Next generation sequencing of sarcomas: Response to crizotinib in two cases with MET amplification.

Abstract

11538 Background: Sarcoma subtypes are often defined by recurrent molecular alterations. The purpose of this study is to review the utility of next generation sequencing (NGS) in sarcoma patients and report clinical outcomes to matched therapies. Methods: The records of all patients seen at the University of Rochester Medical Center (URMC) with sarcoma and NGS profiling between 8/2013 and 3/2020 were reviewed. Responses to agents targeting reported alterations were analyzed. In patients with fluorescent-in-situ hybridization (FISH) testing, fusion events by NGS were compared with FISH results. All highlighted pathogenic alterations on the NGS profile report as well as variants of uncertain significance (VUS) were recorded. Results: Seventy-five patients met inclusion criteria. Of these, 25 received a treatment based on identified alterations; 1 had a complete response (CR), 4 had partial responses (PR), and 4 experienced disease stabilization (SD). We identified two patients with MET amplified sarcoma that responded to treatment with crizotinib. One other patient with a diagnosis of leiomyosarcoma was found to have an unusually high total mutational burden (TMB) and experienced complete pathologic response to dual checkpoint blockade. In 4 cases, testing resulted in a change in subtype diagnosis. Several rare and novel fusions were identified; a sarcoma with TPM4-NTRK3 fusion responded to larotrectinib, while a sarcoma with PML-JAK1 fusion did not respond to ruxolitinib, and a sarcoma with IL7R-BCL2 fusion progressed on venetoclax. Table summarizes matched therapies in responders. Conclusions: NGS profiling led to a targeted therapy with a clinical benefit rate of 12% in this cohort. NGS profiling led to a change in diagnosis in 5% of this cohort. Multi-institutional collaborations to track outcomes of matched therapy would help determine the utility of therapies in rare cancers and unusual alterations.[Table: see text]