Diagnosis and Treatment Monitoring of a Patient with Gastrointestinal Stromal Tumor by Next-Generation Sequencing and Droplet Digital Polymerase Chain Reaction Assay of a PDGFRA Mutation in Plasma-Derived Cell-Free Tumor DNA

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In patients with a suspected malignancy, standard-of care management currently includes histopathologic examination and analysis of tumor-specific molecular abnormalities. Herein, we present a 77-year-old patient with an abdominal mass suspected to be a gastrointestinal stromal tumor (GIST) but without the possibility to collect a tumor biopsy. Cell-free DNA extracted from a blood sample was analyzed for the presence of mutations in GIST-specific genes using next generation sequencing. Furthermore, liquid biopsies were used to monitor the levels of mutant DNA copies during treatment with a tumor-specific mutation droplet digital PCR assay that correlated with the clinical and radiological response. Blood-based testing is a good alternative for biopsy-based testing. However, it should only be applied when biopsies are not available or possible to obtain because overall, in only 50%-85% of the cell-free plasma samples is the known tumor mutation detected.

Original languageEnglish
Pages (from-to)e387-e390
Number of pages4
JournalThe Oncologist
Issue number6
Publication statusPublished - May-2019



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