Myocardial perfusion in cardiac amyloidosis.

AIMS: Cardiac involvement is the main driver of clinical outcomes in systemic amyloidosis and preliminary studies support the hypothesis that myocardial ischaemia contributes to cellular damage. The aims of this study were to assess the presence and mechanisms of myocardial ischaemia using cardiovascular magnetic resonance (CMR) with multiparametric mapping and histopathological assessment. METHODS AND RESULTS: Ninety-three patients with cardiac amyloidosis (CA) (light-chain amyloidosis n = 42, transthyretin amyloidosis n = 51) and 97 without CA (three-vessel coronary disease [3VD] n = 47, unobstructed coronary arteries n = 26, healthy volunteers [HV] n = 24) underwent quantitative stress perfusion CMR with myocardial blood flow (MBF) mapping. Twenty-four myocardial biopsies and three explanted hearts with CA were analysed histopathologically. Stress MBF was severely reduced in patients with CA with lower values than patients with 3VD, unobstructed coronary arteries and HV (CA: 1.04 ± 0.51 ml/min/g, 3VD: 1.35 ± 0.50 ml/min/g, unobstructed coronary arteries: 2.92 ± 0.52 ml/min/g, HV: 2.91 ± 0.73 ml/min/g; CA vs. 3VD p = 0.011, CA vs. unobstructed coronary arteries p < 0.001, CA vs. HV p < 0.001). Myocardial perfusion abnormalities correlated with amyloid burden, systolic and diastolic function, structural parameters and blood biomarkers (p < 0.05). Biopsies demonstrated abnormal vascular endothelial growth factor staining in cardiomyocytes and endothelial cells, which may be related to hypoxia conditions. Amyloid infiltration in intramural arteries was associated with severe lumen reduction and severe reduction in capillary density. CONCLUSION: Cardiac amyloidosis is associated with severe inducible myocardial ischaemia demonstrable by histology and CMR stress perfusion mapping. Histological evaluation indicates a complex pathophysiology, where in addition to systolic and diastolic dysfunction, amyloid infiltration of the epicardial arteries and disruption and rarefaction of the capillaries play a role in contributing to myocardial ischaemia.

HER2-targeted therapies for salivary gland cancers.

Salivary gland cancers (SGCs) are a heterogeneous group of rare tumors including various histological subtypes with different molecular profiling. Human epidermal growth factor receptor 2 (HER2) is one of the most intriguing and studied molecular alterations with prognostic and predictive roles. Indeed, HER2 overexpression is commonly correlated with aggressive histological subtypes and poorer prognosis. However, HER2 may represent the target of personalized treatment. We performed a literature review of use of anti-HER2 targeted agents for treatment of recurrent or metastatic SGCs. The efficacy and safety of anti-HER2 were firstly evaluated in patients affected with other solid tumors, mostly breast and gastric cancers. For SGCs the literature is mainly comprised of case reports or case series and small clinical trials. The most common used drug is trastuzumab in combination with chemotherapy (i.e. taxanes, capecitabine, carboplatin, eribulin) or with another anti-HER2 targeted agent (i.e. pertuzumab). The use of anti-HER2 therapies induces improvement in clinical responses, which are mostly durable. Besides, new anti-HER2 drugs such as antibody-drug conjugates (ADC) (i.e. trastuzumab emtansine, trastuzumab deruxtecan) have been introduced in this setting inducing further therapeutic advances. Anti-HER2 treatment strategy is emerging as potentially effective in selected HER2 overexpressing SGCs. However, prospective and multicentric clinical trials are needed to evaluate the efficacy of these therapeutic regimens within larger cohorts and to assess the most appropriate treatment sequence strategy.

Management of post-mortem examination in SARS-CoV-19 infections.

A brief overview on the management of autopsies during the SARS-CoV-19 epidemic is proposed. In particular, the point is made of the Italian laws on the subject, the characteristics required for the autopsy room and the sampling suggested for the histological examination.

Deep phenotyping of p.(V142I)-associated variant transthyretin amyloid cardiomyopathy: Distinct from wild-type transthyretin amyloidosis?

