Prognostic value of FGFR2 alterations in patients with iCCA undergoing surgery or systemic treatments: A meta-analysis.

BACKGROUND: Over recent years, there has been a notable rise in the incidence of intrahepatic cholangiocarcinoma (iCCA), which presents a significant challenge in treatment due to its complex disease characteristics and prognosis. Notably, the identification of fibroblast growth factor receptor 2 (FGFR2) fusion/rearrangement, a potential oncogenic driver primarily observed in iCCA, raises questions about its impact on the prognostic outcomes of patients undergoing surgical intervention or other therapeutic approaches. METHODS: A comprehensive search from inception to July 2023 was conducted across PubMed, Embase, Web of Science, and the Cochrane Library databases. The objective was to identify relevant publications comparing the prognosis of FGFR2 alterations and no FGFR2 alterations groups among patients with iCCA undergoing surgical resection or other systemic therapies. The primary outcome indicators, specifically Overall Survival (OS) and Disease-Free Survival (DFS), were estimated using Hazard Ratios (HRs) with 95% confidence intervals (CIs), and statistical significance was defined as p < .05. Study quality was assessed using the Newcastle-Ottawa Quality Assessment Scale. Statistical analyses were performed using Review Manager 5.4 software and Stata, version 12.0. RESULTS: Six studies, involving 1314 patients (FGFR2 alterations group n = 173 and no FGFR2 alterations group n = 1141), were included in the meta-analysis. The analysis revealed that the FGFR2 alterations group exhibited a significantly better OS prognosis compared to the no FGFR2 alterations group, with a fixed-effects combined effect size HR = 1.31, 95%CI = 1.001-1.715, p = .049. Furthermore, meta-regression and subgroup analysis showed that the length of the follow-up period did not introduce heterogeneity into the results. This finding indicates the stability and reliability of the study outcomes. CONCLUSION: The current study provides compelling evidence that FGFR2 alterations are frequently associated with improved survival outcomes for patients with iCCA undergoing surgical resection or other systemic treatments. Additionally, the study suggests that FGFR2 holds promise as a safe and dependable therapeutic target for managing metastatic, locally advanced or unresectable iCCA. This study offers a novel perspective in the realm of targeted therapy for iCCA, presenting a new and innovative approach to its treatment.

Elucidating the Role of Wildtype and Variant FGFR2 Structural Dynamics in (Dys)Function and Disorder.

The fibroblast growth factor receptor 2 (FGFR2) gene is one of the most extensively studied genes with many known mutations implicated in several human disorders, including oncogenic ones. Most FGFR2 disease-associated gene mutations are missense mutations that result in constitutive activation of the FGFR2 protein and downstream molecular pathways. Many tertiary structures of the FGFR2 kinase domain are publicly available in the wildtype and mutated forms and in the inactive and activated state of the receptor. The current literature suggests a molecular brake inhibiting the ATP-binding A loop from adopting the activated state. Mutations relieve this brake, triggering allosteric changes between active and inactive states. However, the existing analysis relies on static structures and fails to account for the intrinsic structural dynamics. In this study, we utilize experimentally resolved structures of the FGFR2 tyrosine kinase domain and machine learning to capture the intrinsic structural dynamics, correlate it with functional regions and disease types, and enrich it with predicted structures of variants with currently no experimentally resolved structures. Our findings demonstrate the value of machine learning-enabled characterizations of structure dynamics in revealing the impact of mutations on (dys)function and disorder in FGFR2.

Ser252Trp mutation in fibroblast growth factor receptor 2 promotes branching morphogenesis in mouse salivary glands.

OBJECTIVES: The purpose of this study was to perform morphological and immunohistochemical (IHC) analysis of the submandibular glands (SMGs) in early development in Apert syndrome model mice (Ap mice). METHODS: ACTB-Cre homozygous mice were mated with fibroblast growth factor receptor 2 (Fgfr2+/Neo-S252W) mice; ACTB-Cre heterozygous mice (ACTB-Cre mice) at embryonic day (E) 13.5 served as the control group, and Fgfr2+/S252W mice (Ap mice) served as the experimental group. Hematoxylin and eosin (H&E) staining was performed on SMGs; Total SMG area and epithelial area were determined, and the epithelial occupancy ratio was calculated. Immunostaining was performed to assess the localization of FGF signaling-related proteins. Next, bromodeoxyuridine (BrdU)-positive cells were evaluated to assess cell proliferation. Finally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess apoptosis in SMGs. RESULTS: The epithelial occupancy ratio was significantly higher in SMGs of Ap mice compared with that in SMGs of controls. FGF7 and bone morphogenetic protein 4 (BMP4) exhibited different localizations in SMGs of Ap mice compared with SMGs of controls. Cell proliferation was higher in SMGs of Ap mice compared with that of controls; however, apoptosis did not different significantly between the two groups. CONCLUSION: Our results suggest that enhanced FGF signaling conferred by missense mutations in FGFR2 promotes branching morphogenesis in SMGs of Ap mice.

