Fat1 deletion promotes hybrid EMT state, tumour stemness and metastasis.

FAT1, which encodes a protocadherin, is one of the most frequently mutated genes in human cancers1-5. However, the role and the molecular mechanisms by which FAT1 mutations control tumour initiation and progression are poorly understood. Here, using mouse models of skin squamous cell carcinoma and lung tumours, we found that deletion of Fat1 accelerates tumour initiation and malignant progression and promotes a hybrid epithelial-to-mesenchymal transition (EMT) phenotype. We also found this hybrid EMT state in FAT1-mutated human squamous cell carcinomas. Skin squamous cell carcinomas in which Fat1 was deleted presented increased tumour stemness and spontaneous metastasis. We performed transcriptional and chromatin profiling combined with proteomic analyses and mechanistic studies, which revealed that loss of function of FAT1 activates a CAMK2-CD44-SRC axis that promotes YAP1 nuclear translocation and ZEB1 expression that stimulates the mesenchymal state. This loss of function also inactivates EZH2, promoting SOX2 expression, which sustains the epithelial state. Our comprehensive analysis identified drug resistance and vulnerabilities in FAT1-deficient tumours, which have important implications for cancer therapy. Our studies reveal that, in mouse and human squamous cell carcinoma, loss of function of FAT1 promotes tumour initiation, progression, invasiveness, stemness and metastasis through the induction of a hybrid EMT state.

Genomic profile analysis of leiomyomas with bizarre nuclei and fumarate hydratase deficient leiomyomas: Strengths, weaknesses, and limitations of array-CGH interpretation.

A close relationship has been demonstrated between genomic complexity and clinical outcome in uterine smooth muscle tumors. We studied the genomic profiles by array-CGH of 28 fumarate hydratase deficient leiomyomas and 37 leiomyomas with bizarre nuclei (LMBN) from 64 patients. Follow-up was available for 46 patients (from three to 249 months, mean 87.3 months). All patients were alive without evidence of disease. For 51 array-CGH interpretable tumors the mean Genomic Index (GI) was 16.4 (median: 9.8; from 1 to 57.8), significantly lower than the mean GI in LMS (mean GI 51.8, p < 0.001). We described three groups: (1) a group with FH deletion (24/58) with low GI (mean GI: 11 vs. 22,4, p = 0.02), (2) a group with TP53 deletion (17/58) with higher GI (22.4 vs. 11 p = 0.02), and (3) a group without genomic events on FH or TP53 genes (17/58) (mean GI:18.3; from 1 to 57.8). Because none of these tumors recurred and none showed morphological features of LMS we concluded that GI at the cut-off of 10 was not applicable in these subtypes of LM. By integration of all those findings, a GI <10 in LMBN remains a valuable argument for benignity. Conversely, in LMBN a GI >10 or alteration in tumor suppressor genes, should not alone warrant a diagnosis of malignancy. Nine tumors were tested with Nanocind CINSARC® signature and all were classified in low risk of recurrence. We propose, based on our observations, a diagnostic approach of these challenging lesions.

Combined prenatal US and post-mortem fetal MRI: can they replace conventional autopsy for fetal body abnormalities?

