Open AccessDiagnosis 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
Author(s) -
Boonstra Pieter A.,
ter Elst Arja,
Tibbesma Marco,
Gietema Jourik A.,
Schuuring Ed,
Reyners Anna K.L.
Publication year - 2019
Publication title -
the oncologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.176
H-Index - 164
eISSN - 1549-490X
pISSN - 1083-7159
DOI - 10.1634/theoncologist.2018-0460
Subject(s) - pdgfra , medicine , digital polymerase chain reaction , polymerase chain reaction , stromal tumor , cancer research , mutation , liquid biopsy , stromal cell , imatinib , cell free fetal dna , dna sequencing , pathology , gist , dna , cancer , gene , genetics , biology , pregnancy , fetus , myeloid leukemia , prenatal diagnosis
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.