Editor’s Choice Articles

Atypical teratoid rhabdoid tumor (ATRT) is a rare, aggressive pediatric central nervous system (CNS) tumor that predominantly affects children under the age of 3. It is defined by the inactivation of the SMARCB1 gene, leading to the loss of INI1, a protein essential for cell lineage determination and cell differentiation. Current standard of care treatment requires aggressive multimodal therapy with maximal safe resection, high-dose chemotherapy with autologous stem cell rescue, and radiation, yet overall survival remains < 50%. These intensive regimens have improved overall survival but are associated with significant morbidity and long-term effects. Molecular profiling has significantly advanced the understanding of ATRTs, revealing four molecular subgroups, ATRT-TYR, ATRT-MYC, ATRT-SHH, and ATRT-SMARCA4, each with distinct clinical presentations, oncogenic pathways, and prognoses. Molecular characterization enables better prognostic stratification, guiding treatment decisions and allowing for more personalized therapeutic approaches. Targeted therapies based on these molecular insights remain experimental, and continued exploration of molecular mechanisms and how they differ amongst subgroups is pivotal for the development of less toxic, more effective targeted treatments. Full article

Introduction: MET Exon 14 skipping alterations are drivers of non-small cell lung carcinoma (NSCLC) with responses to tyrosine kinase inhibitors. Amplicon-based DNA NGS assays (DNA NGSs) for the detection of METex14 skipping can yield false-negative results. We examined the efficacy of METex14 skipping with a DNA NGS and reflex RNA-based NGS (RNA NGS) strategy. Materials and Methods: Clinical cases with definitive or suspected lung adenocarcinoma (LungCa), lacking driver mutations with targeted DNA NGS, underwent the RNA NGS to identify oncogenic drivers. Samples with METex14 skipping identified on reflex RNA NGSs were confirmed with Sanger sequencing. Results:METex14 skipping events were detected in 22/762 (2.9%) samples by DNA NGS. RNA NGS identified 10 additional samples, for an overall frequency of 32/762 (4.1%). All 22 METex14 DNA variants affected the donor splice site. Sanger sequencing revealed that missed METex14 variants were largely deletions spanning the ~30 bp intronic region upstream of the splice acceptor site. The failure of DNA NGS to detect all METex14 mutants was due to a lack of coverage of the 3′ splice acceptor site of intron 13, branch point, and polypyrimidine tract. Conclusions: Modification of amplicon-based DNA hotspot assays, with primers that cover both donor and acceptor splice sites, can identify a larger number of METex14 skipping events. Clinical data show that patients with advanced NSCLC and METex14 variants responded to targeted therapy. Full article

Periodontal disease remains a significant global health concern, characterized by complex host–pathogen interactions leading to tissue destruction. This review explored the role of pattern recognition receptors (PRRs) in the pathogenesis of periodontal disease, synthesizing current knowledge on their molecular mechanisms and potential as therapeutic targets. We examined the diverse family of PRRs, focusing on toll-like receptors (TLRs) and NOD-like receptors (NLRs), elucidating their activation by periodontal pathogens and subsequent downstream signaling cascades. This review highlights the intricate interplay between PRR-mediated pathways, including NF-κB and MAPK signaling, and their impact on inflammatory responses and bone metabolism in periodontal tissues. We discussed the emerging concept of PRR crosstalk and its implications for periodontal homeostasis and disease progression. Furthermore, this review addressed the potential of PRR-targeted therapies, exploring both challenges and opportunities in translating molecular insights into clinical applications. By providing an overview of PRRs in periodontal health and disease, this review aims to stimulate future research directions and inform the development of novel diagnostic and therapeutic strategies in periodontology. Full article

Birt–Hogg–Dubé syndrome (BHDS) is an autosomal dominant disease characterized by skin, lung, and renal manifestations. This syndrome is caused by a germline mutation in the FLCN gene, which leads to disruption in multiple downstream pathways. Renal cell carcinomas are one of the serious clinical manifestations of the disease, which usually presents as bilateral and multiple tumors. Morphologically, most of these tumors are classified as hybrid oncocytic tumors. Recent advances in molecular techniques have shed light on the pathogenesis of these renal tumors. In this review, we evaluate and summarize the current knowledge of BHDS, pathologic changes, and its molecular basis with the focus on the renal hybrid oncocytic tumor (HOT), their pathogenesis, and molecular underpinning. Full article

