Blood Test Instead of Biopsy – Research coming out of the Gunderson Health System in Wisconsin and published in CHEST claim that a blood test given immediately following diagnosis can help doctors quickly determine an individual’s course of treatment.
Typically, a biopsy is taken and the results of that biopsy determine the course of treatment. The problem is there can be a time period of four to six weeks to get results, and during that time, the cancer is growing. Lung cancer is particularly difficult to diagnose and advances rapidly, so initiation of treatment as soon as possible is very important. For a patient who is waiting weeks – sometimes months – for biopsy results, they simply may not have that kind of time.
Scientists studied a group of some 20 individuals of which 17 had a diagnosis of non-small cell lung cancer. A genomic test called “GeneStrat” was combined with a proteomic test called “VeriStrat.”
GeneStrat is a genomic test developed by Biodesix, and it provided blood-based mutation results which allowed for a treatment plan to be developed in 72 hours by utilizing ddPCR or Droplet Digital PCR.
So let’s break this down step by step:
PCR stands for Polymerase Reaction Chain, a methodology applied in molecular biology which amplifies a single copy or a small set of copies of a piece of DNA and is capable of generating from several thousand to several millions of copies of the selected DNA sequence. As applied to detecting cancer, PCR methodology is applied directly on genomic DNA to detect malignant cells.
Droplet Digital PCR (ddPCR) is a methodology for applying digital PCR based on water-oil emulsion droplet technology. One single sample is fractionated into 20,000 droplets, and then PCR amplification of the template molecules occurs in each individual droplet. The ability to do such a massive sample portioning is the base of ddPCR.
VeriStrat is another test developed by Biodesix, which provides blood-based predictive and prognostic proteomic information for patients with non-small cell lung cancer (NSCLC) who test negative for EGFR mutations (EGFR wild-type) or whose EGFR mutation status is unknown. A VeriStrat test measures a patient’s response to a growing tumor and the chronic activation of complex proteomic pathways known to be associated with aggressive cancer.
Scientists essentially used the GeneStrat test to identify the mutations and the VertStrat test as a prognostic indicator which helps shape the recommended treatment course – all of that happening in 72 hours as opposed to waiting up to several months to begin treatment.
The research team plans to reveal more of its findings at the CHEST Annual Meeting on October 22-26 at the Los Angeles Convention Center.