Search Results (106)

Fibroblast growth factor receptor 2 (FGFR2) fusions are identified in approximately 10–16% of patients with intrahepatic cholangiocarcinoma (iCCA) and represent actionable targets, with several FGFR inhibitors approved for clinical use. To evaluate the clinical utility and assay performance of an amplicon-based next-generation sequencing (NGS) approach in this setting, we assessed FGFR2 fusion detection using the Oncomine Comprehensive Assay Plus (OCA-P). A total of 75 formalin-fixed paraffin-embedded (FFPE) specimens from biliary, pancreatic, and ampullary malignancies submitted for FGFR2 fusion testing between 1 March 2023 and 30 June 2024 were retrospectively analyzed, including 40 cases of iCCA. All iCCA specimens were successfully analyzed. FGFR2 fusions were detected exclusively in iCCA, yielding a detection rate of 20%. RNA concentrations in iCCA specimens ranged from 0.02 ng/µL to 104 ng/µL; six cases (15%) exhibited yields below 1 ng/µL and 10 cases (25%) ranged between 1 and 2 ng/µL. Despite limited RNA input, OCA-P demonstrated robust performance, successfully identifying FGFR2 fusions at concentrations below 2 ng/µL, levels typically considered suboptimal for partner-agnostic NGS approaches. These findings support the robustness and clinical utility of the OCA-P assay for reliable FGFR2 fusion detection in iCCA, particularly in specimens with limited RNA input. Full article

Skeletal muscle regeneration depends on coordinated transitions of muscle stem cells (MuSCs), also known as satellite cells, from quiescence through activation and proliferative expansion to differentiation and fusion, while self-renewal replenishes the quiescent MuSC pool within a dynamically remodeled niche. Fibroblast growth factor (FGF) signaling regulates these transitions, but its effects vary as MuSCs and their niche change across regenerative stages. FGF output is shaped by ligand availability and extracellular presentation, fibroblast growth factor receptor (FGFR) isoform expression and coreceptor availability, receptor trafficking, intracellular feedback, and the state of the responding cell. Following acute injury, FGF inputs can support MuSC activation and expansion; signaling is subsequently reconfigured during differentiation, fusion, self-renewal, and return to quiescence. Aging-associated regenerative decline, chronic injury and dystrophic remodeling, denervation, and metabolic dysfunction disrupt this coordination and can uncouple FGF activity from productive repair. Rhabdomyosarcoma provides a distinct malignant context in which the FGF network is rewired to sustain oncogenic myogenic cell states. Here, we integrate molecular, cellular, and niche-level evidence across these settings to explain why FGF signaling produces divergent outcomes and to clarify how cellular context and timing should inform therapeutic modulation. Full article

Gastrointestinal (GI) cancers represent a diverse group of malignancies that remain a major cause of cancer-related morbidity and mortality worldwide. Their management is increasingly complex, reflecting differences in tumor biology, anatomical location, stage, and molecular profile. In recent years, advances in molecular diagnostics, immunotherapy, and targeted treatment have moved clinical decision-making beyond a purely organ- and stage-based approach toward more individualized, biomarker-guided care. This narrative review summarizes established and emerging biological and targeted therapies used in esophageal, gastric and gastroesophageal junction, colorectal, pancreatic, hepatocellular, and biliary tract cancers. It focuses on immune checkpoint inhibitors targeting PD-1, PD-L1, and CTLA-4; HER2-directed monoclonal antibodies and antibody–drug conjugates; antiangiogenic and anti-EGFR therapies; and newer strategies involving CLDN18.2, FGFR2b, and tumor-agnostic alterations such as NTRK fusions. The review also considers the predictive biomarkers used to guide treatment selection and the growing integration of systemic therapy with surgery in neoadjuvant, perioperative, adjuvant, and conversion settings. However, clinical efficacy alone does not determine whether new treatments become part of routine practice. Regulatory approval, reimbursement, access to molecular testing, and the availability of specialized multidisciplinary care are equally important. The rapidly evolving treatment landscape for GI cancers therefore requires clinical decisions that account for tumor biology, anatomical resectability, molecular eligibility, expected benefit, treatment-related toxicity, and local access to therapy. Expanding access to comprehensive biomarker testing and effective molecularly guided treatments will be essential to translate progress in precision oncology into more personalized and equitable care for patients with GI cancers. Full article