Decoupling the dynamic mechanism revealed by FGFR2 mutation-induced population shift.

The fibroblast growth factor receptor 2 (FGFR2) is a key component in cellular signaling networks, and its dysfunctional activation has been implicated in various diseases including cancer and developmental disorders. Mutations at the activation loop (A-loop) have been suggested to trigger an increased basal kinase activity. However, the molecular mechanism underlying this highly dynamic process has not been fully understood due to the limitation of static structural information. Here, we conducted multiple, large-scale Gaussian accelerated molecular dynamics simulations of five (K659E, K659N, K659M, K659Q, and K659T) FGFR2 mutants at the A-loop, and comprehensively analyzed the dynamic molecular basis of FGFR2 activation. The results quantified the population shift of each system, revealing that all mutants had a higher proportion of active-like states. Using Markov state models, we extracted the representative structure of different conformational states and identified key residues related to the increased kinase activity. Furthermore, community network analysis showed enhanced information connections in the mutants, highlighting the long-range allosteric communication between the A-loop and the hinge region. Our findings may provide insights into the dynamic mechanism for FGFR2 dysfunctional activation and allosteric drug discovery.Communicated by Ramaswamy H. Sarma.

Treatment of gastric adenocarcinoma: A rapidly evolving landscape.

Gastric adenocarcinoma (GC) and gastroesophageal junction adenocarcinoma represent frequent and severe diseases whose management has radically changed over the last 10 years. With the advent of second- and third-line standard therapies for metastatic GC patients in the 2010s, the molecular dismemberment of the disease and positive trials with immunotherapy and targeted agents will mark the 2020s. New treatment options have emerged in the neoadjuvant, adjuvant, and metastatic setting. In addition to improved multimodal treatment in operable patients, new subgroups have emerged depending on molecular alterations (HER2, Microsatellite instability) or expression of specific proteins in the tumour (PDL1, Claudin 18.2) making immunohistochemistry central in profiling the tumour for an optimal individualised management. The aim of this review is to describe the current standards of management of early and late stage GC and the molecular markers needed today to optimally manage our patients together with future perspectives on this disease.

MicroRNA-125a-3p Modulate Amyloid ß-Protein through the MAPK Pathway in Alzheimer's Disease.

BACKGROUND: MicroRNA (miR)-125a-3p is reported to play an important role in some central nervous system diseases, such as Alzheimer's disease (AD). However, a study has not been conducted on the mechanism of miR-125a-3p in the pathological process of AD. METHODS: First, we assessed the expression of miR-125a-3p in AD cohort. Subsequently, we altered the expressions of miR-125a-3p to assess its role in cell viability, cell apoptosis, amyloid-ß (Aß) metabolism, and synaptic activity. Finally, we identified its potential mechanism underlying AD pathology. RESULTS: This study unveiled the potential function of miR-125a-3p through modulating amyloid precursor protein processing. Additionally, miR-125a-3p influenced cell survival and activated synaptic expression through the modulation of Aß metabolism in the mitogen-activated protein kinase (MAPK) pathway via fibroblast growth factor receptor 2. CONCLUSION: Our study indicates that targeting miR-125a-3p may be an applicable therapy for AD in the future. However, more in vitro and in vivo studies with more samples are needed to confirm these results.

Functional Distinctions of Endometrial Cancer-Associated Mutations in the Fibroblast Growth Factor Receptor 2 Gene.

