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The MET exon 14 skipping mutation is found in approximately 3–4% of non-small cell lung cancers (NSCLC). In 2020, the American Food and Drug Administration approved the first drug targeting this mutation. Capmatinib is a selective MET tyrosine kinase inhibitor. In the European Union, capmatinib is used when the patient needs further treatment after receiving immunotherapy or platinum-based chemotherapy, or both. In the described case, due to disease progression during treatment with pembrolizumab and then with platinum-based chemotherapy, next-generation sequencing was performed, which allowed for detection of the MET gene exon 14 skipping mutation. Targeted therapy with capmatinib was the only method of treatment resulting in a partial response to the disease and improvement of the patient’s quality of life. This case indicates the importance of detailed molecular diagnosis and selection of the optimal method of treatment to prolong survival of the patient with advanced NSCLC. Due to promising results of research conducted so far, in the future, selective MET tyrosine kinase inhibitors — capmatinib and tepotinib — may become the new standard of first-line treatment in NSCLC patients with the MET exon 14 skipping mutation. [ABSTRACT FROM AUTHOR]

Highlights: MET exon 14 skipping is an oncogenic targetable driver mutation in lung cancer. Two novel non-canonical splice site variants identified in MET genome. Predicted splicing strength using in silico splicing prediction tools. Tested routine cytological smear slides for RNA-based molecular diagnostics. RT-PCR and Sanger sequencing analysis confirmed MET exon 14 skipping. Simple Summary: Non-small Cell Lung cancer (NSCLC) contributes to 85% of total lung cancer diagnoses in the United States. With the discovery of various targetable genetic markers and FDA approval of drugs against these markers, genetic testing has become a routine part of the diagnosis and staging process of NSCLC. MET gain of function mutations have been of particular interest as FDA has recently approved two MET inhibitors for the treatment of NSCLC patients with MET exon 14 skipping (METex14) mutations. However, an effective workflow for the classification of various METex14 mutations in the clinical testing laboratory has not been explored. In this report, we reveal two novel METex14 variants and propose a cost-effective and robust workflow for molecular diagnosis of MET variants contributing to exon 14 skipping with the use of readily available specimen sources. Background and aims: The MET exon 14 skipping (METex14) is an oncogenic driver mutation that provides a therapeutic opportunity in non-small cell lung cancer (NSCLCs) patients. This event often results from sequence changes at the MET canonical splicing sites. We characterize two novel non-canonical splicing site variants of MET that produce METex14. Materials and Methods: Two variants were identified in three advanced-stage NSCLC patients in a next-generation sequencing panel. The potential impact on splicing was predicted using in silico tools. METex14 mutation was confirmed using reverse transcription (RT)-PCR and a Sanger sequencing analysis on RNA extracted from stained cytology smears. Results: The interrogated MET (RefSeq ID NM_000245.3) variants include a single nucleotide substitution, c.3028+3A>T, in intron 14 and a deletion mutation, c.3012_3028del, in exon 14. The in silico prediction analysis exhibited reduced splicing strength in both variants compared with the MET normal transcript. The RT-PCR and subsequent Sanger sequencing analyses confirmed METex14 skipping in all three patients carrying these variants. Conclusion: This study reveals two non-canonical MET splice variants that cause exon 14 skipping, concurrently also proposes a clinical workflow for the classification of such non-canonical splicing site variants detected by routine DNA-based NGS test. It shows the usefulness of in silico prediction to identify potential METex14 driver mutation and exemplifies the opportunity of routine cytology slides for RNA-based testing. [ABSTRACT FROM AUTHOR]

