediate- to high-risk patients with thyroid cancer.

PATIENTS

Patients referred for radioiodine treatment after thyroidectomy for intermediate- to high-risk differentiated thyroid carcinoma were included in a prospective observational study and tested for TERT promoter, BRAF, and RAS mutations of their primary tumours. We analysed the relationship between TERT promoter mutations and outcomes.

RESULTS

The prevalence of TERT promoter mutations was 20.2% (35/173) in the total population. It was significantly higher in tumours harbouring aggressive histological features (poorly differentiated carcinoma, tall cell variant of papillary cancer or widely invasive follicular cancer) than in non-aggressive tumours: 32.7% (16/49) versus 15.3% (19/124; p = 0.020). TERT promoter mutations were also strongly associated with age ≥45 years (p = 0.005), pT4 stage (p = 0.015), metastatic disease (p = 0.014), and extrathyroidal extension (p = 0.002). TERT promoter mutations were associated with poor outcomes in the total population (p < 0.001) but not in the subgroup of non-metastatic patients (p = 0.051). However, they were associated with a worse outcome in patients both free of metastases and devoid of aggressive histological features. Neither BRAF nor RAS mutations were associated with event-free survival in non-metastatic patients.

CONCLUSION

Although their prognostic value does not seem to overcome that of histology, TERT promoter mutations may help to better define the prognosis of localized thyroid cancer patients without aggressive histology.

Impact of thyroid surgery volume and pathologic detection on risk of thyroid cancer: A geographical analysis in the Rhône-Alpes region of France

OBJECTIVE

To investigate the impact of the volume of thyroid surgery and pathologic detection on the risk of thyroid cancer.

METHODS

We investigated the influence of the volume of thyroid surgery in a first study that included 23 384 thyroid surgeries and 5302 thyroid cancers collected between 2008 and 2013. Standardized incidence ratios (SIRs) and thyroid intervention rates (STIRs) were used as indicators of cancer risk and surgery volume, respectively. The influence of pathologic detection, using the number of cuts per gram of tissue as the indicator, was studied in a second study that included 1257 thyroid specimens, collected in 2014.

RESULTS

We found departmental variations in SIRs and a significant effect of the STIR on the SIR (men, P = 0.0008; women, P < 0.0001). A 1/100 000 increase in the STIR resulted in a 3% and 1.3% increase in the SIR in men and women, respectively. This effect was greatest for microcancers and absent for tumours >4 cm. The risk of cancer diagnosis was significantly associated with the number of cuts per gram of tissue (OR 6.1, P < 0.001), and was greater for total thyroidectomy than for lobectomy (P = 0.014) and when FNA cytology had been preoperatively performed (P < 0.001). The prevalence of incidental microcancers was highest in the centres performing the highest number of cuts per gram.

CONCLUSIONS

The risk of thyroid cancer, particularly microcancer, is related to the volume of surgery and to the level of pathologist scrutiny. Both factors contribute to the increase in overdiagnosis. This further advocates for appropriate selection of patients for thyroid surgery.

Effect of Buparlisib, a Pan-Class I PI3K Inhibitor, in Refractory Follicular and Poorly Differentiated Thyroid Cancer

BACKGROUND

Dysregulation of the phosphatidylinositol 3-kinase (PI3K) pathway is frequent in advanced follicular (FTC) and poorly differentiated thyroid (PDTC) carcinomas and has been implicated in oncogenesis and tumor progression. This study investigated the efficacy and safety of buparlisib, a pan-PI3K inhibitor in radioiodine refractory FTC and PDTC.

METHODS

The primary endpoint of this open-label, multicenter, phase 2 pilot study was progression-free survival (PFS) at 6 months. The sample size was determined considering that a PFS ≤50% at 6 months would denote an absence of benefits (null hypothesis). Secondary endpoints were objective response rate, PFS at 12 months, overall survival at 6 and 12 months, and safety based on the frequency and severity of adverse events (AEs).