OBJECTIVES: The acceptance of conventional autopsy (CA), the gold standard method for investigating fetal death, often remains problematic. Post-mortem magnetic resonance imaging (PMMRI) is increasingly advocated, particularly for neurologic malformations. However, PMMRI performances to diagnose non-neurologic malformations remain unclear. We aim to clarify whether a full body CA remains needed after prenatal ultrasound (US) and PMMRI in assessing non-neurologic fetal malformations. METHODS: In this retrospective IRB-approved study, during a 6-year period, all fetuses who underwent PMMRI, prenatal US, and full body CA were included. Body abnormalities were identified in US, PMMRI, and CA reports. US and PMMRI images were all reviewed. All abnormalities were graded as major (2 points) or minor (1 point). Each technique (US, PMMRI, CA) was given a score by adding all grading points. In each fetus, results were compared for both separate and combined US and PMMRI to CA. Sensitivity and specificity were calculated for detecting major abnormalities. RESULTS: Fifty fetuses were included. The score of CA, US, and PMMRI was respectively 53, 37, and 46. Compared with US-PMMRI, CA added information in 2 cases (4%) with major abnormalities and 7 cases (14%) with minor abnormalities. PMMRI and US were concordant in 36/50 (72%) fetuses. Separate US/PMMRI sensitivities and specificities for detecting major body malformations respectively were 80%/80% and 100%/94%. Combined US-PMMRI had a sensitivity of 90% and a specificity of 94%. Two cardiac malformations (2/6) were only described by CA. CONCLUSIONS: After prenatal US and PMMRI, few additional fetal body malformations are discovered with CA. Nevertheless, fetal heart autopsy remains mandatory. CLINICAL RELEVANCE STATEMENT: A cardiac conventional autopsy complemented by prenatal ultrasound and post-mortem MRI allows to detect all major fetal body abnormalities. With this efficient and much less invasive approach, a higher acceptance rate of fetal autopsy can be expected. KEY POINTS: • Excepting cardiac malformations, most major fetal body malformations can reliably be identified by prenatal US combined with post-mortem MRI. • In the post-mortem diagnosis of fetal body malformations, a conventional autopsy limited to the fetal heart might replace a full body autopsy after a well-conducted prenatal US and post-mortem MRI.

Identification of the tumour transition states occurring during EMT.

In cancer, the epithelial-to-mesenchymal transition (EMT) is associated with tumour stemness, metastasis and resistance to therapy. It has recently been proposed that, rather than being a binary process, EMT occurs through distinct intermediate states. However, there is no direct in vivo evidence for this idea. Here we screen a large panel of cell surface markers in skin and mammary primary tumours, and identify the existence of multiple tumour subpopulations associated with different EMT stages: from epithelial to completely mesenchymal states, passing through intermediate hybrid states. Although all EMT subpopulations presented similar tumour-propagating cell capacity, they displayed differences in cellular plasticity, invasiveness and metastatic potential. Their transcriptional and epigenetic landscapes identify the underlying gene regulatory networks, transcription factors and signalling pathways that control these different EMT transition states. Finally, these tumour subpopulations are localized in different niches that differentially regulate EMT transition states.

A Two-Step Diagnostic Approach for NTRK Gene Fusion Detection in Biliary Tract and Pancreatic Adenocarcinomas.

BACKGROUND: It is of interest to determine the incidence and molecular characteristics of NTRK gene fusions in patients with bilio-pancreatic cancers, because of possible treatment with TRK inhibitors for advanced tumors. The aim of the present study was to apply the guidelines for NTRK testing algorithm to a series of patients with bilio-pancreatic cancers. METHODS: Immunohistochemistry screening was applied on formalin-fixed paraffin-embedded archival blocks from surgical resections, biopsies, or cytological samples of biliary tract and pancreatic adenocarcinomas. The presence of at least a weak staining in rare tumor cells led to testing by 2 RNA-based NGS panels. RESULTS: For biliary tract tumors, 153 samples have been selected. A total of 140 samples were suitable to perform IHC, and 17 samples were IHC positive. RNA NGS testing of the 17 IHC-positive samples revealed a single NTRK3 gene fusion (ETV6(4)-NTRK3(14)) that was detected by both NGS panels. In this perihilar cholangiocarcinoma, IHC performed on a biopsy showed a weak focal cytoplasmic and nuclear staining. No other NTRK fusion was detected on the 16 other samples with both panels. Overall in the patients screened by IHC and confirmed by NGS, the percentage of NTRK fusions was 0.7%. For pancreatic cancers, 319 samples have been selected and 297 were suitable to perform IHC. Nineteen samples were IHC positive. No fusion was detected by NGS. CONCLUSION: NTRK gene fusions are rare in bilio-pancreatic cancers but testing is of high interest due to possible treatment with specific TRK inhibitors.

