Neurofibromatosis type 1 (NF1) predisposes to a spectrum of peripheral nerve sheath tumors, ranging from benign plexiform neurofibromas (PN) to atypical neurofibromatous neoplasms of uncertain biological potential (ANNUBP) and malignant peripheral nerve sheath tumors (MPNST). Tumorigenesis follows a multistep molecular cascade initiated by biallelic NF1 inactivation, followed by CDKN2A loss and disruption of the Polycomb Repressive Complex 2 (PRC2). These events guide chromatin remodeling, widespread epigenetic dysregulation, and activation of oncogenic pathways such as RAS/MAPK and PI3K/AKT. Here, we integrate genomic, transcriptomic, and epigenomic studies to delineate the molecular trajectories underlying tumor progression and to define promising biomarkers for the early detection of malignant transformation. Emerging liquid biopsy approaches, based on circulating tumor DNA (ctDNA) analyses, reveal distinctive copy number variations (CNVs) and methylation patterns that mirror tissue-derived profiles, enabling the detection of malignant transformation. Together, these findings support a model in which cumulative genetic and epigenetic alterations drive the PN–ANNUBP–MPNST continuum. They also underscore the value of multi-omics and liquid biopsy-based strategies to improve early diagnosis, patient risk stratification, and personalized management of NF1-associated tumors, thereby advancing precision medicine in this complex disease spectrum.

Despite the efficacy of osimertinib in the first-line treatment of advanced EGFR-mutated NSCLC, the development of resistance is nearly inevitable. BRAF mutations and fusions are reported in 1% to 3% of patients with EGFR-mutated NSCLC receiving osimertinib and represent potential targetable alterations.In this case report, we discuss the rationale for EGFR-MEK co-inhibition in a patient with EGFR-mutated NSCLC treated with osimertinib that developed a CTNNA1-BRAF fusion at progression. In addition, we provide a brief overview of the current evidence of BRAF fusions as an acquired resistance mechanism to osimertinib and potential treatment strategies.

Introduction:Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of metastatic melanoma, but a percentage of patients did not show benefit. Circulating tumor DNA (ctDNA) has emerged as a potential non-invasive tool for monitoring disease evolution and treatment response. The present study aimed to evaluate the clinical utility of ctDNA dynamics in patients with metastatic melanoma receiving ICIs, while exploring its role in the oncological course. Materials and methods:The LIQUID-MEL study is a prospective, single-centre pilot study including patients with BRAF/NRAS-mutant metastatic melanoma. ctDNA was quantified using digital droplet PCR (ddPCR) at four different time points. Uni- and multivariable Cox regression models were used to assess the correlation between shedding and progression-free survival (PFS), and overall survival (OS). Results:Overall, 23 patients were included. At baseline, ctDNA was detectable in 5/23 (21.7 %) cases. Baseline ctDNA shedding was associated with shorter PFS (3.88 months vs. 0.69 months, p=0.012). A strong numerical trend was observed also in OS (12.66 months vs. 2.53 months, p=0.287). Shedding at baseline did not demonstrate independent prognostic or predictive value in the uni- and multivariable analysis. The longitudinal analysis revealed intriguing patterns of ctDNA shedding in individual patients. Conclusion:ctDNA detectability and its dynamic changes during treatment may have potential clinical utility in patients with metastatic melanoma, offering a valuable non-invasive tool for monitoring disease and treatment response. The small sample size limited the statistical power of the analysis. Further studies with larger cohorts are needed to validate its role in routine clinical practice.

AIM:A translational multiscale approach, encompassing tumor immune microenvironment (TIME), circulating immune-inflammatory benchmarks, and transcriptomic profiles, was undertaken to identify prognostic biomarkers of immunotherapy (IT) efficacy in patients with advanced pleural mesothelioma (PM). METHODS:Advanced PM patients (n = 17) treated with nivolumab plus ipilimumab were prospectively enrolled in the FIL-QI 2021 study. Baseline blood and tumor samples were analyzed for immune subsets and functional markers (Granzyme B, Ki67) by flow cytometry, cytokines by multiplex ELISA, TILs and PD-L1 by immunohistochemistry, and gene expression by nanostring. Associations with overall survival (OS), progression-free survival (PFS), time-to-treatment failure (TTF), and modified disease control rate (mDCR) were assessed. RESULTS:Higher baseline CD4+ GnzB+ T cells were significantly associated with OS ≥ 12 months (p < 0.001), PFS ≥ 6 months (p = 0.027), and TTF ≥ 6 months (p = 0.016), along with lower CD14+ monocytes (PFS: p = 0.038). Elevated proliferating CD8+ Ki67+ T cells (PFS: p = 0.038; TTF: p = 0.022) also predicted improved outcomes. Low IL-2 levels correlated with OS ≥ 12 months (p = 0.02). TIME analysis showed higher intratumor CD4+ TILs (p = 0.03) and CD4/CD8 ratio (p = 0.016) in long survivors. Transcriptomics revealed nine genes differentially regulated according to clinical outcomes, among which ULBP2 emerged as a strong predictor of poor prognosis (LASSO-Cox regression model). CONCLUSION:Parallel immune and transcriptomic profiling identifies biomarkers predictive of IT benefit in PM.