AIMS: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly recognized cause of heart failure. A total of 3-4% of individuals of African descent carry a TTR gene mutation encoding the p.(V142I) variant, a powerful risk factor for development of variant ATTR-CM (ATTRv-CM); this equates to 1.6 million carriers in the United States. We undertook deep phenotyping of p.(V142I)-ATTRv-CM and comparison with wild-type ATTR-CM (ATTRwt-CM). METHODS AND RESULTS: A retrospective study of 413 patients with p.(V142I) ATTRv-CM who attended the UK National Amyloidosis Centre (NAC) was conducted. Patients underwent evaluation at time of diagnosis, including clinical, echocardiography, and biomarker analysis; a subgroup had cardiac magnetic resonance (CMR) imaging. A total of 413 patients with ATTRwt-CM, matched for independent predictors of prognosis (age, NAC Stage, decade of first presentation), were used as a comparator group. At time of diagnosis, patients with ATTRv-CM had significant functional impairment by New York Heart Association classification (NHYA class ≥ III; 38%) and 6-min walk test distance (median 276 m). Median 5-year survival in ATTRv-CM patients was 31 versus 59 months in matched patients with ATTRwt-CM (p < 0.001). Patients with ATTRv-CM had significant impairment of functional parameters by echocardiography including biventricular impairment, high burden of regurgitant valvular disease and low cardiac output. Multivariable analysis revealed the prognostic importance of right ventricular dysfunction. CMR and histological analysis revealed myocyte atrophy and widespread myocardial infiltration in ATTRv-CM. CONCLUSION: p.(V142I)-ATTRv-CM has an aggressive phenotype characterized by myocyte loss and widespread myocardial infiltration which may account for frequent biventricular failure and poor prognosis in this ATTR-CM genotypic subgroup.

Capmatinib-Induced Liver Injury as Emerging Toxicity of MET Inhibitors in Patients With NSCLC Pretreated With Immune Checkpoint Inhibitors.

Safety data on MET inhibitors in patients with advanced NSCLC harboring MET exon 14 mutation and treated with frontline immune checkpoint inhibitors (ICIs) are still limited. Here, we describe clinical characteristics, liver biopsy features, and management of liver injury of two patients with a diagnosis of MET exon 14-mutant NSCLC receiving capmatinib after ICI failure. On the basis of histologic findings and exclusion of other potential causes, a diagnosis of drug-induced liver injury (DILI) associated with portal fibrosis was made in both cases. The use of hepatoprotective drugs, in addition to oral ursodeoxycholic acid, resulted in liver blood tests normalization. To provide a global safety perspective, we queried the Food and Drug Administration Adverse Event Reporting System and detected a robust disproportionality signal. Out of the 918 total reports with capmatinib from the Food and Drug Administration Adverse Event Reporting System database, DILI was recorded in 43 cases (4.7%), mostly serious (93.0%) with hospitalization and death recorded in 25.6% and 16.3% of the cases, respectively. The median time to onset was 42 days, with discontinuation and positive dechallenge documented in 41.9% and 39.5% of the cases, respectively. Anti-programmed cell death protein-1 agents were coreported in 11 DILI cases. Only two cases of DILI out of 105 reports were found for tepotinib. Our data support a potential association between capmatinib and DILI in patients who have also been previously exposed to immunotherapy. Considering the potential implications for sequence strategy and timing of ICI and MET inhibitor, further investigation is warranted.

A Systematic Review of Diagnostic and Prognostic Biomarkers for Head and Neck Cancer of Unknown Primary: An Unmet Clinical Need.