Functional analysis of somatic mutations in tumorigenesis facilitates the development and optimization of personalized therapy for cancer patients. The fibroblast growth factor receptor 2 (FGFR2) gene is frequently mutated in endometrial cancer (EC), but the functional implications of FGFR2 mutations in cancer development remain largely unexplored. In this study, we introduced a reliable and readily deployable screening method to investigate the effects of FGFR2 mutations. We demonstrated that distinct mutations in FGFR2 can lead to differential downstream consequences, specifically affecting a disintegrin- and metalloprotease 17 (ADAM17)-dependent shedding of the epidermal growth factor receptor (EGFR) ligand heparin-binding EGF-like growth factor (HB-EGF) and phosphorylation of mitogen-activated protein kinases (MAPKs). Furthermore, we showed that the distribution of mutations within the FGFR2 gene can influence their oncogenic effects. Together, these findings provide important insights into the complex nature of FGFR2 mutations and their potential implications for EC. By unraveling the distinct effects of different mutations, our study contributes to the identification of personalized treatment strategies for patients with FGFR2-mutated cancers. This knowledge has the potential to guide the development of targeted therapies that specifically address the underlying molecular alterations associated with FGFR2 mutations, ultimately improving patient outcomes in EC and potentially other cancer types characterized by FGFR2 mutations.

Molecular Detection of FGFR2 Rearrangements in Resected Intrahepatic Cholangiocarcinomas: FISH Could Be An Ideal Method in Patients with Histological Small Duct Subtype.

Background and Aims: Intrahepatic cholangiocarcinoma (ICC) is a subtype of primary liver cancer for which effective therapeutic agents are lacking. Fibroblast growth factor receptor 2 (FGFR2) has become a promising therapeutic target in ICC; however, its incidence and optimum testing method have not been fully assessed. This study investigated the rearrangement of FGFR2 in intrahepatic cholangiocarcinoma using multiple molecular detection methods. Methods: The samples and clinical data of 167 patients who underwent surgical resection of intrahepatic cholangiocarcinoma in Zhongshan hospital, Fudan university were collected. The presence of FGFR2 gene rearrangement was confirmed using fluorescence in situ hybridization (FISH) and targeted next-generation sequencing (NGS). FGFR2 protein expression was determined using immunohistochemistry (IHC). The concordance between the methods was statistically compared. PD-L1 expression was also assessed in this cohort. The clinicopathological characteristics and genomic profile related to FGFR2 rearrangements were also analyzed to assist candidate-screening for targeted therapies. Results: FGFR2 rearrangement was detected in 21 of the 167 ICC cases (12.5%) using FISH. NGS analysis revealed that FGFR2 rearrangement was present in 16 of the 20 FISH-positive cases, which was consistent with the FISH results (kappa value=0.696, p<0.01). IHC showed that 80 of the 167 cases (48%) were positive for FGFR2 expression, which was discordant with both FISH and NGS results. By comparison, FGFR2-positivity tended to correlate with unique clinicopathological subgroups, featuring early clinical stage, histologically small duct subtype, and reduced mucus production (P<0.05), with improved overall survival (p<0.05). FGFR2-positivity was not associated with PD-L1 expression in ICCs. In genome research, we identified eight partner genes fused with FGFR2, among which FGFR2-BICC1 was the most common fusion type. BAP1, CDKN2A, and CDKN2B were the most common concomitant genetic alterations of FGFR2, whereas KRAS and IDH1 mutations were mutually exclusive to FGFR2 rearrangements. Conclusions: FISH achieved satisfactory concordance with NGS, has potential value for FGFR2 screening for targeted therapies. FGFR2 detection should be prioritized for unique clinical subgroups in ICC, which features a histological small duct subtype, early clinical stage, and reduced mucus production.

Intrahepatic cholangiocarcinoma with FGFR2 fusion gene positive that responded to pemigatinib and caused hypophosphatemia.

Intrahepatic cholangiocarcinoma is a condition with a poor prognosis. Traditionally, there was no cure unless important drugs such as gemcitabine, cisplatin, and tegafur/gimeracil/uracil potassium showed efficacy. Pemigatinib has recently become accessible for the treatment of intrahepatic cholangiocarcinoma with FGFR2 fusion or rearrangement gene abnormalities. Hyperphosphatemia is typically linked to pemigatinib. In the current case, pemigatinib was used to effectively treat a 48-year-old woman, and hypophosphatemia was observed. Patients with intrahepatic cholangiocarcinoma should undergo aggressive cancer multigene panel testing as well as careful monitoring of serum phosphorus levels.

