Abstract LB-B24: Identification of the functional significance of mutations using the novel Precision Cancer Analysis System
Authors: Tarcic Gabi , Peled Nir , Barabash Zohar , Barabash-Katzir Naama , Yaakobi Shlomo , Besser Eli , Nevo Hani , Vidne Michael , Adamek Mariusz , Kramer Mordechai R. , Goncharenko Nikolai , Fellig Yakov , Meir Karen , Mostov Keith , Altschuler Yoram 
Published: May 2016

Mounting evidence indicates that growth of pathologically identical cancers in each individual patient is fueled by different sets of driving mutations. The need to identify these drivers stems from the recognized necessity for tailoring therapy and scheduling future surveillance. This personalized medical approach has been shown to result in better treatment outcomes. We present a novel Precision Cancer Analysis system (PCAS) capable of identifying activated signaling pathways by means of a transfected cell-based fluorescent reporter assay yielding a quantitative output of particular pathway activation levels. Being a functional platform PCAS reveals activated pathways regardless of the type of mutation behind it, i.e. whether it is already a known mutation or a variant of unknown significance (VUS) mutation. 20 cancer patients were sequenced for a panel of 37 genes and analyzed by the PCAS. This system quantifies oncogenic activity in the majority of the oncogenic signaling pathways altered by the patients' mutations through a functional assay and does not rely on prior knowledge of the mutations. The system produces a quantitative output enabling grading the different mutants of the same patient, providing prioritization for better drug selection.In 3 tested genes, 16 different mutations were identified- 4 in EGFR, 4 in PIK3CA and 8 in KRAS. Of these 10 were classified as known mutations for which functional annotation exists, and 6 were VUS. In addition to correctly annotating all known mutations, the PCAS further quantified oncogenic activity in all the VUS tested. Measuring the functional mechanism behind known mutations and VUS provides another layer of critical information to the physician. These results clearly demonstrate the value of a functional assay in accurately identifying the optimal course of treatment, particularly by its ability to add actionable information to VUS. The study produced a comprehensive delineation of the oncogenic activity of each patient's individual mutations demonstrating the ability of the PCAS to 1) accurately deliver comparable actionable information as found by NGS, 2) functionally characterize mutations annotated as VUS, and 3) monitor oncogenic activity of signaling pathways induced by different mutations and mutation-combinations enabling informed treatment decisions.

Citation Format: Gabi Tarcic, Nir Peled, Zohar Barabash, Naama Barabash-Katzir, Shlomo Yaakobi, Eli Besser, Hani Nevo, Michael Vidne, Mariusz Adamek, Mordechai R. Kramer, Nikolai Goncharenko, Yakov Fellig, Karen Meir, Keith Mostov, Yoram Altschuler. Identification of the functional significance of mutations using the novel Precision Cancer Analysis System. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-B24.