Peritoneal patch in vascular reconstruction during pancreaticoduodenectomy for pancreatic cancer: a single Centre experience.

BACKGROUND: Concomitant venous resection during pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma with mesenterico-portal vein involvement is increasingly performed to achieve oncological resection. This study aims to report a single centre experience in peritoneal patch (PP) as autologous graft for vascular reconstruction (VR) during PD. METHODS: A retrospective analysis of all patients who underwent PD + VR with PP between December 2019 and September 2020 was performed, using a prospective collected database. Postoperative outcome and pathological margins were evaluated. Venous patency was assessed by computed tomography at day 7 and week 12 post surgery. RESULTS: Fifteen patients underwent PD + VR with PP reconstruction for pancreatic cancer, including one total pancreatectomy. VR consisted of lateral (n = 14) or tubular (n = 1) patch. The median PP length was 30 mm [26.3-33.8] and venous clamping time 30 min [27.5-39.0]. Computed tomography showed a patent VR in 93.3% and 53.3% after 7 days and 12 weeks, respectively; venous patency loss was always asymptomatic. The only postoperative VR-related complication was one mesenteric venous thrombosis. Five other patients experienced VR-unrelated complications: septic shock (n = 3), biliary fistula (n = 1) and post-traumatic subdural hematoma (n = 1). Mortality was nihil. At pathology, R0 resection (≥1 mm) was observed in 40.0% (6/15), venous margin was free in 46.7% (7/15), and venous wall was involved in 40.0% (6/15). CONCLUSIONS: Use of PP as venous substitute during PD + VR is safe and feasible with an acceptable postoperative morbidity, and a decreased but asymptomatic venous patency after 12 weeks which should question the role of anticoagulation therapy.

Implementation of fetal clinical exome sequencing: Comparing prospective and retrospective cohorts.

PURPOSE: We compared the diagnostic yield of fetal clinical exome sequencing (fCES) in prospective and retrospective cohorts of pregnancies presenting with anomalies detected using ultrasound. We evaluated factors that led to a higher diagnostic efficiency, such as phenotypic category, clinical characterization, and variant analysis strategy. METHODS: fCES was performed for 303 fetuses (183 ongoing and 120 ended pregnancies, in which chromosomal abnormalities had been excluded) using a trio/duo-based approach and a multistep variant analysis strategy. RESULTS: fCES identified the underlying genetic cause in 13% (24/183) of prospective and 29% (35/120) of retrospective cases. In both cohorts, recessive heterozygous compound genotypes were not rare, and trio and simplex variant analysis strategies were complementary to achieve the highest possible diagnostic rate. Limited prenatal phenotypic information led to interpretation challenges. In 2 prospective cases, in-depth analysis allowed expansion of the spectrum of prenatal presentations for genetic syndromes associated with the SLC17A5 and CHAMP1 genes. CONCLUSION: fCES is diagnostically efficient in fetuses presenting with cerebral, skeletal, urinary, or multiple anomalies. The comparison between the 2 cohorts highlights the importance of providing detailed phenotypic information for better interpretation and prenatal reporting of genetic variants.

Molecular pathology testing for non-small cell lung cancer: an observational study of elements currently present in request forms and result reports and the opinion of different stakeholders.