New treatments to improve quality of life and survival for castration-resistant prostate cancer patients with bone metastases are needed. We evaluated the safety and efficacy of the oral multikinase inhibitor TAS-115 in 50 patients. Overall, we observed improvements in bone metastasis and pain measures, and acceptable safety profiles with TAS-115. TAS-115 may be a useful treatment for these patients. Introduction: TAS-115 is an oral multikinase inhibitor targeting the MET proto-oncogene, vascular endothelial growth factor receptor, and colony-stimulating factor 1 receptor. We evaluated the efficacy and safety of TAS-115 in castrationresistant prostate cancer (CRPC) patients with bone metastases. Patients and Methods: This phase II study, conducted in Japan, comprised 2 cohorts of CRPC patients. Cohort A included patients with bone metastasis and no history of docetaxel; TAS-115 200 to 400 mg/d was administered with abiraterone and prednisone. Cohort B included patients with symptomatic multiple bone metastases, post- or unfit for docetaxel, randomized 1:1 to receive TAS-115 400 or 600 mg/d orally, once daily, in a repeated weekly schedule of 5 days on/2 days off. The primary endpoint was bone scan index (BSI) response rate at Week 12 in each dose group. Results: Cohorts A and B included 24 and 26 patients, respectively. The 12-week BSI response rates for 200, 300, and 400 mg were 0%, 33.3%, and 16.7% in Cohort A, and for 400 and 600 mg were 7.1% and 25.0% in Cohort B. The best BSI response rates for 200, 300, and 400 mg were 0%, 66.7%, and 16.7% in Cohort A, and for 400 and 600 mg were 7.1% and 33.3% in Cohort B. A = 30% reduction in BPI-SF score was shown in 57.7% of patients in Cohort B. The most frequent Grade = 3 adverse drug reactions were hypophosphatemia (20.8%) in Cohort A and anemia (23.1%) in Cohort B. Conclusion: TAS-115 appears to demonstrate anti-tumor activity and acceptable tolerability in CRPC patients with bone metastases. [ABSTRACT FROM AUTHOR]

Summary: Background osteosarcoma is a rare, primary malignant bone tumour with limited available treatments for advanced or recurrent disease, resulting in a poor prognosis for patients. TAS-115 is a novel tyrosine kinase inhibitor under investigation in a phase I study in patients with solid tumours. We report data of osteosarcoma patients in the expansion cohort of this ongoing study. Patients and methods an analysis of this multicentre, open-label study was performed 6 months after the final patient was enrolled, and included patients aged ≥15 years, with unresectable or recurrent osteosarcoma, and who had refractory to standard therapy or for whom no standard therapy was available. TAS-115 650 mg/day was orally administered in a 5 days on/2 days off schedule. Results a total of 20 patients with osteosarcoma were enrolled. The most common adverse drug reactions (ADRs) were neutrophil count decreased (75%), aspartate aminotransferase increased (50%), and platelet count decreased (50%); 85% of patients had grade ≥ 3 ADRs. Long-term disease control (>1 year) with TAS-115 was achieved in three patients. The best overall response was stable disease (50%); no patient achieved a complete or partial response. Median progression-free survival was 3 months; 4-month and 12-month progression-free rates were 42% and 31%, respectively. Conclusion the safety and tolerability of TAS-115 and long-term disease stability for patients with unresectable or recurrent osteosarcoma were confirmed in this study, suggesting that TAS-115 is a promising novel therapy for advanced osteosarcoma patients. Trial registration number: JapicCTI-132333 (registered on November 8, 2013). [ABSTRACT FROM AUTHOR]

Tyrosine kinase inhibitor (TKI) treatment is the first-line therapy for non-small cell lung cancer (NSCLC) caused by activating mutations of epidermal growth factor receptor (EGFR). However, acquired resistance to EGFR-TKI occurs almost inevitably. Aberrant activation of proto-oncogene MET has been known to confer EGFR-TKI resistance; however, the mechanisms involved remains unclear. Recent evidence implicates epigenetic heterogeneity as playing roles in cancer drug resistance, whereas links involving epigenetic heterogeneity and MET in NSCLC remain poorly understood. We found that expression of EZH2, a histone methyltransferase, was negatively correlated with MET activation and EGFR-TKI resistance in NSCLC cells and clinical samples, suggesting the potential for EZH2 to be used as a biomarker for EGFR-TKI sensitivity. Knockdown or inhibition of EZH2 up-regulated MET expression and phosphorylation, and elevated proliferation and EGFR-TKI resistance of cells in vitro. Meanwhile, inhibition of MET or PI3K/AKT enhanced EZH2 levels and restored sensitivity to EGFR-TKI. These findings indicate a "MET-AKT-EZH2" feedback loop regulating EGFR-TKI-resistance. Furthermore, combination therapy of PI3K/AKT inhibition and EGFR-TKI, which interrupts the loop, enhanced tumor-suppressive effects in an EGFR-TKI-resistant xenograft model, indicating a potential approach against drug resistance in NSCLC. [ABSTRACT FROM AUTHOR]