Pemigatinib treatment for intrahepatic cholangiocarcinoma with FGFR2 fusion detected by a liquid comprehensive genomic profiling test.

The liquid CGP was useful for detecting FGFR2 fusion and the patient experienced typical side effects (nail disorders, hyperphosphatemia, and taste disorders) of pemigatinib that required treatment.

Paradigm shift of chemotherapy and systemic treatment for biliary tract cancer.

Biliary tract cancers (BTC) are frequently identified at late stages and have a poor prognosis due to limited systemic treatment regimens. For more than a decade, the combination of gemcitabine and cis-platin has served as the first-line standard treatment. There are few choices for second-line chemo-therapy. Targeted treatment with fibroblast growth factor receptor 2 inhibitors, neurotrophic tyrosine receptor kinase inhibitors, and isocitrate dehydrogenase 1 inhibitors has had important results. Immune checkpoint inhibitors (ICI) such as pembrolizumab are only used in first-line treatment for microsatellite instability high patients. The TOPAZ-1 trial's outcome is encouraging, and there are several trials underway that might soon put targeted treatment and ICI combos into first-line options. Newer targets and agents for existing goals are being studied, which may represent a paradigm shift in BTC management. Due to a scarcity of targetable mutations and the higher toxicity profile of the current medications, the new category of drugs may occupy a significant role in BTC therapies.

Overexpression of fibroblast growth factor receptor 2 in bone marrow mesenchymal stem cells enhances osteogenesis and promotes critical cranial bone defect regeneration.

Background: Reconstruction of cranial bone defects is one of the most challenging problems in reconstructive surgery, and several biological tissue engineering methods have been used to promote bone repair, such as genetic engineering of bone marrow mesenchymal stem cells (BMSCs). Fibroblast growth factor receptor 2 (Fgfr2) is an important regulator of bone construction and can be used as a potential gene editing site. However, its role in the osteogenesis process of BMSCs remains unclear. This article clarifies the function of Fgfr2 in BMSCs and explores the role of Fgfr2-overexpressed BMSCs carried by light-induced porous hydrogel (GelMA) in the repair of cranial bone defects. Methods: Lenti-virus was used to overexpress Fgfr2 in BMSCs, and cell counting kit-8, transwell, and flow cytometry assays were conducted to investigate the proliferation, migration, and characteristics. After 0, 3, 7, and 10 days of osteogenic or chondrogenic induction, the changes in osteogenic and chondrogenic ability were detected by real-time PCR, western blot, alkaline phosphatase staining, alizarin Red staining, and alcian blue staining. To investigate the viability of BMSCs carried by GelMA, calcein and propyl iodide staining were carried out as well. Finally, a critical cranial bone defect model was established in 6-week-old male mice and micro-computerized tomography, masson staining, and immunohistochemistry of OCN were conducted to test the bone regeneration properties of implanting Fgfr2-overexpressed BMSCs with GelMA in cranial bone defects over 6 weeks. Results: Overexpression of Fgfr2 in BMSCs significantly promoted cell proliferation and migration and increased the percentage of CD200+CD105+ cells. After osteogenic and chondrogenic induction, Fgfr2 overexpression enhanced both osteogenic and chondrogenic ability. Furthermore, in cranial bone defect regeneration, BMSCs carried by light-induced GelMA showed favorable biocompatibility, and Fgfr2-overexpressed BMSCs induced superior cranial bone regeneration compared to a normal BMSCs group and an untreated blank group. Conclusion: In vitro, Fgfr2 enhanced the proliferation, migration, and stemness of BMSCs and promoted osteogenesis and chondrogenesis after parallel induction. In vivo, BMSCs with Fgfr2 overexpression carried by GelMA showed favorable performance in treating critical cranial bone defects. This study clarifies the multiple functions of Fgfr2 in BMSCs and provides a new method for future tissue engineering.

FGFR2 mutations promote endometrial cancer progression through dual engagement of EGFR and Notch signalling pathways.