Soft tissue sarcomas (STSs) are a heterogeneous group of rare mesenchymal malignancies with overlapping morphological and immunohistochemical features, often making definitive diagnosis challenging. Recent advances in next-generation sequencing (NGS) have enabled the identification of recurrent molecular alterations that contribute to tumor classification, prognostic stratification, and precision oncology approaches. This retrospective study aimed to evaluate the diagnostic and clinical impact of molecular profiling in pediatric soft tissue sarcomas using the Oncomine Childhood Cancer Research Assay (OCCRA) panel. Fifty-five frozen tumor samples representing 24 distinct soft tissue sarcoma subtypes were obtained from the Pediatric Oncology Institute -IOP/GRAACC/UNIFESP Biobank (B-053). Molecular analysis was performed using NGS to identify gene fusions, single nucleotide variants (SNVs), copy number variations (CNVs), and insertions/deletions (InDels). Clinically relevant molecular alterations were identified in 70% (37/55) of cases, including 18 fusion transcripts, 13 SNVs, 8 CNVs, and 6 InDels. Recurrent and diagnostically relevant alterations included BCOR::CCNB3, ASPSCR1::TFE3, NFR1::BRAF, FUS::DDIT3, EML4::NTRK3, ETV6::NTRK3, CIC::DUX4, NAB2::STAT6 and SS18::SSX1/2 fusions, as well as amplifications involving PDGFRA, FGFR1, GLI1, CDK4, ERBB3, and KIT. Pathogenic variants affecting genes involved in tumor suppression and chromatin remodeling, including TP53, NF1, DICER1, SMARCA4, PTEN, and PIK3CA, were also detected. Importantly, molecular profiling had significant diagnostic impact in several histologically ambiguous tumors, enabling molecular reclassification and refinement of previously inconclusive or inaccurate pathological diagnoses. In multiple cases, NGS transformed descriptive histopathological interpretations into genetically defined sarcoma entities, including NTRK-rearranged spindle cell neoplasms, CIC-rearranged sarcomas, synovial sarcoma, low-grade fibromyxoid sarcoma, and clear cell sarcoma. Furthermore, the identification of actionable alterations highlighted potential opportunities for targeted therapies and precision medicine approaches. Our findings demonstrate that comprehensive molecular profiling significantly enhances diagnostic accuracy in pediatric soft tissue sarcomas, particularly in morphologically challenging cases. The integration of NGS into routine sarcoma diagnostics enables biologically informed tumor classification and supports personalized therapeutic strategies. Full article

Background: Myeloid/lymphoid neoplasms with FGFR1 rearrangement (MLN-FGFR1), also known as 8p11 myeloproliferative syndrome, are rare and aggressive hematologic malignancies arising from pluripotent stem cells. The FGFR1::ZMYM2 fusion resulting from t(8;13)(p11.2;q12) characteristically co presents as T-lymphoblastic lymphoma in lymph nodes alongside a myeloproliferative neoplasm in the bone marrow. The disease is resistant to tyrosine kinase inhibitors and conventional chemotherapy, and carries a median survival of less than 12 months without allogeneic hematopoietic stem cell transplantation (allo-HSCT). Case Presentation: We report a 23-year-old female who presented with progressive cervical lymphadenopathy and hyperleukocytosis (WBC 186.6 K/μL). Excisional lymph node biopsy demonstrated T-cell acute lymphoblastic lymphoma (T-ALL) with eosinophilic infiltration; immunohistochemistry confirmed lymphoblasts positive for CD1a, CD2, CD3, CD4, CD5, CD7, CD8, and TdT. Concurrent bone marrow biopsy showed a myeloproliferative neoplasm without excess blasts. Chromosomal analysis confirmed t(8;13)(p11.2;q12) with FGFR1::ZMYM2 rearrangement, and NGS identified a concurrent CSF3R variant (Q741*). She received induction chemotherapy per the PEDS AALL1231 protocol (Arm A) followed by consolidation, with a course complicated by hyperleukocytosis, venous thromboembolism, E. coli bacteremia, and severe mucositis requiring PICU admission. Despite initial response, the disease progressed to acute myeloid leukemia (AML) with acquisition of a PTEN variant; the patient was offered but did not complete allo-HSCT and died of refractory AML approximately 10 months after diagnosis. Conclusions: This case highlights the aggressive clinical course and diagnostic challenges of MLN-FGFR1, a rare stem cell-derived myeloid/lymphoid neoplasm. To our knowledge, this appears to be the first reported case documenting sequential CSF3R and PTEN variant acquisition with complete follow-up through fatal AML transformation, and the first to describe treatment with a pediatric ALL induction protocol (PEDS AALL1231) in this setting. The characteristic histomorphologic pattern of eosinophil-rich T-ALL in lymph nodes with concurrent myeloproliferative neoplasm in bone marrow should prompt immediate molecular workup. Allo-HSCT must be pursued urgently at diagnosis, as complications rapidly narrow the transplant window and the disease is uniformly fatal without it. Full article