Hereditary papillary renal cell carcinoma (HPRCC) is an autosomal dominant syndrome characterized by the occurrence of bilateral and multifocal, classic type papillary renal cell carcinomas. In the recent decades, extensive molecular studies have narrowed the molecular underpinnings of this syndrome to missense mutations in tyrosine kinase domain of MET proto-oncogene. Although MET mutations are specific to HPRCC, it has been found in sporadic papillary renal cell carcinomas and as recently reported, in biphasic squamoid alveolar variant of papillary renal cell carcinoma. Dual MET/VEGFR2 kinase inhibitor and tyrosine kinase inhibitors have shown promising results in systemic therapy for HPRCC., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Constitutive activation of the phosphoinositide 3‑kinase (PI3K)/AKT signaling pathway is evident in a diverse array of human cancer types, and targeting the pathway is an attractive therapeutic approach. However, pre‑clinical and clinical studies have demonstrated that the antitumor efficacy of a number of inhibitors of the PI3K/AKT pathway is poor, and the underlying mechanisms are not completely clear. In the present study, activation of MET proto‑oncogene (MET)/signal transducer and activator of transcription 3 (STAT3) signaling was demonstrated during PI3K/AKT inhibition. Western blotting showed that the pharmacological or genetic inhibition of PI3K/AKT signaling triggered compensatory activation of STAT3 and upregulation of the expression of its downstream genes. The results from RTK array analysis and western blotting demonstrated that the hyperactivated STAT3 signaling was demonstrated to be mediated by the activation of MET. In addition, PI3K/AKT inhibition suppressed tumor growth more effectively when combined with inhibitors targeting MET/STAT3 signaling by detecting apoptosis and colony formation. These results were further confirmed in a nude mouse model. Thus, our results highlight a compensatory survival mechanism via the MET/STAT3 signaling pathway after PI3K/AKT signaling inhibition in non‑small cell lung cancer. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVE: MiR-658, paired box gene 3 (PAX3) and met proto-oncogene (MET) are overexpressed in gastric cancer while PAX3 and MET can be regulated by miRNA. Serum miR-658 may be associated with metastasis of gastric cancer (MGC) by affecting PAX3-MET pathway. METHODS: Ninety-eight gastric carcinoma patients with distant MGC (DM group) and ninety-six gastric carcinoma patients with no MGC (NM group) were recruited. Serum miR-658 was validated between DM and NM groups by using quantitative reverse transcription PCR (qRT-PCR). PAX3 and MET levels were measured by Western Blot. The molecular mechanism for the function of serum miR-658 was further validated in gastric cell lines. RESULTS: The results demonstrate that serum level of miR-658 is significantly lower in the NM group than in the DM group ( P < 0.001). Meanwhile, the levels of PAX3 and MET are lower in the NM group than in the DM group too ( P < 0.01). Both overexpression and silence of miR-658 significantly up-regulate or down-regulate the levels of PAX3 and MET in gastric cell lines ( P < 0.05). CONCLUSIONS: The present findings demonstrate that elevated circulating miR-658 is associated with MGC by activating PAX3-MET pathway. [ABSTRACT FROM AUTHOR]