Iatrogenic amyloidosis results from medical therapeutic interventions, leading to the misfolding and aggregation of proteins into amyloid fibrils or to their direct deposition in different tissues. This review aims to provide a comprehensive overview of the iatrogenic amyloidosis pathology, underlying the possible molecular mechanisms, associated pathological manifestations, and clinical implications within modern medicine. By conducting a systematic analysis of the current literature, this paper highlights the diverse instances of iatrogenic amyloidosis triggered by medical procedures such as dialysis, organ and tissue transplantation, and therapeutic drugs. Exploring the intricate molecular pathways and contributing factors involved in protein misfolding and amyloidogenesis, and uncovering the pathological consequences observed in various tissues and organs, allows us to establish appropriate nomenclature and to gain a more profound understanding of the condition, working towards improved medical interventions and treatments. Full article

The chief goal of the Blood Profiling Atlas in Cancer (BloodPAC) consortium is to promote collaborative efforts that support the development and implementation of liquid biopsy tests. Here, we report the results of a pilot study conducted by three BloodPAC members that aimed to demonstrate a multisite liquid biopsy testing framework using longitudinal blood specimens from 38 patients with metastatic breast cancer. Three laboratories receiving identical samples from two clinical sites each applied a different targeted sequencing platform to analyze mutations in cell-free DNA (cfDNA). The resulting mutational profiles reflected common breast cancer alterations, including clinically actionable mutations for 40% of hormone- receptor-positive patients. In 12 genes with shared target regions across sequencing panels, perfect inter-assay concordance was also observed for mutations detected above the lowest common assay limit of detection. Whole-genome copy number profiling of cfDNA and circulating tumor cells (CTCs) further revealed marked heterogeneity in copy number alterations and cfDNA tumor fractions across patients. Additionally, comparison of tumor fraction and CTC abundance demonstrated the complementary nature of cfDNA and CTC analyses. Overall, the framework described in this study may serve as a resource for future trials aiming to identify multimodal liquid biopsy biomarkers to guide clinical care. Full article

The liver is a multi-potent organ with important metabolic, immunological and endocrine functions. Hepatic physiology is maintained at a balanced state via the delicate actions of different liver-resident cells. Among several factors that modulate hepatic physiology, the harmony between the activity of pro- and anti-inflammatory cytokines is a crucial determinant. However, initiation of inflammatory activity can be detrimental if it goes unresolved, leading to severe consequences such as hepatitis, hepatic fibrosis, cirrhosis or even hepatocellular carcinoma (HCC). Different physiological processes can modulate the hepatic microenvironment; one such factor is a cytosolic protein complex called the inflammasome. Inflammasome activation is a consequence of the cellular encounter with pathogens or products of cellular damage. Once activated, inflammasomes promote the maturation of interleukin-1 family cytokines such as IL-1β and IL-18 via activation of caspase-1. These cytokines have a very potent role in modulating hepatic physiology. Various lines of reports suggest that inflammasome activation and IL-1 cytokines play critical roles in liver diseases, including hepatitis, hepatic fibrosis and HCC. Conversely, inhibition of inflammasome activation and/or IL-1 signaling prevents such effects. This review summarizes the mechanisms leading to inflammasome activation and the role it plays in hepatic physiology. Full article

Microscopy of stained blood smears is still a ubiquitous technique in pathology. It is often used in addition to automated electronic counters or flow cytometers to evaluate leukocytes and their morphologies in a rather simple manner and has low requirements for resources and equipment. However, despite the constant advances in microscopy, computer science, and pathology, it still usually follows the traditional approach of manual assessment by humans. We aimed to extend this technique using AI-based automated cell recognition methods while maintaining its technical simplicity. Using the web platform IKOSA, we developed an AI-based workflow to segment and identify all blood cells in DAPI-Giemsa co-stained blood smears. Thereby, we could automatically detect and classify neutrophils (young and segmented), lymphocytes, eosinophils, and monocytes, in addition to erythrocytes and platelets, in contrast to previously published algorithms, which usually focus on only one type of blood cell. Furthermore, our method delivers quantitative measurements, unattainable by the classical method or formerly published AI techniques, and it provides more sophisticated analyses based on entropy or gray-level co-occurrence matrices (GLCMs), which have the potential to monitor changes in internal cellular structures associated with disease states or responses to treatment. We conclude that AI-based automated blood cell evaluation has the potential to facilitate and improve routine diagnostics by adding quantitative shape and structure parameters to simple leukocyte counts of classical analysis. Full article