Apert syndrome is a rare genetic disorder characterized by premature fusion of the cranial sutures, syndactyly of the extremities, and distinct craniofacial deformities. The condition results from mutations in the FGFR2 gene, which disrupt normal craniofacial growth and lead to complex functional and morphological abnormalities. Patients with Apert syndrome commonly present with stomatognathic abnormalities, which significantly affect oral function and facial development. The management of Apert syndrome requires a multidisciplinary therapeutic approach. Surgical treatment strategies are typically staged according to the patient’s age and clinical severity. Early interventions focus on cranial vault expansion procedures, such as fronto-orbital advancement and posterior vault distraction osteogenesis, aiming to relieve intracranial pressure and improve cranial morphology. During childhood and adolescence, midface advancement techniques are commonly performed to address midfacial hypoplasia and associated functional impairments. Early diagnosis and appropriate surgical planning play a crucial role in preventing complications and improving the functional, aesthetic, and psychosocial outcomes of patients with Apert syndrome. This narrative review summarizes current evidence while highlighting areas of ongoing controversy, particularly regarding surgical sequencing, orthodontic management and the integration of digital technologies into multidisciplinary care. Full article

Cholangiocarcinoma (CCA) is an aggressive and molecularly heterogeneous malignancy characterized by a profoundly immunosuppressive tumor microenvironment (TME) and historically limited therapeutic options. Recent advances have redefined the treatment paradigm, with phase III trials establishing chemoimmunotherapy as a standard of care and multi-omic profiling elucidating the interplay between tumor genomics, stromal architecture, and immune regulation. Despite these gains, durable clinical benefit remains confined to a minority of patients, reflecting convergent mechanisms of primary and acquired resistance—including immune exclusion, myeloid-dominant suppression, and genotype-driven “cold” tumor states. In this review, we synthesize emerging insights into the immune landscape of CCA, integrating data from single-cell, spatial, and translational studies to define the cellular and molecular circuits governing immune evasion. Beyond canonical biomarkers such as mismatch repair and microsatellite status, we highlight how spatial organization of immunity—in particular, tertiary lymphoid structures, dynamic myeloid and stromal interactions, and pathway-level features—shape immunotherapy responsiveness. We also examine how tumor-intrinsic alterations, including IDH1 mutation, FGFR2 fusions, KRAS activation, and MTAP loss, define distinct immunologic phenotypes with direct implications for immunotherapeutic response and biomarker-driven patient selection. We evaluate the expanding clinical trial landscape of immunotherapy in CCA and more broadly in BTC, including adoptive cell therapies and cancer vaccines. Together, these advances position CCA as a paradigm of how tumor genotype and microenvironment co-evolve to define immunotherapy sensitivity and resistance. Full article