Metastasis‑associsated in colon cancer 1 (MACC1), a newly identified oncogene, promotes tumor cell proliferation and invasion. In the present study, the expression of MACC1, hepatocyte growth factor (HGF) and its receptor, MET proto‑oncogene (c‑Met), was investigated in human gastric cancer tissues and adjacent normal tissues by immunohistochemistry. The association between the expression levels of the proteins and the clinicopathological parameters of the tumors were statistically analyzed. Furthermore, lentiviral particles expressing MACC1 were used to infect the hepatic satellite cell (HSC) line LX2. The expression of α‑smooth muscle actin (SMA), HGF, matrix metallopeptidase (MMP)‑2 and MMP‑9 in human HSCs was examined by western blotting and reverse transcription‑quantitative polymerase chain reaction. Transwell assays were used to measure the effect of MACC1‑infected or non‑infected HSCs on the migration and invasion abilities of MKN45 and MKN74 gastric carcinoma cells in vitro. The results demonstrated that positive protein expression of MACC1, HGF and c‑Met was significantly higher in human gastric cancer tissues compared with adjacent normal tissues. Positive expression of MACC1 and c‑Met in gastric cancer tissues had no correlation with the sex, age, tumor location and peritoneal metastasis of patients, but was significantly correlated with tumor size, depth of tumor invasion, lymph node metastasis, TNM stage, histological differentiation, and overall (5 years) and disease‑free survival (5 years). Positive expression of each MACC1, HGF and c‑Met protein was demonstrated to be positively correlated with each other in human gastric cancer tissues. Western blotting results confirmed that MACC1 protein was overexpressed in MACC1‑overexpressing lentivirus‑infected HSCs. Overexpression of MACC1 significantly increased HGF, MMP‑2, MMP‑9 and α‑SMA expression levels in HSCs. Results from the Transwell assays indicated an increase in the number of MKN45 or MKN74 cells migrating towards MACC1‑overexpressing HSCs, compared with control HSCs. These findings suggested that MACC1 may regulate the expression of HGF, MMP‑2 and MMP‑9 in HSCs, and may thus promote migration and invasion of gastric carcinoma cells. MACC1, HGF and c‑Met might cooperatively participate in the malignant progression of gastric cancer. In conclusion, MACC1 might serve as a useful molecular target for the diagnosis, treatment and prognosis of gastric cancer. [ABSTRACT FROM AUTHOR]

Abstract: Whole exome sequencing (WES) was used to investigate two Italian siblings with wild‐type RET genotype, who developed medullary thyroid cancers (MTCs) and, later, primary prostate and breast cancers, respectively. The proband's MTC harbored a p.Met918Thr RET mutation; his sister's MTC was RET/RAS wild‐type. Both siblings had a germline mutation (p.Arg417Gln) in the extracellular Sema domain of the proto‐oncogene MET. Experiments involving ectopic expression of MET p.Arg417Gln in MET‐negative T47D breast cancer cells documented the mutant receptor's functionality and its ability to enhance cell migration and invasion. Our findings highlight a possible link between MET germline mutations and MTCs and suggest that MET p. Arg417Gln may promote an invasive malignant phenotype. The possibility that MTC can be driven/co‐driven by a MET mutation has potential management implications, since the tyrosine‐kinase inhibitor cabozantinib—approved for treating advanced MTCs—is a specific MET inhibitor. [ABSTRACT FROM AUTHOR]

Renal cell carcinoma is the most common type of renal malignancy and it originates from the renal tubular epithelium. Due to the diversity in the histopathological and molecular characteristics, it is typically subclassified into five different categories. Papillary renal cell carcinoma is one subclassification and it includes two variants: sporadic and hereditary. Although the hereditary form comprises a smaller number of cases of papillary renal cell carcinoma, an understanding of the molecular pathways and genetic changes continues to play a significant role in the development of new targeted therapies. Along with recommending appropriate lifestyle modification, further investigation into the molecular pathogenesis of hereditary papillary renal cell carcinoma will continue to be invaluable for the clinical management of renal cell carcinoma. In this article, we discuss a case of the hereditary papillary renal cell carcinoma along with an overview of the disease.