Biomarkers are fundamental to modern oncology practice, forming a close link to pathology practice. Pathology results must be accurate, timely, comprehensive, and comprehendible. External proficiency testing is a key tool in maintaining biomarker quality. Here, we demonstrate the feasibility and utility of a novel end-to-end proficiency testing exercise exploring accuracy, turnaround time, and communication. Challenge specimens were made using resected colon cancer tissue, each paired with a fictional clinical vignette, and distributed to participants who were asked to provide all molecular testing required and return a final report for each case upon completion. Reports were redistributed to an assessor team including medical oncologists, each of whom was asked to recommend a systemic therapy based on each lab’s biomarker report. Participants were graded based on their ability to guide oncologists to the correct treatment. Eight laboratories participated. Three laboratories were found to have suboptimal results, two leading oncologists to incorrect therapeutic prescriptions, and one withdrawn. Turnaround time ranged from 6 to 86 days (median 24). Substantial qualitative reporting differences were identified. This study demonstrates the feasibility of end-to-end proficiency testing. The approach provides considerable value beyond analytic accuracy, including specimen management, turnaround time, and communication of results. Results suggest that reporting differences may lead to treatment disparities. This style of quality assurance will help reinforce good practices critical to the delivery of precision cancer care. Full article

A tight association between inflammation and cardiac damage has been extensively recognized. In this review, we will focus on macrophages as key players in the physiology and pathology of the heart and on their role in the functional crosstalk between inflammation and heart disease. In the steady state, macrophages contribute to the homeostasis of cardiac tissue. Indeed, cardiac resident macrophages promote coronary development and tissue homeostasis, favor electric conduction in cardiomyocytes, and contribute to mitochondrial quality control. However, macrophages also take part in adverse cardiac events contributing to the development or the progression of several pathologic conditions. Infiltrating cells derived from circulating monocytes contribute to tissue injury through the release of inflammatory cytokines and catecholamines. In particular, the present review will discuss the role of macrophages in heart failure, atherosclerosis, and anthracycline-dependent cardiotoxicity. Prolonged inflammatory response and increased apoptotic cell death sustained by chronic activation of the transcription factor NFκB are the basis of heart failure pathogenesis. Here, we will discuss the involvement of NFκB signaling in macrophage-dependent cardiac damage and its use as a therapeutic target in the treatment of cardiovascular pathologies. Full article

Background: Understanding the distribution of HPV types in cervical cancer cases is crucial for evaluating the effectiveness of HPV screening and vaccination in reducing cervical cancer burden. This study aimed to assess genotype prevalence in the pre-vaccine era among 178 cervical cancer cases detected during a 20-year screening period in Northern Norway and compare the potential efficacy of HPV vaccines in preventing cervical cancer. Methods: A total of 181 formalin-fixed paraffin-embedded (FFPE) tissue samples from non-vaccinated women diagnosed with cervical cancer between 1995 and 2015 in Troms and Finnmark, Norway, were analyzed using a 45-type HPV DNA test. The results were compared to a 7-type HPV mRNA test targeting oncogenic types included in the nonavalent HPV vaccine. Results: Invalid HPV test results were observed in 1.7% (3/181) of the samples and were subsequently excluded from further analysis. Among the remaining cases, 92.7% (165/178) tested positive for HPV using any test combination. HPV DNA was detected in 159 cases (89.3%), while HPV mRNA was detected in 149 cases (83.7%). The most prevalent HPV types were 16 and 18, responsible for 70.8% of the cases, with the nonavalent vaccine types accounting for 86.6% of cases. HPV 35 was identified in eight cases (4.5%). Conclusion: The bivalent/quadrivalent HPV vaccines have the potential to prevent 76.4% (126/165) of HPV-positive cervical cancer cases, while the nonavalent vaccine could prevent 93.3% (154/165) of cases. Tailoring screening strategies to target HPV types with the highest oncogenic potential may improve cervical cancer detection and enable targeted interventions for high-risk individuals. The use of a 7-type HPV mRNA test holds promise as an advantageous approach. Full article

The detection of driver oncogenic variants and the recent identification of tumor-agnostic genomic biomarkers has driven the use of comprehensive genomic profiling (CGP) for disease diagnosis, prognosis, and treatment selection. The Oncomine™ Comprehensive Assay Plus (OCA+) panel uses DNA and RNA to detect single nucleotide variants (SNVs), small insertions/deletions (Indels), and structural variants (SVs) across 501 genes. Moreover, microsatellite instability (MSI), tumor mutational burden (TMB), and homologous recombination deficiency (HRD) status are assessed in a single workflow. Herein, we present the analytical validation and clinical utilization of OCA+. By using commercial reference materials, we found good analytical sensitivity, specificity, and precision for all biomarkers analyzed. The limit of detection (LoD) was validated for SNVs and Indels at 4%, except for Indels located in homopolymeric regions, where the LoD was 10%. An additional set of 81 tumor samples, including cytology smears, were sequenced to assess the clinical utility of the OCA+ across different tumor types. Among the clinical cohort, OCA+ demonstrated 100% accuracy, sensitivity, and specificity for all biomarkers analyzed, except for MSI assessment of endometrial cancer cases, where 83% accuracy and 67% sensitivity were achieved, compared to PCR and IHC. The validation of accuracy and robustness of this assay supports the OCA+’s utility for solid tumor CGP. Full article

