Clinicopathological Features and Prognosis of Patients Newly Diagnosed With Lung Adenocarcinoma With Both EGFR Mutation and C-MET Amplification / 中国医学科学院学报

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.

FISH patterns of ROS1, MET, and ALK with a correlation of ALK immunohistochemistry in lung cancer: a case for introducing ALK immunohistochemistry ‘Equivocal’ interpretation category in the Ventana anti?ALK (D5F3) CDx assay ? A tertiary cancer center experience

Background: Mutations in ROS1, ALK, and MET genes are targetable alterations in non-small cell lung cancer (NSCLC). They can be evaluated by different techniques, most commonly fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). Methods: We explored the prevalence of ROS1, ALK, MET mutations, discuss clinicopathological associations and FISH signal patterns on 413 consecutive cases of EGFR negative lung carcinoma from March 2016 to April 2017 using FISH for ALK, ROS1, and MET along with ALK (D5F3) IHC. Results: ROS1 gene rearrangement, ALK positivity (IHC and/or FISH), and MET amplification were seen in 18/358 (5%) cases, 76/392 cases (19.4%), and 10/370 (2.7%) cases, respectively. ALK FISH and ALK IHC were positive in 51/300 (17%) and 58/330 cases (17.57%), respectively, while 8/330 (2.4%) cases were ALK IHC “equivocal” of which 3/8 (37.5%) were ALK FISH positive. Of ALK FISH and IHC co-tested cases, 43/238 (18.07%) cases were positive by both techniques, while 15/43 (34.88%) of ALK positive cases showed discordant ALK FISH and IHC results. All ROS1 rearranged and MET amplified cases were adenocarcinoma. Signet ring cell histology was associated with 78.57% likelihood of being either ALK or ROS1 positive. Genomic heterogeneity was seen in 30% of MET amplified cases. Conclusions: ALK/ROS1/MET gene alterations were found in 25.18% of NSCLC cases. An ALK IHC “equivocal” interpretation category should be incorporated into practice. Atypical patterns of ROS1 and genomic heterogeneity need to be evaluated further for any clinical relevance.

Acquired Resistance of MET-Amplified Non-small Cell Lung Cancer Cells to the MET Inhibitor Capmatinib / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Amplified mesenchymal-epithelial transition factor, MET, is a receptor tyrosine kinase (RTK) that has been considered a druggable target in non-small cell lung cancer (NSCLC). Although multiple MET tyrosine kinase inhibitors (TKIs) are being actively developed for MET-driven NSCLC, the mechanisms of acquired resistance to MET-TKIs have not been well elucidated. To understand the mechanisms of resistance and establish therapeutic strategies, we developed an in vitro model using the MET-amplified NSCLC cell line EBC-1. MATERIALS AND METHODS: We established capmatinib-resistant NSCLC cell lines and identified alternative signaling pathways using 3′ mRNA sequencing and human phospho-RTK arrays. Copy number alterations were evaluated by quantitative polymerase chain reaction and cell proliferation assay; activation of RTKs and downstream effectors were compared between the parental cell line EBC-1 and the resistant cell lines. RESULTS: We found that EBC-CR1 showed an epidermal growth factor receptor (EGFR)‒dependent growth and sensitivity to afatinib, an irreversible EGFR TKI. EBC-CR2 cells that had overexpression of EGFR-MET heterodimer dramatically responded to combined capmatinib with afatinib. In addition, EBC-CR3 cells derived from EBC-CR1 cells that activated EGFR with amplified phosphoinositide-3 kinase catalytic subunit α (PIK3CA) were sensitive to combined afatinib with BYL719, a phosphoinositide 3-kinase α (PI3Kα) inhibitor. CONCLUSION: Our in vitro studies suggested that activation of EGFR signaling and/or genetic alteration of downstream effectors like PIK3CA were alternative resistance mechanisms used by capmatinib-resistant NSCLC cell lines. In addition, combined treatments with MET, EGFR, and PI3Kα inhibitors may be effective therapeutic strategies in capmatinib-resistant NSCLC patients.

MET-Amplified Intramucosal Gastric Cancer Widely Metastatic after Complete Endoscopic Submucosal Dissection / Journal of the Korean Cancer Association, 대한암학회지

Intramucosal gastric cancer (IGC) is associated with a very low risk of lymph node metastasis; thus it is the main candidate for minimally invasive surgical procedures, such as endoscopic submucosal dissection (ESD). Herein, we document an extraordinary case of IGC, which showed a very aggressive clinical course. A 66-year-old female underwent ESD for early gastric cancer. Histologically, the tumor consisted mainly of moderately differentiated adenocarcinoma measuring 1.6 cm in diameter, and the tumor was confined to the mucosa. Despite annual esophagogastroduodenoscopic follow-up, the tumor recurred, with wide metastasis to multiple lymph nodes and bones throughout the body after three years. Fluorescence in situ hybridization study demonstrated MET gene amplification as well as low grade polysomy 7 in both original and recurrent tumors. The clinical characteristics of metastatic IGCs and the implication of MET amplification are discussed.