Genistein is a soybean isoflavone; in its aglycone it has various biological activities. Animal experiments, clinical studies and epidemiological investigations suggest that genistein has preventative and curative functions for a number of diseases, particularly in cancer. The present study explored the potential anti-cancer effect of genistein by observing its role in inhibiting A549 human lung cancer cell proliferation and investigating the possible mechanism. A549 cells were exposed to various concentrations of genistein (0, 10, 25, 50, 100 and 200 µM; dissolved in physiological saline) for 1, 2 and 3 days. Subsequently, the viability of A549 cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, cell apoptosis was examined using a flow cytometer, caspase 3/9 activity was measured using commercial kits, reverse transcription quantitative polymerase chain reaction was used to analyze the miR-27a expression and western blotting was used to investigate MET protein expression. T he r esults s uggested a significant i nhibition of A549 cell growth following treatment with genistein in a time- and dose-dependent manner. The current study also indicated that treatment with genistein significantly induces cell apoptosis and promotes caspase-3/9 activation of A549 cells in a dose-dependent manner. Further functional assays revealed that the anti-cancer effect of genistein activated microRNA-27a (miR-27a) expression levels and reduced MET protein expression in A549 cells. In conclusion, the present study demonstrates that genistein inhibits A549 human lung cancer cell proliferation. Furthermore, this study reports, for the first time, a correlation between the anti-cancer effect of genistein and miR-27a-mediated MET signaling. [ABSTRACT FROM AUTHOR]

Renal cell carcinoma is the most common type of renal malignancy and it originates from the renal tubular epithelium. Due to the diversity in the histopathological and molecular characteristics, it is typically subclassified into five different categories. Papillary renal cell carcinoma is one subclassification and it includes two variants: sporadic and hereditary. Although the hereditary form comprises a smaller number of cases of papillary renal cell carcinoma, an understanding of the molecular pathways and genetic changes continues to play a significant role in the development of new targeted therapies. Along with recommending appropriate lifestyle modification, further investigation into the molecular pathogenesis of hereditary papillary renal cell carcinoma will continue to be invaluable for the clinical management of renal cell carcinoma. In this article, we discuss a case of the hereditary papillary renal cell carcinoma along with an overview of the disease. [ABSTRACT FROM AUTHOR]

Objective. To determine whether variations in gene expression exist at multiple subsites along the sinonasal tract in patients with chronic sinusitis with polyps and in healthy controls.Study Design. Prospective, controlled study.Setting. Academic medical center.Subjects and Methods. Tissue expression levels of 5 genes, previously found to be characteristic of ethmoid polyps, were measured using real-time quantitative polymerase chain reaction in 100 sinonasal tissue samples. Specimens harvested from 5 regions—the ethmoid sinus, septum, inferior turbinate, middle turbinate, and lateral nasal wall—in 10 patients with chronic sinusitis and ethmoid polyps were compared to tissue from similar regions in 10 control patients without sinusitis. Western blot analysis was performed to validate differential gene expression at the protein level.Results. Gene expression levels of ethmoid polyps differed significantly from those of healthy ethmoid mucosa, as well as tissue from 4 surrounding anatomical sites in both patients with chronic sinusitis and controls. Alterations specific to the polyp tissue included downregulated genes, prolactin-induced protein (fold change 377.2 ± 169.0, P < .0001), and zinc α2-glycoprotein (fold change 72.1 ± 26.5, P < .0001), as well as upregulated genes, met proto-oncogene (fold change 2.5 ± 0.7, P = .029), and periostin (fold change 7.5 ± 3.4, P = .003). No significant differences in gene expression was found for neurabin 2 (fold change 1.0, P = .99).Conclusion. The transcriptional pattern of ethmoid polyps appears to be unique compared with other subsites in the sinonasal cavity of patients with chronic sinusitis. Care must be taken when collecting specimens for molecular studies of the sinonasal tract to differentiate polyp from nonpolyp tissue in chronic sinusitis. [ABSTRACT FROM PUBLISHER]