Darier′s disease (DD) is a rare, autosomal dominant genodermatosis caused by pathogenic variants in the ATP2A2 gene, which encodes the SERCA2 protein, an endoplasmic reticulum ATPase Ca2+ transporter. These mutations impair the intracellular calcium homeostasis leading to increased protein misfolding, endoplasmic reticulum (ER) stress response, and the activation of the unfolded protein response (UPR), culminating in keratinocyte apoptosis and anomalies in interfollicular epidermal stratification. Clinically, the disease is characterized by the presence of skin lesions with hyperkeratotic papules and an increased susceptibility to inflammatory reactions, bacterial and viral infections. The histological hallmarks include acantholysis, dyskeratosis, and increased apoptotic keratinocytes, referred to as “corp ronds”. The SERCA2b isoform is expressed not only in the epidermis but it is present ubiquitously in all tissues, suggesting that its alteration may have multi-organ effects. The review aims to provide a broad overview of the pathology, from intracellular dysfunction to the clinical manifestations, elucidating the molecular effects of SERCA2 variants found in DD patients and exploring the potential cell signaling pathways that may contribute to disease progression. Beginning with an examination of the cellular alterations, our work then shifts to exploring their impact in an organ-specific context, providing insights into new potential therapeutic strategies tailored to clinical manifestations.

INTRODUCTION:Several biomarkers are currently available to address targeted treatments in cancer patients, with lung malignancies representing one of the best examples. CASE DESCRIPTION:We report the case of a patient affected by advanced non-small cell lung cancer with an uncommon histology and a complex biology. The use of a large next-generation sequencing (NGS) NGS panel allowed us to identify an extremely rare BRAF mutation (V600Q), a MET amplification, a high tumor mutational burden, a germline pathogenetic BRCA1 mutation and a homologous recombination deficiency through RAD51 assay. The treatment decision was driven by the abundance of molecular information. CONCLUSIONS:This case highlights that an attentive and critical evaluation of molecular reports is key for the tailoring of treatment algorithms at the patient-level scale.

Introduction ctDNA is a useful tool for NGS molecular profiling in advanced NSCLC patients. Its clinical applicability in patients with gene rearrangements is still limited due to a lower detection rate of these types of alterations compared to single SNVs or small indels. To this purpose, we performed a study in two Italian centers to assess the concordance between tissue and plasma samples in the detection of genes fusions (ALK, ROS, RET) and METexon14 mutations in advanced NSCLC patients. Methods Patients with a histological diagnosis of oncogene addicted (ALK, ROS1, RET positive or METexon14 mutated) advanced NSCLC were enrolled at the time of first line of TKI treatment. Plasma samples were harvested before the start of TKI treatment and NGS analysis on ctDNA samples using the AVENIO ctDNA Expanded kit was performed. The Positive Percent Agreement (PPA) between tissue and plasma was calculated. Results Fifty-eight rearranged or METexon14 mutated NSCLC patients were included and 57 ctDNA samples were successfully sequenced. An overall PPA of 37% (21/57) was obtained, with a best performance for RET fusion (80%), intermediate for METexon14 skipping mutations (40%) and ALK rearranged (36%) and a worst one for ROS1 rearranged samples (18%). We found TP53, APC and SMAD4 as most prevalent co-mutated genes (21%, 12% and 10% of patients, respectively). Among different factors considered, increased driver detection rate in patients with extra-thoracic metastases (p = 0.0049) was observed. Significantly shorter survival was observed in patients harboring co-occurring KRAS/NRAS mutations in ctDNA. Conclusions ctDNA testing to detect oncogenic fusions or METexon14 mutations in advanced NSCLC patients is useful, even if type of gene alterations and clinical characteristics could influence the driver detection rate. Liquid biopsy represents a complementary tool to tissue genotyping, however more sensitive approaches for gene fusions and METexon14 detection are needed to implement its strength and reliability.