Head and neck cancer of unknown primary (HNCUP) is defined as cervical lymph node metastases without a detectable primary tumor. The management of these patients presents a challenge to clinicians since guidelines in the diagnosis and treatment of HNCUP remain controversial. An accurate diagnostic workup is fundamental for the search for the hidden primary tumor to allow the best adequate treatment strategy. The purpose of this systematic review is to present the currently available data about the diagnostic and prognostic molecular biomarkers for HNCUP. Systematic research in an electronic database was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and identified 704 articles, of which 23 studies were selected and included in the analysis. Fourteen studies investigated HNCUP diagnostic biomarkers and focused on the human papilloma virus (HPV) and the Epstein-Barr virus (EBV) due to the strong associations with oropharyngeal cancer and nasopharyngeal cancer, respectively. HPV status was shown to possess prognostic value, correlating with longer disease-free survival and overall survival. HPV and EBV are the only available HNCUP biomarkers, and they are already used in clinical practice. A better characterization of the molecular profiling and the development of tissue-of-origin classifiers are necessary to improve the diagnosis, staging, and therapeutic management of patients with HNCUP.

Predictive value of portal fibrosis and inflammation in transplanted liver grafts treated with hypothermic oxygenated perfusion.

BACKGROUND: Hypothermic oxygenated perfusion (HOPE) has become widespread for the preservation of liver grafts, making tangled the relationship among the use of extended criteria donors (ECD), graft histology and transplant outcome. AIMS: To prospectively validate the impact of the graft histology on transplant outcome in recipient receiving liver grafts from ECD after HOPE. METHODS: Ninety-three ECD grafts were prospectively enrolled; 49 (52.7 %) were perfused with HOPE according to our protocols. All clinical, histological and follow-up data were collected. RESULTS: Grafts with portal fibrosis stage ≥ 3 according to Ishak's (evaluated with Reticulin stain) had a significantly higher incidence of early allograft dysfunction (EAD) and 6-month-dysfunction (p = 0.026 and p = 0.049), with more days in Intensive Care Unit (p = 0.050). Lobular fibrosis correlated with post-liver transplant kidney function (p = 0.019). Moderate-to-severe chronic portal inflammation was correlated with graft survival on both multivariate and univariate analyses (p < 0.001), but this risk factor is sensibly reduced by the execution of HOPE. CONCLUSIONS: The use of liver grafts with portal fibrosis stage ≥ 3 implies a higher risk of post-transplant complications. Portal inflammation represents an important prognostic factor as well, but the execution of HOPE represents a valid tool to improve graft survival.

Amyloidosis: What does pathology offer? The evolving field of tissue biopsy.

Since the mid-nineteenth century pathology has followed the convoluted story of amyloidosis, recognized its morphology in tissues and made identification possible using specific staining. Since then, pathology studies have made a significant contribution and advanced knowledge of the disease, so providing valuable information on the pathophysiology of amyloid aggregation and opening the way to clinical studies and non-invasive diagnostic techniques. As amyloidosis is a heterogeneous disease with various organ and tissue deposition patterns, histology evaluation, far from offering a simple yes/no indication of amyloid presence, can provide a wide spectrum of qualitative and quantitative information related to and changing with the etiology of the disease, the comorbidities and the clinical characteristics of patients. With the exception of cardiac transthyretin related amyloidosis cases, which today can be diagnosed using non-biopsy algorithms when stringent clinical criteria are met, tissue biopsy is still an essential tool for a definitive diagnosis in doubtful cases and also to define etiology by typing amyloid fibrils. This review describes the histologic approach to amyloidosis today and the current role of tissue screening biopsy or targeted organ biopsy protocols in the light of present diagnostic algorithms and various clinical situations, with particular focus on endomyocardial and renal biopsies. Special attention is given to techniques for typing amyloid fibril proteins, necessary for the new therapies available today for cardiac transthyretin related amyloidosis and to avoid patients receiving inappropriate chemotherapy in presence of plasma cell dyscrasia unrelated to amyloidosis. As the disease is still burdened with high mortality, the role of tissue biopsy in early diagnosis to assure prompt treatment is also mentioned.

Endothelial angiopoietin-2 overexpression in explanted livers identifies subjects at higher risk of recurrence of hepatocellular carcinoma after liver transplantation.