Osteosarcoma (OS) is a primary malignant bone tumour that usually occurs in children and adolescents. OS is a highly aggressive tumour type with a propensity for local invasion and systemic early metastasis to the lungs or other bones. According to the World Health Organization, there are different subtypes of OS, including conventional OS (osteoblastic, chondroblastic, fibroblastic), telangiectatic OS, low-grade OS, small-cell OS, parosteal OS, periosteal OS, and high-grade surface OS. In this mini review, we will discuss the background of OS and histopathological patterns and clinical behaviour of the disease. Understanding the subtypes of OS and their pathogenesis is crucial for developing more precise and effective therapies for OS patients. Full article

Background: A plethora of data supports HPV-based screening to be the preferred strategy for cervical cancer prevention. The shift to a more sensitive first-line test brings the need of effective triage up for discussion. Currently, most algorithms apply cytology as a triage of HPV-DNA positive women. This study compared the performance of a 7-type HPV-mRNA test to cytology. Methods: From 1 January 2019 until 31 December 2021, cervical samples from 58,029 women were examined at the University Hospital of North Norway. A total of 30.5% (17,684/58,029) fulfilled the criteria for HPV-DNA primary screening. All positive samples were triaged by cytology and followed-up according to national guidelines through 2022. Additionally, a 7-type HPV-mRNA test was applied. The study endpoint was a histologically confirmed high-grade lesion (CIN2+). Results: A total of 5.6% (990/17,684) had positive HPV-DNA test, 97.2% (962/990) with valid HPV-mRNA results. A total of 55.5% (534/962) had abnormal cytology (ASC-US+), and 35.1% (338/962) had a positive HPV-mRNA test. A total of 13.9% (134/962) had CIN2+. The sensitivity (CIN2+) of cytology versus the HPV-mRNA test was 76.1% (102/134) versus 73.1% (98/134), p = 0.67. The specificity was 47.8% (396/828) versus 71.0% (588/624), p < 0.001. PPV was 19.1% (102/534) and 29.0% (98/338), p < 0.001, respectively. The number of colposcopies per CIN2+ detected by cytology and HPV-mRNA test was 5.2 and 3.1. Conclusion: The 7-type HPV mRNA test was significantly more specific than cervical cytology in a triage of HPV-DNA positive women. Using this biomarker as the threshold for colposcopy may better balance the benefits and harms of screening. Full article

Somatic MET exon 14 skipping mutations (MET ex14) are targetable driver mutations for non-small cell lung cancer (NSCLC), responsive to MET inhibitors. Objective: This study seeks to further characterize the clinicopathologic features and mutational profile of MET ex14 variant NSCLC. Design: Retrospective review of all MET ex14 tested NSCLC. Testing for selected BRAF, EGFR, HER2, KRAS, and MET mutations was performed using a clinically validated NGS assay, followed by MiSeq sequencing. Variants were classified as significant (Tier1/2) or variants of uncertain significance (VUS) per 2017 AMP/ASCO/CAP Joint Consensus Guidelines. PD-L1 expression was assessed by immunohistochemistry. Results: Of 2296 NSCLCs tested between 2017-7/2019, MET ex14 variants were present in 44 (1.9%). A total of 32 of 44 variants were MET exon 14 skipping, while the other 12 mutations were significant missense (3) or VUS (9). Of nine VUS, five were adjacent to the canonical splice site and likely to impact splicing. Four cases had concomitant mutations. Of 35 cases with known clinical staging, stage 1–2 = 20 (57%), stage 3 = 3 (9%), and stage 4 = 12 (34%). Of 19 resected NSCLSs, histological types and growth pattern included 7 lepidic pattern-predominant. A high percentage of tumors with MET ex14 mutations are positive for PD-L1, and the percentage of cases with PD-L1 expression >50% trends higher in more advanced disease. Conclusions: Most MET variants identified in our cohort (73%) are MET ex14 skipping. The prevalence of MET ex14 variants is 1.9%, and a large percentage of tumors has lower clinical stage and less aggressive pathologic features. Full article

