Metastat tests provides this information over a period of three years Meta-analysis is conducted comparing CTCs profile and metastases profile in order to detect potent markers that are relevant with the site of relapse.
The migration from the primary tumor take place relatively early during tumor progression. Almost less than 2mm in diameter the primary tumor already spreads newly form vessels and cells that perform EMT are migrate through them to the circulation.
The main cells of interest in analytic platform are CTCs, which are obtained by negative selection and sorting via flow cytometer (so that we will obtain viable CTCs from a blood sample). In cases like Glioblastomas cancer cells cannot be detected in a blood sample due to blood-brain-barrier and we need a tissue sample in order to be able to proceed with the test.
There is no analysis assay that can be approved. The only test that is approved is the Cellsearch which enumerates the CTC. The analytic platform of CTCs analysis can be certified only for their accuracy and most of the platforms do.