Genetic Test Evaluation

understanding how genetic tests impact patient management

GeneStrat (Biodesix Inc.)

December 5, 2017

Molecular profiling is used for patients with advanced non-small cell lung cancer (NSCLC) to characterize oncogenic drivers and mechanisms of resistance to help guide appropriate treatment selection. Testing is frequently performed at diagnosis and at disease progression, as the majority of patients will develop resistance to initial treatment within 1 year of initiation. Molecular profiling has usually been performed on tissue biopsy samples. However, these samples can be challenging to obtain, may be associated with adverse events, and may not completely represent the full tumor profile due to clonal heterogeneity. In addition, biopsies can be expensive and it can take several weeks to obtain results, potentially delaying treatment. Therefore, sampling from various bodily fluids (called “liquid biopsy”) is being offered to more easily and serially detect molecular alterations during treatment. This report reviews 1 such molecular profiling test, GeneStrat, which uses plasma from a patient blood sample to analyze cell-free DNA (cfDNA) and RNA for specific variants.