Circulating tumour DNA to predict survival on Dab and Dab/Tram

Work from the Polsky Laboratory


https://meetinglibrary.asco.org/record/174180/abstract

• circulating tumour DNA- easier to access, represents ALL the tumour burden, not just like a single lesion with a biopsy
• detects BRAF mutation in the blood

Important questions:

- does ctDNA have a prognostic value? yes
- can one measure response to treatment by ctDNA? yes
- can one anticipate upcoming resistance to targeted therapy? they didn't check that



patients from the Combi-D study 

1st large-scale ctDNA analysis

technique: droplet digital PCR
very sensitive but only 'as good as you know what to look for'


detectable ctDNA at begin of treatment = poorer prognosis

elevated ctDNA at baseline was associated with survival as a continuous variable, not as categorical (yes/no) variable

higher ctDNA at baseline = worse outcome


INTERESTING
achieving negative ctDNA at 4 weeks was extended with PFS and OS, especially in patients with elevated LDH





More on ddPCR
https://en.wikipedia.org/wiki/Digital_polymerase_chain_reaction