Blood tests to diagnose, check response to therapy, and use as follow-up in melanoma!

Also from the Boston Conference, Society for Melanoma Research -

And as I said earlier this year:   A valid and specific blood draw that could help diagnose, determine the presence of a response to therapy, and be used as follow-up (instead of scans!) would be sooooooooooo  awesome!!!!  Now there's this: 

Non-invasive monitoring of treatment response to immunotherapy in patients with metastatic melanoma.  Gray, Pereira, Calapre, et al.

Current methods for monitoring melanoma dynamics during treatment are limited to LDH levels and imaging to estimate tumour burden. In particular, responses to immune checkpoint inhibitors vary greatly in timing and extent, and may not be accurately reflected through radiological examination. The analysis of circulating tumour DNA (ctDNA) through sensitive methods can provide a rapid, accurate and quantitative method to determine therapeutic effect as early as possible. In this study mutation-specific droplet digital PCR was used to measure plasma concentrations of oncogenic BRAF, NRAS and TERT variants in 47 patients with advanced metastatic melanoma before commencing treatment with the immune checkpoint inhibitors pembrolizumab (N=30) or ipilimumab (N=17). Tumour-associated ctDNA was detected in 32/47 (68%) plasma prior to treatment, in 76% (N=17) of BRAF mutant and 100% (N=2) of NRAS mutant melanomas. In addition, TERT promoter mutations were detected in the plasma of 61% (N=28) of BRAF/NRAS wild-type cases. Monitoring of ctDNA levels in patients positive at baseline, showed a decrease in ctDNA in response to therapies prior to or concurrently with radiographic response. However, a delayed pattern of response was observed in comparison with our previous data in patients treated with MAPK inhibitors, and consistent with clinical measures of response in ipilimumab and pembrolizumab clinical trials. In conclusion, this study demonstrates the utility of ddPCR assays to monitor ctDNA in the plasma of melanoma patients undergoing immunotherapy.  
Yep!  Been yelling about this for some time:

Here's a post about BRAF testing via a blood draw with lots of previous links to liquid biopsy info:  BRAF testing via blood draw....and more

Here's another demonstrating the value of such non-invasive monitoring:  Melanoma antigens in blood are prognostic of OS and correlate with response to ipi

C'mom man!!!  Let's get this going....for everybody!!! -  c