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder characterized by the predisposition to develop tumors such as malignant peripheral nerve sheath tumors (MPNSTs) which represents the primary cause of death for NF1-affected patients. Regardless of the high incidence and mortality, the molecular mechanisms underneath MPNST growth and metastatic progression remain poorly understood. In this proof-of-concept study, we performed somatic whole-exome sequencing (WES) to profile the genomic alterations in four samples from a patient with NF1-associated MPNST, consisting of a benign plexiform neurofibroma, a primary MPNST, and metastases from lung and skin tissues. By comparing genomic patterns, we identified a high level of variability across samples with distinctive genetic changes which allow for the definition of profiles of the early phase with respect to the late metastatic stages. Pathogenic and likely pathogenic variants were abundant in the primary tumor, whereas the metastatic samples exhibited a high level of copy-number variations (CNVs), highlighting a possible genomic instability in the late phases. The most known MPNST-related genes, such as TP53 and SUZ12, were identified in CNVs observed within the primary tumor. Pathway analysis of altered early genes in MPNST pointed to a potential role in cell motility, division and metabolism. Moreover, we employed survival analysis with the TCGA sarcoma genomic dataset on 262 affected patients, in order to corroborate the predictive significance of the identified early and metastatic MPNST driver genes. Specifically, the expression changes related to the mutated genes, such as in RBMX, PNPLA6 and AGAP2, were associated with reduced patient survival, distinguishing them as potential prognostic biomarkers. This study underlines the relevance of integrating genomic results with clinical information for early diagnosis and prognostic understanding of tumor aggressiveness.

Preoperative chemoradiotherapy (CRT) may enhance antitumor immunity by increasing T-cell activation and tumor infiltration. These effects could possibly sensitize tumour cells to immunecheckpoint inhibitors and other immunotherapies. We investigated the immunologic alterations occurring after preoperative CRT for locally advanced rectal cancer (LARC). The multicenter randomized STAR-01 study compared the preoperative CRT regimen with 50.4 Gy in 28 daily fractions with concomitant infused fluorouracil at the dose of 225 mg/m2/d with the same regimen plus oxaliplatin given weekly at the dose of 60 mg/m2 in patients with LARC. Pre- and/or postoperative specimens were available for 305 patients from this trial (109 paired pre- and post-treatment samples). The immunoistochemical evaluation was performed with a panel of immune cells and associated factors such as CD3, CD20, CD4/CD8, PD-1. The pattern of tumor infiltrating lymphocytes (TILs) and related infiltrating lymphocytes (RILs) were also assessed. Microsatellite instability (MSI)/mismatch repair deficiency (dMMR) was evaluated on pre-treatment tumour biopsies. After therapy we observed a decreased CD4/CD8 ratio (P<.0001) and reduced expression levels of CD20 (P<.0001). The expression level of CD3+ and PD-1+ cells after therapy did not change significantly. The relative increase of lymphocytes CD8+ within the CD4/CD8 ratio evaluated on post-operative samples was significantly associated with pathological complete response after CRT (P<.0001), event-free survival (EFS) [hazard ratio (HR)=1.77, 95% confidence interval (CI)=1.08 to 2.89, P=.0227] and overall survival (OS) [HR=2.01, 95% CI=1.19 to 3.4, P=.0087] adjusted for treatment arm and adjuvant chemotherapy. Our data indicate that CRT may induce an enrichment of CD8+ T lymphocytes and this translates in a better response to CRT and survival. Data on MSI status will be presented at the meeting.

BACKGROUND: Resistance to osimertinib in advanced EGFR-mutated non-small cell lung cancer (NSCLC) constitutes a significant challenge for clinicians either in terms of molecular diagnosis and subsequent therapeutic implications.METHODS: This is a prospective single-centre study with the primary objective of characterising resistance mechanisms to osimertinib in advanced EGFR-mutated NSCLC patients treated both in first- and in second-line. Next-Generation Sequencing analysis was conducted on paired tissue biopsies and plasma samples. A concordance analysis between tissue and plasma was performed.RESULTS: Sixty-five advanced EGFR-mutated NSCLC patients treated with osimertinib in first- (n = 56) or in second-line (n = 9) were included. We managed to perform tissue and liquid biopsies in 65.5% and 89.7% of patients who experienced osimertinib progression, respectively. Acquired resistance mechanisms were identified in 80% of 25 patients with post-progression samples, with MET amplification (n = 8), EGFR C797S (n = 3), and SCLC transformation (n = 2) the most frequently identified. The mean concordance rates between tissue and plasma for the EGFR activating mutation and for the molecular resistance mechanisms were 87.5% and 22.7%, respectively.CONCLUSIONS: Resistance to osimertinib demonstrated to be highly heterogeneous, with MET amplification the main mechanism. Plasma genotyping is a relevant complementary tool which might integrate tissue analysis for the study of resistance mechanisms.