Fibroblast growth factor receptor 2 (FGFR2) inhibitors such as pemigatinib are targeted therapies for cholangiocarcinoma with FGFR2 alterations. While generally well tolerated, they are associated with unique adverse events. Calciphylaxis, a potentially fatal vascular calcification disorder, is a rare complication. We present a 43-year-old woman with metastatic intrahepatic cholangiocarcinoma harboring an FGFR2 fusion who developed calciphylaxis after seven months of pemigatinib therapy. Despite drug discontinuation, antibiotics, and multidisciplinary supportive care, she deteriorated rapidly and died from sepsis and advanced disease. Histopathological analysis confirmed dermal and vascular calcifications consistent with calciphylaxis. This case highlights the importance of early recognition of cutaneous lesions in patients on FGFR inhibitors. Prompt cessation of therapy, management of metabolic derangements, and consideration of sodium thiosulfate may be lifesaving. Full article

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy, with rising incidence and a 5-year survival rate of 13%. Late presentation, early metastasis, and intrinsic resistance constrain the efficacy of cytotoxic chemotherapy, which remains the backbone of PDAC treatment, with only modest survival gains and resistance nearly universal. Although KRAS mutations dominate tumour biology (~90% of cases), PDAC is a heterogeneous disease with distinct molecular subtypes that confer differential therapeutic vulnerabilities. Advances in comprehensive molecular profiling have catalysed a paradigm shift toward precision oncology in PDAC. In KRAS-mutant PDAC, mutation-specific inhibitors have established proof-of-concept, particularly in KRAS G12C disease, while next-generation approaches including KRAS G12D inhibitors, RAS-“ON” inhibitors, proteolysis-targeting chimeras (PROTACs), and KRAS-targeted vaccine strategies are expanding the therapeutic landscape. Combination strategies targeting upstream and downstream effectors of the RAS–MAPK pathway are also being explored to enhance the depth and durability of response. In parallel, KRAS-wild-type PDAC has emerged as a molecularly distinct subgroup enriched for rare but actionable alternative oncogenic fusion drivers including NRG1, NTRK, RET, ALK, and FGFR. Additional molecularly directed strategies targeting HER2 alterations, BRAF mutations, EGFR-dependent signalling, and tumour-selectively exposed surface antigens such as CLDN18.2 are under investigation across PDAC irrespective of KRAS mutation status. Synthetic lethal approaches, including targeting the PRMT5/CDKN2A/MTAP axis, represent a further emerging therapeutic strategy. Germline homologous recombination repair defects, particularly involving BRCA1/2 and PALB2, further define clinically important subsets with sensitivity to platinum chemotherapy and PARP inhibition. This review summarises current and emerging targeted and molecularly directed therapeutic strategies in PDAC, emphasising the importance of molecular stratification and recent advances shaping precision oncology in this historically treatment-refractory disease. Full article

Pancreatic ductal adenocarcinoma (PDAC) and biliary tract cancers (BTCs) remain highly lethal gastrointestinal malignancies because of late presentation, marked molecular heterogeneity, and limited durable benefit from conventional systemic therapy. This narrative review summarizes recent advances in both diseases, focusing on practice-informing clinical trials, biomarker-driven treatment strategies, and translational insights into tumor biology and resistance. In PDAC, progress includes refinement of perioperative management, broader germline and somatic testing, recognition of DNA damage repair-deficient subsets, and development of KRAS-directed therapies and rational combination strategies. In BTCs, especially intrahepatic cholangiocarcinoma, comprehensive molecular profiling has expanded precision oncology through actionable alterations such as FGFR2 rearrangements, IDH1 mutations, HER2 amplification/overexpression, BRAF V600E, NTRK fusions, and MSI-high/dMMR status. Immunotherapy has a clearer role in selected BTC populations, whereas in PDAC benefit remains largely restricted to rare biomarker-defined subsets. Across both diseases, circulating tumor DNA is emerging as a promising tool for prognostication, minimal residual disease assessment, response monitoring, and early resistance detection. Contemporary care increasingly depends on early molecular profiling, individualized treatment sequencing, and integration of targeted therapies, biomarker-guided immunotherapy, and clinical trials. Full article