Comprehensive next-generation sequencing (NGS) panels for cancer diagnostics create a bottleneck for interpretation. QIAGEN Clinical Insights Interpret One (QCI) is a clinical decision support software that supports molecular pathologists in the classification of oncology-related variants. This study compares variant assessments by QCI to assessments utilizing current laboratory methods. Eight laboratories were recruited by the external quality assessment organization GenQA. The laboratories submitted VCFs from sequencing studies performed on both hematological disorders and solid tumors for analysis by QCI and an independent laboratory. Results were compared and conflicts were resolved using a panel of experts. In total, 14/149 variants (9%) reported as Tier 1 or Tier 2 by either QCI or the submitting laboratory were found to be discordant after expert panel review. In contrast, 41/149 variants (28%) reflected discrepancy among human reviewers. The expert panel was unable to reach resolution on eight variants. QCI demonstrates high concordance in the classification of actionable mutations with independent laboratory methods and expert assessment. The rate of disagreement among laboratories and the expert panel was greater than the disagreement between QCI and expert assessment. Disagreement among experts highlights the subjectivity of classifying variants. The study demonstrates that QCI interpretation supports streamlining and standardization of NGS variant interpretation. Full article

The study aimed to demonstrate rapid and effective molecular testing on liquid-based cytology (LBC) samples for EGFR, KRAS and BRAF mutations using the Biocartis Idylla™. Rapid on-site evaluation (ROSE) LBC samples for patients with non-small cell lung carcinoma (NSCLC) or pancreatic ductal adenocarcinoma (PDAC) were tested for EGFR, KRAS and BRAF mutations based on the relevance to tumour subtype. The quantification values (Cq values) and mutation detection status were compared between LBC samples and routine formalin-fixed paraffin-embedded (FFPE) clot samples. ROSE LBC samples (n = 54) showed a higher yield of well-preserved tumour and wild type (WT) DNA, demonstrated by lower quantification cycles, no false positives or false negatives, and a higher sensitivity for low allele frequency mutations when compared with FFPE clot samples. The Biocartis Idylla™ provides highly sensitive, reliable and rapid testing for LBC samples for the detection of EFGR and KRAS mutations. BRAF mutations were not detected in the participant cohort; however, all LBC WT BRAF results correlated with the results from the FFPE clot samples. Access to rapid molecular testing using LBC samples can detect the most frequent driver mutations closer to the time of diagnosis, enabling the selection of the most effective first-line targeted therapy sooner, reducing delays or side effects from suboptimal treatments, patient anxiety and costs to healthcare systems, whilst improving patient outcomes. Full article

For molecular diagnostics of lung cancer samples, often only a small amount of material is available. The ever-increasing number of biomarker testing is in contrast to the amount of material obtained. In that case, cytological specimens, such as serous effusion samples, are one possible option. Effusion samples were prepared as sediment smears or cytospins or as a cell block if needed. Suitable tumor cells areas were marked by a cytopathologist and used for molecular diagnostics, including fast track analysis, parallel sequencing, and/or fluorescence in situ hybridization. In 62 cases of malignant effusion with cells of pulmonary adenocarcinoma, molecular diagnostics were carried out. A fast-track result with the high-resolution melting method for hotspot mutation of KRAS Exon 2 and EGFR exon 21 and fragment length analysis of EGFR exon 19 was available for 43 out of 47 samples (92%). Parallel sequencing was successful for 56 out of 60 samples (93.3%). In the same period, 108 FISH analyses were performed for MET amplification, followed by ROS1, RET, and ALK translocation analysis. If only a limited amount of tissue/biopsy is available, a malignant effusion is advisable to perform on the molecular diagnostics with a high success rate. Full article