IntroductionThe Notch intracellular domain (NICD) and its ligands Jagged-1(Jag1), Delta-like ligand (DLL-3) and DLL4 play an important role in neoangiogenesis. Previous studies suggest a correlation between the tissue levels of NICD and response to therapy with bevacizumab in colorectal cancer (CRC). Another marker that may predict outcome in CRC is radiomics of liver metastases. The aim of this study was to investigate the expression of NICD and its ligands and the role of radiomics in the selection of treatment-naive metastatic CRC patients receiving bevacizumab.MethodsImmunohistochemistry (IHC) for NICD, Jag1 and E-cadherin was performed on the tissue microarrays (TMAs) of 111 patients with metastatic CRC treated with bevacizumab and chemotherapy. Both the intensity and the percentage of stained cells were evaluated. The absolute number of CD4+ and CD8+ lymphocytes was counted in three different high-power fields and the mean values obtained were used to determine the CD4/CD8 ratio. The positivity of tumor cells to DLL3 and DLL4 was studied. The microvascular density (MVD) was assessed in fifteen cases by counting the microvessels at 20x magnification and expressed as MVD score. Abdominal CT scans were retrieved and imported into a dedicated workstation for radiomic analysis. Manually drawn regions of interest (ROI) allowed the extraction of radiomic features (RFs) from the tumor.ResultsA positive association was found between NICD and Jag1 expression (p < 0.001). Median PFS was significantly shorter in patients whose tumors expressed high NICD and Jag1 (6.43 months vs 11.53 months for negative cases; p = 0.001). Those with an MVD score ≥5 (CD31-high, NICD/Jag1 positive) experienced significantly poorer survival. The radiomic model developed to predict short and long-term survival and PFS yielded a ROC-AUC of 0.709; when integrated with clinical and histopathological data, the integrated model improved the predictive score (ROC-AUC of 0.823).DiscussionThese results show that high NICD and Jag1 expression are associated with progressive disease and early disease progression to anti VEGF-based therapy; the preliminary radiomic analyses show that the integration of quantitative information with clinical and histological data display the highest performance in predicting the outcome of CRC patients.

Mutations in KRAS are among the most frequent aberrations in cancer, including colon cancer. KRAS direct targeting is daunting due to KRAS protein resistance to small molecule inhibition. Moreover, its elevated affinity to cellular guanosine triphosphate (GTP) has made the design of specific drugs challenging. Indeed, KRAS was considered 'undruggable'. KRASG12C is the most commonly mutated variant of KRAS in non-small cell lung cancer. Currently, the achievements obtained with covalent inhibitors of this variant have given the possibility to assess the best therapeutic approach to KRAS-driven tumors. Mutation-related biochemical assets and the tissue of origin are expected to influence responses to treatment. Further attempts to obtain mutant-specific KRAS (KRASG12C) switch-II covalent inhibitors are ongoing and the results are promising. Drugs targeted to block KRAS effector pathways could be combined with direct KRAS inhibitors, immunotherapy or T cell-targeting approaches in KRAS-mutant tumors. The development of valuable combination regimens will be essential against potential mechanisms of resistance that may arise during treatment.

Introduction: BRAF mutation involved 2–4% of lung adenocarcinoma. Differences in clinicopathologic features and patient outcome exist between V600E and non-V600E BRAF mutated NSCLC. Thus, we sought to assess the frequency and clinical relevance of BRAF mutations in a real-life population of advanced-NSCLC, investigating the potential prognostic significance of distinct genetic alterations. Materials and Methods: The present multicenter Italian retrospective study involved advanced BRAF mutant NSCLC. Complete clinicopathologic data were evaluated for BRAF V600E and non-V600E patients. Results: A total of 44 BRAFmut NSCLC patients were included (V600E, n = 23; non-V600E, n = 21). No significant differences in survival outcome and treatment response were documented, according to V600E vs. non-V600E mutations, although a trend towards prolonged PFS was observed in the V600E subgroup (median PFS = 11.3 vs. 6.0 months in non-V600E). In the overall population, ECOG PS and age significantly impacted on OS, while bone lesions were associated with shorter PFS. Compared to immunotherapy, first-line chemotherapy was associated with longer OS in the overall population, and especially in the BRAF V600E subtype. Conclusions: Here, we report on real-life data from a retrospective cohort of advanced-NSCLC harboring BRAF alterations. Our study offers relevant clues on survival outcome, therapeutic response, and clinicopathologic correlations of BRAF-mutant NSCLC.