BACKGROUND: Mutations in the receptor tyrosine kinase gene fibroblast growth factor receptor 2 (FGFR2) occur at a high frequency in endometrial cancer (EC) and have been linked to advanced and recurrent disease. However, little is known about how these mutations drive carcinogenesis. METHODS: Differential transcriptomic analysis and two-step quantitative real-time PCR (qRT-PCR) assays were applied to identify genes differentially expressed in two cohorts of EC patients carrying mutations in the FGFR2 gene as well as in EC cells harbouring mutations in the FGFR2. Candidate genes and target signalling pathways were investigated by qRT-PCR assays, immunohistochemistry and bioinformatics analysis. The functional roles of differently regulated genes were analysed using in vitro and in vivo experiments, including 3D-orthotypic co-culture systems, cell proliferation and migration protocols, as well as colony and focus formation assays together with murine xenograft tumour models. The molecular mechanisms were examined using CRISPR/Cas9-based loss-of-function and pharmacological approaches as well as luciferase reporter techniques, cell-based ectodomain shedding assays and bioinformatics analysis. RESULTS: We show that common FGFR2 mutations significantly enhance the sensitivity to FGF7-mediated activation of a disintegrin and metalloprotease (ADAM)17 and subsequent transactivation of the epidermal growth factor receptor (EGFR). We further show that FGFR2 mutants trigger the activation of ADAM10-mediated Notch signalling in an ADAM17-dependent manner, highlighting for the first time an intimate cooperation between EGFR and Notch pathways in EC. Differential transcriptomic analysis in EC cells in a cohort of patients carrying mutations in the FGFR2 gene identified a strong association between FGFR2 mutations and increased expression of members of the Notch pathway and ErbB receptor family. Notably, FGFR2 mutants are not constitutively active but require FGF7 stimulation to reprogram Notch and EGFR pathway components, resulting in ADAM17-dependent oncogenic growth. CONCLUSIONS: These findings highlight a pivotal role of ADAM17 in the pathogenesis of EC and provide a compelling rationale for targeting ADAM17 protease activity in FGFR2-driven cancers.

Nintedanib induces apoptosis in human pterygium cells through the FGFR2-ERK signalling pathway.

AIM: To investigate whether nintedanib can inhibit pterygium cells through the fibroblast growth factor receptor 2 (FGFR2)/extracellular-signal-regulated kinase (ERK) pathway. METHODS: Human primary pterygium cells were cultured in vitro. After treatment with nintedanib, the cell morphology was observed under microscopy, the morphological changes of the nucleus were observed after DAPI staining, apoptosis was analyzed by Annexin-V FITC/PI double staining, and the changes of apoptosis-associated proteins were detected by Western blot. The binding ability of nintedanib to FGFR2 was predicted by molecular docking. Finally, by silencing FGFR2, we explored whether nintedanib inhibited FGFR2/ERK pathway. RESULTS: The results showed that nintedanib inhibited the growth of pterygium cells and caused nuclear pyknosis. The results of Annexin-VFITC/PI double staining showed that nintedanib was able to induce early and late apoptosis of pterygium cells, significantly increasing the expression of apoptosis-associated proteins Bax and cleaved-Caspase3 (P<0.05), and reducing the expression of Bcl-2 (P<0.05). In addition, nintedanib significantly inhibited ERK1/2 phosphorylation through FGFR2 (P<0.05). After silencing the expression of FGFR2, there was no significant difference in the inhibition of ERK1/2 phosphorylation by nintedanib (P>0.05). CONCLUSION: Nintedanib induces apoptosis of pterygium cells by inhibiting FGFR2/ERK pathway.

Expression levels of RUNX3 and FGFR2 in peripheral blood of severe acute pancreatitis and their clinical significance.