BACKGROUND: For patients with non-small cell lung cancer (NSCLC), targeted therapies are becoming part of the standard treatment. It is of question which information the clinicians provide on test requests and how the laboratories adapt test conclusions to this knowledge and regulations. METHODS: This study consisted of two components; 1) checking the presence of pre-defined elements (administrative and key for therapy-choice) on completed requests and corresponding reports in Belgian laboratories, both for tissue- and liquid biopsy (LB)-testing and b) opinion analysis from Belgian pathologists/molecular biologists and clinicians during national pathology/oncology meetings. RESULTS: Data from 4 out of 6 Belgian laboratories with ISO-accreditation for LB-testing were analyzed, of which 75% were university hospitals. On the scored requests (N = 4), 12 out of 19 ISO-required elements were present for tissue and 11 for LB-testing. Especially relevant patient history, such as line of therapy (for LB), tumor histology and the reason for testing were lacking. Similarly, 11 and 9 out of 18 elements were present in the reports (N = 4) for tissue and LB, respectively. Elements that pathologists/molecular biologists (N = 18) were missing on the request were the initial activating mutation, previous therapies, a clinical question and testing-related information. For reporting, an item considered important by both groups is the clinical interpretation of the test result. In addition, clinicians (N = 28) indicated that they also wish to read the percentage of neoplastic cells. CONCLUSIONS: Communication flows between the laboratory and the clinician, together with possible pitfalls were identified. Based on the study results, templates for complete requesting and reporting were proposed.

First Case Report of a Uterine Angiolipoleiomyoma With KRAS and KIT Mutations.

Angiolipoleiomyoma is a very rare lesion of the uterus. To the best of our knowledge, only 20 cases have been described in the literature. It is an insufficiently defined entity, which is not included in the WHO classification. This lesion may be therefore underdiagnosed and underestimated. We describe here a case of a 58-yr-old woman who underwent routine gynecological examination. Ultrasonography revealed a heterogeneous myometrial mass, while magnetic resonance imaging showed a voluminous corporeal and fundic myometrial mass protruding into the uterine cavity. A total hysterectomy was performed. The macroscopic examination revealed an intramural solitary round mass with a heterogeneous cut-surface. Microscopically, the lesion consisted of an admixture of smooth muscle, adipose tissue, and blood vessels. Desmin was positive, while HMB45 was negative in the tumor. Molecular tests were performed and revealed, for the first time to our knowledge, a case of an angiolipoleiomyoma harboring KRAS and KIT mutations.

Discovery and 3D imaging of a novel ΔNp63-expressing basal cell type in human pancreatic ducts with implications in disease.

OBJECTIVE: The aggressive basal-like molecular subtype of pancreatic ductal adenocarcinoma (PDAC) harbours a ΔNp63 (p40) gene expression signature reminiscent of a basal cell type. Distinct from other epithelia with basal tumours, ΔNp63+ basal cells reportedly do not exist in the normal pancreas. DESIGN: We evaluated ΔNp63 expression in human pancreas, chronic pancreatitis (CP) and PDAC. We further studied in depth the non-cancerous tissue and developed a three-dimensional (3D) imaging protocol (FLIP-IT, Fluorescence Light sheet microscopic Imaging of Paraffin-embedded or Intact Tissue) to study formalin-fixed paraffin-embedded samples at single cell resolution. Pertinent mouse models and HPDE cells were analysed. RESULTS: In normal human pancreas, rare ΔNp63+ cells exist in ducts while their prevalence increases in CP and in a subset of PDAC. In non-cancer tissue, ΔNp63+ cells are atypical KRT19+ duct cells that overall lack SOX9 expression while they do express canonical basal markers and pertain to a niche of cells expressing gastrointestinal stem cell markers. 3D views show that the basal cells anchor on the basal membrane of normal medium to large ducts while in CP they exist in multilayer dome-like structures. In mice, ΔNp63 is not found in adult pancreas nor in selected models of CP or PDAC, but it is induced in organoids from larger Sox9low ducts. In HPDE, ΔNp63 supports a basal cell phenotype at the expense of a classical duct cell differentiation programme. CONCLUSION: In larger human pancreatic ducts, basal cells exist. ΔNp63 suppresses duct cell identity. These cells may play an important role in pancreatic disease, including PDAC ontogeny, but are not present in mouse models.

Osseous Metaplasia in Low-grade Ovarian Serous Carcinoma With a BRAF Mutation: A Case Report.

