[Clinicopathological Features and Prognosis of Patients Newly Diagnosed With Lung Adenocarcinoma With Both EGFR Mutation and C-MET Amplification].

Objective To explore the clinicopathological features and prognosis of the patients newly diagnosed with lung adenocarcinoma with both EGFR mutation and C-MET amplification.Methods The pathological sections were reviewed.EGFR mutation was detected by amplification refractory mutation system-quantitative real-time polymerase chain reaction,and C-MET amplification by fluorescence in situ hybridization.The clinicopathological features and survival data of the patients newly diagnosed with lung adenocarcinoma with both EGFR mutation and C-MET amplification were analyzed retrospectively.Results In 11 cases of EGFR mutation combined with C-MET amplification,complex glands and solid high-grade components were observed under a microscope in 10 cases except for one case with a cell block,the tissue structure of which was difficult to be evaluated.The incidence of lung adenocarcinoma in the patients with EGFR mutation combined with C-MET amplification at clinical stage Ⅳ was higher than that in the EGFR mutation or C-MET amplification group (all P<0.001),whereas the difference was not statistically significant between the EGFR mutation group and C-MET amplification group at each clinical stage (all P>0.05).There was no significant difference in the trend of survival rate between EGFR gene group and C-MET amplification group (χ2=0.042,P=0.838),while the survival of the patients with EGFR mutation combined with C-MET amplification was worse than that of the patients with EGFR mutation (χ2=246.72,P<0.001) or C-MET amplification (χ2=236.41,P<0.001).Conclusions The patients newly diagnosed with lung adenocarcinoma with EGFR mutation plus C-MET amplification demonstrate poor histological differentiation,rapid progress,and poor prognosis.The patients are often in the advanced stage when being diagnosed with cancer.Attention should be paid to this concurrent adverse driving molecular event in clinical work.With increasing availability,the inhibitors targeting C-MET may serve as an option to benefit these patients in the near future.

Dramatic Response to Cabozantinib in a Patient with Refractory Hepatocellular Carcinoma with c-MET Amplification.

We report a case of a patient with c-MET amplified hepatocellular carcinoma (HCC) who had a dramatic response to cabozantinib despite being refractory to four previous lines of systemic therapy. The patient had previously received regorafenib plus nivolumab as first-line treatment, lenvatinib as second-line, sorafenib as third-line, and ipilimumab plus nivolumab as fourth-line treatment in sequence. However, all regimens showed early progression within 2 months. The patient's HCC was well-controlled, with a partial response (PR) of over 9 months after beginning cabozantinib treatment. Although there were mild adverse events such as diarrhea and elevated liver enzymes, they were tolerable. Next-generation sequencing (NGS) of the patient's previous surgical specimen indicated amplification of c-MET genes. Although it is well known that cabozantinib has excellent effectiveness for inhibiting c-MET at the preclinical level, to the best of our knowledge this is the first case of dramatic response to cabozantinib in a patient with advanced HCC with c-MET amplification.

Early On-Treatment Prediction of the Mechanisms of Acquired Resistance to EGFR Tyrosine Kinase Inhibitors.

BACKGROUND: Prediction of resistance mechanisms for epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) remains challenging. Thus, we investigated whether resistant cancer cells that expand shortly after EGFR-TKI treatment would eventually cause the resistant phenotype. METHODS: We generated two EGFR-mutant lung cancer cell lines resistant to gefitinib (PC9GR and HCC827GR). The parent cell lines were exposed to short-term treatment with gefitinib or paclitaxel and then were assessed for EGFR T790M mutation and C-MET expression. These experiments were repeated in vivo and in clinically relevant patient-derived cell (PDC) models. For validation in clinical cases, we measured these gene alterations in plasma circulating tumor DNA (ctDNA) before and 8 weeks after starting EGFR-TKIs in four patients with EGFR-mutant lung cancer. RESULTS: T790M mutation was only detected in the PC9GR cells, whereas C-MET amplification was detected in the HCC827GR cells. The T790M mutation level significantly increased in PC9 cells after short-term treatment with gefitinib but not in the paclitaxel. C-MET mRNA expression was only significantly increased in gefitinib-treated HCC827 cells. We confirmed that the C-MET copy number in HCC827 cells that survived after short-term gefitinib treatment was significantly higher than that in dead HCC827 cells. These findings were reproduced in the in vivo and PDC models. An early on-treatment increase in the plasma ctDNA level of these gene alterations was correlated with the corresponding resistance mechanism to EGFR-TKIs, a finding that was confirmed in post-treatment tumor tissues. CONCLUSIONS: Early on-treatment kinetics in resistance-related gene alterations may predict the final mechanism of EGFR-TKI resistance.