Background: Though the precise criteria for accessing LT are consistently being applied, HCC recurrence (HCC-R_LT) still affects more than 15% of the patients. We analyzed the clinical, histopathological, and biological features of patients with HCC to identify the predictive factors associated with cancer recurrence and survival after LT. Methods: We retrospectively analyzed 441 patients with HCC who underwent LT in our center. Overall, 70 (15.8%) of them developed HCC-R_LT. We matched them by age at transplant and etiology with 70 non-recurrent patients. A comparable cohort from the Liver Transplant Centre of Bologna served as validation. The clinical and biochemical characteristics and pre-LT criteria (Milan, Metroticket, Metroticket_AFP, and AFP model) were evaluated. Histological analysis and immunohistochemistry for angiopoietin-2 in the tumor and non-tumor tissue of explanted livers were performed. Patients' follow-up was until death, last clinical evaluation, or 31 December 2021. In patients with HCC-R_LT, the date of diagnosis of recurrence and anatomical site has been reported; if a biopsy of recurrence was available, histologic and immunohistochemical analyses were also performed. Results: Patients were followed up for a mean period of 62.7 ± 54.7 months (median, 39 months). A higher risk of HCC-R_LT was evident for factors related indirectly (AFP) or directly (endothelial angiopoietin-2, microvascular invasion) to biological HCC aggressiveness. In multivariate analysis, only angiopoietin-2 expression was independently associated with recurrence. Extremely high levels of endothelial angiopoietin-2 expression were also found in hepatic recurrence and all different metastatic locations. In univariate analysis, MELD, Metroticket_AFP Score, Edmondson-Steiner grade, microvascular invasion, and endothelial angiopoietin-2 were significantly related to survival. In multivariate analysis, angiopoietin-2 expression, Metroticket_AFP score, and MELD (in both training and validation cohorts) independently predicted mortality. In time-dependent area under receiver operating characteristic curve analysis, the endothelial angiopoietin-2 expression had the highest specificity and sensitivity for recurrence (AUC 0.922, 95% CI 0.876-0.962, p < 0.0001). Conclusions: Endothelial angiopoietin-2 expression is a powerful independent predictor of post-LT tumor recurrence and mortality, highlighting the fundamental role of tumor biology in defining the patients' prognosis after liver transplantation. The great advantage of endothelial angiopoietin-2 is that it is evaluable in HCC biopsy before LT and could drive a patient's priority on the waiting list.

Correlation of molecular alterations with pathological features in hepatocellular carcinoma: Literature review and experience of an Italian center.

Hepatocellular carcinoma (HCC) represents the primary carcinoma of the liver and the fourth leading cause of cancer-related deaths. The World Health Organization estimates an increase in cases in the coming years. The risk factors of HCC are multiple, and the incidence in different countries is closely related to the different risk factors to which the population is exposed. The molecular mechanisms that drive HCC tumorigenesis are extremely complex, but understanding this multistep process is essential for the identification of diagnostic, prognostic, and therapeutic markers. The development of multigenic next-generation sequencing panels through the parallel analysis of multiple markers can provide a landscape of the genomic status of the tumor. Considering the literature and our preliminary data based on 36 HCCs, the most frequently altered genes in HCCs are TERT, CTNNB1, and TP53. Over the years, many groups have attempted to classify HCCs on a molecular basis, but a univocal classification has never been achieved. Nevertheless, statistically significant correlations have been found in HCCs between the molecular signature and morphologic features, and this leads us to think that it would be desirable to integrate the approach between anatomic pathology and molecular laboratories.

Progression of echocardiographic parameters and prognosis in transthyretin cardiac amyloidosis.

