ESMO recommendations on the standard methods to detect NTRK fusions in daily practice and clinical research.

BACKGROUND: NTRK1, NTRK2 and NTRK3 fusions are present in a plethora of malignancies across different histologies. These fusions represent the most frequent mechanism of oncogenic activation of these receptor tyrosine kinases, and biomarkers for the use of TRK small molecule inhibitors. Given the varying frequency of NTRK1/2/3 fusions, crucial to the administration of NTRK inhibitors is the development of optimal approaches for the detection of human cancers harbouring activating NTRK1/2/3 fusion genes. MATERIALS AND METHODS: Experts from several Institutions were recruited by the European Society for Medical Oncology (ESMO) Translational Research and Precision Medicine Working Group (TR and PM WG) to review the available methods for the detection of NTRK gene fusions, their potential applications, and strategies for the implementation of a rational approach for the detection of NTRK1/2/3 fusion genes in human malignancies. A consensus on the most reasonable strategy to adopt when screening for NTRK fusions in oncologic patients was sought, and further reviewed and approved by the ESMO TR and PM WG and the ESMO leadership. RESULTS: The main techniques employed for NTRK fusion gene detection include immunohistochemistry, fluorescence in situ hybridization (FISH), RT-PCR, and both RNA-based and DNA-based next generation sequencing (NGS). Each technique has advantages and limitations, and the choice of assays for screening and final diagnosis should also take into account the resources and clinical context. CONCLUSION: In tumours where NTRK fusions are highly recurrent, FISH, RT-PCR or RNA-based sequencing panels can be used as confirmatory techniques, whereas in the scenario of testing an unselected population where NTRK1/2/3 fusions are uncommon, either front-line sequencing (preferentially RNA-sequencing) or screening by immunohistochemistry followed by sequencing of positive cases should be pursued.

Identification of Tyrosine-Phosphorylated Proteins Upregulated during Epithelial-Mesenchymal Transition Induced with TGF-ß.

The epithelial-to-mesenchymal transition (EMT) is a unique process for the phenotypic changes of tumor cells characterized by a transition from polarized rigid epithelial cells to migrant mesenchymal cells, thus conferring the ability of tumor invasion and metastasis. A major challenge in the treatment of lung adenocarcinoma is to identify early stage patients at a high risk of recurrence or metastasis, thereby permitting the best therapeutic strategy and prognosis. In this study, we used a transforming growth factor-ß (TGF-ß)-induced EMT model to quantitatively identify protein tyrosine phosphorylation during the course of EMT in relation to malignant characteristics of lung adenocarcinoma cells. We performed relative quantitation analysis of tyrosine-phosphorylated peptides in TGF-ß-treated and -untreated lung adenocarcinoma cells and identified tyrosine-phosphorylated proteins that were upregulated in TGF-ß-treated cells. These include tensin-1 (TNS1) phosphorylated on Y1404, hepatocyte growth factor receptor (c-Met) phosphorylated on Y1234, and NT-3 growth factor receptor (TrkC) phosphorylated on Y516. We also found that these protein phosphorylation profiles were specifically observed in tissue samples of patients with poor prognostic lung adenocarcinoma. Tyrosine phosphorylations of these proteins represent possible candidates of prognostic prediction markers for lung adenocarcinoma.