A 44-yr-old woman presented with lower, painless abdominal discomfort and a vacuolated mass measuring 12 cm on the right-hand side of the pelvis. She subsequently underwent a bilateral salpingo-oophorectomy. An osseous lesion was identified in the left ovary, which was hard in consistency and was associated with a multicystic complex lesion. Microscopic examination of the left ovary showed clusters of serous cells with moderate atypia, surrounded by a desmoplastic stroma with large areas of bone matrix. To the best of our knowledge, this is the first reported case of low-grade serous carcinoma with osseous metaplasia and a BRAF mutation.

Unspecific post-mortem findings despite multiorgan viral spread in COVID-19 patients.

BACKGROUND: Post-mortem studies can provide important information for understanding new diseases and small autopsy case series have already reported different findings in COVID-19 patients. METHODS: We evaluated whether some specific post-mortem features are observed in these patients and if these changes are related to the presence of the virus in different organs. Complete macroscopic and microscopic autopsies were performed on different organs in 17 COVID-19 non-survivors. Presence of SARS-CoV-2 was evaluated with immunohistochemistry (IHC) in lung samples and with real-time reverse-transcription polymerase chain reaction (RT-PCR) test in the lung and other organs. RESULTS: Pulmonary findings revealed early-stage diffuse alveolar damage (DAD) in 15 out of 17 patients and microthrombi in small lung arteries in 11 patients. Late-stage DAD, atypical pneumocytes, and/or acute pneumonia were also observed. Four lung infarcts, two acute myocardial infarctions, and one ischemic enteritis were observed. There was no evidence of myocarditis, hepatitis, or encephalitis. Kidney evaluation revealed the presence of hemosiderin in tubules or pigmented casts in most patients. Spongiosis and vascular congestion were the most frequently encountered brain lesions. No specific SARS-CoV-2 lesions were observed in any organ. IHC revealed positive cells with a heterogeneous distribution in the lungs of 11 of the 17 (65%) patients; RT-PCR yielded a wide distribution of SARS-CoV-2 in different tissues, with 8 patients showing viral presence in all tested organs (i.e., lung, heart, spleen, liver, colon, kidney, and brain). CONCLUSIONS: In conclusion, autopsies revealed a great heterogeneity of COVID-19-associated organ injury and the remarkable absence of any specific viral lesions, even when RT-PCR identified the presence of the virus in many organs.

Non-occlusive Mesenteric Ischemia as a Fatal Complication in Acute Pancreatitis: A Case Series.

BACKGROUND: Vascular complications of severe acute pancreatitis are well known and largely described unlike non-occlusive mesenteric ischemia, which is a rare and potentially fatal complication. Non-occlusive mesenteric ischemia is an acute mesenteric ischemia without thrombotic occlusion of blood vessels, poorly described as a complication of acute pancreatitis. METHODS: We retrospectively reviewed a prospectively maintained registry of all pancreatic diseases referred to our center from 2013 to 2018, in order to determine the causes of early death. We identified three patients who died within 48 h after hospital admission from severe acute pancreatitis complicated by irreversible non-occlusive mesenteric ischemia. Their clinical presentation, management, and outcomes were herein reported. RESULTS: Three consecutive patients with severe acute pancreatitis developed non-occlusive mesenteric ischemia within the first 5 days after onset of symptoms and died 48 h after non-occlusive mesenteric ischemia diagnosis despite optimal intensive care management and surgery, giving a prevalence of 3/609 (0.5%). Symptoms were unspecific with consequently potential delayed diagnosis and management. High doses of norepinephrine required for hemodynamic support (n = 3) potentially leading to splanchnic vessels vasoconstriction, transient hypotension (n = 3), and previous severe ischemic cardiomyopathy (n = 1) could be involved as precipitating factors of non-occlusive mesenteric ischemia. CONCLUSION: Non-occlusive mesenteric ischemia can be a fatal complication of acute pancreatitis but is also challenging to diagnose. Priority is to reestablish a splanchno-mesenteric perfusion flow. Surgery should be offered in case of treatment failure or deterioration but is still under debate in early stage, to interrupt the vicious circle of intestinal hypoperfusion and ischemia.