AIMS: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly diagnosed disease. Echocardiography is widely utilized, but studies to confirm the value of echocardiography for tracking changes over time are not available. We sought to describe (i) changes in multiple echocardiographic parameters; (ii) differences in rate of progression of three predominant genotypes; and (iii) the ability of changes in echocardiographic parameters to predict prognosis. METHODS AND RESULTS: We prospectively studied 877 ATTR-CM patients attending our centre between 2000 and 2020. Serial echocardiography findings at baseline, 12 months and 24 months were compared with survival. Overall, 565 patients had wild-type ATTR-CM and 312 hereditary ATTR-CM (201 with V122I; 90 with T60A). There was progressive worsening of structural and functional parameters over time, patients with V122I ATTR-CM showing more rapid worsening of left and right ventricular structural and functional parameters compared to both wild-type and T60A ATTR-CM. Among a wide range of echocardiographic analyses, including deformation-based parameters, only worsening in the degree of mitral (MR) and tricuspid regurgitation (TR) at 12- and 24-month assessments was associated with worse prognosis (change at 12 months: MR, hazard ratio 1.43 [95% confidence interval 1.14-1.80], p = 0.002; TR, hazard ratio 1.38 [95% confidence interval 1.10-1.75], p = 0.006). Worsening in MR remained independently associated with poor prognosis after adjusting for known predictors. CONCLUSION: In ATTR-CM, echocardiographic parameters progressively worsen over time. Patients with V122I ATTR-CM demonstrate the most rapid deterioration. Worsening of MR and TR were the only parameters associated with mortality, MR remaining independent after adjusting for known predictors.

COVID-19 and the Brain: The Neuropathological Italian Experience on 33 Adult Autopsies.

Neurological symptoms are increasingly recognized in SARS-CoV-2 infected individuals. However, the neuropathogenesis remains unclear and it is not possible to define a specific damage pattern due to brain virus infection. In the present study, 33 cases of brain autopsies performed during the first (February-April 2020) and the second/third (November 2020-April 2021) pandemic waves are described. In all the cases, SARS-CoV-2 RNA was searched. Pathological findings are described and compared with those presently published.

Dysplastic nevi and melanoma: microRNAs tell a divergent story.

BACKGROUND: dysplastic nevi (DN) share some clinical and histological features with melanoma and have been considered intermediate lesions toward malignant transformation. However, scientific evidence of DN representing melanoma precursors is still incomplete, and many observations pointed toward their being a distinct biological entity. The current definition of DN is also confusing and the practical consequence of this uncertainty is the excessive excision of DN with severe atypia. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and whose global expression can classify normal and pathological tissues. OBJECTIVES: given these considerations, we decided to perform a small RNA profiling study in a group of DN and invasive melanomas obtained from the same patient, to assess tumor evolution according to the global microRNA expression. METHODS: we performed a small-RNA sequencing of 6 DN, 2 congenital nevi and 4 cutaneous melanomas obtained from 4 subjects and evaluated the global miRNA expression correlation between samples. RESULTS AND CONCLUSIONS: the hierarchical clustering and principal component analyses of global miRNA expression, independently grouped together DN and their matching congenital nevi and showed a divergence of DN miRNA profile from melanoma. Our study suggests that DN have a peculiar and different miRNA expression profile compared to melanomas developed in the same patient, thus supporting the hypothesis that DN are distinct biological entities and not melanoma precursors.

[Sudden cardiac death in young people and in adults: primary and contributing causes. The experience of the multidisciplinary network in Emilia-Romagna]. / La morte improvvisa giovanile e in età adulta: cause e concause. L'esperienza della rete multidisciplinare in Emilia-Romagna.

BACKGROUND: The multidisciplinary network of Emilia-Romagna for the study of juvenile sudden cardiac death (SCD) was started in Bologna in June 2018 in order to: (1) define the spectrum of etiologies and mechanisms of SCD in young people; (ii) standardize diagnostic terminology and categories; (iii) identify potentially hereditary genetic heart diseases and define the contribution of post-mortem genetic analysis (so-called molecular autopsy) to the overall diagnostic process; (iv) identify preclinical forms of the pathologies in the first-degree relatives of the deceased subject using both phenotypic and genotypic evaluation and, where possible, undertake therapeutic/prophylactic measures (primary prevention). METHODS: In the first 2 years of activity (01/06/2018-27/08/2020) 50 cases of SCD came to the attention of the Cardiovascular Pathology Unit of the S. Orsola-Malpighi Polyclinic in Bologna, from Centres of Forensic Medicine and Pathological Anatomy in most of the region. RESULTS: Sixty-two percent of cases were sent by forensic pathologists, 36% by clinical pathologists and 2% by the family of the deceased. Medico-legal cases were prompted by autopsies requested by the Judicial Authority in 70% of cases; 55.5% of patients referred by pathologists came from the Cardiovascular Tissue Bank, as part of the regional program for the quality and safety control of organs and tissues from multiorgan-multitissue donors. The average age of the subjects was 35 ± 13.6 years (70% male, range: 1-55 years; median: 38 years). The spectrum of the final diagnoses includes: structurally normal hearts 14%, cardiomyopathies 40%, coronary heart disease 23%, Brugada syndrome 6%, aortic dissection 4%, substance abuse 6%, valvular heart disease 2%, mixed causes 2%. CONCLUSIONS: The network is necessarily centered on post-mortem pathological activities, but it does not end with these. If in 60% of cases the pathological autopsy examination was decisive in identifying the cause of death, in the other cases a detailed final diagnosis was reached only with more complex pathways involving molecular genetics, clinical genetics, and toxicology.