Background: We aimed at obtaining more information on the structure of fecal calprotectin (CP) as a basis for establishing improved quantitative assays and detection of Neutrophil Extracellular Traps (NETs) in stools. Commercial fecal CP assays produce different results, probably due to differences in antibodies, extraction procedures, and standards used. In addition, the structure of fecal CP may be different from that in the standard so that rules for immunoassays are violated. We aimed at solving these problems by studying the structure of fecal CP and developing new antibodies and assay procedures including some for NETs in stools. Methods and Findings: Stool samples from children with abdominal symptoms were extracted by a conventional and a new procedure. Some extracts were run on anion exchange and size exclusion chromatography, and fractions were tested on ELISAs by use of ten new mouse monoclonal antibodies against the CP subunit S100A9. Hybrid ELISAs (named HELISA) were established using anti-DNA or anti-histones for coating of microwells, and enzyme labelled anti-CP was used for development. By ion exchange chromatography, five to ten fecal CP subfraction peaks differing in net electric charge were found, all of which contained the major chromatin components. The presence of DNA and histones followed calprotectin in the chromatographic fractions suggesting that NETs are generated in the gut lumen. The new CP monoclonals reacted very differently against the subfractions so that a mixture of them (called MiMo) must be used to obtain reliable assay values for fecal CP. A new method called FELISA was developed where standards and samples are applied directly in Nunc (Denmark) MaxiSorp plates, without any catching antibody. It takes advantage of the property of CP to bind strongly to the plastic in wells. This method has a higher sensitivity because it will detect CP molecules with only one antigenic epitope available. It will give more reliable estimates and more efficient selection of patients for complex diagnostic procedures. We also developed an alternative to the FELISA: a competitive ELISA where S100A9 coated in microwells will compete with CP in standards and samples for binding to a properly diluted HRP-anti-CP solution. In this method, the presence of other proteins in extraction or dilution buffers will not interfere. Using the HELISA, about 65% of the patients had detectable fecal NETs in concentrations between 150 and 1500 ng/mL; however, the values correlated poorly with CP values. Extraction of fecal samples with a simple buffer of TBS, and pH 5 with 5 mM EDTA, gave a yield of about 90%, while the yields of commercial kits are not specified or lie around 50%. A fecal CP standard will bring methods in accordance with the requirements for immunoassays that the structure of CP in the standard and sample must be the same. A mixture of fecal anion exchange fractions as a standard may be a solution to this problem. The principle worked in the first trial by giving the same values after storage of such a standard at 5C for four months. Conclusions: Fecal CP consists of at least five subfractions containing NETs or degradation products thereof. Commercial kits should not be accepted for clinical use unless it has been shown that they can detect all subfractions which may require the use of a mixture of monoclonals. The methods presented here can be used for such a quality control. The HELISA methods can be used for assays on NETs in stools and to study their possible pathogenic effects in the gut. Use of the FELISA and the S100A9 competitive method may give increased sensitivity, higher precision, and better selection of patients for more complex procedures. Full article

RET alterations are recognized as key oncogenic drivers in different cancer types, including non-small cell lung cancer (NSCLC). Multikinase inhibitors (MKIs) with anti-RET activities resulted in variable efficacy with significant toxicities because of low target specificity. Selective RET kinase inhibitors, such as pralsetinib and selepercatinib, demonstrated high efficacy and favorable tolerability in advanced RET-rearranged NSCLC patients, leading to their introduction in the clinical setting. Among the different approaches available for the identification of RET rearrangements, next-generation sequencing (NGS) assays present substantial advantages in terms of turnaround time and diagnostic accuracy, even if potentially limited by accessibility issues. The recent advent of novel effective targeted therapies raises several questions regarding the emergence of resistance mechanisms and the potential ways to prevent/overcome them. In this review, we discuss molecular testing and treatment strategies to manage RET fusion positive NSCLC patients with a focus on resistance mechanisms and future perspectives in this rapidly evolving scenario. Full article

Centromeric proteins are the foundation for assembling the kinetochore, a macromolecular complex that is essential for accurate chromosome segregation during mitosis. Anti-centromere antibodies (ACAs) are polyclonal autoantibodies targeting centromeric proteins (CENP-A, CENP-B, CENP-C), predominantly CENP-B, and are highly associated with rheumatologic disease (lcSSc/CREST syndrome). CENP-B autoantibodies have also been reported in cancer patients without symptoms of rheumatologic disease. The rise of oncoimmunotherapy stimulates inquiry into how and why anti-CENP-B autoantibodies are formed. In this review, we describe the clinical correlations between anti-CENP-B autoantibodies, rheumatologic disease, and cancer; the molecular features of CENP-B; possible explanations for autoantigenicity; and, finally, a possible mechanism for induction of autoantibody formation. Full article

The development of targeted therapies has improved survival rates for patients with advanced non-small cell lung cancer (NSCLC). However, tissue biopsy is unfeasible or inadequate in many patients, limiting biomarker testing and access to targeted therapies. The increasing numbers of established and emerging biomarkers with available targeted treatments highlights the challenges associated with sequential single-gene testing and limited tissue availability. Multiplex next-generation sequencing (NGS) offers an attractive alternative and represents a logical next step, and in cases where the tumour is inaccessible, tissue biopsy yields insufficient tumour content, or when the patient’s performance status does not allow a tissue biopsy, liquid biopsy can provide valuable material for molecular diagnosis. Here, we explore the role of liquid biopsy (i.e., circulating cell-free DNA analysis) in Europe. Liquid biopsies could be used as a complementary approach to increase rates of molecular diagnosis, with the ultimate aim of improving patient access to appropriate targeted therapies. Expert opinion is also provided on potential future applications of liquid biopsy in NSCLC, including for cancer prevention, detection of early stage and minimum residual disease, monitoring of response to therapy, selection of patients for immunotherapy, and monitoring of tumour evolution to enable optimal adaptation/combination of drug therapies. Full article