Distal pancreatectomy for pancreatic neoplasia: is splenectomy really necessary? A bicentric retrospective analysis of surgical specimens.

BACKGROUND: While distal pancreatectomy with splenectomy (DPS) is the reference treatment for pancreatic body and tail neoplasia, oncological benefits of splenectomy have never been demonstrated. Involvement of spleen, splenic hilum and lymph nodes (LN) was therefore assessed on DPS specimens. METHODS: All DPS pancreatic neoplasia specimens obtained in 2 Brussels University Hospitals over 15 years (2004-2018) were reviewed retrospectively, using both preoperative radiological imaging and postoperative pathological analyses of splenic parenchyma, hilar tissue and LN. RESULTS: The total of 130 DPS specimens included 85 adenocarcinomas, 37 neuroendocrine neoplasms and 8 other carcinomas. Tumours involved the pancreatic body without tail invasion for 59 specimens (B, Body group), and the pancreatic tail with/without body for 71 (T, Tail group). At pathology, direct splenic and/or hilar involvement was observed in 13 T specimens (13/71, 18.3%), but in none belonging to the Body group. The observed numbers of splenic hilar LN (only reported in 49/130 patients) were low, only one T adenocarcinoma had positive splenic LN in addition to direct splenic involvement. CONCLUSION: Splenectomy remains justified during pancreatectomy for neoplasia involving the pancreatic tail, but in case of pancreatic body tumours, its benefits should be questioned in the light of absent splenic LN/parenchymal involvement.

SMAD4 Mutation in Small Cell Transformation of Epidermal Growth Factor Receptor Mutated Lung Adenocarcinoma.

The large screening of exons 18 to 21 of the epidermal growth factor receptor (EGFR) gene may lead to the discovery of rare, atypical molecular alterations for which the sensitivity to tyrosine kinase inhibitors (TKIs) remains uncertain. We are reporting a rare exon 18 EGFR mutation (p.E709_710 > D) that confers sensitivity to second-generation EGFR TKI (afatinib), lasting for 1 year. Tumor progression biopsy showed small cell lung cancer transformation, associated with a SMAD4 mutation. KEY POINTS: A rare exon 18 epidermal growth factor receptor mutation with sensitivity to afatinib is reported.Small cell transformation was observed at tumor progression.Acquisition of a SMAD4 mutation was observed at tumor progression.

Treatment of solitary thyroid nodules according to size, preoperative fine-needle aspiration cytology and frozen section: a retrospective single centre study.

Background: In order to avoid unnecessary thyroidectomies, it is important to predict the nature of thyroid nodules the more accurately possible. The size of the nodule as a predictive factor for malignancy is very controversial. Another point of debate is the accuracy of preoperative fine-needle aspiration cytology (FNAC) and frozen section (FS). The aim of our study is to correlate the nodule size with the final histological diagnosis and to estimate the accuracy of preoperative FNAC and FS. Methods: Retrospective study including 387 operated patients with ultrasound-detected solitary thyroid nodules from 01 January 2001 to 31 December 2013. The following data were collected: patient age and sex, nodule size, FNAC, FS and final histology results. Results: The odds ratio for malignancy within nodules <40 mm was 2.12 (95% CI: 1.104-4.084). The specificity of FNAC was 97.78% and the negative predictive value (NPV) was 97.78% for nodules ≥40 mm and 93.2% and 96.5% for nodules <40 mm, respectively. The observed specificity and NPV of FS ranged from 98% to 100% and from 87.4% to 98%, respectively. When combining FNAC and FS, the specificity and the NPV were 99% and 98%, respectively. Conclusions: The nodule size is not a predictive factor for thyroid cancer and therefore nodules ≥40 mm should not be routinely resected. A lege artis preparation and performance of FNAC along with an expertise on cytological interpretation can considerably diminish false-negative rate. FS can offer additional accuracy on FNAC results and should, therefore, be a part of patient treatment.