Purpose: Severe acute pancreatitis (SAP) is a life-threatening inflammatory syndrome of the pancreas. This study aimed to analyze the clinical significance of runt-associated transcription factor 3 (RUNX3) and fibroblast growth factor receptor 2 (FGFR2) expression alterations in SAP. Methods: This study included 18 SAP patients in Wuzhong People's Hospital from November 2019 to December 2021 and 18 healthy controls. RUNX3 and FGFR2 expression levels were determined by RT-quantitative PCR. Correlations between RUNX3/FGFR2 and sex, age, etiology, CRP, procalcitonin, AST, LDH, BUN, Acute Physiology and Chronic Health Evaluation II (APACHE II), Ranson score, Bedside Index for Severity in Acute Pancreatitis (BISAP) score, sequential organ failure assessment (SOFA), and modified computed tomography severity index (MCTSI) score were analyzed. Diagnostic values of RUNX3 and FGFR2 in SAP were analyzed using the receiver-operating characteristic curve. The binding of RUNX3 to FGFR2 was analyzed by chromatin immunoprecipitation. Results: RUNX3 and FGFR2 were downregulated in peripheral blood of SAP patients. RUNX3 and FGFR2 were negatively correlated with CRP, procalcitonin, AST, LDH, BUN, APACHE II score, Ranson score, BISAP score, SOFA score, and MCTSI score. Sensitivity and specificity of RUNX3 level of <0.9650 for SAP diagnosis were 88.89% and 72.22%, respectively. Sensitivity and specificity of FGFR2 level of <0.8950 for SAP diagnosis were 66.67% and 83.33%, respectively. RUNX3 was enriched in the FGFR2 promoter and was positively correlated with FGFR2. Conclusion: RUNX3 and FGFR2 were downregulated in peripheral blood of SAP patients and served as candidate biomarkers for SAP diagnosis. RUNX3 bound to the FGFR2 promoter to promote FGFR2 transcription.

Prognostic significance for recurrence of fibroblast growth factor receptor 2 in intrahepatic cholangiocarcinoma patients undergoing curative hepatic resection.

AIMS: The fibroblast growth factor receptor 2 (FGFR2) fusion gene is frequently found as a genetic abnormality in the FGFR pathway in patients with intrahepatic cholangiocarcinoma (ICC). The FGFR fusion protein, produced from the FGFR fusion gene, is thought to cause tumor cell growth. To date, there have been few reports on the relationship between pathologic FGFR2 expression and prognosis in patients who have undergone hepatectomy for ICC, and on the relationship between FGFR2 and tumor-infiltrating lymphocytes (TILs). METHODS AND RESULTS: We enrolled 92 patients who underwent hepatectomy for ICC and performed immunohistochemical staining for FGFR2 and cluster of differentiation 8, and hematoxylin and eosin staining for evaluating TILSs. The relationships between the FGFR2 and clinicopathological characteristics and outcomes were analyzed, and patients were classified into positive (n = 18) and negative (n = 74) FGFR2 groups. The FGFR2-positive group contained more men (p < 0.0001) and had lower serum albumin (p = 0.0355) and higher carcinoembryonic antigen (p = 0.0099). Furthermore, multivariable analyses revealed that the FGFR2-positive group had worse disease-free survival (DFS) (p = 0.0002). Multivariate analysis showed that the independent prognostic factors for DFS were maximum tumor size (≥5 cm) (p = 0.0011), tumor localization (perihilar type) (p = 0.0180), and FGFR2 positivity (p = 0.0029). There was no significant difference in TILs count between the two groups. CONCLUSION: We showed that FGFR2 high expression was an independent prognostic factor for recurrence of resected ICC.

Does subtyping of high-grade pulmonary neuroendocrine carcinomas have an impact on therapy selection?

Background: Small cell lung cancer (SCLC) and large cell neuroendocrine carcinomas (LCNEC) are characterized by a rapid progressive course. Therapy for SCLC has not much changed for decades, and in LCNEC controversies exist, favoring either SCLC-like or non-small cell lung cancer (NSCLC)-like therapy. Three subtypes of SCLC identified in cell cultures, namely ASCL1, NeuroD1, and POU2F3 have been confirmed by immunohistochemistry. The fourth type based on the expression of YAP1 was questioned, and another type, inflamed SCLC, was proposed. Methods: SCLC and LCNEC samples were investigated by immunohistochemistry for different subtypes. Additionally, immunohistochemical markers as potential tools to identify patients who might respond to targeted treatment were investigated. For validation a biopsy set was added. Results: ASCL1, NeuroD1, and POU2F3 were expressed in different percentages in SCLC and LCNEC. Similar percentages of expression were found in biopsies. ATOH was expressed in combination with one of the subtypes. YAP1 and TAZ were expressed in some SCLC and LCNEC cases. HES1 expression was seen in few cases. Predominantly stroma cells expressed programmed cell death ligand 1 (PD-L1). The dominant MYC protein was N-MYC. Aurora kinase A (AURKA) was expressed in the majority of both carcinomas, whereas fibroblast growth factor receptor 2 (FGFR2) in few. Conclusions: SCLC and LCNEC can be subtyped into ASCL1-, NeuroD1-, and POU2F3-positive types. AURKA expression and positivity for N-MYC protein was not associated with subtypes. AURKA and FGFR2 are both possible targets for inhibition in SCLC and LCNEC, but patients' selection should be based on expression of the enzyme. Combined chemo- and immunotherapy might be decided by PD-L1 staining of stroma cells.