Low level of interobserver concordance in assessing histological subtype and tumor grade in patients with penile cancer may impair patient care.

Differentiation between penile squamous cell carcinoma patients who can benefit from limited organ-sparing surgery and those at significant risk of lymph node metastasis is based on histopathological prognostic factors including histological grade and tumor histological subtype. We examined levels of interobserver and intraobserver agreement in assessment of histological subtype and grade in 207 patients with penile squamous cell carcinoma. The cases were assessed by seven pathologists from three hospitals located in Sweden and Italy. There was poor to moderate concordance in assessing both histological subtype and grade, with Fleiss kappas of 0.25 (range: 0.02-0.48) and 0.23 (range: 0.07-0.55), respectively. When choosing HPV-associated and non-HPV-associated subtypes, interobserver concordance ranged from poor to good, with a Fleiss kappa value of 0.36 (range: 0.02-0.79). A re-review of the slides by two of the pathologists showed very good intraobserver concordance in assessing histological grade and subtype, with Cohen's kappa values of 0.94 and 0.91 for grade and 0.95 and 0.84 for subtype. Low interobserver concordance could lead to undertreatment and overtreatment of many patients with penile cancer, and brings into question the utility of tumor histological subtype and tumor grade in determining patient treatment in pT1 tumors.

MicroRNA expression profiling with a droplet digital PCR assay enables molecular diagnosis and prognosis of cancers of unknown primary.

Metastasis is responsible for the majority of cancer-related deaths. Particularly, challenging is the management of metastatic cancer of unknown primary site (CUP), whose tissue of origin (TOO) remains undetermined even after extensive investigations and whose therapy is rather unspecific and poorly effective. Molecular approaches to identify the most probable TOO of CUPs can overcome some of these issues. In this study, we applied a predetermined set of 89 microRNAs (miRNAs) to infer the TOO of 53 metastatic cancers of unknown or uncertain origin. The miRNA expression was assessed with droplet digital PCR in 159 samples, including primary tumors from 17 tumor classes (reference set) and metastases of known and unknown origin (test set). We combined two different statistical models for class prediction to obtain the most probable TOOs: the nearest shrunken centroids approach of Prediction Analysis of Microarrays (PAMR) and the least absolute shrinkage and selection operator (LASSO) models. The molecular test was successful for all formalin-fixed paraffin-embedded samples and provided a TOO identification within 1 week from the biopsy procedure. The most frequently predicted origins were gastrointestinal, pancreas, breast, lung, and bile duct. The assay was applied also to multiple metastases from the same CUP, collected from different metastatic sites: The predictions showed a strong agreement, intrinsically validating our assay. The final CUPs' TOO prediction was compared with the clinicopathological hypothesis of primary site. Moreover, a panel of 13 miRNAs proved to have prognostic value and be associated with overall survival in CUP patients. Our study demonstrated that miRNA expression profiling in CUP samples could be employed as diagnostic and prognostic test. Our molecular analysis can be performed on request, concomitantly with standard diagnostic workup and in association with genetic profiling, to offer valuable indications about the possible primary site, thereby supporting treatment decisions.

Genetic Characterization of Cancer of Unknown Primary Using Liquid Biopsy Approaches.