Background: Achondroplasia, the most common genetic dwarfism caused by the FGFR3 mutation (autosomal dominant, 80% de novo), results in a disproportionately short stature. Thoracolumbar kyphosis (TLK), combined with characteristic spinal canal stenosis, increases the risk of symptomatic compression, yet the literature lacks clear thresholds for symptom onset or progressive deformity angles. Methods: A 16-year-old female with achondroplasia presented with rapidly progressive kyphosis despite conservative management (bracing and therapy). Over six months, she developed neurogenic claudication; bilateral leg pain; weakness; and paresthesia that worsened with standing/walking, which was relieved by flexion/sitting. Imaging demonstrated surgical-threshold kyphosis with progressive spinal misalignment. Her symptoms indicated compressive myeloradiculopathy from lumbar stenosis, critical given achondroplasia’s congenitally narrowed canal and heightened neurologic vulnerability. Results: Staged surgery planned: Posterior fusion T6-L4 with pedicle screws and then extensive decompression (laminectomy/foraminotomy T11-L3), L1 corpectomy with expandable titanium cage, and Ponte osteotomies. Intraoperative complications included a malpositioned left T10 screw breaching the anterior/lateral cortex near the aorta, requiring urgent revision. Postoperatively: Neurogenic bladder, wound leakage, and E. coli urinary tract infection (UTI) with fever (treated with IV antibiotics). After infection resolution, definitive surgery removed the malpositioned screw and completed decompression, corpectomy, cage placement, bone grafting, and osteotomies, successfully resolving neurological symptoms. However, 13 cm trunk lengthening caused severe functional impairment—disproportionately short arms prevented independent toileting and dressing. Left arm lengthening via external fixation restored partial function. At 2.5-year follow-up, there was solid fusion, no neurological deficits, and improved quality of life. Conclusions: Surgery addresses severe TLK, vertebral wedging, and neurogenic claudication in achondroplasia. Vertebral column resection effectively corrects TLK and neurological deficits but carries a high complication risk. This should be reserved for severe TLK with hypoplastic vertebrae, performed by experienced surgeons. Critically, correction magnitude must preserve limb–trunk proportions to prevent functional disability, as excessive lengthening may necessitate additional limb procedures for independence restoration. Full article

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare lung malignancy characterized by an aggressive clinical course and an unfavorable prognosis. Next-generation sequencing (NGS) has revealed that LCNECs exhibit molecular features resembling either small-cell lung carcinoma (SCLC-like LCNEC) or non-small cell lung carcinoma (NSCLC-like LCNEC). This study aimed to characterize the incidence of actionable gene variants in a retrospective cohort of LCNEC patients using a targeted NGS approach. Microscopic diagnosis was established according to the 2021 World Health Organization (WHO) classification using a standard immunohistochemical (IHC) panel. In total, 216 LCNEC tumor samples were analyzed for molecular variants in 17 genes using the RNA-based Archer FusionPlex Lung NGS assay (Integrated DNA Technologies, USA) and the MiSeq platform (Illumina, USA)—an algorithm utilized for routine NSCLC diagnosis. Overall, 46 variants were identified in 46/216 (21.3%) tumor samples, with 28/216 (13%) LCNECs harboring at least one actionable molecular variant potentially targetable by registered or investigational agents. KRAS variants (5%; including G12C at 2%) and PIK3CA variants (5%) were the most prevalent, followed by RET single-nucleotide variants (3%), uncommon EGFR variants (1%), and BRAF class II and III variants (<1%). Notably, no classical EGFR exon 18–21 mutations nor ALK, FGFR1/2/3, or ROS1 alterations (mutations or fusions) were detected, despite the technical capability of the assay to identify such variants. A novel in-frame gene fusion (TMEM79::NTRK1) was identified in a single tumor sample (0.5%). Our results confirm that LCNECs harbor potentially targetable alterations in KRAS, PIK3CA, RET, BRAF, and NTRK1, albeit at lower frequencies than those typically observed in NSCLC. Full article