Lung cancer is the leading cause of cancer death worldwide. Despite the emergence of highly effective targeted therapies, up to 30% of advanced stage non-small cell lung cancer (NSCLC) patients do not undergo tissue molecular testing because of scarce tissue availability. Liquid biopsy, on the other hand, offers these patients a valuable opportunity to receive the best treatment options in a timely manner. Indeed, besides being much faster and less invasive than conventional tissue-based analysis, it can also yield specific information about the genetic make-up and evolution of patients’ tumors. However, several issues, including lack of standardized protocols for sample collection, processing, and interpretation, still need to be addressed before liquid biopsy can be fully incorporated into routine oncology practice. Here, we reviewed the most important challenges hindering the implementation of liquid biopsy in oncology practice, as well as the great advantages of this approach for the treatment of NSCLC patients. Full article

The discovery and clinical validation of biomarkers predictive of the response of non-squamous non-small-cell lung carcinomas (NS-NSCLC) to therapeutic strategies continue to provide new data. The evaluation of novel treatments is based on molecular analyses aimed at determining their efficacy. These tests are increasing in number, but the tissue specimens are smaller and smaller and/or can have few tumor cells. Indeed, in addition to tissue samples, complementary cytological and/or blood samples can also give access to these biomarkers. To date, it is recommended and necessary to look for the status of five genomic molecular biomarkers (EGFR, ALK, ROS1, BRAFV600, NTRK) and of a protein biomarker (PD-L1). However, the short- and more or less long-term emergence of new targeted treatments of genomic alterations on RET and MET, but also on others’ genomic alteration, notably on KRAS, HER2, NRG1, SMARCA4, and NUT, have made cellular and blood samples essential for molecular testing. The aim of this review is to present the interest in using cytological and/or liquid biopsies as complementary biological material, or as an alternative to tissue specimens, for detection at diagnosis of new predictive biomarkers of NS-NSCLC. Full article

The past decade has witnessed significant advances in the application of molecular diagnostics for the pre-operative risk-stratification of cytologically indeterminate thyroid nodules. The tests that are currently marketed in the United States for this purpose combine aspects of tumor genotyping with gene and/or microRNA expression profiling. This review compares the general methodology and clinical validation studies for the three tests currently offered in the United States: ThyroSeq v3, Afirma GSC and Xpression Atlas, and ThyGeNEXT/ThyraMIR. Full article

Somatic copy number variations (CNV; i.e., amplifications and deletions) have been implicated in the origin and development of multiple cancers and some of these aberrations are designated targets for therapies. Although FISH is still considered the gold standard for CNV detection, the increasing number of potentially druggable amplifications to be assessed makes a gene-by-gene approach time- and tissue-consuming. Here we investigated the potential of next generation sequencing (NGS) custom panels to simultaneously determine CNVs across FFPE solid tumor samples. DNA was purified from cell lines and FFPE samples and analyzed by NGS sequencing using a 20-gene custom panel in the GeneReader Platform^®. CNVs were identified using an in-house algorithm based on the UMI read coverage. Retrospective validation of in-house algorithm to identify CNVs showed 97.1% concordance rate with the NGS custom panel. The prospective analysis was performed in a cohort of 243 FFPE samples from patients arriving at our hospital, which included 74 NSCLC tumors, 148 CRC tumors, and 21 other tumors. Of them, 33% presented CNVs by NGS and in 14 cases (5.9%) the CNV was the only alteration detected. We have identified CNV alterations in about one-third of our cohort, including FGFR1, CDK6, CDK4, EGFR, MET, ERBB2, BRAF, or KRAS. Our work highlights the need to include CNV testing as a part of routine NGS analysis in order to uncover clinically relevant gene amplifications that can guide the selection of therapies. Full article

Thyroid nodules are a common finding in the adult population including the fact that more than 50% of individuals, over the age of 60, have thyroid nodules. The majority have been mostly detected with ultrasonography and 10% by palpation. The majority of these nodules are benign, whereas 5–15% of them are malignant. The pre-operative diagnosis of cancer is a critical challenge in order to ensure that each patient can be treated with the best tailored management with a reduction of unnecessary surgery for benign lesions. Fine needle aspiration cytology (FNAC) represents the first and most important diagnostic tool for the evaluation of thyroid lesions. According to the literature, FNAC is able to render a conclusive diagnosis in up to 70–80% of all cases. For the remaining 20–30% of nodules, cytological diagnoses fall into the category of indeterminate lesions mostly due to the lack of specific morphological features. According to the Bethesda system for reporting thyroid cytopathology (TBSRTC), indeterminate lesions can be sub-stratified into three different subcategories including “atypia of undetermined significance/follicular lesion of undetermined significance-AUS/FLUS”; “follicular or Hürthle cell neoplasm/suspicious for follicular or Hürthle cell neoplasm-FN/SFN”; and “suspicious for malignancy-SFM”. Many of these indeterminate lesions undergo repetition or diagnostic lobectomy. Nonetheless, the majority of these cases will have a benign diagnosis due to the fact that the rate of cancer ranges between 6 and 30%. It stands to reason that the application of ancillary technique, mostly molecular testing, emerged as a critical additional tool for those thyroid indeterminate lesions. Since the early 1990s, material collected from cytological samples yields sufficient and adequate cells for the detection of point mutation or gene fusions. Nonetheless, the further availability of new sequencing technologies such as next-generation sequencing (NGS) has led to more comprehensive molecular applications adopted now in clinical use. The current review investigates the multiple advances in the field of molecular testing applied in thyroid cytology. Full article

