Validation of Molecular Diagnostic Thecnologies for Lung Cancer Patients.

B. Lung Cancer Non-small cell lung cancer (NSCLC) is a common cause of cancer mortality throughout the world. In 2007, there were 1.5 million new lung cancer cases diagnosed worldwide, including around 733,100 cases in the South American Region.6 Approximately 85% of lung cancer is histologically defined as non small cell and the remaining 14% as small cell. The majority of patients with NSCLC present with inoperable locally advanced (Stage IIIB) or metastatic (Stage IV) disease for which no curative treatment is yet available. In newly diagnosed patients with good performance status, platinum based doublet-combination chemotherapies are associated with a median overall survival (OS) of 7.4 to 9.9 months. 7, 8, 9, 10, 11, 12 Therefore, newer agents with novel mechanisms of action are still desperately needed for this serious life-threatening disease. 15,16 The rapid and efficient identification of key driver genes in non-small-cell lung cancer (NSCLC) is becoming increasingly important.17 Clinical screening efforts have revealed that the most common mutations in lung cancer specimens involve EGFR and KRAS, along with 10 other genes that show a prevalence of mutation in 5% or less of tumors. The ALK gene is rearranged in around 3%-5% of patients with NSCLC and has been the focus of intense basic and clinical research, suggesting that the frequency of the gene rearrangement is similar in Asian and Western patients. ROS1 is a receptor tyrosine kinase of the insulin receptor family. Chromosomal rearrangements involving the ROS1 gene were originally described in glioblastomas, where ROS1 (chromosome 6q22) is fused to the FIG gene (chromosome 6q22 immediately adjacent to ROS1), 16 and have been shown to be transforming in transgenic mice.17 More recently, ROS1 fusions were identified as potential driver mutations in an NSCLC cell line (HCC78; SLC34A2-ROS1) and an NSCLC patient sample (CD74-ROS1). 18 These fusions led to constitutive kinase activity and were associated with sensitivity in vitro and in vivo to crizotinib. As of December 2013, 16 different variants have been found.16, 17, 18 The present study is designed to advance the molecular testing methodologies to identify ALK+ and ROS1+ NSCLC patients. Advanced next generation sequencing screening methodologies will be used to identify NSCLC patients whose tumors contain a ROS1 gene inversion or translocation or an ALK translocation. A parallel test for ALK+ by either the Abbott ALK FISH test or the Ventana ALK IHC test is necessary to validate the NGS test in all samples. A parallel test for ROS1+ by either the Kreatech FISH test or the D4D6 ROS1 IHC test may be necessary to validate the NGS test in all samples.