From an epidemiological perspective, polymorphous low-grade neuroepithelial tumor (PLNTY) represents a small proportion of brain tumors encountered in epilepsy surgery series. Their rarity and relatively recent recognition likely contribute to underdiagnosis and poor prognosis. In terms of histopathological features, they are similar to oligodendrogliomas. Molecular analyses can be used to show the fusion between fibroblast growth factor receptor (FGFR3) and transforming acidic coiled coil (TACC) proteins, which most commonly results in progression towards glioblastoma (GBM). We report a case of a 62-year-old man who underwent left frontal craniotomy to remove a frontal mass. Histologically, the glial lesion consisted of elements associated with oligodendroglia-like features. Immunohistochemistry was positive for glial fibrillary acidic protein (GFAP), oligodendrocyte transcription factor 2 (OLIG2), and α-thalassemia X-linked mental retardation syndrome (ATRX) nuclear expression, but negative for isocitrate dehydrogenase 1 (IDH1) and BRAF-V600E. Next-generation sequencing showed the FGFR-TACC3 fusion, and taken together, these findings supported the final diagnosis of PLNTY. During follow-up, the patient underwent a second neurosurgery, where histological evaluation indicated a GMB. This article presents clinical and radiological data, morphology, immunohistochemistry, molecular features, and treatment to enhance the clinical and pathological understanding of PLNTY with FGFR3-TACC3 fusion for all professionals involved in medical decisions. Full article

Rhabdomyosarcoma is a small round-cell soft tissue tumor that occurs mainly in pediatric and adolescent/young adult (AYA) patients but also rarely in adults. Multidisciplinary treatments including multidrug therapy and local therapy (surgery and/or radiation) are the current standard of care, and treatment strategies are determined according to the estimated risk based on the patient’s age, site of onset, and histologic type, as well as the disease stage. New treatment developments in recent years have been based on risk; lower cumulative doses of alkylating agents to reduce late toxicity for low-risk patients are being studied, and long-term maintenance therapy or the addition of new drugs inhibitors to standard multidisciplinary therapy for intermediate- to high-risk patients have been investigated. For high-risk and metastatic patients, novel molecular targeted drug candidates are being evaluated. The target candidates for rhabdomyosarcoma have included the RAS-signaling pathway, ALK, NTRK, FGFR, and MSI-High. In addition, fusion genes (e.g., PAX3/7-FOXO1), which play an important role in diagnostic and prognostic factors, are also being investigated as potential therapeutic targets as their underlying backgrounds are gradually becoming clear. This review summarizes the overall picture of the development of novel therapies for rhabdomyosarcoma and discusses the direction that should be taken in the future. Full article

Fibroblast growth factor receptor 2 (FGFR2) rearrangements represent one of the most actionable molecular alterations in biliary tract cancer, particularly in intrahepatic cholangiocarcinoma (iCCA). Approximately 10–16% of iCCA cases harbor FGFR2 fusions or rearrangements, defining a distinct molecular subtype characterized by sensitivity to FGFR-targeted therapies. Selective FGFR tyrosine kinase inhibitors, including the reversible inhibitor pemigatinib and the irreversible inhibitor futibatinib, have demonstrated clinically meaningful response rates and durable disease control in patients with previously treated FGFR2-altered iCCA, leading to regulatory approvals and the incorporation of FGFR inhibition into contemporary treatment paradigms. However, the development of acquired resistance—most commonly driven by secondary kinase-domain mutations and activation of bypass signaling pathways—remains a major limitation to sustained therapeutic benefit. This review summarizes the biological basis of FGFR2 alterations, highlights current clinical evidence supporting FGFR inhibition, and discusses the evolving landscape of resistance mechanisms. We further examine emerging therapeutic strategies aimed at overcoming resistance, including next-generation FGFR inhibitors and rational combination approaches. In addition, we highlight the growing role of circulating tumor DNA as a noninvasive tool for longitudinal molecular monitoring and treatment guidance. Together, these insights underscore the central role of FGFR2-directed therapy in precision oncology for biliary tract cancer and provide a framework for optimizing and extending targeted treatment in this molecularly defined disease subset. Full article