In the era of personalized medicine, there is an increasing demand for comprehensive and complex diagnosis using minimally invasive techniques. Nowadays, it is mandatory to integrate biomarkers in the diagnostic process, as well as in the treatment and clinical management of many cancer patients. Patients with non-small cell lung cancer (NSCLC), for instance, are frequently diagnosed in advanced stages, at a point when only cytological material or small biopsies can be obtained. This pathology constitutes an interesting challenge for the testing of biomarkers in cytology. Furthermore, there is a growing development of imaging techniques that guide non-invasive approaches to obtain small biopsies or cytological samples. This has allowed fine needle aspiration cytology and fine needle aspiration biopsy (FNAC, FNAB) to become front-line procedures in the management of patients with NSCLC. It is well known that the list of biomarkers to be tested in these patients continues to increase. Nevertheless, there are several of essential biomarkers that should always be analyzed in all patients with NSCLC, not only in non-squamous but also in some squamous carcinomas (SqCC). Some of them, such as PDL1, are tested by immunocytochemistry (ICC), while others, mainly ALK and ROS1, can be tested by ICC and confirmed using other techniques such a Fluorescence In Situ Hybridization (FISH). Other biomarkers, namely EGFR and BRAF mutations, are currently evaluated by polymerase chain reaction (PCR)-based techniques including Next-Generation Sequencing (NGS). In this review, we will address the particularities and challenges that ICC and FISH pose in different types of cytological samples from an eminently practical point of view. Full article

Activation of the PI3K–AKT–mTOR pathway occurs in several human cancers, including hormone receptor (HR)-positive breast cancer (BC) where is associated with resistance to endocrine therapy and disease progression. In BC, the most common PI3K–AKT–mTOR pathway alteration is represented by PIK3CA oncogenic mutations. These mutations can occur throughout several domains of the p110α catalytic subunit, but the majority are found in the helical and kinase domains (exon 9 and 20) that represent the “hotspots”. Considering the central role of the PI3K–AKT–mTOR pathway in HR-positive BC, several inhibitors (both pan-PI3K and isoform-specific) have been developed and tested in clinical trials. Recently, the PI3Kα-selective inhibitor alpelisib was the first PI3K inhibitor approved for clinical use in HR-positive metastatic BC based on the results of the phase III SOLAR-1 trial. Several methods to assess PIK3CA mutational status in tumor samples have been developed and validated, including real-time polymerase chain reaction (PCR), digital droplet PCR (ddPCR), BEAMing assays, Sanger sequencing, and next-generation sequencing (NGS) panels. Several new challenges will be expected once alpelisib is widely available in a clinical setting, including the harmonization of testing procedures for the detection of PI3K–AKT–mTOR pathway alterations. Herein, we provide an overview on PI3K–AKT–mTOR pathway alterations in HR-positive BC, discuss their role in determining prognosis and resistance to endocrine therapy and highlight practical considerations about diagnostic methods for the detection of PI3K–AKT–mTOR pathway activation status. Full article

With a growing number of clinically relevant biomarkers needed to guide the management of patients with non-small cell lung cancer (NSCLC), pathologists are keenly aware of the need to collect adequate tissue not only for a diagnosis, but also for ancillary studies to provide predictive and prognostic information. Small specimens collected by minimally invasive techniques such as fine needle aspiration and core needle biopsy often fall short in meeting adequacy requirements for lung cancer molecular biomarkers. The College of American Pathologists (CAP) recently published an evidence-based clinical practice guideline, “Collection and Handling of Thoracic Small Biopsy and Cytology Specimens for Ancillary Studies”, to help direct clinicians and pathology laboratory personnel to optimally collect and handle thoracic small specimens for ancillary testing. This review summarizes the published guideline statements and provides a brief overview of the recommendations and how they impact the practice of pathology. Full article