Purpose: The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, exhibit up to a 70% response rate against non-small cell lung cancer (NSCLC) harboring somatic activating mutations of the EGFR gene ( EGFR). The mechanism of intrinsic resistance of EGFR mutation-positive NSCLC against EGFR-TKIs is not known. The current study assesses the relationship between the molecular expression of EGFR signals and the response to gefitinib treatment in patients with pulmonary adenocarcinoma to elucidate the mechanism of intrinsic resistance to gefitinib. Methods: The present study included 30 patients with pulmonary adenocarcinoma who were treated with gefitinib for a postoperative recurrence. The correlation between the response to gefitinib treatment and various clinical and molecular features was evaluated. Results: EGFR mutations were detected in 20 (66.7%) of the 30 patients. The response to gefitinib treatment was a complete response in 1 case, partial response in 12 cases, stable disease in 4 cases, and progressive disease in 13 cases. Both univariate and multivariate analyses showed the presence of an EGFR mutation, and the expression of phospho-EGFR (p-EGFR) significantly correlated with a better response to gefitinib treatment. Ten of the 16 p-EGFR positive patients were disease controlled, but all 4 p-EGFR negative patients were intrinsically resistant to EGFR-TKIs ( P = 0.025). Other factors including sex, smoking status, serum carcinoembryonic antigen and cytokeratin-19 fragment levels, EGFR, Met proto-oncogene, phospho-Met, and hepatocyte growth factor expression were not associated with the response to gefitinib treatment. Conclusion: These results suggest that, even if EGFR mutations were observed, a p-EGFR negative state might be a cause of intrinsic resistance to EGFR-TKIs. [ABSTRACT FROM AUTHOR]

Objective: To identify genes whose expression is most characteristic of chronic rhinosinusitis and aspirin-sensitive asthma through genome-wide transcriptional profiling of nasal polyp tissue. Study Design: Prospective, controlled study conducted at a tertiary care institution. Methods: Thirty genome-wide expression microarrays were used to compare nasal polyp tissue from patients with chronic rhinosinusitis alone (CRS, n = 10) or chronic rhinosinusitis and a history of aspirin-sensitive asthma (ASA, n = 10) to normal sinonasal mucosa from patients who underwent surgery for non-sinus related conditions (controls, n = 10). Genes found to be most characteristic of each polyp phenotype, as determined from bioinformatic analyses, were validated using real-time quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry in different patient sets. Results: The transcriptional signature of the control mucosa was distinctly different from that of either polyp phenotype. Genes most characteristic of the CRS phenotype included two upregulated genes-met proto-oncogene (MET) and protein phosphatase 1 regulatory subunit 9B (PPP1R9B)-and two downregulated genes- prolactin-induced protein (PIP) and zinc alpha2-glycoprotein (AZGP1). The gene most characteristic of the ASA phenotype was periostin (POSTN), which was upregulated relative to controls. Differences between the CRS and ASA phenotypes were associated with alterations in the 6p22, 22q13, and 1q23 chromosomal regions. Conclusions: Nasal polyps appear to have characteristic transcriptional signatures compared to normal sinonasal mucosa. The five genes identified in this study likely play roles in the pathogenesis of polyps associated with CRS and ASA, and are therefore attractive targets for novel medical therapies for these common debilitating diseases. [ABSTRACT FROM AUTHOR]

