Is this something private labs offer?
I guess it'd be really cheap if it was deployed nationwide. Furthermore, predictions would be a lot more sensitive / specific as they would be tuned with millions of datapoints.
It's the same for other technologies such as TCR-seq. They could theoretically bring immense prevention benefits, but it's really hard to bootstrap them without collaboration from big healthcare systems as you need thousands of datapoints to get it going. Very frustrating.
Bonus points if you can genotype them, i.e. measure common genetic variants using a chip similar to e.g. the one used by 23andme. Most tumors have an association with variants in the HLA region, and pre-screening susceptible individuals will reduce sample sizes and therefore initial costs to bootstrap.
The same applies to TCR-seq and other biomarkers which are incredibly useful to detect autoimmune disorders really early in the process.
In case you are interested in discussing this further, just get in touch via email (on my profile).