Cancers of unknown primary (CUPs) comprise a heterogeneous group of rare metastatic tumors whose primary site cannot be identified after extensive clinical-pathological investigations. CUP patients are generally treated with empirical chemotherapy and have dismal prognosis. As recently reported, CUP genome presents potentially druggable alterations for which targeted therapies could be proposed. The paucity of tumor tissue, as well as the difficult DNA testing and the lack of dedicated panels for target gene sequencing are further relevant limitations. Here, we propose that circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) could be used to identify actionable mutations in CUP patients. Blood was longitudinally collected from two CUP patients. CTCs were isolated with CELLSEARCH® and DEPArrayTM NxT and Parsortix systems, immunophenotypically characterized and used for single-cell genomic characterization with Ampli1TM kits. Circulating cell-free DNA (ccfDNA), purified from plasma at different time points, was tested for tumor mutations with a CUP-dedicated, 92-gene custom panel using SureSelect Target Enrichment technology. In parallel, FFPE tumor tissue was analyzed with three different assays: FoundationOne CDx assay, DEPArray LibPrep and OncoSeek Panel, and the SureSelect custom panel. These approaches identified the same mutations, when the gene was covered by the panel, with the exception of an insertion in APC gene. which was detected by OncoSeek and SureSelect panels but not FoundationOne. FGFR2 and CCNE1 gene amplifications were detected in single CTCs, tumor tissue, and ccfDNAs in one patient. A somatic variant in ARID1A gene (p.R1276∗) was detected in the tumor tissue and ccfDNAs. The alterations were validated by Droplet Digital PCR in all ccfDNA samples collected during tumor evolution. CTCs from a second patient presented a pattern of recurrent amplifications in ASPM and SEPT9 genes and loss of FANCC. The 92-gene custom panel identified 16 non-synonymous somatic alterations in ccfDNA, including a deletion (I1485Rfs∗19) and a somatic mutation (p. A1487V) in ARID1A gene and a point mutation in FGFR2 gene (p.G384R). Our results support the feasibility of non-invasive liquid biopsy testing in CUP cases, either using ctDNA or CTCs, to identify CUP genetic alterations with broad NGS panels covering the most frequently mutated genes.

Unraveling the role of microRNA/isomiR network in multiple primary melanoma pathogenesis.

Malignant cutaneous melanoma (CM) is a potentially lethal form of skin cancer whose worldwide incidence has been constantly increasing over the past decades. During their lifetime, about 8% of CM patients will develop multiple primary melanomas (MPMs), usually at a young age and within 3 years from the first tumor/diagnosis. With the aim of improving our knowledge on MPM biology and pathogenesis, we explored the miRNome of 24 single and multiple primary melanomas, including multiple tumors from the same patient, using a small RNA-sequencing approach. From a supervised analysis, 22 miRNAs were differentially expressed in MPM compared to single CM, including key miRNAs involved in epithelial-mesenchymal transition. The first and second melanoma from the same patient presented a different miRNA profile. Ten miRNAs, including miR-25-3p, 149-5p, 92b-3p, 211-5p, 125a-5p, 125b-5p, 205-5p, 200b-3p, 21-5p, and 146a-5p, were further validated in 47 single and multiple melanoma samples. Pathway enrichment analysis of miRNA target genes revealed a more differentiated and less invasive status of MPMs compared to CMs. Bioinformatic analyses at the miRNA isoform (isomiR) level detected a panel of highly expressed isomiRs belonging to miRNA families implicated in human tumorigenesis, including miR-200, miR-30, and miR-10 family. Moreover, we identified hsa-miR-125a-5p|0|-2 isoform as tenfold over-represented in melanoma than the canonical form and differentially expressed in MPMs arising in the same patient. Target prediction analysis revealed that the miRNA shortening could change the pattern of target gene regulation, specifically in genes implicated in cell adhesion and neuronal differentiation. Overall, we provided a putative and comprehensive characterization of the miRNA/isomiR regulatory network of MPMs, highlighting mechanisms of tumor development and molecular features differentiating this subtype from single melanomas.