Background: MNNG HOS transforming gene (MET) exon 14 mutations in lung cancer, including exon 14 skipping and point mutations, have been attracting the attention of thoracic oncologists as new therapeutic targets. Tumors with these mutations almost always acquire resistance, which also occurs in other oncogene-addicted lung cancers. However, the resistance mechanisms and treatment strategies are not fully understood., Methods: We generated Ba/F3 cells expressing MET exon 14 mutations by retroviral gene transfer. The sensitivities of these cells to eight MET-tyrosine kinase inhibitors (TKIs) were determined using a colorimetric assay. In addition, using N-ethyl-N-nitrosourea mutagenesis, we generated resistant clones, searched for secondary MET mutations, and then examined the sensitivities of these resistant cells to different TKIs., Results: Ba/F3 cells transfected with MET mutations grew in the absence of interleukin-3, indicating their oncogenic activity. These cells were sensitive to all MET-TKIs except tivantinib. We identified a variety of secondary mutations. D1228 and Y1230 were common sites for resistance mutations for type I TKIs, which bind the active form of MET, whereas L1195 and F1200 were common sites for type II TKIs, which bind the inactive form. In general, resistance mutations against type I were sensitive to type II, and vice versa., Conclusions: MET-TKIs inhibited the growth of cells with MET exon 14 mutations. We also identified mutation sites specific for TKI types as resistance mechanisms and complementary activities between type I and type II inhibitors against those mutations. These finding should provide relevant clinical implication for treating patients with lung cancer harboring MET exon 14 mutations., (Copyright © 2019 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Background: Recent studies revealed MET exon 14 skipping (METex14) as a biomarker that predicts the response to MET inhibitors in non-small-cell lung cancer (NSCLC). However, METex14 genomic alterations exhibit a highly diverse sequence composition, posing a challenge for clinical diagnostic testing. This study aimed to find a reasonable diagnostic assay for METex14 and identify its clinicopathologic implications., Materials and Methods: We performed a comprehensive analysis of METex14 in 414 EGFR/KRAS/ALK/ROS1-negative (quadruple negative) surgically resected NSCLCs. We used real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Sanger sequencing for the first assay, followed by next-generation sequencing (NGS; hybrid-capture targeted DNA/RNA sequencing). Clinicopathologic implications of the METex14 group were analyzed in a total of 880 NSCLCs., Results: METex14 was confirmed in 13 (3.1%) patients by DNA- and RNA-NGS. After comparison of assay results, qRT-PCR and NGS demonstrated the highest concordance rate. The mean variant allele frequency was 10.5% and 49% in DNA- and RNA-NGS, respectively. DNA-NGS revealed various lengths of indel and substitutions around and in exon 14. Moreover, METex14 was associated with adenocarcinoma (4.8%; 11/230) or sarcomatoid carcinoma (9.5%; 2/21), old age, never-smokers, and early stage of disease., Conclusions: METex14 occurs in about 3% of NSCLCs and has characteristic clinicopathologic features. NGS should be the first assay of choice as a multiplex testing. Sanger sequencing can detect METex14, but sensitivity can be hampered by large deletions or low allele frequency. qRT-PCR, an mRNA-based method, is sensitive and specific and can be appropriate for screening METex14 as a single gene testing., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cholangiocarcinomas (CCAs) are hepatobiliary cancers with features of cholangiocyte differentiation; they can be classified anatomically as intrahepatic CCA (iCCA), perihilar CCA (pCCA), or distal CCA. These subtypes differ not only in their anatomic location, but in epidemiology, origin, etiology, pathogenesis, and treatment. The incidence and mortality of iCCA has been increasing over the past 3 decades, and only a low percentage of patients survive until 5 years after diagnosis. Geographic variations in the incidence of CCA are related to variations in risk factors. Changes in oncogene and inflammatory signaling pathways, as well as genetic and epigenetic alterations and chromosome aberrations, have been shown to contribute to the development of CCA. Furthermore, CCAs are surrounded by a dense stroma that contains many cancer-associated fibroblasts, which promotes their progression. We have gained a better understanding of the imaging characteristics of iCCAs and have developed advanced cytologic techniques to detect pCCAs. Patients with iCCAs usually are treated surgically, whereas liver transplantation after neoadjuvant chemoradiation is an option for a subset of patients with pCCAs. We review recent developments in our understanding of the epidemiology and pathogenesis of CCA, along with advances in classification, diagnosis, and treatment., (Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.)