Expression and clinical significance of FGFR1 and FGFR2 in laryngeal squamous cell carcinoma.

Background: Fibroblast growth factor receptor 1 (FGFR1) and fibroblast growth factor receptor 2 (FGFR2) may be of significance in the development of laryngeal squamous cell carcinoma (SCC) tissues. Examination of the expression results of these factors may offer new insights into treatment of the disease, such as genetic and histological targeted target therapy. Methods: We selected tissue from 30 cases of laryngeal SCC, 23 cases of adjacent normal mucosa, and 26 cases of benign laryngeal mucosal tissues from patients who received surgery at the Otolaryngology Department of the Affiliated Hospital of Chengde Medical College between September 2020 and January 2022. The laryngeal cancers included nine cases of supraglottic, 20 glottic (vocal cord), and one case of subglottic cancer, while all benign laryngeal mucosal lesions were obtained from vocal cord polyps. The expression of FGFR1 and FGFR2 was detected in 30 laryngeal cancers, 23 adjacent normal mucosa, and 26 vocal cord polyps by immunohistochemical technology [immunohistochemistry (IHC)], and the correlation analysis of their expression in laryngeal cancer was performed. P<0.05 was represented statistically significant. Results: The expression of FGFR1 and FGFR2 was significantly different in laryngeal SCC and the normal tissue >0.5 cm from the tumor margin (P<0.05), and between laryngeal SCC and vocal polyps (P<0.05). There was no difference in FGFR1 and FGFR2 expression (P>0.05) between normal mucosal margins and vocal cord polyp tissue, and no correlation between FGFR1 and FGFR2 in laryngeal SCC and sex, age, smoking history, alcohol consumption history, tumor diameter, tumor lymph node metastasis, tumor differentiation degree, and Tumor-Node-Metastasis (TNM) stage (P>0.05), A moderate positive correlation between FGFR1 expression and FGFR2 expression in laryngeal SCC was seen (Rs=0.499, P<0.01). Conclusions: FGFR1 and FGFR2 may participate in the occurrence of SCC of the throat: (I) positive FGFR1 and FGFR2 expressions are not associated with gender, age, smoking history, alcohol consumption history, tumor diameter, lymph node metastasis, degree of differentiation, or TNM stage. (II) FGFR2 increases successively with higher FGFR1 expression and with a positive correlation in laryngeal SCC.

Peritoneal Seeding Is More Common in Gastric Cancer Patients with FGFR2 Amplification or High Tumor Mutation Burden.

Fibroblast growth factor receptor-2 (FGFR2) gene alterations have been identified in solid tumors. FGFR2 amplification is found in 2−9% of gastric carcinomas. We hypothesized that FGFR2 could be associated with peritoneal seeding and studied 360 advanced gastric carcinoma patients; 222 (61.7%) were male, 246 (73.7%) had poorly differentiated histology, and 175 (48.6%) presented with peritoneal seeding. High tumor mutation burden (TMB) was observed in 44 (12.2%) patients, high microsatellite instability (MSI) was observed in 12 (3.33%) patients, ERBB2 amplification was observed in 44 (12.2%) patients, EBV positivity was observed in 10 (10/278; 3.6%) patients, and PD-L1 positivity was observed in 186 (186/264; 70.5%) cases. We found FGFR2 amplification in 26 (7.2%) patients, of which 12 (46.2%) were female and 22 (84.6%) had poorly differentiated histology. In these 26 cases, the copy number of FGFR2 amplification ranged from 3.7 to 274. Eighteen of them showed seeding, and this association was statistically significant (18/26, 69.2%; 157/334, 47%; p = 0.023). In addition, high TMB was significantly associated with seeding (p = 0.028; OR = 1.83). Poorly differentiated histology was significantly associated with seeding (p = 0.04) but not with FGFR2 amplification (p > 0.1). Seeding was frequent in gastric carcinoma patients with FGFR2 amplification, in patients with high TMB, or in those who were female. The subgroup of patients with FGFR2 amplification could be potential candidates for targeted therapeutic agents.