RESULTS

Forty-three patients (19M/24 F; median age: 67 years) with metastatic, radioiodine refractory, progressive disease received buparlisib, 100 mg, daily. Histology was PDTC in 25 (58%), FTC in 17 (40%), and Hürthle cell carcinoma in 1 (2%). RAS mutation was found in 44% (12/27) and activation of the PI3K pathway in 35% (8/23) of tested tumors. The probability of PFS was 41.7% [95% confidence interval (CI) 7.7-55.5] at 6 months and 20.9% [CI 0-35.7] at 12 months, lower than the 50% expected PFS. At 6 months, 25.6% patients had stable disease, 48.8% were progressive and 25.6% had stopped treatment due to AE. The response to therapy was not influenced by age, sex, histology, or genetic alterations. The overall survivals at 6 and 12 months were 85.9% [CI 76-97] and 78.7 % [CI 67-92], respectively. The mean tumor growth rate decreased from 3.78 mm/month [CI 2.61-4.95] before treatment to 0.8 mm/month [CI -0.2-1.88] during treatment (p < 0.02). Severe grade 3-4 AEs occurred in 27 patients (63%), including hepatitis (25%), hyperglycemia (21%), mood disorders (12%), and skin toxicity (12%), with favorable outcome after temporary or permanent treatment discontinuation or dose reduction.

CONCLUSIONS

Buparlisib did not result in significant efficacy in advanced FTC and PDTC. However, the decrease in tumor growth rate may suggest incomplete inhibition of oncogenic pathways and/or escape mechanisms. This should lead to evaluate combined therapy associating inhibitors of both the PI3K and mitogen-activated protein kinase pathways.

[DICER1 mutated, solid/trabecular thyroid papillary carcinoma in an 11-year-old child]

We report the case of an 11-year-old patient diagnosed with a solid variant of papillary thyroid carcinoma. Papillary thyroid carcinoma (PTC) is the most common thyroid cancer, representing 80-90% of all newly diagnosed thyroid cancers. Among the many variants described, solid/trabecular variant of papillary thyroid carcinoma is a rare entity and account for 3% of thyroid cancers. It is more common in children and young adults, and it is seen in higher proportion in post radiation papillary thyroid carcinoma cases. Histologically, solid variant papillary carcinoma is characterized by a predominantly solid, trabecular or insular growth pattern, and the presence of cytological features typical of PTC. Its main differential diagnosis is poorly differentiated thyroid carcinoma. It has a less favorable prognosis than the classical papillary type, with a higher risk of distant metastasis, extrathyroidal extension and lympho-vascular invasion. It is associated with a slightly lower long-term survival in adult cases, but not in children. The management of solid variant PTC includes surgery, associated or not with postoperative radioiodine ablation, according to the aggressiveness criteria. Our patient had a DICER1 somatic mutation. Carriers of germline DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 syndrome, with a higher risk of numerous tumors and infrequently differentiated thyroid carcinomas.

The Long Non-Coding RNA RP5-1024C24.1 and Its Associated-Gene MPPED2 Are Down-Regulated in Human Thyroid Neoplasias and Act as Tumour Suppressors

Background: Well-differentiated papillary thyroid carcinoma (PTC) represents the thyroid neoplasia with the highest incidence. Long non-coding RNAs (lncRNAs) have been found deregulated in several human carcinomas, and hence, proposed as potential diagnostic and prognostic markers. Therefore, the aim of our study was to investigate their role in thyroid carcinogenesis. Methods: We analysed the lncRNA expression profile of 12 PTC and four normal thyroid tissues through a lncRNA microarray. Results: We identified 669 up- and 2470 down-regulated lncRNAs with a fold change >2. Among them, we focused on the down-regulated RP5-1024C24.1 located in an antisense position with respect to the MPPED2 gene which codes for a metallophosphoesterase with tumour suppressor activity. Both these genes are down-regulated in benign and malignant thyroid neoplasias. The restoration of RP5-1024C24.1 expression in thyroid carcinoma cell lines reduced cell proliferation and migration by modulating the PTEN/Akt pathway. Inhibition of thyroid carcinoma cell growth and cell migration ability was also achieved by the MPPED2 restoration. Interestingly, RP5-1024C24.1 over-expression is able to increase MPPED2 expression. Conclusions: Taken together, these results demonstrate that RP5-1024C24.1 and MPPED2 might be considered as novel tumour suppressor genes whose loss of expression contributes to thyroid carcinogenesis.

