UPDATE: When I wrote this June blog, I failed to link it to the February 28, 2020 CMS announcement that it was undertaking a review of liquid biopsy tests for colorectal cancer screening. The CMS NCD review and the AHRQ liquid biopsy review are likely related. The NCD tracking page is here. CMS opened this agenda item on February 28, 2020, and will issue a proposed decision memo on August 28, 2020.
Here, you'll see they are showing an in-progress report with a link that ties to an 8 page outline and key questions document. I've also put the 8 page outline in the cloud here. It's dated May 2020.
My first guess is that CMS may consider undertaking an NCD in the liquid biopsy space once this review is completed (which probably will take 6-12 months).
On the other hand, CMS may find the space too complex, diverse, and fast-moving for an NCD. CMS might state in an NCD that FDA-approved tests in this space would be Medicare-covered, while LDT tests would be up to local MACs.
In the structured questions, they're prepared for most any use of liquid biopsy - for example, from colon cancer screening to rule in/rule out suspected cancer (e.g. nodule on imaging) to the more familiar testing of tumor oncogenes like ALK via liquid biopsy.
Update: The AHRQ comment period ran May 27-June 12.
Update: For a July 2020 consensus review in Nat Rev Clin Oncol on LBx in colorectal cancer, 14pp, Dasari et al., here.