Primary Enteric Adenocarcinoma Lung with Mesenchymal Epithelial Transition Factor Amplification: A Case Report.

INTRODUCTION: Primary enteric adenocarcinoma (PEAC) of the lung is a rare variant characterized by the presence of colorectal adenocarcinoma like components. A rare case of PEAC of lung with over-expression of mesenchymal epithelial transition factor (MET) receptor tyrosine kinase protein is being presented. CASE REPORT: A 75-year old female presented with chest pain, cough, hemoptysis and fever for 2 months duration. Computerized tomography (CT) scan revealed a spiculated mass in left upper lobe of lung. A needle core biopsy was performed. The histopathological examination revealed a tumor composed of tall columnar cells with vesicular nuclei arranged in an acinar and glandular formation with luminal necrosis. On immunostaining, cytokeratin 7, thyroid transcription factor 1 and CDX-2 were positive. Based on the morphological and immunostaining profile a diagnosis of PEAC of the lung was rendered. Ancillary testing for driver mutations revealed over expression of c-MET while epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) rearrangement and C-ros oncogene 1, receptor tyrosine kinase (ROS 1) were negative. DISCUSSION: PEAC of the lung which was first described by Tsao and Fraser, is an uncommon variant and rarely harbors any driver mutations. MET over expression is present in 3-7% cases of lung adenocarcinoma and is indicative of aggressive tumor behavior. Colo-rectal adenocarcinomas with MET amplification have poor overall survival. The histogenesis of PEAC may be implicated to the dysregulation of MET pathway. Targeted therapy using MET inhibitors in cases that have MET amplification has predictive implications. CONCLUSION: This is a rare case of PEAC with c-MET over expression. The MET axis that is implicated in pathogenesis of colonic adenocarcinomas might also be the molecular pathway for the development of PEAC.

Crizotinib in c-MET- or ROS1-positive NSCLC: results of the AcSé phase II trial.

BACKGROUND: In 2013, the French National Cancer Institute initiated the AcSé program to provide patients with secure access to targeted therapies outside of their marketed approvals. Efficacy and safety was then assessed using a two-stage Simon phase II trial design. When the study design was designed, crizotinib was approved only as monotherapy for adults with anaplastic lymphoma kinase plus non-small-cell lung cancers (NSCLC). PATIENTS AND METHODS: Advanced NSCLC patients with c-MET ≥6 copies, c-MET-mutated, or ROS-1-translocated tumours were enrolled in one of the three cohorts. Patients were treated with crizotinib 250 mg twice daily. Efficacy was assessed using the objective response rate (ORR) after two cycles of crizotinib as primary outcome. Secondary outcomes included disease control rate at four cycles, best ORR, progression-free survival, overall survival, and drug tolerance. RESULTS: From August 2013 to March 2018, 5606 patients had their tumour tested for crizotinib targeted molecular alterations: 252 patients had c-MET ≥6 copies, 74 c-MET-mutation, and 78 ROS-1-translocated tumour. Finally, 25 patients in the c-MET ≥6 copies cohort, 28 in the c-MET-mutation cohort, and 37 in the ROS-1-translocation cohort were treated in the phase II trial. The ORR was 16% in the c-MET ≥6 copies cohort, 10.7% in the mutated, and 47.2% in the ROS-1 cohort. The best ORR during treatment was 32% in the c-MET-≥6 copies cohort, 36% in the c-MET-mutated, and 69.4% in the ROS-1-translocation cohort. Safety data were consistent with that previously reported. CONCLUSIONS: Crizotinib activity in patients with ROS1-translocated tumours was confirmed. In the c-MET-mutation and c-MET ≥6 copies cohorts, despite insufficient ORR after two cycles of crizotinib, there are signs of late response not sufficient to justify the development of crizotinib in this indication. The continued targeting of c-MET with innovative therapies appears justified. CLINICAL TRIAL NUMBER: NCT02034981.