Role of Dicer1 in thyroid cell proliferation and differentiation

DICER1 plays a central role in the biogenesis of microRNAs and it is important for normal development. Altered microRNA expression and DICER1 dysregulation have been described in several types of tumors, including thyroid carcinomas. Recently, our group identified a new somatic mutation (c.5438A>G; E1813G) within DICER1 gene of an unknown function. Herein, we show that DICER1 is overexpressed, at mRNA level, in a significant-relative number of papillary (70%) and anaplastic (42%) thyroid carcinoma samples, whereas is drastically downregulated in all the analyzed human thyroid carcinoma cell lines (TPC-1, BCPAP, FRO and 8505c) in comparison with normal thyroid tissue samples. Conversely, DICER1 is downregulated, at protein level, in PTC in comparison with normal thyroid tissues. Our data also reveals that DICER1 overexpression positively regulates thyroid cell proliferation, whereas its silencing impairs thyroid cell differentiation. The expression of DICER1 gene mutation (c.5438A>G; E1813G) negatively affects the microRNA machinery and cell proliferation as well as upregulates DICER1 protein levels of thyroid cells but has no impact on thyroid differentiation. In conclusion, DICER1 protein is downregulated in papillary thyroid carcinomas and affects thyroid proliferation and differentiation, while DICER1 gene mutation (c.5438A>G; E1813G) compromises the DICER1 wild-type-mediated microRNA processing and cell proliferation.

Molecular testing of BRAF, RAS and TERT on thyroid FNAs with indeterminate cytology improves diagnostic accuracy

OBJECTIVE

Liquid-based (LB)-FNA is widely recognized as a reliable diagnostic method to evaluate thyroid nodules. However, up to 30% of LB-FNA remain indeterminate according to the Bethesda system. Use of molecular biomarkers has been recommended to improve its pathological accuracy but implementation of these tests in clinical practice may be difficult. Here, we evaluated feasibility and performance of molecular profiling in routine practice by testing LB-FNA for BRAF, N/HRAS and TERT mutations.

METHODS

We studied a large prospective cohort of 326 cases, including 61 atypia of undetermined significance, 124 follicular neoplasms, 72 suspicious for malignancy and 69 malignant cases. Diagnosis of malignancy was confirmed by histology on paired surgical specimen.

RESULTS

Mutated LB-FNAs were significantly associated with malignancy regardless of the cytological classification. Overall sensitivity was 60% and specificity 89%. Importantly, in atypia of undetermined significance and follicular neoplasm patients undergoing surgery according to the Bethesda guidelines, negative predictive values were 85.4% and 90% respectively. TERT promoter mutation was rare but very specific for malignancy (5.5%) suggesting that it could be of interest in patients with indeterminate cytology.

CONCLUSIONS

Mutation profiling can be successfully performed on thyroid LB-FNA without any dedicated sample in a pathology laboratory. It is an easy way to improve diagnostic accuracy of routine LB-FNA and may help to better select patients for surgery and to avoid unnecessary thyroidectomies.

Predicting thyroid nodule malignancy at several prevalence values with a combined Bethesda-molecular test

Investigation of thyroid nodules using fine-needle aspiration cytology (FNAC) gives indeterminate results in up to 30% of samples using the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). We present a combined Bethesda-molecular predictor of nodule malignancy to improve the accuracy of the preoperative diagnosis of thyroid nodules. To detect a molecular signature of thyroid nodule malignancy, a molecular test was performed on FNACs from 128 thyroid nodules from prospectively included patients, collected in a tertiary center. The test relied on a transcriptomic array of 20 genes selected from a previous study. An optimal set of seven genes was identified using a logistic regression model. Comparison between the combined predictor (TBSRTC + molecular) and TBSRTC alone used the area under the ROC curve (AUC). Performance of the combined predictor was calculated according to various malignancy prevalence values and benefit-to-harm ratios (B/Hr) (favoring sensitivity or specificity). In our population (36% malignancy prevalence) and with a B/Hr of 1, the combined predictor achieved 95% specificity and 76% sensitivity. The AUC was 93.5%; higher than that of TBSRTC (P = 0.004). Among indeterminate nodules (30% malignancy prevalence), sensitivity and specificity were 52.2% and 96.2%, respectively, with a B/Hr of 1, or 95.7% and 64.2% with a B/Hr of 4 (favoring sensitivity), allowing avoidance of 64% of unnecessary surgeries at the cost of only one false-positive result. In conclusion, this predictor could improve the detection of thyroid nodule malignancy, taking into account malignancy prevalence and B/Hr, and reduce the number of unnecessary thyroidectomies.