The Prognostic Value of the Combination of Low VEGFR-1 and High VEGFR-2 Expression in Endothelial Cells of Colorectal Cancer.

Research on tumor angiogenesis has mainly focused on the vascular endothelial growth factor (VEGF) family and on methods to block its actions. However, reports on VEGF receptor (VEGFR) expression in tumor-associated endothelial cells (ECs) are limited. Thus, we evaluated VEGF, VEGFR-1 and VEGFR-2 expression in ECs of colorectal cancer (CRC) using immunohistochemistry. VEGF, VEGFR-1 and -2 expression in ECs was quantitatively evaluated by digital image analysis in a retrospective series of 204 tumor tissue samples and related to clinical variables. The data show that the VEGF, VEGFR-1 and VEGFR-2 expression in ECs is heterogeneous. Multivariate analysis including a set of clinicopathological variables reveals that high EC VEGFR-1 expression is an independent prognostic factor for overall survival (OS). The combination of low VEGFR-1 and high VEGFR-2 expression in ECs outperforms models integrating VEGFR-1 and VEGFR-2 as separate markers. Indeed, this VEGFR-1_VEGFR-2 combination is an independent negative prognostic factor for OS (p = 0.012) and metastasis-free survival (p = 0.007). In conclusion, this work illustrates the importance of studying the distribution of VEGF members in ECs of CRC. Interestingly, our preliminary data suggest that high VEGFR-1 and low VEGFR-2 expression in ECs appear to be involved in the progression of CRC, suggesting that targeting EC VEGFR-1 could offer novel opportunities for CRC treatment. However, a prospective validation study is needed.

Clinical Application of Targeted Next Generation Sequencing for Colorectal Cancers.

Promising targeted therapy and personalized medicine are making molecular profiling of tumours a priority. For colorectal cancer (CRC) patients, international guidelines made RAS (KRAS and NRAS) status a prerequisite for the use of anti-epidermal growth factor receptor agents (anti-EGFR). Daily, new data emerge on the theranostic and prognostic role of molecular biomarkers, which is a strong incentive for a validated, sensitive and broadly available molecular screening test in order to implement and improve multi-modal therapy strategy and clinical trials. Next generation sequencing (NGS) has begun to supplant other technologies for genomic profiling. Targeted NGS is a method that allows parallel sequencing of thousands of short DNA sequences in a single test offering a cost-effective approach for detecting multiple genetic alterations with a minimum amount of DNA. In the present review, we collected data concerning the clinical application of NGS technology in the setting of colorectal cancer.

Next-generation sequencing improves the diagnosis of thyroid FNA specimens with indeterminate cytology.

AIMS: The assessment of thyroid nodules is a common clinical challenge. Fine-needle aspiration (FNA) is the standard pre-operative tool for thyroid nodule diagnosis. However, up to 30% of the samples are classified as indeterminate. This often leads to unnecessary surgery. In this study, we evaluated the added value of next-generation sequencing (NGS) for helping in the diagnosis of FNA samples. METHODS AND RESULTS: We analysed retrospectively 34 indeterminate FNA samples for which surgical resection was performed. DNA was obtained from cell blocks or from stained smears and subjected to NGS to analyse mutations in 50 genes. Mutations in BRAF, NRAS, KRAS and PTEN, that are known to be involved in thyroid cancer biology, were detected in seven FNA samples. The presence of a mutation in these genes was a strong indicator of cancer because five (71%) of the mutation-positive FNA samples had a malignant diagnosis after surgery. Moreover, there was only an 8% cancer risk in nodules with an indeterminate cytological diagnosis but with a negative molecular test. CONCLUSION: This study demonstrates that thyroid FNA can be analysed successfully by NGS. The detection of mutations known to be involved in thyroid cancer improves the sensitivity of thyroid FNA diagnosis.