Classically, a new diagnostic test is created and its developer produces a series of studies showing it is clinically valid and has strong clinical utility in patient care. In two articles I ran across this month, studies are run and published to show potential improvements to existing generic (not product-specific) LCDs.
The first is a paper in JAMA Oncology by Hampel et al. of the OSU with coauthors from U.W./Seattle, here. Both Ohio and Washington are "MolDx" states and cover Lynch syndrome testing under LCD such as L36161 or equivalents. See here. This LCD covers Lynch testing through a fairly convoluted system of steps and pathways (see AMP's original comment here.)
Hampel et al. provide data on 419 consecutive CRC cases worked up for Lynch syndrome with NGS panels. They report that "Up-front tumor sequencing in CRC is simpler and has superior sensitivity to current multi-test approaches to Lynch Syndrome screening." They also note that Lynch testing (which is recommended now in all colon cancer cases) can thus be performed in parallel with driver oncogene testing for therapy selection.
The second is a paper in Annals of Surgical Oncology by Yang et al. which in its title directly addresses Medicare policy criteria (see article here.) A relevant policy is the MolDx hereditary breast and ovarian cancer LCD (HBOC; e.g. here.) Medicare requires that a patient already have a personal history of breast cancer, unlike USPSTF guidelines for BRCA testing. However, even leaving that in place, the authors note that among 4196 Medicare patients, the rate of BRCA positivity was about 9-10%, within and without Medicare's additional criteria. This "suggests the need for significant expansion and simplification of Medicare criteria."
Under the suggestion, Medicare patients would still have the entry criteria of personal history of breast cancer. However, that would become the main requirement. (For a biomarker test, in a breast cancer patient, does Medicare "have to" require an additional family history besides the cancer itself? No, it doesn't in the case of Lynch syndrome biomarkers in colon cancer nor in the case of e.g. Her2 biomarkers in breast cancer, to give two examples.)
The levels of evidence in the articles above would argue to fairly simple standards for policy change.
Genomic Lynch testing overlaps with targeted therapy oncogene drivers (e.g. in a panel test), and simply has superior sensitivity (fewer false negatives). The current HBOC criteria seem to serve no purpose (segregating patients with 9% vs 10% risk) and are therefore not objectively justified.
Under recent law for Medicare creation of preventive services, the agency could open an NCD to determine that the USPTF benefit for BRCA testing in women without a personal history of breast cancer should be applied to Medicare patients as well. Medicare has never opened this particular NCD topic.