Introduction Targeting Kirsten Rat Sarcoma (KRAS) has been deemed impossible for long time, but new drugs have recently demonstrated promising results. Evidence on the outcome of KRAS-mutant advanced-NSCLC treated with new standard regimens are still scarce. Thus, we aimed at assessing the incidence and clinical impact of KRAS mutations in a real-life population of advanced-NSCLC, exploring the prognostic significance of distinct alterations. Materials and Methods The present multicenter retrospective study, conducted by 5 Italian Centers from January 2018 to February 2020, involved 297 advanced KRAS mutant NSCLC. Complete clinico-pathological data were evaluated. Results Out of 297 patients, 130 carried KRAS_G12C mutation, while 167 presented with mutations other than G12C. Within KRAS_non-G12C group, 73%, 16.8% and 8.9% harboured G12X, codon 13 and Q61H alterations, respectively. No significant differences in survival outcome and treatment response were documented according to KRAS_G12C versus non-G12C, nor KRAS_G12C versus G12X versus other mutations. On univariate analysis ECOG PS, number and sites of metastatic lesions and PD-L1 status significantly impacted on survival. A clear trend towards worse prognosis was apparent in chemotherapy-treated patients, while immunotherapy-based regimens were associated to prolonged survival. Investigating the outcome of PD-L1 ≥ 50% population, we did not detect any significant difference between KRAS_G12C and non-G12C subsets. Conclusion Here, we report on real-life data from a large retrospective cohort of advanced NSCLC harbouring KRAS alterations, with particular attention to G12C mutation. Our study offers useful clues on survival outcome, therapeutic response and clinico-pathological correlations in KRAS-mutant setting, especially in the upcoming era of KRAS G12C targeting therapy.

IntroductionALK tyrosine kinase inhibitors (TKIs) are the standard treatment for advanced ALK-positive NSCLC. Nevertheless, drug resistance inevitably occurs. Here, we report a case of a patient with metastatic ALK-positive lung adenocarcinoma with an impressive resistance to sequential treatment with ALK TKIs mediated by YES1 and MYC amplification in a contest of epithelial-to-mesenchymal transition and high progressive chromosomal instability.MethodsThe patient received, after chemotherapy and 7 months of crizotinib, brigatinib and lorlatinib with no clinical benefit to both treatments. A study of resistance mechanisms was performed with whole exome sequencing on different biological samples; primary cell lines were established from pleural effusion after lorlatinib progression.ResultsAt whole exome sequencing analysis, YES1 and MYC amplifications were observed both in the pericardial biopsy and the pleural effusion samples collected at brigatinib and lorlatinib progression, respectively. Increasing chromosomal instability from diagnostic biopsy to pleural effusion was also observed. The addition of dasatinib to brigatinib or lorlatinib restored the sensitivity in primary cell lines; data were confirmed also in H3122_ALK-positive model overexpressing both YES1 and MYC.ConclusionsIn conclusion, YES1 and MYC amplifications are candidates to justify a rapid acquired resistance to crizotinib entailing primary brigatinib and lorlatinib resistance. In this context, a combination strategy of ALK TKI with dasatinib could be effective to overcome a rapid resistance.

Despite much progress in improving graft outcome during cardiac transplantation, chronic allograft vasculopathy (CAV) remains an impediment to long-term graft survival. MicroRNAs (miRNAs) emerged as regulators of the immune response. Here, we aimed to examine the miRNA network involved in CAV. miRNA profiling of heart samples obtained from a murine model of CAV and from cardiac-transplanted patients with CAV demonstrated that miR-21 was most significantly expressed and was primarily localized to macrophages. Interestingly, macrophage depletion with clodronate did not significantly prolong allograft survival in mice, while conditional deletion of miR-21 in macrophages or the use of a specific miR-21 antagomir resulted in indefinite cardiac allograft survival and abrogated CAV. The immunophenotype, secretome, ability to phagocytose, migration, and antigen presentation of macrophages were unaffected by miR-21 targeting, while macrophage metabolism was reprogrammed, with a shift toward oxidative phosphorylation in naïve macrophages and with an inhibition of glycolysis in pro-inflammatory macrophages. The aforementioned effects resulted in an increase in M2-like macrophages, which could be reverted by the addition of L-arginine. RNA-seq analysis confirmed alterations in arginase-associated pathways associated with miR-21 antagonism. In conclusion, miR-21 is overexpressed in murine and human CAV, and its targeting delays CAV onset by reprogramming macrophages metabolism.