For clarification, it tests for 47 genes which are associated with increased risk of cancer. It doesn’t help tell you whether or not you have cancer, in contrast to blood tests like Galleri, which can do that.
The thing all of these have in common is that they aren't FDA-approved, they're just CLIA assays.
Invitae's test in the original article is FDA-approved, which is no small feat. That's not easy to do and lends a lot of credence to their tech.
If Grail could get their test FDA-approved, they would have done so.
I'll also point out that detecting germline variants (which is what Invitae is doing) is considerably easier than somatic variants, which is what tests ala Grail and PGDx do. Of course this doesn't discount the work of Invitae, absolutely sound tech behind it.
I worked at PGDx for ~5 years and wrote an appreciable chunk of their bioinformatics pipeline, though I moved on to a different industry back in 2020 and am now out of date by that much. Though if you had asked me then, I would have bet that the first liquid biopsy test would be out by now; when I left was a short while after they had the first solid tumor somatic test FDA-approved.
I haven't looking into this specifically, so I have no idea if that works for the types of cancers this tests for. My point is applies to testing just generally speaking
2 years later, I still haven't found a way to take this test and have it's results be meaningful to any actionable health outcomes.
I believe the only thing I can do is find a sketchy online doctor willing to prescribe it, and then roll the dice on whether any related testing or care based upon the results would be covered by insurance (my doctors biggest concern)
It's also weird that your doctor would be worried that insurance won't cover the costs of cancer being detected early. Saving money in this situation is not something that is on the top of my mind. Worst case I incur debt and then declare bankruptcy if I survive.
Blood you can't really mess up because a phlebotomist handles the protocol.
For lots of people this means they'll get lots of testing, lots of treatment, lots of harm caused by testing and treatment, and some of them will die early, and some of them will die at the same time, and some of them will have their life extended by all this testing and treatment.
It's really complex for the general public to understand this because it involves probability and statistics and these are both things that are very tricky for people to understand. (See eg Monty Hall or regression to the mean or anything involving percentages).
I'm certain that expected time of death is a nonincreasing function of detection time -- this would necessarily be the case if the treatment never harmed the patient, and even though that's sadly not the case, prescribing a course of treatment that on average shortens patient lives must surely contradict "First do no harm".
If you assign a low quality-of-life score to time spent undergoing certain harsh treatments like chemo, then you could certainly reduce your "total quality of life" (that is, the integral over your lifetime of quality-of-life-at-each-moment) by starting treatment too early. I think that's a reasonable way to frame it. But in terms of maximising lifespan, the earlier you detect it, the better.
Some people will also be unlucky enough to get false positives on the follow-up test, and eventually you may end up performing unnecessary invasive interventions on 30,000 people who don't have the underlying condition.
It's not to say that:
> the earlier you detect it, the better.
Is wrong, per se. But we'll need to narrow down the criteria for who should be recommended to get these tests in order to minimize harms from false-positives. So you'd want to identify risk factors and have a way to check if someone has those risk factors before testing them.
Just because I don't have a genetic risk for some cancers doesn't mean that I'll be OK to smoke. Different cancers have different causes, not all of which are genetic.
It's like saying that since you don't live in an area prone to earthquakes, you can also ignore other possible natural disasters (flooding, tornadoes, landslides, etc).
She also started having yearly tests for ovarian cancer, and only a few years later one of those tested positive, so she had one ovary removed.
Personally, I used to get a yearly colonoscopy after a tumour and a positive gene test, but these days I no longer have a colon ...
Also, patient can get an ultrasound exam (or other applicable) more frequently for an organ that's under a higher risk.
It is crazy that people still comment as if a health insurance company in the US can deny or price insurance based on healthiness. It’s been over a decade since anyone would have been asked for anything but age/location/smoking status when getting health insurance.
That said, most people know absolutely nothing about health insurance or health care in the US beyond the memes.
My bad, and your larger point was still correct.